Abstract: A vehicle wheel anti-lock braking system (ABS) is provided including a master cylinder and a wheel brake. A controller cognizant of the rotational condition of the wheel provides a signal when the wheel condition is within preset parameters. An actuator frame is also provided having a bore fluidly communicating with the wheel brake. A piston is mounted within the bore for providing a variable control volume in communication with the wheel brake and for modulating the pressure therein. A reversible motor reciprocally powers the piston. The motor has a rotor with a connected disc. A friction surface is provided for engagement with the disc to lock the position of the piston. A plunger is also provided to urge the friction surface into engagement with the disc. An electromagnetic core, responsive to a signal by the controller, moves the plunger to a position allowing cessation of engagement between the friction surface and the disc thereby allowing rotation of the motor and movement of the piston.

Abstract: A vehicle wheel anti-lock braking system (ABS) is provided including a master cylinder and a wheel brake. An ABS controller cognizant of the rotational condition of the wheel provide a signal when the wheel condition is within preset parameters. An isolation valve responsive to close upon an activation signal given by said controller prevents fluid communication between the master cylinder and the wheel brake. An actuator frame is also provided having a bore fluidly communicating with the wheel brake. A piston is mounted within the bore for providing a variable control volume in communication with said wheel brake for and modulating the pressure therein. A reversible motor reciprocally powers piston. The motor has a rotor with a connected disc. A friction surface is provided for engagement with the disc to lock the position of the piston. A plunger is also provided to urge said friction surface into engagement with said disc.