Patent ID: 8627748

Claim:
A drill rod wrench for use on a drilling apparatus for loosening a drill rod segment of a drill rod having a diameter falling within a predetermined diameter range, with respect to an adjacent drill rod segment of the drill rod, which includes, in its operative configuration with respect to a drilling apparatus having a support structure supporting the apparatus in a location where drilling is required, a carrier member that is pivotally supported on the support structure of the drilling apparatus in a configuration in which the wrench is displaceable between an inoperative stowed-away configuration when drilling is permitted and an operative configuration in which the wrench is operable for loosening a drill rod segment; a gripping member that defines an open mouth formation within which a drill rod segment to be gripped for loosening is positionable, the gripping member being displaceably located on the carrier member for rotational displacement about a longitudinal axis of a drill rod segment operatively positioned within the mouth formation of the gripping member, the gripping member having gripping elements located in the mouth formation for gripping a side of the drill rod segment; a lever arm pivotally located on the gripping member for pivotal displacement relative to the gripping member about a lever pivot axis, the lever arm defining a convex wedge face that, by pivotal displacement of the lever arm with respect to the gripping member and with a drill rod segment operatively positioned within the mouth formation of the gripping member, acts on the drill rod segment for urging the drill rod segment into gripping engagement with the gripping elements, the convex wedge face when gripping the drill rod segment being located substantially diametrically opposite the gripping elements when gripping the drill rod segment and that, by rotational displacement of the gripping member about a longitudinal axis of the drill rod segment so gripped, performs a wedging action on the drill rod segment until the drill rod segment loosens due to such rotation, for further urging the drill rod segment into gripping engagement with the gripping elements of the gripping member; and displacement mechanisms providing for displacement of the gripping member and the lever arm for gripping and loosening of the drill rod segment with respect to an adjacent drill rod segment.