Patent ID: 7748299

Claim:
A wrench comprising: a handle and a head connected to an end of the handle, the head including a fixed jaw and a groove defined in an end of the head and opening through a top surface of the head, a through hole defined through the head and an axis of the through hole being perpendicular to an axis of the groove; a sliding jaw having a cylindrical guide portion which includes two toothed surfaces defined in axial direction of the portion, the guide portion movably inserted into the groove; a control unit including two pawls which are engaged with the through hole and located on two sides of the head, each pawl including an engaging surface in a first end thereof and the engaging surface composed of teeth which are removably engaged with one of the two toothed surfaces, a second end of each pawl being biased by a resilient member which pushes the pawl toward the guide portion, and an operation unit including two operation members and at least one pin, the two operation members located on the two sides of the head and the pin connecting the operation members and the pawls on the two sides of the head.