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US 5,564,794 AGranted
Train brake pipe pressure exhaust control system and regulating valve therefor
AssigneeWestinghouse Air Brake Company
InventorJames E. Hart
Life of this patent
Estimating the term…
Abstract
A brake pipe pressure control system for a railroad train including a regulating valve device under control of a microprocessor wherein the regulating valve device is housed in the existing end-of-train device and effects service and emergency reductions of brake pipe pressure from the rear end of the train in correspondence with service and emergency reductions initiated at the locomotive.
Claims29
A regulating valve device for reducing the fluid pressure in a railroad train brake pipe at a location remote from the train locomotive comprising:
- a) an exhaust passage open to atmosphere;
- b) a supply passage to which said brake pipe is connected;
- c) a control passage;
- d) a bore having said exhaust passage and said supply passage opening thereinto;
- e) an annular valve seat in said bore between said exhaust passage and said supply passage;
- f) an exhaust valve member having a protrusion cooperatively arranged with said bore to provide a variable flow orifice therebetween;
- g) a valve seal element on said exhaust valve member adjacent said valve seat;
- h) a spring acting on said exhaust valve member in a direction to effect engagement of said valve seal element with said valve seat;
- i) a control piston having a first chamber on one side thereof to which said control passage is connected and a second chamber on the opposite side thereof to which said supply passage is connected;
- j) an actuating stem between said control piston and said exhaust valve member, said control piston being operative in response to a pressure differential between said first and second chambers to effect disengagement of said valve seal element from said valve seat via said actuating stem without displacing said protrusion from said bore provided said pressure differential occurs as a result of a fluid pressure change in either one of said first and second chambers relative to the other of said first and second chambers at a service rate that is less than a predetermined emergency rate.
7 more elements
For a railroad train having a brake pipe extending continuously from the locomotive to a remote location in said train, a brake pipe pressure control system comprising:
- a) means at said remote location for receiving a brake pipe pressure command signal;
- b) a regulating valve device to which said brake pipe is connected at said remote location;
- c) transducer means for providing a feedback signal corresponding to the brake pipe pressure effective at said regulating valve device;
- d) electro-pneumatic means for controlling fluid pressure communication between said brake pipe and said regulating valve device and between said regulating valve device and atmosphere;
- and
- e) control means for operating said electro-pneumatic means to establish said fluid pressure communication between said regulating valve device and atmosphere in response to said command signal being less than said feedback signal, said regulating valve device comprising:
- (i) an exhaust passage open to atmosphere;
- (ii) a supply passage to which said brake pipe is connected;
- (iii) a first control passage to which said brake pipe is connected;
- (iv) a bore having said exhaust passage and said supply passage opening thereinto;
- (v) an annular valve seat in said bore between said exhaust passage and said supply passage;
- (vi) an exhaust valve member having a valve seal element adjacent said valve seat;
- (vii) a spring acting on said exhaust valve member in a direction to effect engagement of said valve element with said valve seat;
- (viii) a control piston having first and second chambers formed on opposite sides thereof to which said first control passage is connected and a second chamber formed on the opposite side thereof to which said supply passage is connected;
- and
- (ix) an actuating stem between said control piston and said exhaust valve member, said control piston being operative in response to a pressure differential between said first and second chambers to effect disengagement of said valve element from said valve seat via said actuating stem against the force of said spring when said pressure differential occurs as a result of a fluid pressure change in either one of said first and second chambers relative to the other of said first and second chambers.
13 more elements
Dependencies are inferred from the claim text.