Patent ID: 6017098
Filing Date: 2000-01-25
Classification: B60T

Abstract:
An improvement to a brake pipe control device defining (i) a primary passage network that interconnects a brake pipe to a charging cut-off valve and an emergency vent valve housed in such brake pipe control device and (ii) a control passage network that interconnects a source of control pressure to cut-in, cut-out, release, application and emergency magnet valves used to cause operation of such charging cut-off and emergency vent valves and exhaust and supply valves of such brake pipe control device, said improvement comprising:(a) a first check valve incorporated into such control passage network between an inlet channel thereof that connects to such source and a branched channel thereof that connects to such release, cut-in, cut-out and emergency magnet valves, said first check valve disposed to prevent air from flowing to such source from such branched channel when pressure in such source is low relative to pressure in such branched channel;(b) a connective passageway defined in such brake pipe control device that interconnects such branched channel and such primary passage network; and(c) a second check valve incorporated into said connective passageway and disposed to allow air to flow from such primary passage network to such branched channel when pressure in such source is low relative to pressure in such brake pipe so as to maintain pressure in such branched channel thereby allowing such magnet valves during operation thereof to cause proper operation of such exhaust, supply, charging cut-off and emergency vent valves of such brake pipe control device even if such source fails to provide air at such control pressure ordinarily expected.