Abstract: A hydraulic actuator for a vehicle suspension includes: a pump assembly including an electric motor coupled to first and second pumps to transfer hydraulic fluid to a discharge header; a first isolation valve having an elastomeric seat and configured to selectively block fluid flow from a port in fluid communication with a height-adjustable damper to the discharge header; and a second isolation valve having a metal seat and connected in series with the first isolation valve to selectively block fluid flow from the port to the discharge header. The first pump transfers hydraulic fluid from a supply fluid passage to a first discharge header, and the second pump transfers hydraulic fluid from the supply fluid passage to a second discharge header. A recirculation valve selectively controls fluid flow from the second discharge header to the supply fluid passage.

Abstract: A hydraulic actuator for a vehicle suspension includes: a pump assembly including an electric motor coupled to first and second pumps to transfer hydraulic fluid to a discharge header; a first isolation valve having an elastomeric seat and configured to selectively block fluid flow from a port in fluid communication with a height-adjustable damper to the discharge header; and a second isolation valve having a metal seat and connected in series with the first isolation valve to selectively block fluid flow from the port to the discharge header. The first pump transfers hydraulic fluid from a supply fluid passage to a first discharge header, and the second pump transfers hydraulic fluid from the supply fluid passage to a second discharge header. A recirculation valve selectively controls fluid flow from the second discharge header to the supply fluid passage.

Abstract: The present invention discloses a braking apparatus for a vehicle having a brake pedal. The braking apparatus includes a master cylinder having a reservoir for retaining a brake fluid. At least one hydraulically actuated brake is in fluid communication with the master cylinder and a control unit is in electrical communication with the hydraulically actuated brake. A replenishment system is in fluid communication with the master cylinder and in electrical communication with the control unit for feeding the brake fluid into the replenishment system during a first condition and feeding the brake fluid from the replenishment system into the hydraulically actuated brake during a second condition after initial depression of the brake pedal to provide consistent pedal feel and braking pressure.

Abstract: Apparatus including a brake control assembly having a brake fluid accumulator assembly. The brake fluid accumulator assembly includes a brake fluid orifice, at least one brake-fluid-accumulating piston bore, a controllable bi-directional motor, and at least one piston. The brake fluid orifice is fluidly connectable to a brake apply master cylinder and is fluidly connectable to a wheel brake. The at-least-one brake-fluid-accumulating piston bore is fluidly connected to the brake fluid orifice. The motor has a first motor driving direction and an opposite second motor driving direction. The at-least-one piston is each positioned in and slidable within a corresponding brake-fluid-accumulating piston bore and is each movable by the motor, in the first motor driving direction, to move in compression within the corresponding brake-fluid-accumulating piston bore.

Abstract: The present invention discloses a braking apparatus for a vehicle having a brake pedal. The braking apparatus includes a master cylinder having a reservoir for retaining a brake fluid. At least one hydraulically actuated brake is in fluid communication with the master cylinder and a control unit is in electrical communication with the hydraulically actuated brake. A replenishment system is in fluid communication with the master cylinder and in electrical communication with the control unit for feeding the brake fluid into the replenishment system during a first condition and feeding the brake fluid from the replenishment system into the hydraulically actuated brake during a second condition after initial depression of the brake pedal to provide consistent pedal feel and braking pressure.

Abstract: Apparatus including a brake control assembly having a brake fluid accumulator assembly. The brake fluid accumulator assembly includes a brake fluid orifice, at least one brake-fluid-accumulating piston bore, a controllable bi-directional motor, and at least one piston. The brake fluid orifice is fluidly connectable to a brake apply master cylinder and is fluidly connectable to a wheel brake. The at-least-one brake-fluid-accumulating piston bore is fluidly connected to the brake fluid orifice. The motor has a first motor driving direction and an opposite second motor driving direction. The at-least-one piston is each positioned in and slidable within a corresponding brake-fluid-accumulating piston bore and is each movable by the motor, in the first motor driving direction, to move in compression within the corresponding brake-fluid-accumulating piston bore.

