US Patent 9032848 Torque wrench and method of operating the same

A torque wrench includes a hollow body, a clutch mechanism, a force-applying member, and driving arms. The clutch mechanism is mounted in the hollow body. The force-applying member is pivotally mounted in the hollow body. Each of driving arms has a coupling end is detachably mounted at the second end of the force-applying member and a driving end for driving a workpiece, wherein each of the driving arms is coaxial to the force-applying member when the coupling end thereof is mounted at the second end of the force-applying member, and wherein the interchangeable driving arms are different in length from each other.