CONTROL VALVE DEVICE ARRANGED FOR DIRECT OR GRADUATED RELEASE OPERATION

摘要

In a brake control valve device for railway vehicles in which a bias spring acts on the piston stack assembly of the valve device, an additional air reservoir and a differential check valve are arranged to assure proper full service brake pressure, when the control valve device is operated in a direct release mode, thereby overcoming the effect of the bias spring in producing a force balance to cause the piston stack assembly to assume a lap condition before full service brake pressure is achieved. The arrangement has no adverse effect when the control valve device is operated in a graduated release mode.