Abstract: A compact controlled braking system including a hydraulic control unit having a first housing and a motor positioned within the first housing and an electronic control unit connected to the hydraulic control unit, the electronic control unit having a second housing, wherein at least a portion of the motor is received within the second housing.

Abstract: A controlled brake apparatus and method of operating a brake apparatus utilize a pre-charge circuit connected directly between the fluid reservoir of a master cylinder of the apparatus and the inlet of a controlled braking pump, to thereby direct pre-charge flow and pressure to the controlled braking pump inlet in a parallel circuit relationship to a primary hydraulic circuit, rather than in a series flow arrangement through the primary hydraulic circuit as was the case in prior brake systems. The pre-charge circuit includes an integral back-flow check valve, and an accumulator.

Abstract: An electro-hydraulic control unit for a controlled braking system includes a hydraulic control unit (HCU) having a controlled braking pump and a pre-charge pump driven by a single motor. The HCU also includes one or more hydraulic components for controlling a flow of hydraulic fluid in the braking apparatus.

Abstract: Cold temperature performance of a pump for a controlled braking systems is enhanced, and internal flow restrictions of the pump are minimized, by placing the poppet return spring in a separate cavity out of the flow path through the pump. The separate spring cavity also allows travel of the poppet to be limited, thereby also limiting the loss of volumetric efficiency due to flow forces generated by cold, viscous fluid pushing the poppet an increasing distance from the seating area.

Abstract: Cold temperature performance of a pump for a controlled braking systems is enhanced, and internal flow restrictions of the pump are minimized, by placing the poppet return spring in a separate cavity out of the flow path through the pump. The separate spring cavity also allows travel of the poppet to be limited, thereby also limiting the loss of volumetric efficiency due to flow forces generated by cold, viscous fluid pushing the poppet an increasing distance from the seating area.

Abstract: A vehicle braking system has a self-apply control which is effective to control the vehicle wheels under braking situations, traction control situations and chassis control situations. The self-apply control includes an electronic control unit (ECU) to establish the operation of the brakes. A positive displacement pump is utilized to provide fluid during self-apply operation. The output pressure of the pump is controlled by a variable pressure isolation valve which is controlled by the ECU to establish the maximum pressure required during each situation such that excess fluid pressure is not generated at the pump. the isolation valve has a stepped diameter bore in which a valve spool is disposed. The valve spool and the bore cooperate to form a unique dampening structure. The valve land and the bore wall form a flow restriction to and from a dampening chamber formed by the bore step and the valve land.

Abstract: The solenoid control valves of a solenoid-operated automotive antilock braking system are cyclically controlled to enable the valves to operate in a stable, partially open position that provides a desired fluid flow while minimizing noise associated with acceleration and deceleration of the controlled fluid. After an incipient lock-up condition is detected and the solenoid valve has been energized to hold and/or permit a partial release of the brake pressure, the solenoid is initially de-energized for a defined interval designed to reduce the current to a scheduled value. In this interval, the solenoid current is re-circulated through a free-wheeling diode for a smooth decay, allowing the valve to slowly open in a smooth and stable fashion. Then the solenoid is pulse-width modulated (PWM) at a frequency and duty cycle designed to maintain the solenoid current at the scheduled value. The interval of PWM is relatively brief to avoid any instability associated with the current pulsation.

Abstract: A braking system includes a master cylinder that is operational to introduce a manually effected braking pressure in the braking system and includes a wheel brake that is responsive to the manually effected braking pressure. A modulator is interconnected in the braking system between the master cylinder and the wheel brake and includes a pump that has an inlet and an outlet wherein the inlet is in continuous open fluid communication with the wheel brake through a first fluid passageway. The first fluid passageway is free of any flow restrictive orifices and the first fluid passageway is not in fluid communication with an accumulator. The modulator also includes a normally open valve that is positioned in a second fluid passageway and the second fluid passageway extends between the wheel brake and both the pump outlet and the master cylinder.