Patent ID: 7287447

Claim:
A fastener installation tool, comprising: a tool head; a socket carried by said tool head for receiving and supporting a threaded nut; drive means for rotatably driving said socket to install the nut onto a threaded fastener; a fixture pin carried by said tool head generally coaxially within said socket for longitudinal sliding displacement therein as the nut is installed onto the threaded fastener, said fixture pin having a front tip end for engaging and retaining the threaded fastener to prevent fastener rotation during thread-on installation of the nut, said fixture pin further having a key of noncircular cross section formed thereon; a clutch unit comprising a cartridge mounted on said tool head for movement between a first position engageable with said key and including a spring-loaded clutch member for normally preventing rotation of said fixture pin within said socket, said clutch unit in said first position permitting rotation of said fixture pin within said socket in response to a torque load applied to said fixture pin in excess of a predetermined limit, whereby said clutch unit safeguards said fixture pin against breakage in response to a torque overload condition; said clutch unit being further movable to a second position disengaged from said key for facilitated access to said fixture pin for removal and replacement; and a clamp member for releasibly retaining said clutch unit normally in said first position, said clamp member comprising a spring mounted on said tool head and movable between a normal position releasibly retaining said clutch unit in said first position, and an out-of-the-way position permitting clutch unit movement to said second position.