DAVID ERNEST AYERS
Engineers in Richmond, VA

4668023, May 26, 1987

Aug 9, 1985

6/764162

Peter Every - Livonia MI
Edward N. Fuller - Manchester MI
David T. Ayers - Richmond VA

Kelsey-Hayes Company - Romulus MI

B60T 802

303100

The present invention concerns a control valve for use in a vehicle anit-lock braking systm adapted to control the application of pressurized brake fluid to at least one selected vehicle brake. The valve includes an outer housing having an inlet coupled to receive pressurized brake fluid from the vehicle master cylinder and an outlet coupled to supply pressurized brake fluid to the selected vehicle brakes. A passageway is formed in the housing for connecting the inlet to the outlet. A normally open isolation valve is located in the passageway and is utilized to control the flow of fluid through the passageway between the inlet and the outlet. When an incipient wheel lock condition is detected, the isolation valve can be closed to prevent a further increase in pressure to the controlled brakes and to hold the pressure supplied to the controlled brakes at a relatively constant level. After the isolation valve has been closed and it is desired to further increase the pressure to the controlled brakes, the valve can be momentarily opened to enable increased pressure from the vehicle master cylinder to be supplied to the controlled brakes. In accordance with the present invention, a damping mechanism is associated with the isolation valve for damping the movement of the valve as the valve is moved from the closed position.