James F Walter

US Patent:

50801830, Jan 14, 1992

Filed:

Apr 16, 1991

Appl. No.:

7/686136

Inventors:

Percy W. Schumacher - Houston TX
James C. Walter - Houston TX

Assignee:

Camco International Inc.

International Classification:

E21B 1022

US Classification:

175371

Abstract:

A seal assembly (46) for a rotary drill bit (10) having a pressure balanced lubrication system is mounted in a pocket (48) between a journal (16) and a roller cutter (18). The seal assembly (46) has a pair of rigid seal rings (50, 52) in sliding sealing contact with each other and a pair of elastomeric seal rings (54, 56) in side by side relation sealing against the inner peripheral surfaces (62, 64) of the rigid seal rings (50, 52) for continuously urging the sealing faces (58, 60) of the rigid seal rings (50, 52) into sliding sealing contact. The pressure balanced lubrication system has a pressure compensating diaphragm (38) and lubricant passages (40, 42, 44) extending directly from the lubricant reservoir (35) to the lubricant chamber (48A) in the pocket (48) for minimizing fluid pressure differentials between the lubricant chamber (48A) and the drilling fluid chamber (48B). Drilling fluid in the drilling fluid chamber (48B) acts against the rear faces (63, 65) of the metal seal rings (50, 52) to hold the sealing faces (58, 60) in sliding sealing contact.

US Patent:

50406248, Aug 20, 1991

Filed:

Aug 13, 1990

Appl. No.:

7/566129

Inventors:

Percy W. Schumacher - Houston TX
James C. Walter - Houston TX

International Classification:

E21B 1024

US Classification:

175371

Abstract:

A seal assembly (46) for a rotary drill bit (10) having a pressure balanced lubrication system is mounted in a pocket (48) between a journal (16) and a roller cutter (18). The seal assembly (46) has a pair of rigid seal rings (50,52) in sliding sealing contact with each other and a pair of elastomeric seal rings (54,56) in side by side relation sealing against the inner peripheral surfaces (62,64) of the rigid seal rings (50, 52) for continuously urging the sealing faces (58, 60) of the rigid seal rings (50, 52) into sliding sealing contact. The pressure balanced lubrication system has a pressure compensating diaphragm (38) and lubricant system has a pressure compensating diaphragm (38) and lubricant passages (40, 42, 44) extending directly from the lubricant reservoir (35) to the lubricant chamber (48A) in the pocket (48) for minimizing fluid pressure differentials between the lubricant chamber (48A) and the drilling fluid chamber (48B). Drilling fluid in the drilling fluid chamber (48B) acts against the rear faces (63, 65) of the metal seal rings (50, 52) to hold the sealing faces (58, 60) in sliding sealing contact.

US Patent:

56762143, Oct 14, 1997

Filed:

Apr 3, 1996

Appl. No.:

8/627171

Inventors:

David E. Pearce - Spring TX
James C. Walter - Mesquite TX

Assignee:

Camco International Inc. - Houston TX

International Classification:

E21B 1018

US Classification:

175340

Abstract:

A moth type rolling cutter drill bit has a plurality of rolling cutters mounted on legs, each rolling cutter having a back face portion and a gage face portion, and a high velocity fluid nozzle which directs a stream of high velocity fluid toward the cutter. Each cutter has a row of gage teeth to cut the gage of the borehole, and at least one of the cutters has a plurality of flow channels spaced apart around its gage face portion to provide fluid communication from the back face of the cutter and between and around pairs of adjacent gage teeth. Each flow channel is inclined at an angle to a radius of the cutter so as to be oriented towards the stream of fluid from the high velocity nozzle as the teeth adjacent to the flow channel engage the formation being drilled.

US Patent:

49916718, Feb 12, 1991

Filed:

Mar 13, 1990

Appl. No.:

7/492789

Inventors:

David E. Pearce - Houston TX
James C. Walter - Houston TX

Assignee:

Camco International Inc. - Houston TX

International Classification:

E21B 1020

US Classification:

175369

Abstract:

A rotary drill bit (10) having a roller cutter (28) retained on a journal (24) by an externally threaded retainer ring (52) mounted within an annular groove (48) in the journal (24). The radii (R1, R2) formed at the inner and outer corners of the groove (48) are designed by suitable formulas to provide adequate strength for the journal (24) including the flange (50) adjacent the groove (48).