Robert Vernon Slaughter

US Patent:

60331178, Mar 7, 2000

Filed:

Dec 1, 1997

Appl. No.:

8/982081

Inventors:

Peter Cariveau - Stillwater OK
Robert H. Slaughter - Ponca City OK
Roger Didericksen - Ponca City OK
Chris Edward Cawthorne - The Woodlands TX
Gary Ray Portwood - Kingwood TX

Assignee:

Smith International, Inc. - Houston TX

International Classification:

F16C 3372

US Classification:

384 94

Abstract:

A sealed-bearing drill bit for use in an earthen annulus is provided having a dual seal arrangement. The drill bit includes at least one leg having a journal segment, and a roller cone mounted upon the journal segment and forming at least one bearing cavity therebetween. An annular primary seal is disposed between the leg and roller cone and between the bearing cavity and the earthen annulus. An annular secondary seal is disposed between the annular primary seal and the earthen annulus and is capable of substantially preventing the ingress of debris from the earthen annulus to the annular primary seal.