| 摘要 |
Empty-load fluid pressure brake equipment for a railroad car. An automatic changeover valve is operated by the pressure developed in the controlled outlet connection of a triple valve. In the empty position of the changeover valve, a volume reservoir is placed in communication with the outlet connection and the pressure developed in that connection is supplied to the brake cylinder through a proportioning valve so that a brake cylinder pressure is developed which is a predetermined fraction of the cylinder pressure developed by the same brake pipe pressure reduction in the load position. The ratio of cylinder pressure on an empty car to that on a loaded car is constant for all applications, and the volume reservoir is sized with regard to this ratio so that the equalization pressures are the same on an empty car as on a loaded car. An initial opening bias is exerted on the proportioning valve so as to prevent proportioning action during the initial stages of brake cylinder pressure development. |
