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Cylinder gripping apparatus |
| RE31993 |
Cylinder gripping apparatus
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| Patent Drawings: | |
| Inventor: |
Wesch, Jr. |
| Date Issued: |
October 1, 1985 |
| Application: |
06/515,546 |
| Filed: |
July 20, 1983 |
| Inventors: |
Wesch, Jr.; William E. (Lone Star, TX)
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| Assignee: |
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| Primary Examiner: |
Myracle; Jerry W. |
| Assistant Examiner: |
Roskos; Joseph W. |
| Attorney Or Agent: |
Vaden, Eickenroht, Thompson & Jamison |
| U.S. Class: |
138/90; 269/139; 277/558; 279/119; 73/49.5; 73/49.8 |
| Field Of Search: |
; 73/49.8; 73/49.5; 73/49.6; 73/49.1; 138/90; 279/110; 279/118; 279/119; 279/121; 279/123; 269/139; 277/205; 277/26R; 277/26A; 414/745 |
| International Class: |
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| U.S Patent Documents: |
3434337; 4077250 |
| Foreign Patent Documents: |
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| Other References: |
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| Abstract: |
A cylinder gripping apparatus having a jaw, a body and a floating interfacing assembly having a curved surface bearing against an opposing surface or groove, the interfacing assembly being operable to generate a proportional gripping force in response to an axial force upon the cylinder to be gripped. The jaw is not connected to the body. The interfacing assembly is operable to permit a transverse displacement of the jaw. |
| Claim: |
What is claimed is:
1. A cylinder gripping apparatus, comprising:
a jaw, said jaw having a friction surface adapted for gripping a cylinder;
a body, said body being adapted to axially receive the cylinder, said body having a front and a rear;
an interfacing assembly, said interfacing assembly being interposed between said jaw and said body, said interfacing assembly being adapted to urge said jaw into gripping engagement with the cylinder when said jaw is urged generally rearwardlywith respect to said body, said interfacing assembly being adapted to provide a radial counterforce in response to an axial force upon the cylinder, said radial counterforce being proportional to said axial force, said interfacing assembly having acurved surface on one end of said interfacing assembly, said curved surface being cooperable with an opposing face to permit a transverse displacement of said jaw from an initial position to a displaced position.
2. The apparatus according to claim 1, wherein said opposing face comprises a planar surface upon said jaw, said planar surface being located upon a side of said jaw generally opposite to said friction surface of said jaw.
3. The apparatus according to claim 1, wherein said opposing face comprises a curved surface upon said jaw, said curved surface being located upon a side of said jaw generally opposite to said friction surface of said jaw.
4. The apparatus according to claim 1, wherein said opposing face comprises a curved surface being adapted to receive said end of said interfacing assembly having said curved surface.
5. The apparatus according to claim 1, wherein said opposing face comprises a planar surface upon said body.
6. A cylinder gripping apparatus, comprising:
a jaw, said jaw having a friction surface adapted for gripping a cylinder, said jaw having a first bearing groove;
a body, said body being adapted to axially receive the cylinder, said body having a side wall, said side wall of said body having a second bearing groove, said body having a front and a rear; and,
an angularly disposed floating force translation lug, said lug being engageable in said first and second bearing grooves, said lug being adapted to operatively associate said jaw with said body, said lug being adapted to urge said jaw intogripping engagement with the cylinder when said jaw is urged generally rearwardly with respect to said body, said lug being adapted to permit said jaw to disengage the cylinder when said jaw is urged generally forwardly with respect to said body.
7. The apparatus to claim 6, further comprising:
a first stay connected to said jaw, said first stay being adapted to cover at least a portion of a cross sectional area of said first bearing groove in said jaw, said first stay being adapted to laterally retain said lugs within said firstbearing groove while leaving said lugs free to rotatively pivot within said first bearing groove; and
a second stay connected to said side wall of said body, said second stay being adapted to cover at least a portion of a cross sectional area of said second bearing surface in said side wall, said second stay being adapted to laterally retain saidlugs within said second bearing groove while leaving said lugs free to rotatively pivot within said second bearing groove.
8. The apparatus according to claim 7, further comprising:
a resilient member disposed against said body, said resilient member being interposed between said body and said jaw, said resilient member being adapted to urge said jaw into engagement with the cylinder.
9. The apparatus according to claim 8, further comprising:
actuating means connected to said lug for rotationally pivoting said lug whereby said jaw is urged generally forwardly permitting said jaw to disengage the cylinder; and,
an elastic member connected between said side wall of said body and said jaw, said elastic member being adapted to urge said jaw radially outward, said elastic member being adapted to urge said lug into operative engagement with said first andsecond bearing grooves.
10. The apparatus according to claim 9, wherein:
said first bearing groove comprises a first arcuate bearing surface and further comprises a sloped forward surface, said forward surface being adapted to permit said lug to rotate in a first sense with respect to said jaw;
said second bearing groove comprises a second arcuate bearing surface and further comprises a sloped rearward surface, said rearward surface being adapted to permit said lug to rotate in a first sense with respect to said sidewall of said body;
said lug having a first arcuate end and a second arcuate end, said first arcuate end being adapted to substantially continguously engage said first arcuate bearing surface of said first bearing groove, said second arcuate end being adapted tosubstantially contiguously engage said second arcuate bearing surface of said second bearing groove, said lug being rotatably engageable against said first and second arcuate bearing surfaces.
11. A hydrostatic testing apparatus for capping an open end of a pipe comprising:
a jaw, said jaw having a first bearing groove, said jaw having a friction surface adapted for gripping the pipe;
a body, said body being adapted to axially receive a pipe, said body having a second bearing groove; and,
a force translation lug, said lug being unconnected to said body and said jaw, said lug being disposable against said body and against said jaw, said lug being adapted to rotatively engage within said first and second bearing grooves, said lugbeing operable to urge said friction surface of said jaw against an outside surface of the pipe when said lug is rotated in a first sense with respect to said body.
12. The apparatus according to claim 11, said body having an interior zone, further comprising:
a purge valve connected to said body; and,
a passageway to place said purge valve in fluid communication with the interior zone of said body.
13. The apparatus according to claim 11, further comprising:
a seal axially positioned within said body and adpated to form a hydraulic seal between said body and the pipe to be capped, said seal having a first lip disposable against the inner surface of said body, the seal having a second lip connected tosaid first lip and adapted to displace toward an outer surface of the pipe to be capped.
14. A cylinder gripping apparatus, comprising:
a body, said body being adapted to axially receive a cylinder, said body having a side wall, said side wall having an inclined inner surface;
a jaw, said jaw having a friction surface adapted to grip the cylinder;
a plurality of generally cylindrical rollers, said rollers being unconnected to said jaw and said body, said rollers being interposed between said jaw and said body, said rollers being operable to facilitate the movement of said jaw relative tosaid body along said inclined inner surface, said inclined inner surface being adapted to urge said jaw into engagement with an outer surface of the cylinder when said jaw is urged rearwardly with respect to said body.
15. The apparatus according to claim 14, further comprising:
a plurality of channels formed traversely along said inclined inner surface, said channels being adapted to receive said rollers, said channels being generally cylindrically shaped in substantial correspondence with the shape of said rollers.
16. The apparatus according to claim 14, further comprising:
a plurality of channels formed transversely along said jaw upon a surface of said jaw generally opposite said friction surface, said channels being adapted to receive said rollers, said channels being generally cylindrically shaped in substantialcorrespondence with the shape of said rollers.
17. The apparatus according to claim 15 or 16, further comprising:
a resilient member disposed against said body, said resilient member being adapted to urge said jaw into engagement with the cylinder;
actuating means pivotally connected to said body for urging said jaw generally forwardly with respect to said body; and,
an elastic member connected between said body and said jaw, said elastic member being adapted to urge said jaw radially outwardly toward said body into operative engagement with said rollers, said elastic member being operable to maintain saidrollers within said channels.
18. A cylinder gripping apparatus, comprising:
a body, said body being adapted to axially receive a cylinder;
a cam arm pivotally attached to said body, said cam arm having a generally arcuate cam surface; and,
a jaw, said jaw having a friction surface adapted for gripping the cylinder, said jaw having a groove in a surface generally opposite to said friction surface, said groove being adapted to receive said cam arm, said cam arm being operable to urgesaid jaw into engagement with an outer surface of the cylinder when said cam arm is rotated with respect to said body.
19. The apparatus according to claim 18, further comprising:
a plurality of elastic members, connected between said body and said jaw, said elastic members being adapted to urge said jaw radially outward toward said body, said elastic members being operable to urge said jaw into operative engagement withsaid cam arm;
a forward alignment lip connected to the forward edge of said jaw; and,
a rear alignment lip connected to the rear edge of said jaw.
20. A cylinder gripping apparatus, comprising:
a jaw, said jaw having a friction surface adapted for gripping a cylinder, said jaw being adapted to dispose against a force translation lug;
a body, said body being adapted to axially receive the cylinder, said body having a side wall, said side wall of said body being adapted to dispose against a force translation lug, said body having a front and a rear; and,
an angularly disposed force translation lug, said lug having at least one generally spherical end, said lug being interposed between said body and said jaw, said lug being adapted to urge said jaw into gripping engagement with the cylinder whensaid jaw is urged generally rearwardly with respect to said body, said spherical end of said lug being adapted to engage a generally corresponding spherical groove, said spherical end and said spherical groove being operable to permit said jaw to engagethe cylinder in generally corresponding alignment with the cylinder.
21. The apparatus according to claim 20, wherein:
said spherical groove is located upon said side wall of said body; and
said force translation lug is pivotally connected to said jaw.
22. The apparatus according to claim 20, wherein:
said spherical groove is located upon said jaw; and wherein said force translation lug is pivotally connected to said side wall of said body.
23. The apparatus according to claim 20, wherein:
said force translation lug further comprises a second generally spherical end remote from said first spherical end; and,
said spherical groove is located upon said side wall of said body;
and further comprising:
a second spherical groove generally corresponding to said second spherical end, said second spherical groove being located upon said jaw, said ends of said force translation lug being adapted to engage said grooves, said force translation lugbeing operable to permit radial, axial and transverse movement of said jaw with respect to said body.
24. A platform jacking apparatus, comprising:
a body, said body being connectable to a platform, said body having a guide sleeve, said body being adapted to axially receive a platform leg,
a first set of jaws, said jaws being adapted to grip the platform leg, said jaws being in operative association with said body, said jaws being adapted to provide a first radial counterforce in response to an axial force upon the platform leg,said first radial counterforce being proportional to said axial force,
a jaw housing, said jaw housing being adapted to axially receive the platform leg, said jaw housing being adapted to coaxially fit within said guide sleeve of said body, said jaw housing being adapted to reciprocally slide within said guidesleeve,
a second set of jaws, said jaws being adapted to grip the platform leg, said jaws being in operative association with said jaw housing, said jaws being adapted to provide a second radial counterforce in response to said axial force, said secondradial counterforce being proportional to said axial force,
actuation means connected to said body and disposed against said jaw housing for reciprocally moving said jaw housing within said guide sleeve, said actuation means being operable to extend and retract said jaw housing within said guide sleeve;
said first jaws being mutually cooperable with said second jaws and said actuation means to grip the platform leg when said second jaws are disengaged from the platform leg and said jaw housing is being retracted by said actuation means; and,
said second jaws and said actuation means being mutually cooperable with said first jaws to grip the platform leg when said first jaws are disengaged from the platform leg and said jaw housing is being extended by said actuation means, saidactuation means, said second jaws, said jaw housing, and said body being operable to raise the platform when said jaw housing is extended by said actuation means.
25. The apparatus according to claim 24, further comprising:
a first releaser, said first releaser being connected to said body, said first releaser being in operative association with said first jaws, said first releaser being operable to disengage said first jaws from the platform leg to permit saidactuation means to extend said jaw housing and raise the platform;
a second releaser, said second releaser being connected to said jaw housing, said second releaser being in operative association with said second jaws, said second releaser being operable to disengage said second jaws from the platform leg topermit said actuation means to retract said jaw housing.
