The SK111OXX safety sprocket from R + W America, Bensenville, Ill. (, uses a patented ball-detent arrangement to disengage within 3 msec of a torque overload. It reengages and resumes driving once the overload is cleared. Disengagement torque can range from 14 oz/in. to 1,843 lb/ft and shafts can be 0.125 to 7 in. in diameter. The low-cost solution is backlash-free and combines sprocket, bearing, and torque limiter in one package. It can also be configured so that disengagements trigger a motor cutoff switch.