Patent ID: 8186246
Filing Date: 2012-05-29
Classification: B25B,E21B,F16D

Abstract:
1. A jaw assembly for gripping a wellbore tubular, the jaw assembly comprising: a plurality of gripping members each having a substantially circular cross-section; a gripping member support structure including a plurality of gripping member retainer recesses spaced apart along a longitudinal axis of the gripping member support structure, wherein each retainer recess includes a first ramp surface and a second ramp surface that are oblique relative to the longitudinal axis of the gripping member support structure and wherein each retainer recess is configured to hold at least one gripping member, and the at least one gripping member is capable of moving along the ramp surfaces, and a lever movable between a first position, a second position and a third position, wherein the lever in the first position causes the at least one gripping member to engage a portion of the first ramp surface, and as a result of the engagement, the wellbore tubular is prevented from moving relative to the jaw assembly in a first direction; the lever in the second position causes the at least one gripping member to engage a portion of the second ramp surface, and as a result of the engagement, the wellbore tubular is prevented from moving relative to the jaw assembly in a second direction; the lever in the third position causes the at least one gripping member to be positioned between the ramp surfaces which allows the wellbore tubular free movement relative to the jaw assembly.