26. A member gripping apparatus for gripping a member having a predetermined cross-sectional shape, comprising:
a jaw, said jaw having a friction surface adapted for gripping a member, said friction surface generally conforming to the shape of the member to be gripped;
a body, said body being adapted to axially receive the member, said body having a front and a rear;
an interfacing assembly, said interfacing assembly being interposed between said jaw and said body, said interfacing assembly being adapted to urge said jaw into gripping engagement with the member when said jaw is urged generally rearwardly withrespect to said body, said interfacing assembly being adapted to provide a radial counterforce in response to an axial force upon the member, said radial counterforce being proportional to said axial force, said interfacing assembly having a curvedsurface of one end of said interfacing assembly, said curved surface being cooperable with an opposing face to permit a transverse displacement of said jaw from an initial position to a displaced position.
27. The apparatus according to claim 26, wherein said opposing face comprises a planar surface upon said jaw, said planar surface being located upon a side of said jaw generally opposing to said friction surface of said jaw.
28. The apparatus according to claim 26, wherein said opposing face comprises a curved surface upon said jaw, said curved surface being located upon a side of said jaw generally opposite to said friction surface of said jaw.
29. The apparatus according to claim 26, wherein said opposing face comprises a curved surface being adapted to receive said end of said interfacing assembly having said curved surface.
30. The apparatus according to claim 26, whererin said opposing face comprises a planar surface upon said body.
31. A member gripping apparatus comprising:
a jaw, said jaw having a friction surface adapted for gripping a member, said jaw having a first bearing groove;
a body, said body being adapted to axially receive the member, said body having a side wall, said side wall of said body having a second bearing groove, said body having a front and a rear; and,
an angularly disposed floating force translation lug, said lug being engageable in said first and second bearing grooves, said lug being adapted to operatively associate said jaw with said body, said lug being adapted to urge said jaw intogripping engagement with the member when said jaw is urged generally rearwardly with respect to said body, said lug being adapted to permit said jaw to disengage the member when said jaw is urged generally forwardly with respect to said body.
32. The apparatus according to claim 31, further comprising:
a first stay connected to said jaw, said first stay being adapted to cover at least a portion of a cross sectional area of said first bearing groove in said jaw, said first stay being adapted to laterally retain said lugs within said firstbearing groove while leaving said lugs free to rotatively pivot within said first bearing groove; and,
a second stay connected to said side wall of said body, said second stay being adapted to cover at least a portion of a cross sectional area of said second bearing surface in said side wall, said second stay being adapted to laterally retain saidlugs within said second bearing groove while leaving said lugs free to rotatively pivot within said second bearing groove.
33. The apparatus according to claim 32, further comprising:
a resilient member disposed against said body, said resilient member being interposed between said body and said jaw, and resilient member being adapted to urge said jaw into engagement with the member.
34. The apparatus according to claim 33, further comprising:
actuating means connected to said lug for rotationally pivoting said lug whereby said jaw is urged generally forwardly permitting said jaw to disengage the member; and,
an elastic member connected between said side wall of said body and said jaw, said elastic member being adapted to urge said jaw radially outwardly, said elastic member being adapted to urge said lug into operative engagement with said first andsecond bearing grooves.
35. The apparatus according to claim 34, wherein:
said first bearing groove comprises a first actuate bearing surface and further comprises a sloped forward surface, said forward surface being adapted to permit said lug to rotate in a first sense with respect to said jaw;
said second bearing groove comprises a second arcuate bearing surface and further comprises a sloped rearward surface, said rearward surface being adapted to permit said lug to rotate in a first sense with respect to said sidewall of said body; and,
said lug having a first arcuate end and a second arcuate end, said first arcuate end being adapted to substantially engage said first arcuate bearing surface of said first bearing groove, said second arcuate end being adapted to substantiallycontiguously engage said second arcuate bearing surface of said second bearing groove, said lug being rotatably engageable against said first and second arcuate bearing surfaces.
36. A member gripping apparatus for gripping a member having a predetermined cross-sectional shape, comprising:
a body, said body being adapted to axially receive a member, said body having a side wall, said side wall having an inclined inner surface;
a jaw, said jaw having a friction surface adapted to grip the member, said friction surface generally conforming to the shape of an outer surface of the member to be gripped;
a plurality of generally cylindrical rollers, said rollers being unconnected to said jaw and said body, said rollers being interposed between said jaw and said body, said rollers being operable to facilitate the movement of said jaw relative tosaid body along said inclined inner surface, said inclined inner surface being adapted to urge said jaw into engagement with the outer surface of the member when said jaw is urged rearwardly with respect to said body.
37. The apparatus according to claim 36, further comprising:
a plurality of channels formed traversely along said inclined inner surface, said channels being adapted to receive said rollers, said channels being generally cylindrically shaped in substantial correspondence with the shape of said rollers.
38. The apparatus according to claim 36, further comprising:
a plurality of channels formed transversely along said jaw upon a surface of said jaw generally opposite said friction surface, said channels being adapted to receive said rollers, said channels being generally cylindrically shaped in substantialcorrespondence with the shape of said rollers.
39. The apparatus according to claim 37 or claim 38, further comprising:
a resilient member disposed against said body, said resilient member being adapted to urge said jaw into engagement with the member to be gripped;
actuating means pivotally connected to said body for urging said jaw generally forwardly with respect to said body; and,
an elastic member connected between said body and said jaw, said elastic member being adapted to urge said jaw radially outwardly toward said body into operative engagement with said rollers, said elastic member being operable to maintain saidrollers within said channels.
40. A bar gripping apparatus for gripping a bar having a predetermined cross-sectional shape, comprising:
a body, said body being adapted to axially receive a bar;
a cam arm pivotally attached to said body, said cam arm having a generally arcuate cam surface; and,
a jaw, said jaw having a friction surface adapted for gripping the bar, said friction surface being adapted to conform to the shape of an outer surface of the bar, said jaw having a groove in a surface generally opposite to said friction surface,said groove being adapted to receive said cam arm, said cam arm being operable to urge said jaw into engagement with the outer surface of the bar when said cam arm is rotated with respect to said body.
41. The apparatus according to claim 40, further comprising:
a plurality of elastic members, connected between said body and said jaw, said elastic members being adapted to urge said jaw radially outward toward said body, said elastic members being operable to urge said jaw into operative engagement withsaid cam arm;
a forward alignment lip connected to the forward edge of said jaw; and,
a rear alignment lip connected to the rear edge of said jaw.
42. A member gripping apparatus, comprising:
a jaw, said jaw having a friction surface adapted for gripping a member, said jaw being adapted to dispose against a force translation lug;
a body, said body being adapted to axially receive the member, said body having a side wall, said side wall of said body being adapted to dispose against a force translation lug, said body having a front and a rear; and,
an angularly disposed force translation lug, said lug having at least one generally spherical end, said lug being interposed between said body and said jaw, said lug being adapted to said jaw into gripping engagement with the member when said jawis urged generally rearwardly with respect to said body, said spherical end of said lug being adapted to engage a generally corresponding spherical groove, said spherical end and said spherical groove being operable to permit said jaw to engage themember in generally corresponding alignment with the member.
43. The apparatus according to claim 42, wherein:
said spherical groove is located upon said side wall of said body; and,
said force translation lug is pivotally connected to said jaw.
44. The apparatus according to claim 42, wherein:
said spherical groove is located upon said jaw; and,
wherein said force translation lug is pivotally connected to said side wall of said body.
45. The apparatus according to claim 42, wherein:
said force translation lug further comprises a second generally spherical end remote from said first spherical end; and,
said spherical groove is located upon said side wall of said body;
and further comprising:
a second spherical groove generally corresponding to said second spherical end, said second spherical groove being located upon said jaw, said ends of said force translation lug being adapted to engage said grooves, said force translation lugbeing operable to permit radial, axial and transverse movement of said jaw with respect to said body. .Iadd.
46. A member gripping apparatus for gripping a cylinder, pipe or solid bar having a predetermined cross sectional shape, comprising:
a jaw, said jaw having a friction surface adapted for gripping a member;
a body, said body being adapted to axially receive the member, said body having a front and rear;
an interfacing assembly, said interfacing assembly being interposed between said jaw and said body, said interfacing assembly being adapted to urge said jaw into gripping engagement with the member when said jaw is urged generally transverse withrespect to said body, said interfacing assembly being adapted to provide a radial counterforce in response to a rotational force about the longitudinal axis of the member, said radial counterforce being proportional to said rotational force, saidinterfacing assembly adapted to move relative with said jaw and said body to permit transverse displacement of said jaw with respect to said body between an initial position and a displaced position said radial counterforce on the member created by saidinterfacing assembly and the contact area of said jaw friction surface being predetermined whereby said radial counterforce is less than the yield strength of the member..Iaddend. .Iadd.
47. A member gripping apparatus for a cylinder, pipe or solid bar with a predetermined cross sectional shape, comprising:
a jaw, said jaw having a friction surface for gripping the member, said jaw having a first bearing groove generally opposite said friction surface;
a body, said body having a side wall, said side wall of said body having a second bearing groove, said body having a front and a rear; and
an angularly disposed floating force translation lug being engageable in said first and second bearing grooves, said lug being adapted to operatively associate said jaw with said body, said lug being adapted to urge said jaw transversely intogripping engagement with the member when said body is rotated about its longitudinal axis in a first direction, said lug being adapted to permit said jaw to disengage the member when said body is rotated in a second direction..Iaddend. .Iadd.
