Patent ID: 6260635
Filing Date: 2001-07-17
Classification: E21B

Abstract:
A rotary cone drill bit, comprising:a bit body having an upper portion adapted for connection to a drill string;a journal having a first end operatively attached to said bit body and having a thrust flange near a second end of said journal, which is opposite said first end;a cutter cone which is rotatably attached to said journal;a ball race comprising an first annular groove in said journal between said first and said second ends and a second annular groove in said cone adjacent said first annular groove;a plurality of ball bearings arranged in said ball race;a first journal bearing surface between said ball race and said first end of said journal;a second journal bearing surface between said ball race and said rust flange;a first bushing which floats between said journal and said cone at said first journal bearing surface; andsecond bushing which floats between said journal and said cone at said second journal bearing surface.