Invention Grant
- Patent Title: Secondary retainer for a downhole hammer bit
- Patent Title (中): 井下锤头二次保持架
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Application No.: US12022786Application Date: 2008-01-30
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Publication No.: US07665548B2Publication Date: 2010-02-23
- Inventor: Lance D. Underwood
- Applicant: Lance D. Underwood
- Applicant Address: US TX Houston
- Assignee: Smith International Inc.
- Current Assignee: Smith International Inc.
- Current Assignee Address: US TX Houston
- Agency: Osha • Liang LLP
- Main IPC: E21B10/36
- IPC: E21B10/36

Abstract:
A bit retainer system includes a bit having a head and a shank, a driver sub disposed around the shank of the bit and adapted to engage a hammer case, a bit retainer including a segmented retainer ring configured with a circumferential groove on an outside diameter of the segmented ring, the bit retainer disposed around the shank of the bit and abutting an upper end of the driver sub. The bit retainer system further includes a secondary retainer disposed around the bit retainer, wherein the secondary retainer includes a plurality of webs disposed at selected locations along the secondary retainer configured to engage the circumferential groove of the segmented retainer ring.
Public/Granted literature
- US20080135298A1 SECONDARY RETAINER FOR A DOWNHOLE HAMMER BIT Public/Granted day:2008-06-12
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