| Patent Number |
Title Of Patent |
Date Issued |
| 5119892 |
Notary drill bits |
June 9, 1992 |
| A rotary drill bit comprises a bit body having a shank for connection to a drill string and a passage for supplying drilling fluid to the face of the bit, which carries a plurality of polycrystalline diamond preform cutting elements. The cutting elements on one side of a diameter of the |
| 5109935 |
Rotary drill bits |
May 5, 1992 |
| A rotary drill bit comprises a bit body having a shank for connection to a drill string and a passage for supplying drilling fluid to the face of the bit, which carries a plurality of polycrystalline diamond preform cutting elements. In order to reduce bit whirl, the cutting elements are |
| 5101691 |
Methods of manufacturing cutter assemblies for rotary drill bits |
April 7, 1992 |
| A method of manufacturing a cutter assembly for a rotary drill bit includes the step of bonding to a carrier a cutting element which comprises a thin hard facing layer already bonded to a less hard backing layer, the backing layer having a greater coefficient of thermal expansion than th |
| 4995887 |
Cutting elements for rotary drill bits |
February 26, 1991 |
| A cutting element for a rotary drill bit comprises a layer of polycrystalline diamond material having a front face and a rear face, a backing layer of less hard material bonded to the rear face of the diamond layer, and a front layer of less hard material bonded to the front face of |
| 4987800 |
Cutter elements for rotary drill bits |
January 29, 1991 |
| A preform cutting element, for a rotary drill bit, includes a layer of polycrystalline diamond material having a front cutting face, a rear face and a peripheral surface, a cutting edge being provided by at least part of the junction between the front cutting face and the peripheral surf |
| 4956238 |
Manufacture of cutting structures for rotary drill bits |
September 11, 1990 |
| A cutting structure, for a rotary drill bit, is of the kind comprising a preform cutting element having a front cutting face formed of superhard material, such as polycrystalline diamond, and a rear face bonded to a carrier of less hard material, such as cemented tungsten carbide. The |
| 4949598 |
Manufacture of rotary drill bits |
August 21, 1990 |
| A rotary drill bit is manufactured by forming a main bit body part from a machinable metal, such as steel, machining sockets in the outer surface of the main bit, inserting in each socket a thermally stable cutting structure or former which substantially fills at least the mouth of the |
| 4898252 |
Cutting structures for rotary drill bits |
February 6, 1990 |
| A cutting structure for a rotary drill bit includes a cutting element 30 having a front layer 32 formed of polycrystalline diamond, bonded to a backing layer 33 formed of tungsten carbide. The cutting element is bonded to a carrier 33 which is formed of a number of detachable individual |
| 4878403 |
Manufacture of rotary drill bits |
November 7, 1989 |
| In the manufacture of a bit body by a powder metallurgy process, a hollow mold is formed in the configuration of at least a portion of the outer surface of the bit body, and elongate pockets of generally V-section are then formed in the interior surface of the mold, to receive portions o |
| 4873895 |
Manufacture of rotary drill bits |
October 17, 1989 |
| There is provided a method of manufacturing a rotary drill bit of the kind including a plurality of cutting structures mounted in sockets in the bit body and projecting from the face of the bit. The method comprises providing a clearance between each cutting structure and its socket and |
