| Patent Number |
Title Of Patent |
Date Issued |
| 6883618 |
Variable timing for front chamber of pneumatic hammer |
April 26, 2005 |
| The lower end portion of a pneumatic impact hammer cylinder has at least one upper fluid passage and at least one lower fluid passage. A U-shaped sleeve is mounted in a circumferential groove in the lower end portion of the piston. The sleeve includes a base, upper and lower legs extendi |
| 6698537 |
Bit retention system |
March 2, 2004 |
| A bit retainer for a percussion bit assembly has a bore and upper and lower lips extending into the bore. Multiple slots extend from the lower end of the retainer member to a terminal end disposed intermediate the upper and lower ends, forming multiple cantilever beam segments. The canti |
| 6070678 |
Bit retention system |
June 6, 2000 |
| A substantially tubular retainer member is provided, having a bore of substantially uniform internal diameter which can slip over the retention shoulder of the percussion bit, whether that shoulder is solid or threaded. Pins are then driven through holes in the retainer, under the re |
| 6021856 |
Bit retention system |
February 8, 2000 |
| A downhole hammer bit including at least one bit impact head mounted to a vertical guide member by a plurality of retaining ring segments. Opposed surfaces of the bit impact head and the guide member have corresponding circumferential grooves or groove sections that define a channel or |
| 5992537 |
Back end connection in a downhole drill |
November 30, 1999 |
| A pneumatic downhole impact drill has a backhead for mounting an inlet check valve and a mounting hub for mounting a fluid delivery tube. A split ring has an interior circumferential groove forming upper and lower shoulders and comprises two substantially identical semi-circular ring |
| 5984021 |
Porting system for back chamber of pneumatic hammer |
November 16, 1999 |
| A pneumatic downhole impact drill has a porting system for automatically supplying pneumatic pressure fluid from a fluid delivery tube received within an axial bore in the impact piston to the opposite ends of the piston operating cylinder as the piston reciprocates. A flange on the |
| 5205363 |
Porting system for pneumatic impact hammer |
April 27, 1993 |
| A pneumatic downhole impact drill having a porting system for automatically supplying pneumatic pressure fluid from a fluid delivery tube received within a coaxial bore in the impact piston to the opposite ends of the piston operating cylinder as the piston reciprocates. The porting syst |
| 4962822 |
Downhole drill bit and bit coupling |
October 16, 1990 |
| A downhole impact drill having a drill bit head with a drill bit sector for drilling an enlarge hole upon rotation of the drill. The bit is mounted within a chuck for movement between a retracted, working position in which the bit is coaxially mounted for drilling and an extended, non-wo |
| 4919221 |
Impact drill bit assembly and replaceable parts thereof |
April 24, 1990 |
| A downhole drill bit having an elongated male drive shank, a separate female impact head mounted on the drive shank, the drive shank and head having cooperating external and internal, head drive splines extending helically in one angular direction to urge the drive shank and head tog |
