Bremsventil fuer eine aus mindestens zwei Bremskreisen bestehende hydraulische Konstantdruck-Bremsanlage,insbesondere fuer Kraftfahrzeuge

1326571 Valves for hydraulic dual braking systems WESTINGHOUSE BREMSENUND APPARATEBAU GmbH 15 Oct 1970 [3 Nov 1969] 49067/70 Heading F2F A valve assembly for a dual hydraulic vehicle braking system comprises two hollow coaxial valve shutter members 11, 12 having conical parts 13, 14 which with seats 21, 26 define valves 13, 21 and 14, 26 controlling communication between reservoirs 37, 38 and the respective brake circuits, the valve 14, 26 being operable by pressure from the reservoir 37 but in the event of a pressure failure in the first circuit being operable mechanically by the shutter element 11. In operation, an actuating piston 20 is first displaced by a brake pedal in the direction of arrow 39 to close a valve 17, 11 which normally links the first brake circuit with a return pipe via a bore 31. The valve 13, 21 is then opened to allow hydraulic pressure to flow to the first brake circuit from the first reservoir 37 via a bore 35, bore 4, annular chamber 28 and bore 33. The hydraulic pressure in the first brake circuit provides "feel" for the valve assembly operator and will cause the valve 13, 21 to close when the pressure in bore 15 of the shutter element 11 comes into equilibrium with the operating force. The pressure in the first hydraulic circuit also acts on a second actuating piston 22 to cause closure of a valve 18, 25 which normally links the second brake circuit with a return pipe via a bore 32 and subsequently opening of the valve 14, 26 which allows hydraulic pressure to flow to the second circuit from the second reservoir 38 via a bore 36, a bore 6, annular chamber 30 and bore 34. However if the fluid pressure in the first circuit fails the valve 14, 26 is opened mechanically through the interlink of piston 20, member 11 and piston 22.