48. The apparatus of claim 47, further comprising:
a first stay connected to said jaw, said first stay being adapted to cover at least a portion of a cross sectional area of said first bearing groove in said jaw, said first stay being adapted to laterally retain said lugs within said firstbearing groove while leaving said lugs free to rotatively pivot within said first bearing groove; and
a second stay connected to said side wall of said body, said second stay being adapted to cover at least a portion of a cross sectional area of said second bearing surface in said side wall, said second stay being adapted to laterally retain saidlugs within said second bearing groove while leaving said lugs free to rotatively pivot within said second bearing groove..Iaddend. .Iadd.49. The apparatus according to claim 47, wherein said first bearing groove in said jaw is spherical, cooperatingwith a spherical end on said lug, the opposite end of said force
translation lug is pivotally attached to said body..Iaddend. .Iadd.50. The apparatus according to claim 47, wherein the radial counterforce created by said force translation lug and the contact area of the jaw friction surface arepredetermined to allow radial counterforce on the member without exceeding the members yield strength..Iaddend. .Iadd.51. A member gripping apparatus for gripping a cylinder, pipe or solid bar having a predetermined cross-sectional shape, comprising:
a jaw, said jaw having a friction surface adapted for gripping the member;
a body, said body being adapted to axially receive the member, said body having a front and a rear; and
an interfacing assembly, said interfacing assembly being interposed between said jaw and said body, said interfacing assembly being adapted to urge said jaw into engagement with the member and to provide a radial counterforce between said bodyand the member in response to a rotational force on said body about the longitudinal axis of the member, said interfacing assembly being adapted to move relative with respect to said jaw between an initial and a displaced position in gripping engagementwith the member, said radial counterforce created by said interfacing assembly and the contact area of said jaw friction surface on the member being predetermined whereby said radial counterforce is less than the
yield strength of the member..Iaddend. .Iadd.52. A member gripping apparatus for gripping a cylinder, pipe or solid bar having a predetermined cross sectional shape, comprising:
a jaw, said jaw having a friction surface adapted for gripping the member;
a body, said body being adapted to axially receive the member, said body having a first bearing means generally opposite said jaw, said body further having a front and a rear; and
an interfacing assembly interposed between said jaw and said body and having a second bearing means generally opposite said body, said interfacing assembly including an angularly disposed force translation device being engaged with said first andsecond bearing means and adapted to operatively associate said interfacing assembly and said body, said force translation device being adapted to provide a radial counterforce between said body and said interfacing assembly in response to a rotationalforce on said body about the rotational axis of the member, said radial counterforce being proportional to said rotational force and said radial counterforce urging said jaw from an initial position to a displaced position in gripping engagement with themember..Iaddend. .Iadd.53. The apparatus according to claims 46, 51 or 52, wherein said jaw is pivotedly connected to said interfacing assembly..Iaddend. .Iadd.54. The apparatus of claim 53 wherein said pivotal connection between said jaw and saidinterfacing assembly is positioned in a predetermined location whereby said radial counterforce on the member is balanced over said jaw friction surface contact area with the member..Iaddend. .Iadd.55. A member gripping apparatus for gripping acylinder, pipe or solid bar having a predetermined cross sectional shape, comprising;
a jaw, said jaw having a friction surface adapted for gripping the member, said jaw having a first bearing means generally opposite said friction surface;
a body, said body being adapted to axially receive the member, said body having a second bearing means, and said body further having a front and a rear; and
an angularly disposed force translation device engaged with said first and scond bearing means and adapted to operatively associate said jaw with said body, whereby said jaw is moveable between an initial position and a displaced position ingripping engagement with the member, said force translation device being adapted to provide a radial counterforce on said jaw in response to a rotational force on said body in a first direction about is longitudinal axis, said radial counterforce beingproportional to said rotational force and urging said jaw into said displaced position, said force translation device further being adapted to enable said jaw to disengage the member and return to said initial position in response to a rotational forceon said body in a second direction about its longitudinal
axis. .Iaddend. .Iadd.56. The apparatus according to claims 47 or 53 wherein said jaw is pivotedly connected to said force translation lug..Iaddend. .Iadd.57. The apparatus according to claim 56 wherein said pivotal connection between saidjaw and said force translation lug is positioned in a predetermined location whereby said radial counterforce on the member is balanced over said jaw friction surface contact area with the member..Iaddend. .Iadd.58. The apparatus of claims 52 or 55,wherein said radial counterforce applied to the member through said jaw friction surface contact area does not exceed the yield strength of the member..Iaddend. .Iadd.59. The apparatus of claims 52 or 55, wherein said angularly disposed forcetranslation device is adapted to assume a predetermined angle of less than 45.degree. when said jaw is in said displaced position, said angle being measured between a first line through the longitudinal axis of the member and an end of said forcetranslation device opposite said body, and a second line through a centerline between said first and second bearing means..Iaddend. .Iadd.60. The apparatus of claim 59, wherein said angle is between 10.degree. and 40.degree...Iaddend. .Iadd.61. Theapparatus of claim 59, wherein said angle is 20.degree...Iaddend. .Iadd.62. The apparatus of claims 52 or 53, wherein at least one end of said force translation device is spherical and said bearing means in engagement with said end of said forcetranslation device is a spherical groove adapted to receive said end of said force translation device..Iaddend. .Iadd.63. The apparatus of claims 52 or 55, wherein at least one of said first and second bearing means is a pivot and an end of said forcetranslation device is rotatably connected to said pivot..Iaddend. .Iadd.64. The apparatus of claims 52 or 55, wherein at least one of said first and second bearing means comprises a hinge and an end of said force translation device is rotatablyconnected to said hinge..Iaddend. .Iadd.65. A member gripping apparatus for gripping a cylinder, pipe or solid bar having a predetermined cross sectional shape, comprising;
two or more jaws, each of said jaws having a friction surface adapted for gripping the member, said jaws being concentrically disposed with respect to the member;
a body, said body being adapted to axially receive the member and said body having a front and a rear; and
two or more interfacing assemblies, each interfacing assembly being interposed between said body and one of said jaws, and adapted to operatively associate said jaws with said body, said jaws being simultaneously displaceable between an initialposition and a displaced position in gripping engagement with the member, each of said interfacing assemblies adapted to provide a radial counterforce between said interfacing assemblies and said body in response to a rotational force on said body, saidradial counterforce being proportional to said rotational force and said radial counterforce urging each of said jaws into said displaced position, said interfacing assemblies each including means for urging said jaws into said initial position in theabsence of a rotational force about the member, said radial counterforce created by said interfacing assemblies and the contact area of said jaw friction surfaces on the member being predetermined wherein the total radial counterforce exerted on themember is less than the yield strength of the
member..Iaddend. .Iadd.66. A member gripping apparatus for gripping a cylinder, pipe or solid bar having a predetermined cross sectional shape, comprising;
two or more jaws, each of said jaws having a friction surface adpated for gripping the member, said jaws being concentrically disposed with respect to the member;
a body, said body being adapted to axially receiving the member and said body having a front and a rear; and
two or more interfacing assemblies, each interfacing assembly being interposed between said body and one of said jaws, and adapted to operatively associate said jaws with said body, said jaws being simultaneously displaceable between an initialposition and a displaced position in gripping engagement with the member, each of said interfacing assemblies being adapted to provide a radial counterforce between said interfacing assemblies and said body in response to a rotational force on said bodyin a first direction about its longitudinal axis, said radial counterforce being proportional to said rotational force and said radial counterforce urging each of said jaws into said displaced position, said interfacing assemblies adapted to urge saidjaws into said initial position in response to a rotational force on said body in a second direction about the longitudinal axis, said radial counterforce created by said interfacing assemblies and the contact area of said jaw friction surfaces on themember being predetermined wherein the total radial counterforce exerted on the member is less than the yield strength on the
member..Iaddend. .Iadd.67. The apparatus according to claims 65 or 66 wherein each of said jaws is pivotedly connected to one of said interfacing assemblies..Iaddend. .Iadd.68. The apparatus according to claim 67 wherein each of said pivotalconnections between said jaws and said interfacing assemblies are each positioned in a predetermined location whereby said radial counterforce on the member is balanced over said jaw friction surface contact areas with the member..Iaddend. .Iadd.69. The apparatus of claims 65 or 66, further comprising one or more resilient members, each of said members having one end attached to said body and another end attached to one of said jaws whereby said jaws are urged into said initial position..Iaddend. .Iadd.70. The apparatus of claims 46, 47, 51, 52, 55, 65 or 66, wherein said jaw friction surface is case hardened..Iaddend. .Iadd.71. The apparatus of claim 53, wherein said pivotal connection between said jaw and said interfacing assembly comprisesa hinge..Iaddend. .Iadd.72. The apparatus according to claim 53, wherein said pivotal connection between said jaw and said interfacing assembly comprises a spherical projection on one of said jaw or said interfacing assembly, said spherical projectionengaging a similarly shaped spherical groove adapted for receiving the spherical end in the
other of said jaw and said interfacing assembly..Iaddend. .Iadd.73. The apparatus according to claims 46, 47, 51, 52, 55, 65, or 66, wherein said friction surface of said jaw is releasably mounted on said jaw whereby said jaw friction surfacemay be periodically removed and replaced by a new friction surface..Iaddend. .Iadd.74. The apparatus according to claims 46, 47, 51, 52, 55, 65 or 66, further comprising retaining means provided to maintain the apparatus in operationalintegrity..Iaddend. |
| Description: |
CROSS REFERENCE TO RELATED APPLICATIONS
This application discloses subject matter related to U.S. Pat. .[.application Ser. No. 037,140.]. .Iadd.No. 4,276,771 issued July 7, 1981.Iaddend., entitled "Hydrostatic Testing Apparatus", .[.filed May 8, 1979,.]. having the sameapplicant, the disclosure of which is incorporated herein by reference. This application also discloses subject matter related to U.S. Pat. No. 4,077,250, issued to the same inventor on Mar. 7, 1981, entitled "Pipe Closure Apparatus", thespecification of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
This invention relates generally to an apparatus for gripping a cylinder, pipe or tube. More particularly, this invention concerns an apparatus having a plurality of jaws adapted for gripping a cylinder, pipe or tube. The jaws are in operativeassociation with a body such that the radial gripping counterforce exerted by the jaws upon the cylinder, pipe or tube is proportional to an axial force upon the cylinder tending to urge the cylinder in an axial direction with respect to the body. Ifthe cylinder, pipe or tube attempts to move axially with respect to the body, an interfacing assembly urges the jaws into gripping engagement with the cylinder.
In a hydrostatic testing apparatus, it is necessary to grip a pipe or tube to be hydrostatically tested with sufficient force to sealingly engage the apparatus upon the pipe. It is necessary that the hydrostatic testing apparatus grip the pipewith sufficient force to reduce or minimize the danger of the pipe slipping out of the testing apparatus.
In the past, it has been common to grip a pipe or cylinder with hydraulic rams and threaded devices to slips which apply an outside force to hold a hydrostatic testing device or cap onto the pipe. Such devices must be tightened to the pipe undersubstantially zero internal pressure conditions because the slips must be firmly engaged before the pipe can be pressurized. Tightening during pressurization of the pipe is impractical and dangerous. During zero pressure conditions there is no internalfluid pressure to offset the clamping pressure or gripping force. Thus, such devices must necessarily stress the outer wall of the pipe while there is little or no internal pressure to offset the pipe gripping force. If the initial gripping force isinadequate, the hydrostatic testing cap will slip off during internal pressurization of the pipe. If the initial gripping force is excessive, the pipe may be deformed or weakened. For pressure testing, the jaws or slips of such devices must beinitially tightened to a holding force sufficient to withstand test pressure before the pipe is pressurized.
U.S. Pat. No. 4,077,250, granted to applicant herein, discloses a pipe closure apparatus having gripper means connected to a spline or rib by means of a rotatable link attached to a mounting pin. This patent failed to disclose gripper meanswhich are unconnected to a spline or rib, but which are interfaced with the spline or rib in a manner adapted to provide a radial counterforce which is proportional to the fluid pressure in the pipe.
The earlier patent teaches the use of a single rotatable link joining a gripper to a rib. A single link introduces stability problems and may create undesirable stresses upon the diameter of a pipe and the rib. Moreover, the earlier patentfails to address the unexpected uneven distribution of the load forces upon the pipe achieved by the gripper means disclosed in that patent where the gripper means is not permitted to move generally parallel to the axis of the pipe, or to movetransversely with respect to the axis of the pipe.
In prior art jacking systems for offshore oil drilling platforms, it has been common to grip platform legs with shear pins, slips or hydraulic rams. Such hydraulic rams shear pins or slips had to be manually set. The gripping force upon theplatform leg was not necessarily related to the weight of the platform deck. Oftentimes, a drilling platform becomes unleveled such that the forces upon other platform legs may increase substantially. Existing devices for leveling a platform requirethe gripping means to be released from a platform leg before leveling forces can be applied. Releasing the gripping means from one platform leg in order to permit leveling necessarily increases the danger of the platform sliding down the platform legand creating stress upon the remaining platform legs. Releasing the gripper means for leveling purposes creates a danger of platform system failure.
In addition, if one jacking device failed, the stress upon the remaining platform legs could increase substantially. The failure of jacking systems presents a serious hazard to offshore drilling operations. When the stress upon prior artjacking devices increases, there is no mechanism to assure that the gripping force upon the platform leg will also increase in response to such stresses.
Prior art jacking systems are also unsatisfactory in that many such systems require that shear pin holes be aligned or that gears be meshed. Thus, the platform may not be jacked and leveled by moving the platform any desired distance. Theplatform may be moved only from one pin hole to another.
Prior art blowout preventer devices, used to prevent pipe from being blow out of a hole during drilling operations typically use hydraulic or threaded systems to grip the pipe. Such prior art systems must be set by external gripping forces. Such devices oftentimes cause hoop stresses upon the pipe when engaged. Because the gripping force is not related to the force tending to push the pipe out of the hole, the pipe must be gripped with an adequate force to prevent a blowout regardless ofthe existence of any downhole pressure. Thus, under substantially zero downhole pressure conditions, the pipe tends to be overstressed. Moreover, existing systems may be slow to engage. Prior art blowout preventer devices require manual setting andare not automatic or self-engaging.
If a large downhole pressure suddenly develops, there is no mechanism in such prior art blowout preventer devices to automatically set or increase the gripping force. Thus, such prior art devices are ineffective to prevent a blowout unless theyhave previously been set upon the pipe with sufficient force to withstand the sudden increase and in downhold pressure. Such prior art blowout preventers must also be released in order to permit the withdraw of casing, coupling or upset portions on thedrill string.
