A parking brake apparatus including a bolt screw rotated by a driving force transmitted from an actuator, one or more pistons disposed at one side or both sides of the bolt screw, one or more screw nuts accommodated in the piston, screwed to an end of the bolt screw, and moved along with the rotation of the bolt screw, one or more elastic members disposed around the screw nut within the piston, and elastically deformed, in response to a displacement of the screw nut while the screw nut is moved by a set distance, to press the piston toward a shoe, and a load transfer unit disposed in the piston, and configured to transmit, to the piston, a displacement of the screw nut when the screw nut moves more than the set distance, thereby pressing the piston toward the shoe.

A drum brake assembly includes a brake drum, a brake shoe and lining assembly operably displaceable to contact the brake drum, and an electric actuator assembly. The electric actuator assembly has an electric motor with an output shaft, a gear reduction driven by the output shaft, a linear translation assembly having a gear nut driven by the gear reduction, and a connection portion of the linear translation assembly. The output shaft drives the gear reduction through a suitable gear type that can convert a rotation torque of the output shaft to the gear reduction at a right angle. The linear translation assembly linearly translates when the gear nut is driven. As a result of the linear translation, the connection portion actuates the brake shoe and lining assembly to contact the brake drum.

A drum brake apparatus may include: a housing; a main braking part installed at one side of the housing, and driven by hydraulic pressure to pressurize shoes during main braking; and a parking braking part installed at the other side of the housing, and driven by an electromotive force to pressurize the shoes during parking braking.

An assembly that includes a main housing. A motor is supported in a motor housing that is supported in the main housing. The motor has an output shaft and a locking mechanism. The motor is adapted to generate a first rotational direction torque and a second rotational direction torque. The motor is adapted to transfer the first rotational direction torque and the second rotational direction torque to a destination via the output shaft. The locking mechanism is adapted to prevent the output shaft from back driving in the second rotational direction after the first rotational direction torque has been transferred to the destination. The motor housing is adapted to rotate in the main housing to unlock the locking mechanism so that the second rotational direction torque can be transferred to the destination.

In an electric parking brake device configured in such a way that a parking brake state resulting from pulling of a brake cable is released by loosening the brake cable, the brake cable is formed by twisting together a plurality of wires in such a way as to generate a twisting force in a fixed direction when pulled, and the direction in which the twisting force generated by the brake cable in a pulled state acts on a screw shaft is set to be the same direction as the direction in which a nut is rotated to loosen the brake cable. This makes it possible to reduce an operating sound and to reduce wear of members constituting a rotation restricting device.

A method for activating a parking brake function of a drum brake of a brake system of a vehicle, wherein a parking situation is taken into account in order to reduce the holding force to be exerted.

An electric parking brake actuator mounting assembly includes a brake backplate of a drum brake, having a rear surface opposite to a front surface configured to be facing a brake drum when the brake backplate is mounted on a motor vehicle, wherein the rear surface of the brake backplate includes a support base configured to receive a pull spindle of an electromechanical actuator, a supporting bracket including at least one coupling plate, configured to be attached to the rear surface of the brake backplate, and an actuator mounting surface configured to be coupled to and support the electromechanical actuator, wherein the actuator mounting surface includes a spindle seat, configured to receive the pull spindle of the electromechanical actuator, and a pin lock seat, configured to receive and lock an engagement pin of the electromechanical actuator.

A parking lock mechanism comprises: a parking gear disposed on a power transmission member mechanically coupled to a drive wheel; and a parking pawl provided with a lock claw configured to mesh with the parking gear and switching between a lock state in which the lock claw is meshed with the parking gear and an unlock state in which meshing between the lock claw and the parking gear is released. In the mechanism, the lock claw includes a first end surface and a second end surface opposite to each other in a face width direction, the lock claw includes a tooth tip surface provided with a retreated portion at a corner on the second end surface side, and a position of a center of gravity of the parking pawl is on the second end surface side relative to a center plane in the face width direction of the lock claw.

In an electric parking brake device configured in such a way that a parking brake state resulting from pulling of a brake cable is released by loosening the brake cable, the brake cable is formed by twisting together a plurality of wires and the direction of twisting is rotational direction of the nut when the brake cable is pulled. This makes it possible to reduce an operating sound and to reduce wear of members constituting a rotation restricting device.

A sphere drive line retarder is presented that is mounted to a drive shaft from an engine. The sphere drive line retarder comprises a sphere rotor mounted to the drive shaft and housed within a retarder housing. The sphere drive line retarded has a piston assembly comprising at least one piston, a brake shoe mounted to each piston, and hemispherical friction material mounted to the brake shoe. The hemispherical friction material is located between the sphere rotor and the brake shoe. Each piston is housed within a piston housing that is hydraulically isolated from the retarder housing. The retarder housing contains hydraulic fluid to cool the sphere rotor.