US Patent 8943864 Proportional torque shaft clutch assembly

A system for securing a cam of a locking mechanism to a rotatable shaft, which comprises a cam for actuating a locking mechanism and a clutch that includes, in part, a sleeve body having a distal end affixed to a face of the cam and a sleeve bore having a tapered sleeve journal and a sleeve screw portion with internal threads opposite the sleeve journal. The clutch also includes a collet that is installed within the sleeve bore and which has a collet nut extending outwardly from a proximal end of the sleeve bore, a collet bore, and an outer surface having an axially-split and tapered collet journal abutting the sleeve journal and a collet screw portion with external threads engaged with the sleeve screw portion. The system further includes a rotatable shaft that is secured within the collet bore with a break-away torque that is proportional to an assembly torque applied to the collet nut. After assembly of the clutch to both the cam and the rotatable shaft, a drive torque applied to the shaft which is less than the break-away torque causes the cam to rotate with the shaft, while a drive torque that is greater than the break-away torque causes the shaft to spin within the collet bore.