Patent ID: 6196339
Filing Date: 2001-03-06
Classification: E21B,F16C,Y10S

Abstract:
A drill bit for use in a borehole at least partially containing drilling fluid, comprising:a bit body having at least two bit components, said bit components including at least one leg, said leg having a journal segment, said bit components further including a roller cone rotatably mounted upon said journal segment and forming at least one bearing cavity therebetween;an annular primary seal disposed between said leg and said roller cone;an annular secondary seal disposed between said leg and said roller cone and between said annular primary seal and the borehole;an annular space disposed between said annular primary seal and said annular secondary seal, said annular space at least partially containing fluid and being in substantially absolute fluid isolation from said bearing cavity; andmeans for permitting the passage of fluid from said annular space to the borehole.