GB1341761A - Double circuit braking valve assemblies - Google Patents

Abstract

1341761 Dual circuit brake valves ROBERT BOSCH GmbH 19 April 1971 [26 Feb 1970] 24309/71 Heading F2F A dual circuit braking valve assembly coinprises a first valve 8 operable by a device 2 to connect an outlet 4 for a first brake circuit to an inlet 3 for storage air, and a second valve 14 operable by movement of a piston member 17, which is acted upon by air pressure in the first brake circuit, to connect an outlet 6 for a second brake circuit to an inlet 5 for storage air in the event of failure of the first circuit, an adjusting screw 10<SP>1</SP> of the device 2 is operable to move a plunger 15 downwardly to cause actuation of valve 14. The piston member 17 will then be moved upwardly by the pressure in the second circuit and three lever units 22 arranged around the plunger 15 act to deliver a reaction force from the piston member 17 to the plunger 15. Each lever unit 22 has three bearing surfaces 23, 24, 25 which have engagement respectively with a pressure disc 21 mounted on a shoulder 20 of the plunger 15, the piston member 17 and a bearing ring in the valve housing 1 and the reaction force on the plunger 15 may be altered by altering the distances between the bearing surfaces 23, 24, 25; the lever units 22 are biased upwardly by a spring 27. In the non-actuated state of the assembly, chambers 30, 32 thereof are connected to atmosphere through a connection 7. The piston member 17 has a ring attachment 17<SP>1</SP> formed with a valve seat 17<SP>11</SP> and the plunger 16 also has a movable valve seat 16 actuable on a valve closing body 19 of the second valve 14. The chamber 32 is connected to a space 34 above the piston member 17 by a channel 35.