Patent ID: 7146715

Claim:
Apparatus for installing a rivet nut having an internally threaded shaft wherein said apparatus includes a power tool containing an air motor for rotational motion and a hydraulic piston and chamber to provide linear or axial motion and a screw adapted to engage the threaded shaft of the nut wherein said power tool rotates said screw in a first direction when actuated, the improvement which comprises: a) a fluid outlet coupled to said hydraulic chamber coupled to a hydraulic power supply, said power supply being fluidly coupled to said power tool whereby said power supply includes clutchless torque predetermining means for determining when a predetermined torque is placed on said screw, then stalling or stopping said motor and rotation of said screw while continuing to supply air to said motor, said torque predetermining means including means for sensing the air pressure level in the stopped or stalled motor and activating a piston mounted internally of said power tool and delivering hydraulic fluid at a preset pressure to said piston, said piston being movable from a forward position, adapted to rotate said screw in a first direction, and then to a rearward position, adapted to rotate said piston in a direction opposite to said first direction while pulling said screw axially.