Electro-pneumatic apparatus for graduated brake release
AssigneeGeneral Signal Corporation
InventorsThomas H. Engle, John J. Harris
Life of this patent
Estimating the term…
Abstract
An electro-pneumatic circuit is provided for cycling a holding magnet valve located in the brake cylinder exhaust pipe of a rail car brake system. As brake pipe pressure rises to signal full or partial release of the brakes, the holding valve is alternately opened and closed to provide a graduated release. The circuit is particularly adapted for rail cars having an electrical train line for controlling the holding valve to permit such cars to be used with other types of cars having a purely pneumatic control for graduated brake release.
Claims10
Apparatus for providing graduated, pneumatically controlled brake pressure release in a rail car brake system of the type having an electrically controlled, normally open holding valve for controlling depressurization of brake cylinders of rail car brake actuators, said apparatus comprising:
- a brake pipe for passing fluid pressure signals along said rail car brake system to control application and release of said brake actuators;
- a source of electrical power having an output circuit connected to close said holding valve when current flows in said output circuit;
- an auxiliary volume;
- first normally closed switch means connected in said output circuit to conduct current from said source, for opening said output circuit when the pressure in said brake pipe exceeds the pressure in said auxiliary volume by a predetermined amount;
- flow control means responsive to current flow in said output circuit for connecting said auxiliary volume to said brake pipe when said output circuit is open;
- and
- means for maintaining the pressure in said auxiliary volume no greater than the pressure in said brake pipe,
- whereby said output circuit is alternately opened and closed during repressurization of said brake pipe to signal a brake release, thereby providing graduated release of pressure in said brake cylinder pipe as said holding valve opens and closes.
Apparatus for providing graduated, pneumatically controlled brake pressure release in a rail car brake system of the type having an electrically controlled, normally open holding valve for controlling depressurization of brake cylinder pipe leading to rail car brake actuators, said apparatus comprising:
- a brake pipe for passing fluid pressure signals along said rail car brake system to control application and release of said brake actuators;
- a source of electrical power having an output circuit connected to close said holding valve when current flows in said output circuit;
- and
- means for alternately opening and closing said output circuit in response to repressurization of said brake pipe to effect release of said brake actuators, thereby providing graduated release of pressure in said brake cylinder pipe as said holding valve opens and closes.
Dependencies are inferred from the claim text.