Prior art hanging systems for pipe, tubing and casing, such as systems employed to prevent pipe from being dropped down into a hole during workover and drilling operations, commonly referred to as "hangers", and systems used to grip pipe going inand out of a well, commonly referred to as "elevators" or "snubbers", required that an expensive derrick be constructed at the drill site in order to permit operation of the hanging device. Such prior art devices typically employ slips that must bemanually reset. In order to pass casing, coupling or upset portions of the pipe or drill string, such prior art devices require that the slips be released and expanded to permit the pipe and casing to be passed. While the slips are released for thepassage of the casing, the safety hanging device is inoperative. Thus, during such periods, the pipe or drill string is exposed to the risk of being dropped into the hole.
The adverse economic consequences and delays encountered when drill pipe or other devices are dropped into a hole and the difficulty of retrieving the pipe or such devices requires that a safety hanging apparatus be available to guard againstdropping the pipe at all times during drilling operations.
In addition, many prior art hanging devices, including snubbers, elevators and hangers, cannot take upward pressure upon the pipe without impairing their operation.
While prior art arrangements have exhibited a degree of utility in gripping a pipe, cylinder or tube, room for significant improvement remains. The problems enumerated in the foregoing are not intended to be exhaustive, but rather are among manywhich tend to impair the effectiveness of previously known devices for gripping cylinders or pipes. Other noteworthy problems may also exist; however, those presented above should be sufficient to demonstrate that the prior arrangements appearing in theart have not been altogether satisfactory.
This invention relates generally to an apparatus for capping and sealing the end of a pipe, tube or cylinder during hydrostatic testing. More particularly, this invention concerns an apparatus having a plurality of jaws pivotally mounted on aplurality of arms, and the arms are in turn pivotally mounted to a body adapted to axially receive a pipe, tube or cylinder. With jaws of an area determined in accordance with the present invention the mechanical pressure upon the outer wall of the pipesubstantially equals or is proportional to the fluid pressure upon the inner wall of the pipe. Therefore, the wall of the pipe is compressed; the outer diameter of the pipe is not substantially stressed. The apparatus is adapted to cap the pipe duringhydrostatic testing without generating significant hoop stresses upon the pipe itself.
While the present invention is described with referenced to capping a pipe, it is intended that "pipe" wherever used herein shall include tubing or other cylindrical objects. The invention may also facilitate grasping a cylindrical object forother purposes.
Hydrostatic testing of pipes, upset tubing, and other cylindrical objects is necessary to insure that the pipe or tubing will withstand pressure levels equal to or greater than those which are expected to be encountered during use. Hydrostatictesting is generally a requirement of the American Petroleum Institute (A.P.I.) for most types of pipes.
In the absence of adequate hydrostatic testing during the installation of a petroleum or oil by-product pipeline, hidden flaws in the pipe may cause it to burst. An erupted pipe may go undetected for relatively long periods of time and loose asignificant portion of its contents, which may have adverse consequences for the environment. In addition, the adverse economic consequences involved in repairing a broken pipeline and the consequential down time can be severe. The resultantdisruptions in the supply of oil, natural gas, or other commodity intended to be transported through the pipeline, in addition to the foregoing, require pipe and tubing to be adequately tested hydrostatically prior to or during the installation of suchpipeline.
Manufacturing operations for producing pipe or tubing expected to withstand pressure during use require hydrostatic testing as a quality control measure. Unless pipe and upset tubing are tested, undetected flaws can create serious safety hazardsto an end user. Therefore, hydrostatic pressure testing has become a practical necessity for pipe, fittings and tubing after fabrication.
In the past, it has been common to weld a cap onto the end of a pipeline or an unthreaded or unflanged pipe to be tested. Welding requires expensive skilled labor to perform the welding operations. This work cannot ordinarily be performed byunskilled laborers. The cap must be securely welded to withstand test pressurization without blowing off of the end of the pipe. In some cases, stress relieving and X-raying of the welded cap is required. After testing, the cap must be off of thepipe. Not only is welding time-consuming and expensive, but also, the danger of explosion in some environments may be so great that welding operations are not feasible.
Prior art devices have included caps adapted to be screwed onto the end of the pipe or tubing to be tested. Such devices utilize the threads of the pipe to secure the device to the pipe. It is believed that API specifications require that suchdevices be tightened hand-tight only. Otherwise, the threads of the pipe may be damaged. However, a hand-tight cap will not withstand high pressure testing. Thus, to achieve a satisfactory seal, such devices are often overtighened resulting instripped threads and damage to the pipe or fitting. Threads unknowingly stripped during installation present a latent danger that can kill or injure if pressurization causes the cap to blow off of the end of the pipe during testing. Such devices maynot have the structural integrity to withstand testing pressures and may be blown off, thus presenting a serious threat of injury.
Moreover, such devices must be tightened under substantially zero internal pressure conditions because tightening during pressurization is impractical and dangerous. During zero internal pressure conditions there is no internal fluid pressure tooffset the clamping pressure. Thus, the threads and other portions of the pipe must be stressed, and damage to the pipe or threads may result. Clearly, such prior art devices are unusable on pipe with damaged threads or no threads at all. It is oftenimpractical to machine new threads onto the end of the damaged pipe because of the costs and delay involved. Thus, the cost of pipe ruined by such devices renders these known devices impractical in many cases.
In order to safely perform a hydrostatic test, all air and other gaseous matter must be expunged from the inner volume of the pipe. Failure to remove substantially all of the air creates an explosion hazard that can pose a serious danger toanyone in the vicinity of the testing apparatus. Most prior art devices fail to have a positive safeguard against such trapped air type explosions.
For example, in the past it has also been common to attach a cap onto the end of a pipe with bolts, screws, or other fastening means. Such methods of capping a pipe have been unsatisfactory, however. Not only are such methods time-consuming,but injuries and even deaths can result from such caps being blown off of the pipe during high pressure testing, because such methods and apparatus fail to provide a satisfactory means for eliminating air or gas from the interior of the pipe.
Known methods of removing air from a pipe include tilting the uncapped end of a joint of pipe in an upward direction, thereby causing air bubbles to migrate to the raised end of the pipe. Such tilting methods often result in pipe handlingproblems because the pipe may slip or be dropped. The expense and time required for such handling methods, in addition to the hazard posed when such pipe is dropped or slips, renders such methods unsatisfactory. Moreover, long sections of pipelinecannot be conveniently tilted or may be too long for the pipe handling apparatus available.
Another example of a prior art mechanism utilizes a set of independently operated jaws. Each jaw is manually tightened against the pipe by means of a screw or bolt which is adjusted with a wrench to jam the jaw against the pipe whollyindependently of the other jaws. This type of mechanism is unsatisfactory at least insofar as it may create hoop stresses or deformations upon the pipe. For high pressure testing, the jaws must be tightened to a holding force sufficient to withstandtest pressure before the pipe is pressurized. This imposes excessive stresses on the walls of the pipe which are likely to overstress, deform or weaken the pipe.
Other devices employ hydraulic rams and threaded devices to slips which apply an outside force to hold the cap onto the pipe. Necessarily, such devices must stress the outer wall of the pipe while there is little or no internal pressure tooffset the pipe gripping force. If the initial gripping force is inadequate, the cap will slip off during internal pressurization of the pipe. Such known devices have a tendency to deform or damage the pipe.
Representative prior art patents illustrating problems of the type overcome by the present invention are U.S. Pat. Nos. 2,699,802; 3,647,108; 3,765,560; 3,885,521; 1,746,071; 2,399,544; 2,445,645; 2,480,358; 2,851,061; 3,108,012; 3,125,464;3,525,111; and 3,703,947.
U.S. Pat. No. 4,077,250, granted to applicant herein, discloses a pipe closure apparatus having gripper means connected to a spline or rib by means of a rotatable link attached to a mounting pin. This patent failed to address the problem ofremoving air from the pipe in order to reduce the hazard of explosion. Moreover, this patent fails to address the problem of extrusion of the seal during high pressure testing.
The earlier patent disclosed an alignment ring positioned axially to the rear of a gripper means. The rotatable link was attached to a spline or rib, which was in turn joined to the body of closure plate. However, this arrangement was found tobe unsatisfactory in some instances. When pressure is introduced into the pipe, the gripper means is urged in a direction generally toward the rear of the body. The gripper means therefore urges the spline or rib generally radially outward. Difficulties were encountered in manufacturing a commercially practical spline or rib adequate to withstand the radially outward force generated by the gripper means during high pressure testing. It was found that an enormous rib was required towithstand high pressure testing because of the manner in which the load was transmitted to the rib in the earlier patent.
The prior art patent also has failed to address the problem created by dirt, grime or air which may become entrapped within a U-shaped seal. The entrapment of air, dirt, debris or other foreign matter within a seal may inhibit, if not renderinoperative, the intended operation of the seal. Nor did the earlier patent have a pre-loaded lip to assure zero leakage during low pressure filling of the pipe.
The earlier patent was not adapted for testing pipe with upsets, bell ends or coupling ends. In order to pass such pipe ends, the alignment ring had to be made too large to effectively align the pipe during testing. That patent had nocentralizer means for centering such a pipe after passing the larger end of the pipe.
The earlier patent teaches the use of a single rotatable link joining a gripper to a rib. A single link has proved to be unsatisfactory in some instances. A single link introduces stability problems and may create undesirable stresses upon thediameter of a pipe and the rib. Moreover, the earlier patent fails to address the unexpected uneven distribution of the load forces upon the pipe achieved by the gripper means disclosed in that patent where the gripper means is not permitted to movegenerally parallel to the axis of the pipe.
The prior patent was not adaptable to test several different pipe sizes with a single apparatus. The prior patent failed to provide means for readily adapting the apparatus to fit different pipe sizes.
While prior art arrangements have exhibited a degree of utility in capping the end of a pipe or tube to permit hydrostatic testing, room for significant improvement remains. The problems enumerated in the foregoing are not intended to beexhaustive, but rather are among many which tend to impair the effectiveness of previously known apparatus for capping pipes. Other noteworthy problems may also exist; however, those presented above should be sufficient to demonstrate that the poorarrangements appearing in the art have not been altogether satisfactory.
SUMMARY OF A PREFERRED EMBODIMENT OF THE INVENTION
Recognizing the need for an improved apparatus for gripping a cylinder or pipe for hydrostatic testing for jacking operations upon offshore drilling platforms, for gripping drill pipe to prevent a blowout and for gripping drill pipe, tubing andcasing in safety hanging systems and other wellhead workover applications, it is, therefore, a general intent in disclosing the present invention to provide a novel apparatus for gripping a cylinder, pipe or tube, which minimizes or reduces the problemsof the type previously noted. The present invention has further useful application in gripping a pipe, tube or cylinder for other purposes.
A feature of the cylinder gripping apparatus resides in the ability to permit the cylinder, pipe or tube to move in one direction with respect to a body, and to prevent the cylinder from moving in a second opposite direction with respect to thebody. A correlated feature resides in the ability of the cylinder gripping apparatus to grip the pipe with a force which is proportional to the axial force upon the pipe tending to move the pipe with respect to the body. In an application as a blowoutpreventer, the cylinder gripping apparatus includes the more detailed feature of increasing its grip upon the pipe in response to an increase in downhole pressure tending to forced the pipe out of the well. Thus, a sudden increase in downhole pressurewill result in a sudden increase in the gripping force upon the pipe.
A feature resides in the provision of floating lugs which allow jaws to grip a cylinder, pipe or tube with a proportional gripping force which opposes rotational movement of the cylinder.
In an application as a snubber, the invention includes the feature of back-to-back gripping apparatus which grip pipe in both axial directions while tubing is installed or removed. One set of back-to-back gripping apparatus holds the tubingwhile another back-to-back apparatus reciprocates axially to jack the tubing in or out of the well. During this operation, the tubing is secured at all times in both axial directions. The gripping means of the present invention has the additionalfeature of incorporating lugs which will not only grip the pipe axially but will grip the pipe with a force proportional to a rotational torque for making up or unscrewing joints of pipe.
