RAILWAY BRAKE VALVE ASSEMBLY

摘要

A brake valve assembly suitable for use in a railway air brake system to control flow of air between the on-board reservoir and a respective brake cylinder. The valve assembly may include a plurality of internal valves to permit three states of fluid transfer, i.e., delivery, exhaust and lap. The internal valves are controlled by respective solenoids that act directly on the valve element. Internal forces due to fluid pressure are balanced using counterbalance assemblies preferably including a flexible, rolling diaphragm disposed adjacent to a configured follower member. The counterbalance assemblies maintain substantial balance throughout the reciprocative stroke of the valve element.