Abstract: A vehicle parking brake system automatically adapts to the road surface condition when operated while the vehicle is moving. The parking brake pressure is automatically controlled, in response to an operator command to initiate the parking brake function or in response to a failure of the hydraulic front brakes while the vehicle is moving, to establish and limit wheel slip at a desired controlled slip between each of the braked wheels and the road surface so as to automatically adapt to the road surface coefficient of friction.

Abstract: An integrated anti-lock braking (ABS)/traction control (TC) braking system in a preferred embodiment is provided for a vehicle having a fluid actuated brake including a system controller cognizant of the condition of the wheel, a master cylinder for delivering pressurized fluid to the wheel brake, an actuator frame with a bore being fluidly connected with the master cylinder and the wheel brake, first fluid line fluidly connecting the master cylinder with the wheel brake, a valve for preventing fluid communication between said master cylinder and the wheel brake through the first fluid line when the controller places the braking system in an ABS mode, a valve for preventing fluid communication between the first fluid line or the actuator bore and the master cylinder when the controller places the braking system in a TC mode, a first piston slidably mounted in the bore with a valve opening portion, a mechanism to reversibly move the piston in response to the controller, and a valve piston slidably mounted with

Abstract: Controlled movement of a motor driven pressure modulator is provided by commanding maximum current to the motor by application of system voltage resulting in the motor current initially rising rapidly to the motor stall current. The motor accelerates at a rate that is a function of the difference between the motor torque and the load torque represented by the load on the modulator. As the motor speed increases, the motor current decreases. When the motor current decreases below the stall current by a predetermined amount representing a predetermined speed of the motor, the motor current is turned off for a wait period that is based upon the time that it took for the motor speed to attain the predetermined speed. Thereafter, maximum motor current is again commanded and the cycle repeated to provide for motor speed control.

Abstract: An integrated anti-lock braking system (ABS)/traction control (TC) braking system for a vehicle having a fluid activated brake for a wheel is provided the system in one embodiment includes a system controller for signaling the system to an ABS or TC mode, a master cylinder for delivering pressurized fluid to the wheel brake, an actuator with a longitudinal bore having a first stop. A hollow primary piston is slidably mounted within the longitudinal bore biased towards the first stop. The interior of the primary piston is fluidly connected with its exterior. A secondary piston is slidably mounted within the primary piston and movable in one direction to pressurize the wheel brake and movable in an opposite direction to relieve said wheel brake in response to the controller.

Abstract: A vehicle braking system having a wheel lock control arrangement with isolation valves, solenoid, and brake control valves for the system. In one arrangement, each wheel brake and isolation valve has its own solenoid and control valve. Additionally, the isolation valve is configured in a manner to prevent premature drop out from isolation and to prevent any flow from a master cylinder brake apply pressure circuit to a pump pressure circuit.

Abstract: A vehicle braking system having a wheel lock control arrangement with isolation valves for each wheel brake and either three or four solenoid and brake control valves for the system. In one arrangement, each wheel brake and isolation valve has its own solenoid and control valve. In other arrangements two front wheel brakes have separate solenoid controlled operating valves and the two rear wheel brakes have a single solenoid controlling operating valve controlling both isolation valves. Traction control is incorporated into the system so that a wheel brake required braking for traction control purposes may be applied by pump pressure without the vehicle brakes themselves having to be applied through service braking.