Variable diameter pulley with improved pusher ring

Claim 1

A variable diameter pulley comprising an output shaft, first and second conical pulley flanges coaxially mounted on said shaft, a V-belt trained between said two pulley flanges, said first pulley flange secured to said shaft, said second pulley flange axially displaceable on said shaft between a closed position in clutching engagement with said V-belt and an open position releasing and declutching said V-belt, said second pulley flange having a coaxial sleeve extending therefrom away from said first pulley flange, a compression coil spring surrounding said shaft and interposed between said two pulley flanges to urge the second pulley flange to V-belt declutching position, a pusher ring coaxially carried by the outer end of said sleeve and having an exposed surface facing away from said first pulley flange, said exposed surface including a radially inner flat face portion perpendicular to said shaft, followed by a radially outer bevelled, frusto-conical face portion, a support secured to said shaft and centrifugally responsive lever members pivoted on said support intermediate their ends and having radially inner ends engaging the exposed surface of said pusher ring for exerting an axial force thereon in a direction to move said second flange towards V-belt clutching position against the action of said spring, the inner ends of said lever members, during their centrifugally induced progressive pivotal movement, first contacting said bevelled frusto-conical face portion to displace said second pulley flange towards clutching engagement with said V-belt without clutching the same and then contacting said flat face portion to effect clutching engagement with said V-belt.