Normally disengaged electro-magnetic spring clutch capable of field adjustment of the wrap angle

摘要

The adjustment means is for permitting field adjustment of wrap-down angle or engagement time for the spring of a normally disengaged, electro-magnetic spring clutch which comprises a helical spring which surrounds first and second drums and is in interference fit with the first drum and connected to a rotatable armature, the armature being rotationally arrested upon energization of an electro-magnetic coil to effect contraction of the helical spring into interference fit with the second drum. The adjustment means comprises a pin and slot lost motion interconnection between the armature and the first drum which functions to allow rotative movement of the first drum relative to the armature when the rotation of the armature is arrested to effect an engaged operative condition. The adjustment means also includes retaining means theremoval of which permits the armature to be axially moved relative to the first drum for disengaging the pin and slot and permits the armature and the spring to be rotated relative to the first drum without disconnection of the spring from the first drum and armature.