Abstract: A bi-stable clutch is introduced comprising an input and output shaft, a hub assembly attached to output shaft, a hub assembly attached to output shaft and operatively associated with a friction ring which rotates with output shaft of the unique bi-stable clutch. The input shaft is connected to a rotor which drives an armature plate to which the rotor is rotatably attached. The rotor and armature plate are forced apart when the clutch is engaged creating an air gap between the two large enough to not be overcome by the permanent magnet field attracting the armature plate due to a force caused by compression coil springs and the armature plate remains in contact with the rotor and the clutch remains engaged without continuous current transmitting torque from the input to the output shaft.

Abstract: A pulsed brake drive for an electro-magnetic brake incorporating a permanent magnet which can be pulsed into either an on or off stable state wherein the brake is driven by a very short pulse depending on brake voltage. In the event of a failure of any one phase of the line the drive shuts off the motor and applies the brake. Further, if the power supply to the motor is off, the brake, which is normally on, can be released and then re-applied by a pushbutton. Power to drive the brake is battery supplied which in turn is kept fully charged at all times from main AC power. It is this unique circuitry and combination which introduces an energy efficient motor brake driven by a short pulse-not dependent on continuous voltage.

Abstract: A unique electromagnetic brake which, when pulsed with a D.C. current, will latch and hold in either of two extreme positions; on position and off position. A continuous current is not necessary to maintain either position which eliminates power loss from a limited power supply and heat dissipation problems.