SHORT TRAVEL DETECTOR FOR EMPTY/LOAD BRAKE CONTROL

摘要

An empty/load brake control system mountable on a sprung and an unsprung member of a railway car and disposed between the car brake control valve and brake cylinder for adjusting the brake cylinder pressure during a brake application according to the car load condition. Such system includes an empty/load sensor valve device with an inlet passage connected to the brake control valve and an outlet passage connected to the brake cylinder. It further includes a sensor arm coupled to a sensor cable whose movement is controlled by a sprung member and a terminal member disposed on an end of sensor cable, in contact with sprung member so that any downward movement of sprung member forces such terminal member in a similar downward direction and similarly pulls on the sensor cable. A piston, under pressure, urges the sensor arm to rotate and retract sensor cable but must overcome resistance of a spring. The system includes a load proportional valve having a proportioning mode of operation and a non-proportioning mode of operation in which sensor piston is fluidly connected to a balance piston for supplying fluid under pressure to a second pressure area of the balance piston when the valve device is in an empty setting thereby providing a proportioning mode of operation, and not supplying fluid under pressure to the second pressure area of the balance piston when empty/load sensor valve is in load setting thereby providing a non- proportioning mode of operation.