Of independent significance, the gripping apparatus includes an interfacing assembly which is more economical to construct and operate. A more detailed feature resides in the utilization of force translation lugs to interface the jaw with thecylinder. The utilization of such force translation lugs renders the cylinder gripping apparatus inexpensive to construct and simple to operate.
Yet another feature of the cylinder gripping apparatus is the provision for an interfacing assembly which permits the jaw to be easily aligned with the cylinder, even when the cylinder is not axially centered within the body. The interfacingassembly permits radial, axial and transverse movement of the jaw with respect to the body in order to permit the jaw to correctly align itself upon the cylinder.
In an application as a drilling platform jacking apparatus, the cylinder gripping apparatus includes the related feature of providing a jacking apparatus which increases its grip upon the platform leg in response to increased pressures generatedby unleveling of the platform deck or the failure of a jacking apparatus upon another leg of the platform. This feature reduces the incidence of failure of the jacking apparatus.
A cylinder gripping apparatus according to a presently preferred embodiment of the invention intended to substantially incorporate the foregoing features includes a jaw adapted for gripping a cylinder, a body adapted to axially receive thecylinder, and an interfacing assembly. The interfacing assembly is interposed between the jaw and the body and is adapted to urge the jaw into gripping engagement with the cylinder when the cylinder is urged in a first direction with respect to thebody. The interfacing assembly is adpated to allow the jaw to release from the cylinder when the cylinder is moved in a second direction with respect to the body.
The interfacing assembly is adapted to provide a radial gripping force in response to an axial force upon the cylinder which is proportional to that axial force. The interfacing assembly is adapted to permit radial, axial and transverse movementof the jaw with respect to the body in order to permit the jaw to align itself upon the cylinder when the cylinder is not perfectly centered within the axis of the body or when the cylinder is deformed.
The interfacing assembly may comprise a force translation lug which is engagable within bearing grooves upon the jaw and the body.
The interfacing assembly may also comprise a plurality of generally cylindrical rollers interposed between the jaw and the body. In this embodiment, the body has an inclined side wall. The rollers are operable to facilitate the movement of thejaw relative to the body along the inclined side wall of the body in order to urge the jaw into gripping engagement with the cylinder. Channels adapted to receive the cylindrical rollers may be formed either in the jaw or in the side wall of the body.
The interfacing assembly may alternatively comprise a cam arm pivotally attached to the body having a generally arcuate cam surface. The jaw may have a groove adapted to receive the cam surface of the cam arm. The cam arm is operable to urgethe jaw into engagement with a cylinder when the cam arm is rotated with respect to the body.
Employed as a platform jacking apparatus, the cylinder gripping apparatus may employ two sets of jaws. One set of the jaws is operable to grip the platform leg while the other set is released. Actuating means or hydraulic cylinders areconnected to one set of the jaws to provide a means for jacking the platform deck up upon the platform leg.
Examples of the more important features of this invention have thus been summarized rather broadly in order that the detailed description thereof that follows may be better understood, and in order that the contribution to the art may be betterappreciated. There are, of course, additional features of the invention that will be described hereinafter and which will also form the subject of the claims appended hereto. Other features of the present invention will become apparent with referenceto the following detailed description of a presently preferred embodiment thereof in connection with the accompanying drawings, wherein like reference numerals have been applied to like elements.
Recognizing the need for an improved method and apparatus for capping an end of a pipe for hydrostatic testing, it is, therefore, my general intent in disclosing the present invention to provide a novel method and apparatus for capping an openend of a pipe, which minimizes or reduces the problems of the type previously noted. The present invention has further useful application in gripping a pipe, tube or cylinder for other purposes.
A feature of the capping apparatus resides in a particular geometric arrangement of the arms, jaws and body, such that during hydrostatic testing, hoop stresses or undesirable forces imposed by the jaws and arms onto a pipe are minimized. Afurther feature of the invention resides in a novel centralizer adapted to axially center the pipe within the body of the apparatus.
Yet another feature of the invention resides in the novel arrangement of an air purge valve with passageways interconnecting the valve to a pressurized region within the interior region of the body in the pipe. The purge valve is adapted toexpunge trapped air from the pressure zone. This feature reduces the hazard of explosions caused by air feature reduces the hazard of explosions cause by air trapped within the pressurized region within the interior of a pipe capped in accordance withthe invention.
An additional feature of my invention resides in the adaptability of the apparatus to a wide range of pipe diameters and pipe surfaces. Replaceable jaw tooth segments, interchangeable cam piece surfaces, and adapters facilitate the hydrostatictesting of varying pipe sizes and permit the movement of pipe couplings, upsets and bell ends through or into the apparatus of the present invention.
Of independent significance is the feature residing in the novel arrangement of a flexible member seal, a spacer and a ring. The ring is adapted to slide into contact with the pipe surface and prevent the extrusion of the seal during highpressure testing.
Another feature pertains to the particular arrangement for connecting the jaw tooth segment to an arm.
A further feature of my invention resides in the ability to hydrostatically test pipe or tubing without deforming the pipe or tubing, even under high pressure testing. The mechanical force per square inch applied to the surface of the pipe by mytesting apparatus is proportional to the invention pressure per square inch of the fluid or water upon the inside surface of the pipe. Thus, as a practical matter, only the wall of the pipe is compressed by proportionally opposite pressure forces; theouter diameter of the pipe is not substantially stressed.
Of independent significance is the feature pertaining to the novel means for engaging and disengaging the jaws upon the pipe. This feature resides in the quick placing of the apparatus upon the pipe to easily secure a safe sealing engagement ofthe end of the pipe and to minimize the time required to handle the apparatus. An engagement means is disclosed for accurately aligning the jaws with synchronized sleeves.
In using the apparatus of this invention, nothing is screwed on the pipe or tubing, nothing is screwed off, and nothing is forced onto the pipe or tubing. Threads are not necessary to facilitate capping in the pipe. Existing threads are notused. No significant outside force is required to hold the testing apparatus to the pipe or tubing. The force applied to hold the apparatus to the pipe is self generating and is always proportional to the internal pressure of the pipe, providing anadded safety feature; the greater the pressure, the harder the holding force.
Moreover, a feature of my invention pertains to the ability to test over upsets, threads and couplings. A related feature is the ability to cap the end of the pipe without damaging the pipe threads or couplings.
A collateral feature of my invention is the speed and ease with which pipe or tubing may be tested. Skilled welders are not required. Untrained workers may easily, quickly and safely install my apparatus to pipe or tubing. Many man-hours maybe saved. The apparatus may be operated for long periods with minimal wear and maintenance. Hydrostatic testing may be performed quickly, economically and safely.
A further feature of my invention resides in the adaptability of the apparatus to serve as an end closure. Appropriate means may be provided to join two of my apparatus together with a bore through the front wall of the caps to provide aweldless joint between two pipe sections for connecting such pipe when welding operations are not feasible, due to the danger of explosion or otherwise. A valve or other device may also be attached to the end of a pipe.
Another feature of may invention resides in the operability of my apparatus despite the presence of oil, dirt, rust or mill scale on the pipe. The jaw tooth segment is adaptable to grip such pipe; and the seal is operable to seal such pipe.
Finally, a feature of my invention pertains to the adaptability of my apparatus for hydrostatically testing a varity of pipe end types, including, for example, plain end pipe, threaded pipe, threaded casing, threaded non-upset tubing, threadedpipe with made-up coupling, casing with made-up coupling, upset tubing with made-up coupling, non-upset tubing with made-up coupling, external upset tubing with and without made-up coupling, and bell end pipe. It will be appreciated that other types ofpipe, tubing or other cylindrical objects may also be capped or held with the disclosed invention.
A pipe capping apparatus according to a presently preferred embodiment of the invention intended to substantially incorporate the foregoing features includes, in addition to the elements enumerated above, a body and a plurality of jawsmechanically coupled through a radial translator adapted to translate an axial pressure force upon the body into a radial force that is evenly applied to the outside wall of a pipe. The body, radial translator and jaws operate to sealingly hold the endof the pipe to facilitate pressurization. A pressure barrier apparatus comprising a flexible seal, and a spacer and an extrusion inhibiting ring included for high pressure testing, cooperates in sealingly engaging the pipe.
More specifically, the flexible seal has a pair of lips formed upon a seal body. The lips define a pressure zone between the lips that also facilitates flushing debris, dirt and rust from the seal and allows trapped air to escape. Lugs upon theseal pre-stress the seal to facilitate initial engagement of the lips.
A tension plate is provided to facilitate the construction of a more economical and stronger body able to withstand the forces imposed on the pipe capping apparatus during high pressure testing.
A plurality of cantilevered arms pivotally attached to the body are provided to axially center the pipe within the body. Drive means engage a drive surface upon the cantilevered arms to rotate the cantilevered arms. A handle serves as a meansfor actuating the drive means.
An improved attachment arrangement is provided to couple the jaw to the body. In particular, dual links are provided which result in a more stable linkage between the jaw and the body. Other arrangements for coupling the jaw to the body arealso disclosed.
Example of the more important features of this invention have thus been summarized rather broadly in other that the detailed description thereof that follows may be better understood, and in order that the contributed to the art may be betterappreciated. There are, of course, additional features of the invention that will be described hereinafter and which will also form the subject of the claims appended hereto. Other features of the present invention will become apparent with referenceto the following detailed description of a presently preferred embodiment thereof in connection with the accompanying drawings, wherein like reference numerals have been applied to like elements, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a partial cutaway side view of an embodiment of a pipe capping apparatus constructed in accordance with the present invention.
FIG. 2 shows an end view of the pipe capping apparatus of FIG. 1 illustrating the centralizer.
Similar to FIG. 2, FIG. 3 shows another end view of the centralizer. FIG. 4 shows a front view of an alternative embodiment of a jaw, jaw holder and arm.
FIG. 5 is a partialy cutaway side view of the embodiment depicted in FIG. 4.
FIG. 6 shows an elevation view of the pressure barrier apparatus depicting the lugs and interstices between the lugs.
FIG. 7 shows a cross-sectional view of the pressure barrier apparatus taken through section lines 7--7 in FIG. 6.
FIG. 8 shows a cross-sectional view of the pressure barrier apparatus for low pressure applications, the surface of the pipe, and the surface of the body.
FIG. 9 illustrates a cross-sectional view of an alternative embodiment of a pressure barrier apparatus for high pressure applications.
FIG. 9A illustrates an enlarged view of a portion of FIG. 9.
FIG. 10 is another view of the apparatus depicted in FIG. 9, showing the apparatus during pressurization.
FIGS. 10A and 10B illustrate enlarged views of portions of FIG. 10.
FIG. 11 and FIG. 12 show a cross-sectional elevational view of the ring illustrated in FIG. 9.
FIG. 12 shows a view of the ring illustrated in FIG. 11 during pressurization.
FIG. 13 and FIG. 14 illustrate an alternative embodiment of the ring depicted in FIG. 11 and FIG. 12, respectively.
FIG. 15 illustrates a cross-sectional elevational front view of the interface between the jaw tooth segment and the wall of the pipe.
FIG. 16 is a partial cross-sectional side view of an alternative embodiment of the means for engaging and disengaging the jaws upon the pipe.
FIG. 17 is an additional side view of the embodiment disclosed in FIG. 16 showing the jaws retracted.
FIG. 18 depicts a side view of another alternative embodiment of the means for engaging and disengaging the jaws upon the pipe.
FIG. 19 shows an additional side view of the apparatus illustrated in FIG. 18 showing the jaws retracted.
FIG. 20 depicts a side view of an embodiment of a cylinder gripping apparatus constructed in accordance with the present invention.
FIG. 21 shows a cut-away end view of the cylinder gripping apparatus depicted in FIG. 20.
FIG. 22 shows a side view of an alternative embodiment of the cylinder gripping apparatus.
