Patent ID: 7159494

Claim:
A torque wrench for preventing transmission of excess torque to a connecting shaft of a replaceable instrument tip comprising: a housing; a core selectively rotatably engageable with the housing, said core having an axial bore therein and a spring-receiving channel in communication with the axial bore; a retaining spring received in the channel, said retaining spring selectively securing a connecting shaft of a replaceable instrument tip within the axial bore; and a selective engagement member disposed between the core and an interior of the housing, said selective engagement member including at least one engagement arm in selective communication with one of a plurality of ramps within the housing, and wherein upon application of torque up to threshold level, rotation of the housing causes rotation of the core, and upon application of torque in excess of the threshold level, rotation of the housing causes the at least one engagement arm to lose engagement with one of the ramps, preventing rotation of the core.