Patent ID: 8424939
Filing Date: 2013-04-23
Classification: E21B

Abstract:
1. An improvement in a gripping tool having a gripping assembly with a grip surface carried by movable grip elements to radially move the grip surface from a retracted to an extended position, the gripping assembly being activated by axial movement, the improvement comprising: a tri-cam linkage comprising a drive cam body, a driven cam body and at least one intermediate cam body, the drive cam body and the at least one intermediate cam body providing a drive cam pair with a cam surface on the drive cam body engaging a first cam surface on the at least one intermediate cam body, the at least one intermediate cam body and the driven cam body providing a driven cam pair with a second cam surface on the at least one intermediate cam body acting in opposition to the first cam surface and engaging a cam surface on the driven cam body, the tri-cam linkage acting between a body of the gripping tool and the gripping assembly translating bi-rotary movement in either a clockwise or counterclockwise direction of the body relative to the grip surface into axial movement to drive axial stroke activation of the gripping assembly.