Similar to FIG. 22, FIG. 23 shows a side view of the embodiment illustrated in FIG. 22 depicting the retainers or stays.
FIG. 24 illustrates a partially cut-away end view of the embodiment depicted in FIG. 23.
FIG. 25 is a side view of an alternative embodiment of the cylinder gripping apparatus.
FIG. 26 is a side view of yet another alternative embodiment of the cylinder gripping apparatus.
FIG. 27 illustrates a side view of an alternative embodiment of the cylinder gripping apparatus.
FIG. 28 depicts a partially cut-away side view of an embodiment of the cylinder gripping apparatus employed as a safety hanging apparatus for a pipe.
FIG. 29 shows an enlarged side view of the force translation lug and the bearing groove in the body.
FIG. 30 illustrates a cut-away bottom view of the apparatus shown in FIG. 29.
FIG. 31 shows a partially cut-away bottom view of the apparatus illustrated in FIG. 28.
FIG. 32 depicts an embodiment of the cylinder gripping apparatus employed as a drilling platform jacking apparatus.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
Turning now to the drawings in FIG. 20, there is depicted a side view of a portion of a cylinder gripping apparatus 200. The cylinder gripping apparatus 200 comprises a body 201, a jaw 202 and an interfacing assembly 203. The body 201 is onlypartially shown in FIG. 20.
As best shown in FIG. 21, the jaw 202 has a friction surface 204 adapted for gripping a cylinder 205. The friction surface 204 may comprises serrations, teeth, a smooth friction surface, or other conventional friction surfaces.
With reference to FIG. 20, the interfacing assembly 203 may comprise floating force translation lugs 206. The interfacing assembly also comprises a resilient member, elastic member or spring 207. The elastic member 207 is connected to the jaw202 at a first spring anchor point 208. The elastic member 207 is connected to the body 201 at a second spring anchor point 209.
The floating force translation lugs 206 are floating in the sense that the lugs 206 are unconnected to either the body 201 or the jaw 202. The lugs 206 fit into first bearing grooves or sockets 210 formed in the jaw 202. The other end of thelugs 206 fit into second bearing grooves or sockets 211.
As shown in FIG. 21, the lug 206 has a first arcuate end or curved end 212 and a second arcuate or curved end 213. The first arcuate end 212 is adapted to fit into the first bearing groove 210. Similarly, the second arcuate end 213 is adaptedto fit into the second bearing groove 211.
As best shown in the side view depicted in FIG. 20, the forced translation lugs 206 are angularly disposed between the body 201 and the jaw 202. The first bearing groove 210 has a first arcuate or curved bearing surface 214 which tapers to asloped forward surface 215. The sloped forward surface 215 allows the lug 206 to rotate in a first sense inside the first bearing groove 210. In FIG. 20, the first sense of rotation is clockwise with respect to the jaw 202.
Similarly, the second bearing groove 211 comprises a second arcuate or curved bearing surface 216 which tapers to a sloped or planar rearward surface 217. The sloped rearward surface 217 permits the lug 206 to rotate in a first sense withrespect to the body 201.
The lugs 206 are floating and thus unconnected to the body 201 or the jaw 202. Therefore, it is desirable to provide a means for compressively engaging the jaw 202 toward the body 211 in order to hold the lugs 206 within the first and secondbearing grooves 210 and 211. In the present instance, this is essentially accomplished by the elastic member 207. When the jaw 202 is not engaged against a cylinder 205, the elastic member 207 tends to urge the jaw 202 toward the body 201, thus holdingthe lugs 206 in engagement within the first and second bearing grooves 210 and 211.
It will be appreciated that some actuating means may be provided to urge the jaw 202 into initial engagement with the cylinder 205. When the jaw 202 is engaged against a cylinder 205 and an axial force urges the cylinder 205 in a forwarddirection, or to the right in FIG. 20, then the lugs 206 will tend to rotate in a second sense, or counterclockwise in FIG. 20. The tendency of the lugs 206 to rotate in a second sense will tend to urge the jaw 202 into gripping engagement with thecylinder 205. The gripping force between the jaw 202 and the cylinder 205 will be proportional to the axial force exerted upon the cylinder 205. Thus, the force translation lugs 206 provide a radial counterforce in response to the axial force upon thecylinder.
When the cylinder 205 is not perfectly axially aligned with respect to the body 201, it is desirable to permit the jaw 202 to move in a direction transverse to the axis of the body 201. As best shown in FIG. 21, it is desirable to allow the jaw202 to move transversely, i.e., to the left or right, in order to allow the friction surface 204 to engage the cylinder 205. The curved ends 212 and 213 cooperate with the first opposing face 218 of the jaw 202 and the second opposing face 219 of thebody 201 to permit a transverse displacement of the jaw 202 from an initial axially aligned position to a displaced position either to the right or to the left of FIG. 21. Thus, the floating lug 206 permits the friction surface 204 of the jaw 202 toengage the cylinder 205 even when the cylinder 205 is not perfectly axially aligned within the body 201.
Thus, the floting nature of the lug 206 which is interposed between the jaw 202 and the body 201 permits movement between the jaw 202 and the body 201 with at least three degrees of freedom. That is, the jaw 202 may move axially, radially andtransversely with respect to the body 201. These degrees of freedom of movement that are permitted the jaw 202 with respect to the body 201 facilitate the effective engagement of the jaw 202 against the cylinder 205 even for imperfectly alignedcylinders 205.
In some applications, such as a wellhead snubber apparatus, it may be desirable to grip a pipe, tube or cylinder 205 to prevent rotation of the pipe, tube or cylinder 205 about the axis of the body 201. As shown in FIG. 21, the floating lug 206may be positioned in offset position 400 (shown as a broken line). In the offset position 400, the lug 206 will tend to oppose clockwise rotation of the pipe 205. The gripping force of the jaw 202 upon the pipe 205 will be proportional to the clockwisetorque upon the pipe 205. Similarly, counterclockwise rotation of the pipe 205 may be prevented by a jaw 202 with the lug 206 offset in an opposite direction, or to the right in FIG. 21 (not shown).
It will be appreciated that a second cylinder gripping apparatus 200 may be connected to the same pipe 205 as a first gripping apparatus 200 with a set of lugs 206 offset in an opposite direction in order to prevent both clockwise andcounterclockwise rotation of the same pipe 205.
Turning now to FIG. 22, another embodiment of the interfacing assembly 203 is shown. The interfacing assembly 203 comprises floating lugs 220 interposed between the body 201 and the jaw 202. The floating lugs 220 may be fabricated differentlyfrom the lugs 206 illustrated in FIGS. 20 and 21. As best shown in FIG. 24, the lug 220 has a first curved or arcuate end 221 and a second curved or arcuate end 222. The first curved end 221 is wider than the second curved end 222. The first curvedend 221 may be substantially the same width as the jaw 202. As best shown in FIG. 24, the first bearing groove 210 may extend across substantially the entire width of the jaw 202.
The first end 221 of the lug 220 may be held within the first bearing groove 210 by a set of first stays or retaining means 223. The first stays 223 are fixedly held against the jaw 202 by fastening means 224. Fastening means 224 may comprise abolt, screw, pin, or other conventional fastening mechanisms.
Similarly, the second end 222 of the lug 220 may be held within the second bearing groove 211 by a set of second stays or retaining means 225. The second stays 225 are fixedly held against the body 201 by fastening means 226. Fastening means226 may comprise a bolt, screw, pin, or other conventional fastening mechanisms.
Fastening means 224 and 226 are connected to the jaw 202 and the body 201, respectively. The first and second stays 223 and 225 are not connected to the lug 220. This can best be seen with reference to FIG. 23. The first and second stays 223and 225 are adapted to cover at least a portion of the cross-sectional area of the first and second bearing surfaces or grooves 210 and 211 in the jaw 202 and the body 201, respectively. The first and second stays 223 and 225 are adapted to laterallyretain the lug 220 within the first and second bearing grooves 210 and 211, while leaving the lugs 220 free to rotatively pivot within the bearing grooves 210 and 211.
The stays 223 and 225 may be omitted, as shown in FIG. 22, and are not essential for the operation of the cylinder gripping apparatus.
Thus, as shown in FIG. 22, the first and second curved ends 221 and 222 of the lug 220 cooperate with first and second opposing faces 218 and 219 of the jaw 202 and the body 201, respectively, to permit a transverse displacement of the cylinder205 from an initial axially aligned position to a displaced position. This degree of freedom of movement of the jaw 202 in the transverse direction permits the jaw 202 to more evenly engage the cylinder 205 when the cylinder 205 is not perfectly axiallyaligned within the body 201.
As shown in FIG. 22, the opposing face 218 of the jaw 202 has a curved surface or bearing groove 210 adapted to receive the curved end 221 of the floating lug 220.
An elastic member 207 tends to urge the jaw 202 toward the body 201 in order to hold the lugs 220 into engagement within the first and second curved surfaces 210 and 211. A compression member or spring 227 tends to urge the jaw 202 intoengagement with the cylinder 205. As shown in FIG. 22, the compression member 227 is interposed between the front of the body 201 and the jaw 202.
Actuating means 228 is connected to the lug 220 for rotationally pivoting the lug 220. Actuating means 228 may comprise a handle. Actuating means 228 may be used to rotationally pivot the lug 220 in a first sense, or clockwise as shown in FIG.22, to permit the jaw 202 to disengage the cylinder 205.
It will be noted that the elastic member 207 tends to urge the jaw 202 radially outwardly with respect to the body 201, thus urging the lugs 220 into operative engagement with the first and second bearing grooves 210 and 211. When the cylinder205 is removed from the body 201, the elastic member 207 tends to hold the jaw 202 and the body 201 into engagement with the lugs 220.
As shown in FIG. 23, the first bearing groove 210 comprises a first curved or arcuate bearing surface 214 which tapers to a sloped or planar forward surface 215. Similarly, the second bearing groove 211 comprises a second curved or arcuatebearing surface 216 which slopes to a planar or sloped rearward surface 217.
It will be appreciated that a floating force translatin by 206 may be constructed with a first arcuate, curved or spherical end 212 as shown in FIGS. 20 and 21, and with a second end fashioned in accordance with the embodiment described abovewith reference to FIGS. 22, 23 and 24.
Referring to FIG. 25, a side view of another embodiment of the present invention is illustrated. The interfacing assembly 203 is interposed between the sidewall of the body 201 and the jaw 202. In the present instance, the interfacing assembly203 has curved or arcuate surfaces 229 which engage an opposing face 230 of the sidewall of the body 201. The curved or circular surfaces 229 form the outer surface of generally cylindrical or circular rollers 231. In a preferred embodiment, therollers 231 are formed in the shape of cylindrical rods.
The rollers 231 are adapted to fit within channels 234 in the jaw 202. The channels 234 are formed transversely along the inner surface 235 of the jaw 202. As shown in FIG. 25, the inner surface 235 of the jaw 202 is inclined or sloped. Similarly, the opposing face 229 of the sidewall of the body 201 is similarly sloped or inclined.
The rollers 231 are floating, and are thus unconnected to either the jaw 202 or the body 201. The elastic member 207 tends to urge the jaw 202 radially outwardly toward the sidewall of the body 201. Thus, the elastic member 207 tends to holdthe rollers 231 in the channels 234.
The rollers 231 facilitate the movement of the jaw 202 along the planar sloped opposing face 230 of the body 201. The rollers 231 are operable to facilitate the movement of the jaw 202 relative to the body 201 along the inclined inner surface230.
The inclined inner surface 230 is adapted to urge the jaw 202 into engagement with the outer surface of the cylinder 205 when the jaw 202 is urged rearwardly, or to the right in FIG. 25, with respect to the body 201. A compression member,resilient member or spring 227 is adapted to urge the jaw 202 rearwardly with respect to the body 201.
Actuating means 232 is pivotally connected to the body 201 at a pivot point 233. Actuating means 232 may comprise a handle, in a preferred embodiment. Actuating means 232 is adapted to urge the jaw 202 generally forwardly, but that is to theleft in FIG. 25, with respect to the body 201. Thus, actuating means 232 may be used to disengage the jaw 202 from the cylinder 205.
