A rotational coupling device includes an armature configured for coupling to a shaft for rotation with the shaft about an axis, but axially movable relative to the shaft. An electromagnet assembly is disposed on one side of the armature and fixed against rotation. A collar is disposed on the opposite side of the armature. The collar is configured for rotation with the shaft, but fixed against axial movement relative to the shaft and includes a permanent magnet. When a current having a first polarity is provided to the electromagnet assembly, the armature moves in one axial direction into engagement with a member of the coupling device to transmit a torque between the member and the armature. The permanent magnet urges the armature in the opposite axial direction to disengage the armature from the member when the current is not provided to the electromagnet assembly.

An apparatus includes a flywheel, a first pivotable caliper, a first magnet supported by the first caliper opposite the flywheel, a second pivotable caliper and a second magnet supported by the second caliper opposite the flywheel. In one implementation, the apparatus further includes a first cam follower coupled to the first caliper, a second cam follower coupled to the second caliper and at least one cam member including a first cam surface against which the first cam follower moves and a second cam surface against which the second cam follower moves, wherein movement of the at least one cam member pivots the first caliper and the second caliper to move the first magnet and the second magnet relative to the flywheel. In another implementation, the apparatus further includes a strain gauge carried by the first caliper to output signals indicating braking torque.

A coupling and control assembly includes an internal latching mechanism to hold a support member and a coupling member together in position so that the support member and the second coupling member rotate together without using any energy.

Electromechanical actuator mechanisms for storm brakes are provided. The actuator mechanisms generally comprise an electro-mechanical release system and a permanent magnet eddy current brake system with adjustable air gap for varying brake setting time, and for energy dissipation of the storm brake main spring force or weight.

A brake assembly includes a brake disc in rotational engagement with a wheel of a vehicle, a brake pad which frictionally engages the brake disc in a dynamic braking operation and a parking brake operation, a dynamic actuator adapted to bring the brake pad and brake disc into the frictional engagement in the dynamic braking operation, and a parking brake actuator associated with the dynamic actuator such that, in the parking brake operation, the frictional engagement of the brake disc and brake pad is maintained.

A unidirectional rotary brake contains: a body, multiple rollers, two driving rings, and at least one returning means. The body includes an internal face and two end faces, wherein the internal face has multiple accommodation grooves, each accommodation groove has a locking segment and a unlocking segment, and each end face has a surrounding groove. Each of the multiple rollers is columnar and has a diameter which is more than the first depth of the locking segment of each accommodation groove of the body and is less than a second depth of the unlocking segment of each accommodation groove of the body, and each roller has two limiting posts. Each of the multiple orifices is more than each of the two limiting posts and is less than the diameter of each roller. A number of the at least one returning means is less than that of the multiple rollers.

A parking brake system including a motor; a rotary to linear stage mechanism in communication with the motor; and a torque locking mechanism in communication with the motor. The torque locking mechanism includes a rotor; a core; and locking members. During a parking brake apply the motor is adapted to rotate the rotor and move the rotary to linear stage mechanism so that at least one brake pad or at least one brake shoe is moved against a surface to generate a clamp force. After the clamp force is generated and the motor ceases to rotate the rotor, the core and the locking members are magnetically attracted and the locking members move towards the core as a result of the magnetic attraction so that the generated clamp force is maintained after the motor ceases to rotate the rotor.

A primary piston of a tandem master cylinder includes: a body provided with a skirt, having in the rear thereof a cavity for the plunger and the push rod connected to the brake pedal and in the front a cavity defining the primary chamber. The piston is made of a plastic material and at least one magnet is built into the body of the piston.

A brake (26) for an elevator system (10) and method of using the brake (26) is disclosed. The brake (26) may comprise first and second brake linings (38) configured to be frictionally engageable with a rail (14) of the elevator system (10), a first biasing member (34) configured to urge the first brake lining (38) to engage the rail (14), and a first actuator (30) configured to move the first brake lining (38) to disengage the rail (14) when the first actuator (30) is energized. The brake (26) may be configured to be mounted on an elevator car (16) of the elevator system (10).

A device for a brake system comprises a rotating plate including magnets having a first polarity. The rotating plate engages an output shaft of a motor. The device includes a non-rotating plate including magnets, one or more of which have the first polarity and one or more of which have a second polarity. The non-rotating plate moves axially between an engaged position and a non-engaged position. In the engaged position, the magnets in the rotating plate magnetically attract the one or more magnets in the non-rotating plate with the second polarity so that non-rotating plate moves into contact with the rotating plate. In the non-engaged position, the magnets in the rotating plate magnetically repel the one or more magnets in the non-rotating plate with the first polarity so that the non-rotating plate moves out of contact with the rotating plate and thus rotation of the rotating plate is allowed.