Abstract: A ball screw apparatus includes a cylindrical screw shaft having a spiral groove in an outside peripheral surface, a cylindrical ball nut surrounding the screw shaft and having a spiral groove in an inside peripheral surface, and a plurality of bearing balls rotatably interposed the two spiral grooves, which are aligned and spaced apart such that the bearing balls are free to rotate as the ball nut rotates about and moves along the screw shaft. One or more of the screw shaft and the ball nut may include a spiral wire coil and a coil shape retention device. The opposed peripheral surfaces of adjacent coils of each spiral wire coil form the walls of one of the spiral grooves. Each coil shape retention device prevents the associated spiral wire coil from changing shape when the ball nut moves spirally relative to the screw shaft.

Abstract: A disc brake with a caliper housing having first and second side walls, the first wall having a cavity with a piston slidably mounted therein, the piston having a first shoe for frictional engagement with one of the sides of a rotor, the housing also having a bridge spanning the sides of the rotor and extending from the bridge, the housing having a second wall with an attached second shoe for frictional engagement with the rotor opposite the first shoe. A bracket is connected with the vehicle having first leading and second trailing reaction arms. The caliper is slidably mounted with the bracket arms. Extending the piston from the caliper housing to actuate the brake brings the shoes into engagement with the rotor and causes the inboard shoe to react on the trailing bracket arm and the caliper housing to react in the trailing direction into the leading bracket arm.

Abstract: An electrically actuated brake is provided with an adjustment mechanism to compenate for wear of the brake shoes. The brake in a preferred embodiment includes a motor driven actuator to apply the brake shoes and a first rotative member torsionally associated with a rotor of the motor. A spring returns the brake shoes from an actuated position to a release position causing the first rotative member to rotate in a releasing direction. A second rotative member having a first surface for making torsional transferring engagement with the first rotative member when the first rotative member is rotating in a friction member applying or releasing direction is provided. The second rotative member also has a second surface of a non-torsional transferring engagement. The second surface is exposed to the first rotative member when the first rotative member has rotated in an applying direction beyond a predetermined limit due to wear of the brake shoes.