The rollers 231 may be confined to the channels 234 by stays 225 (not shown).
Because the rollers 231 are floating, the jaw 202 is permitted to move transversely with respect to the body 201. This transverse movement of the jaw 202 permits the jaw to grip the cylinder 205 even when the cylinder 205 is not axially centeredwithin the body 201. Thus, the curved surface of the rollers 231 is cooperable with the opposing face 230 of the body 201 to permit a transverse displacement of the jaw 202 from an initial axially aligned positioned to a displaced position.
It will be appreciated that the channels 234 are preferably generally cylindrically shaped in substantial correspondence with the shape of the rollers 231. A first boss, finger or projection 236 limits the transverse movement of the jaw 202 withrespect to the body 201. The boss 236 prevents the jaw 202 from completely slipping out of the cylinder gripping apparatus 200. Similarly, a second boss, finger or projection 237 is formed upon the rear of the jaw 202.
FIG. 26 illustrates an alternative embodiment of the interfacing assembly 203 interposed between the jaw 202 and the body 201.
In the present instance, generally cylindrical roller 238 have curved, arcuate or generally round surfaces 239 which are cooperable with an opposing planer inclined face 240 of the jaw 202 to permit movement of the jaw 202 with respect to thebody 201. The rollers 238 fit within generally cylindrically shaped channels 241 formed transversely along the inclined or sloped inner surface 230 of the side wall of the body 201. The rollers 238 permit the jaw 202 to move transversely with respectto the body 201 in a manner similar to the interfacing assembly described with reference to FIG. 25.
In other respects the interfacing assembly 203 depicted in FIG. 26 is constructed and operated similar to the interfacing assembly 203 described with reference to FIG. 25.
Turning now to FIG. 27, the interfacing assembly 203 is interposed between the body 201 and the jaw 202. In the present instance, the interfacing assembly 203 has a curved surface 242 which interfaces with an opposing face 243 of the jaw 202. The opposing face 234 of the jaw 202 is located generally opposite to the friction surface 204 of the jaw 202.
The opposing face 234 of the jaw 202 has a curved surface or groove 244 formed in a position generally in correspondence with the curved surface 242 of the interfacing assembly 203. The curved surface 242 of the interfacing assembly 203 iscooperable with the opposing face 234 of the jaw 202 to permit the jaw 202 to move not only radially and axially with respect to the body 201, but also transversely with respect to the body 201. Thus, if the cylinder 205 is not axially centered withinthe body 201, the curved surface 242 will permit the jaw 202 to move from an initial axially centered position to a displaced position in correspondence with the uncentered or displaced position of the cylinder 205. Thus, the interfacing assembly 203permits the jaw 202 to be displaced transversely with respect to the body 201 in order to more effectively engage the cylinder 205 when the cylinder 205 is deformed or uncentered within the body 201.
The interfacing assembly 203 further comprises a cam arm or force translation arm 245 which may be pivotally connected to the body 201 at a second pivot point 246. The cam arm 245 is operable to urge the jaw 202 into engagement with the outersurface of the cylinder 205 when the cam arm 245 is rotated in a second sense, or counterclockwise in FIG. 27, with respect to the body 201.
Elastic members or springs 247 are connected to the jaw 202 at first spring anchor points 248 and are connected to the body 201 at second spring anchor points 249. The elastic members 247 tend to urge the jaw 202 radially outwardly with respectto the body 201. Thus, the elastic members 247 tend to urge the jaw 202 into engagement with the generally arcuate cam surface 242 of the cam arm 245.
In the present instance the jaw 202 has a forward alignment lip 250 and a rear alignment lip 251. The alignment lips 250 and 251 are connected to the forward and rear edges of the jaw 202 respectively, as shown in FIG. 27. The alignment lips250 and 251 operate to disengage the entire jaw 202 from the cylinder 205 in the event that either the forward or rear end of the jaw 202 does not initially disengage from the cylinder 205. If the cam arm 245 is rotated in a first sense, or clockwise inFIG. 27, with respect to the body 201, the jaw 202 will be urged radially outwardly from the cylinder 205 by the elastic members 247. In the event that the rear portion of the jaw 202 does not initially disengage from the cylinder 205, the forwardalignment lip 250 will contact the inner surface 219 of the body 201. Thus, further rotation of the cam arm 245 in a first sense with respect to the body 201 will cause the jaw 202 to pivot about the point where the forward alignment lip 250 contactsthe inner surface 219 of the body 201 and will cause the rear portion of the jaw 202 to disengage from the cylinder 205.
In the present invention, the cam arm 245 has actuation means or a handle 252 connected to it. An elastic member or spring 253 may be connected between the handle 252 and the body 201. The elastic member 253 will tend to urge the cam arm 245 torotate in a second sense with respect to the body 201 and thus urge the jaw 202 into engagement with the cylinder 205.
It will be appreciated that the interfacing assemblies 203 illustrated in FIGS. 22, 25, 26 and 27 are adapted to provide a radial counterforce in response to an axial force upon the cylinder. If an axial force is exerted upon the cylinder 205when the jaw 202 is in engagement with the cylinder 205, and the cylinder 205 is urged to the right in FIGS. 22, 25, 26 and 27, the interfacing assemblies 203 will provide a radial counterforce or gripping force which is proportional to the axial forceexerted upon the cylinder 205.
It will also be appreciated that, similar to FIG. 27, the interfacing assembly 203 illustrated in FIGS. 20, 21, 22, 23 and 24 may be pivotally connected at one end to either the jaw 202 or the body 201.
In FIG. 28, an embodiment of the present cylinder gripping apparatus is shown for use in connection with a safety hanger or blowout preventer apparatus for use in connection with drilling operations. The embodiment illustrated in FIG. 28 mayalso have utility as a snubber.
As illustrated in FIG. 28, the body 201 has an upper cylinder, pipe or tube passageway or opening 254 and a lower pipe, tube or cylinder passageway or opening 255. The body 201 is adapted to axially receive the pipe, tube or cylinder 205. Thejaws 202 have a friction surface 204 adapted to grip the drill pipe 205.
In the present instance, the interfacing assembly 203 comprises angularly disposed floating force translation lugs or arms 256. The lug 256 is floating because it is unconnected to the body 201 or the jaw 202. The lug 256 has a first curvesurface or arcuate surface 257 on one end and a second curved or arcuate surface 258 on the other end. The first curved end 257 is adapted to fit within a first bearing groove 259. Similarly, the second curved end 258 is adapted to fit within a secondbearing groove 260. The bearing grooves 259 and 260 are constructed similar to the bearing grooves 211 and 214 illustrated in FIGS. 22, 23 and 24. For example, as best shown in FIG. 29, the second bearing groove 260 comprises a second curved or arcuatebearing surface 261 which tapers to a generally planar or inclined surface 262.
As best shown in FIG. 29, the lug 256 is floating in the sense that it is not connected to the body 201. First and second retaining means or stays 265 and 266 are connected or fastened to the jaw 202 and the body 201 respectively. The stays 265and 266 retain the lugs 256 when the pipe 205 is withdrawn from the body 201, as will be more fully described below.
Referring to FIG. 29, the stay 266 has an aperture or opening 263. The aperture 263 is adapted to receive a projection or pin 264 connected to the lug 256. As best shown in FIG. 30, the pin 264 is connected to the lug 256 and extends throughthe aperture 263 in the stay 266. When the jaw 202 engages the pipe 205, the lug 256 engages the grooves 259 and 260. When the lug 256 is engaged with the grooves 259 and 260, the pin 264 does not contact the stay 266. As best shown in FIG. 29, theaperture 263 is larger than the pin 264. Thus, the lug 256 is essentially floating. The pin 264 cooperates with the stay 266 to retain the lug 256 when the pipe 205 is withdrawn from the body 201.
As best shown in FIGS. 29 and 30, the stay 266 is connected to the body 201 by fastening means 267. Fastening means 267 may comprise a bolt, screw, pin or other conventional fastening mechanisms. Referring to FIG. 28, the first stay 265 issimilarly connected to the jaw 202. In addition, the lug 256 has a corresponding pin 268 which is adapted to fit within an aperture in the first stay 265. It will be appreciated that either end of the lug 256 may be pivotally connected to the body 201or jaw 202.
The operation of the interfacing assembly 203 illustrated in FIGS. 28 through 31 and providing a radial counterforce or gripping force upon the pipe 205 in response to an axial force upon the pipe 205 is similar to the interfacing assemblies 203described above with reference to FIGS. 20 through 27.
The interfacing assembly 203 illustrated in FIG. 28 further comprises a jaw housing 269. The jaw housing 269 has arm passage openings 270 which permit the lugs 256 to pass through the jaw housing 269. A compression member or spring 271 isprovided between the body 201 and the jaw housing 269. The spring 271 tends to urge the jaw housing 269 downward as shown in FIG. 28. This tends to urge the jaws 202 into engagement with the pipe 205.
A wiper 272 is provided to remove dirt, grime and other foreign matter from the surface of the pipe 205. The wiper 272 operates to prevent dirt and other matter upon the surface of the pipe 205 from interfering with the gripping surface 204 ofthe jaws 202.
A releaser, jaw releasing cylinder or cylinder means 273 is connected to the body 201. The releaser 273 has a rod 274 shown in FIG. 28 in the retracted position. The rod 274 is operable to be extended from the releaser 273 so that it contactsthe jaw housing 269 and urges it upward. The releaser 273 is adapted to compress the spring 271 and thus disengage the jaw 202 from the pipe 205.
It will be appreciated that a second similar body 275 may be stacked with the body 201 to provide more than one set of jaws 202 to grip the pipe 205. The pipe 205 is shown in FIG. 28 with a casing 276. A second set of jaws provided in thesecond body 275 would operate to grip the pipe 205 when the casing 276 was passed through the body 201.
Employed as a safety hanger apparatus, the embodiment of the invention illustrated in FIG. 28 would permit the drill pipe 205 to be removed from the hole by moving it upward. However, if the drill pipe 205 was dropped, the jaws 202 wouldautomatically engage the drill pie 205 and prevent it from falling into the hole (not shown). The jaws 202 are adapted to permit the drill pipe 205 to be moved upwardly in FIG. 28, and are adapted to prevent the drill pipe 205 from being dropped downthe hole or for moving downwardly in FIG. 28.
It will be appreciated that the embodiment of the invention illustrated in FIG. 28 may have useful application for other types of pipe, tubes or cylinders. The present invention is not intended to be limited to drill pipe.
In the event that it is desired to drill and move the drill pipe 205 downwardly, a similar body 201 may be employed as a blowout preventer by turning the body 201 upside down from the position shown in FIG. 28. In such a position, the jaws wouldpermit the drill pipe 205 to be drilled down into the hole, but would not allow the drill pipe 205 to be blown out of the hole even in the event of a sudden increase in downhole pressure. The gripping force of the jaws 202 upon the drill pipe 205 willbe proportional to the downhole pressure. Thus, the gripping force of the jaws 202 upon the drill pipe 205 will increase in proportion to any increases in the downhole pressure. Thus, a great safety feature is achieved by the present invention becausea sudden increase in downhole pressure will be immediately offset by an increase in the radial counterforce or gripping force of the jaws 202 upon the drill pipe 205.
The releaser 273 is operable to disengage the jaws 202 when it is desired to move the drill pipe 205 in a direction opposite to the direction of movement permitted by the jaws 202.
FIG. 32 depicts an embodiment of the cylinder gripping apparatus having utility as an offshore drilling platform deck jacking apparatus.
Although any of the interfacing assemblies previously described with reference to FIGS. 20 through 31 may be used to interface jaws with a body, the illustrated embodiment of the platform jacking apparatus 277 comprises a first jaw 21, a fist arm22, a first pivot point 23, a second pivot point 24, a first extension 117, a first guide or synch sleeve 123, a first shoe or fastening means 119, a first actuation means 121, a first shaft 125 and a first fastening means 127, as are described morefully with respect to FIGS. 18 and 19 in the application for a hydrostatic testing apparatus, Application Ser. No. 037,140, filed May 8, 1979, by the same applicant, which is incorporated herein by reference.
