AUTOMATIC GRIPPER GRASPING AND HOLDING ROD OF EXCAVATOR

摘要

An automatic gripper, useful especially for gripping and holding drilling rods on a drilling rig, has a chassis with a front end in the form of a fork equipped with retractable jaws (50). The jaws are retracted by pushing contact with a drilling rod (40) when the rod enters the fork, whereupon a return mechanism (72) automatically restores the jaws to a closed position. The chassis is held fixed on a horizontal pivot axis by rupturable pins or the like. The pins rupture to permit the chassis to pivot when subjected to a predetermined torque, with friction members being provided to frictionally limit the pivotal movement of the chassis. The gripper is thus protected against damage from impacts with the rod lifting mechanism of the drilling rig, for example.