Abstract: An electromagnetically actuated jaw clutch for torsionally driving the feed roll of a carding machine includes a pair of annular, rack-toothed face gears spring biased away from each other in opposed relation to establish a nonengaged position when the clutch is de-energized. Energization of the jaw clutch magnetically forces the annular face gears against each other into an engaged interlocked position for effective driving of the feed roll. A torque overload condition established by jamming of the feed roll causes the rack-toothed face gears to ride out of engagement and separate from each other. Such torque overload separation of the face gears is sensed by a proximity switch which deactivates the clutch electromagnet and selected portions of the carding machine.