Similarly, a second jaw 58, second arm 57, third pivot point 60, fourth pivot point 59, second extension 118, second guide or synch sleeve 124, second shoe 120, second actuation means 122, second shaft 126 and second fastening means 128 operatein a manner similar to the corresponding elements illustrated and described with reference to FIGS. 18 and 19 of Application Ser. No. 037,140, filed May 8, 1979, for a hydrostatic testing apparatus, by the same applicant, which is incorporated herein byreference.
In the embodiment shown in FIG. 32, a third arm 278 is pivotally connected to the body at a fifth pivot point 279. The third arm 278 is pivotally connected to the first jaw 21 at a sixth pivot point 280. A fourth arm 281 is pivotally connectedto the body 290 at an eighth pivot point 282. The fourth arm 281 is connected to the second jaw 58 at an eighth pivot point 283. The body 290 is connected to a platform 284 in the present instance, the platform 284 comprises a conventional offshoredrilling platform. The first and second jaws 21 and 58 comprise a first set of jaws which are adapted to grip a platform leg 285. A first compression member or spring 286 is interposed between the first jaw 21 and the body 290. The spring 286 isadapted to urge the first jaw 21 into engagement with the platform leg 285. A second compression member or spring 287 similarly urges the second jaw 58 into engagement with the platform leg 285. A third jaw 288 and a fourth jaw 289 comprise a secondset of jaws adapted to grip the platform leg 285. The second set of jaws 288 and 289 operate in a manner similar to the first set of jaws 21 and 58. The body 290 has a guide sleeve 291 which is adapted to receive a jaw housing 292 which is annularlyshaped as shown in FIG. 32. The jaw housing 292 is adapted to axially receive the platform leg 285. The body 290 is similarly adapted to axially receive the platform leg 285. The jaw housing 292 is adapted to reciprocally slide within the guide sleeve291 of the body 290. Actuation means or cylinder means 293 is connected to the body 290. Actuation means 293 has a shaft 294 which is operable to reciprocally extend or retract within actuation means 293. The shaft 294 is connected to the jaw housing292.
The platform 284 may be jacked up the platform leg 285 by allowing the second set of jaws 288 and 289 to engage the platform leg 285 while the shafts 294 are in the retracted position. When the shafts 294 are in the retracted position, the jawhousing 292 will be retracted within the guide sleeve 291 of the body 290. Thus, cylinder means 293 may be used to extend shafts 294 to push the jaw housing 292 downwardly with respect to the body 290. Thus, the body 290 and the platform 284 are raisedwith respect to the platform leg 285 while the jaw housing 292 remains stationary with respect to the platform leg 285.
In FIG. 32, the shaft 294 is shown in the fully extended position. The shaft may be extended a distance X as shown in FIG. 32. Thus, for each motion, the platform 284 may be jacked up a distance X.
When the shaft 294 has reached the fully extended position, the first set of jaws 21 and 58 are allowed to engage the platform leg 285. Thus, the first set of jaws 21 and 58 will hold the platform 284 in position as the shafts 294 and the secondset of jaws 288 and 289 are retracted within the guide sleeve 291. It will be appreciated that both the first set of jaws 21 and 58 and the second set of jaws 288 and 289 will permit the platform leg 285 to be moved in one direction with respect to thebody 290 and the jaw housing 292, but will not permit the platform leg 285 to be moved in an opposite direction with respect to the body 290 or the jaw housing 292.
The first and second springs 286 and 287 are adapted to insure that the first set of jaws are urged generally radially inwardly with sufficient force to insure that the first set of jaws 21 and 58 maintain contact with the platform leg 285. Thus, if the second set of jaws 288 and 289 should fail for any reason, the first set of jaws 21 and 58 would automatically grip the platform leg 285 with a gripping force proportional to the weight of the platform 284 or proportional to the stressesupon the platform leg 285. Similarly, a third and fourth spring or compression member 295 and 296 urge the second set of jaws 288 and 289 into engagement with the platform leg 285.
In the present instance, a plurality of wipers 297 is provided between the jaw housing 292 and the guide sleeve 291 and the platform leg 285. The wipers 297 tend to keep sea water or other unwanted matter from contaminating the interior of theguide sleeve 291. Air vent ports 298 provide fluid communication between the air within the interior of the guide sleeve 291 and the external atmosphere.
A plurality of second wipers 299 is provided between the body 290 and the platform leg 285.
In the illustrated embodiment, the first and third arms 22 and 278 are pivotally connected to a first spline or rib 300 formed from the body 290. Similarly, the second and fourth arms 57 and 281 may be pivotally connected to a second spline orrib 301 formed from the body 290.
The actuation means 121 and 122 may also comprise a first releasor operable to release the first set of jaws 21 and 58 from engagement with the platform leg 285. Similarly, actuation means 302 and 304 may comprise a second releasor operable torelease the second set of jaws 288 and 289 from engagement with the platform leg 285. The second releasor 302 and 304 is operable to disengage the second set of jaws 288 and 289 to permit the retraction of the jaw housing 292 within the guide sleeve291.
The platform 284 may be lowered, also by synchronized operation of first and second releasers 121 and 122, and 302 and 304, in a manner generally opposite to that described above with reference to jacking the platform 284 up.
It will be appreciated that the cylinder gripping apparatus described above may find utility in any application where it is desirable to grip a cylinder, rod pipe or tube to keep the cylinder, rod pipe or tube from going in an unwanted direction. The cylinder gripping apparatus may be employed with utility to hold the end of a pipe to be forged during the process of upsetting tubing. Alternatively, the cylinder gripping apparatus may find utility in holding tubing during the process of bellingwhere a mandrel is inserted and welded to a pipe or tube. Similarly, any operation that requires a pipe, tube or cylinder to be held or gripped where large axial forces tend to urge the pipe, tube or cylinder in an unwanted direction.
Turning first to FIG. 1, there is shown a partial cutaway view of a pipe capping apparatus 19 according to the present invention. In a preferred embodiment, a body 20 and a jaw assembly or jaw 21 are coupled together with a radial forcetranslator 39. The radial force translator 39 transforms the axial force exerted upon the body 20 by a fluid introduced into the interior region 40 of a pipe 26 to a force radially inwardly. The pressure from the fluid is applied to the body 20generally in an interior zone 41 within the body 20. The radial force translator 39 transforms this axial force into a radially inward force, or a radial counterforce, which is applied to the outer walls of the pipe 26 by the jaws 21. This radialcounterforce must be sufficient to hold the pipe during pressurization. Pursuant to the invention, the radial counterforce is always larger and proportional to the axial force upon the body 20 to assure that the apparatus 19 will not be forced off ofthe pipe 26 during pressurization. Thus, when no pressure is exerted upon the fluid within the pipe 26, little force will be exerted against the outer surface of the pipe 26 by the jaws 21. As a safety feature, the greater the pressure upon the inside40 of the pipe 26, the greater the gripping force exerted by the jaws 21 upon the outer surface of the pipe 26.
In a preferred embodiment, the radial force translator 39 comprises an arm 22 pivotally disposed against or connected to the body 20 at a first pivot point or pin 23. The arm 22 is also connected to the jaw 21 at a second pivot point or pin 24. The first pivot point 23 and the second pivot point 24 are adapted to permit the arm 22 to rotate. Rotation of the arm 22 permits the jaw or jaw assemnbly 21 to move into and out of engagement with the surface of the pipe 26.
The radial translator 39 transforms the axial force into a radial counterforce proportional to the tangent of a translation angle T. Different translation angles T may be selected to give the desired amount of radial counterforce. Thetranslation angle T will depend upon the length of the arm 22, measured between the first pivot point 23 and the second pivot point 24, and the distance of the first and second 23 and 24 from the outer wall of the pipe.
The radial counterfore will always be proportionally related to the axial pressure force. The axial pressure force will be substantially equal to the internal fluid pressure multiplied times the cross-sectional area of the pipe 26. The radialforce translator 39 is operable to produce a radial counterforce applied by the jaws 21 to the pipe 26 which is proportional to the pressure multiplied times the cross-sectional area of the pipe 26, all divided by the tangent of the translation angle T.
It is contemplated that the translation angle T may be an angle anywhere between 10.degree. and 45.degree.. It has been found that a preferred embodiment of the radial force translator 39 employs a translation angle T between 30.degree. and40.degree.. In the practice of a preferred embodiment, it has been found that a translation angle T of 37.degree. provides satisfactory results.
The translation angle T is determined by a jaw face offset C, a length of the arm 22 measured between the center of the first pivot point 23 and the center of the second pivot point 24, and an arm offset D. In a preferred embodiment, the locationof the first pivot point 23 should be chosen such that it is located in a tension member 42 of the body 20. The diameter of the pipe 26 to be tested will also be known.
The strength of the material composing the jaw 21 is important in determining the jaw face offset C. The pin 24 is preferably located as close to the pipe 26 as possible consistant with required clearances and allowable stresses. In a preferredembodiment where the jaw 21 comprises a single member, the jaw face offset C is substantially equal to a distance of 2 or 21/2 diameters of a pin inserted into the second pivot point 24. In a preferred embodiment, the jaw 21 may be fabricated fromsteel, or more specifically heat-treated steel. In the practice of a preferred embodiment, it has been found that highly ductle carbuerized steel (AISI 1040 or 8620) provides satisfactory results for the jaw tooth segment 47. The teeth surface shouldpreferably be case hardened to Rockwell C-50 or C-60.
Generally, it has been found that the allowable shear stress upon the pin 24, and also the pin 23, should not exceed 25% of the ultimate yield of the steel composing the pins 24 or 23.
The radial force or clamping force should be greater than the axial pressure force exerted upon the body 20. The axial force is substantially equal to the pressure of the fluid in the inner zone 41 of the body 20 times the cross-sectional areaof the pipe 26. The radial force is equal to the axial force divided by the tangent of the transformation angle T.
Referring to FIG. 1, it is desirable to have the second pivot point 24 located upon the jaw assembly 21 such that the tendency of the front teeth 92 to bite into the pipe 26 with more force than the other teeth 92 is minimized. It is desirableto evenly distribute the radial gripping force exerted by the jaw 21 upon the pipe 26 evenly over the area of the jaw 21 in contact with the surface of the pipe 26.
In practice, it has been found desirable to place the second pivot point 24 to the rear of the jaw holder 45 of the jaw assembly 21, or in the case of a single member jaw 21, to the rear of the jaw 21. This reduces the tendency of the frontteeth 92 to bite into the surface of the pipe 26.
Useful results may be obtained by placing the second pivot point 24 generally in the center of the rear one-half of the jaw 21.
More specifically, in a preferred embodiment, the second pivot point 24 should be connected to the rear portion of the jaw 21 a distance F (shown in FIG. 1) from the front of the jaw 21 which is sufficient to minimize the tendancy of the frontteeth 92 to overbite into the pipe 26 and to mar, deform or leave excessive teeth imprints in the surface of the pipe 26. In practice, the second pivot point 24 may be connected a distance F from the front of the jaw 21 which is equal to the jaw faceoffset C multiplied times the crosssection area of the pipe 26 multiplied times the maximum test pressure that will be desired, all divided by a pipe stress factor. In practice, a pipe stress factor of 2,000 has been found to provide satisfactoryresults. It will be appreciated that the pipe stress factor may be less than 2,000. This factor is based upon the amount of pressure that may be exerted by the front teeth 92 of the jaw 21 upon the pipe 26. The pipe stress factor 2,000 is based upon apermissible radially inwardly force upon the front teeth 92 and may be defined as 2,000 pounds per inch upon the front jaw surface circumferentially contacting the surface of the pipe 26. It will be appreciated that the pipe stress factor is a functionof the maximum test pressure desired and the jaw face offset C.
As discussed above, the jaw face offset C is made as small as possible consistent with the amount of clearance required to prevent movement | | | |
