SECONDARY RETAINER FOR A DOWNHOLE HAMMER BIT,申请号US20080022786-传众专利搜索

SECONDARY RETAINER FOR A DOWNHOLE HAMMER BIT

申请公布号：US2008135298(A1)

申请号：US20080022786

申请日期：2008.01.30

申请公布日期：2008.06.12

申请人：

SMITH INTERNATIONAL, INC.

发明人：UNDERWOOD LANCE D.

分类号：E21B10/36;E21B7/24

主分类号：E21B10/36

摘要：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.