Patent ID: 8714882
Filing Date: 2014-05-06
Classification: E21B

Abstract:
1. A bolting rig for inserting a rod into a surface, the bolting rig comprising: a base; a feed frame movably coupled to the base, the feed frame having a first end and a second end and defining a longitudinal axis therebetween; a rotation unit coupled to the feed frame and configured to receive and rotate the rod; a pair of arms coupled to the feed frame and movable with the rotation unit relative to the base; and an actuator for moving the pair of arms between at least a first position and a second position, wherein in the first position the arms are configured to receive the rod between the arms, and in the second position the arms are configured to exert a gripping force on the rod, wherein the arms are movable to a third position in which the pair of arms are configured to permit rotational and translational movement of the rod relative to the pair of arms while limiting lateral movement of the rod, and wherein the actuator includes a hydraulic cylinder in fluid communication with a relaxer cylinder, such that movement of the relaxer cylinder displaces a fixed fluid volume, moving the pair of arms from the second position to the third position and reducing the gripping force on the rod.