GB1364510A - Control valve for motor vehicle breaking systems - Google Patents

Abstract

1364510 Driver valves CLAYTON DEWANDRE CO Ltd 16 Oct 1972 [19 Nov 1971] 53831/71 Heading F2F A manually operated brake control valve has an inlet 5, a delivery port 3, an exhaust chamber 7, oppositely disposed valve seatings 4, 6, and a valve element 10 engageable alternatively with the seatings and moved by hand operated means between a first position engaging one seating 4 to close off the inlet and allow communication between the delivery port and the exhaust chamber, and a second position engaging the other seating 6 to close off the exhaust chamber and allow communication between the inlet and delivery ports, a spring 17 urging the valve element towards the first position so that the valve element is only held in the second position by inlet air pressure exceeding a predetermined value. Spring applied brakes are held off when air passes from the inlet 5 to the outlet 3, the valve element 10 engaging the seating 6 and a control handle 19 being in a position D. When the inlet pressure drops, the spring 17 moves the element 10 against the seating 4 to exhaust the air and apply the brakes, the handle 19 moving to a position V against the detent 20. Subsequent increase in inlet air pressure does not reset the element 10 since the effective area under pressure is decreased to the area of the seating 4. Movement of the handle 19 to position D raises the element 10 via members 13, 14, 11 and a lost motion connection. For parking, the handle 19 is lifted over the detent 20 to position P and takes up the lost motion to force the element on to the seating 4 for brake application.