POWER NUTRUNNER WITH SHUT-OFF

摘要

A power nutrunner comprising a planetary reduction gearing (12) and a torque limiting release clutch (13) disposed between a ring gear (25) and the tool housing (11), wherein the ring gear (25) is tubular in shape and having an outer annular shoulder (41) at its one end carrying cam teeth (42) for cooperation with a spring biassed thrust element (45) via balls (43) and cam surface (44). The thrust element (45) encircles the ring gear (25) and is rotationally locked relative to the housing (11) via a ball spline connection (47-49). A clutch release and signal producing Reed relay (58) is coupled to the ring gear (25) by means of a pivoting lever (59) carrying one of a pair of permanent magnets (71, 72) for activating the Reed relay.