Automatic stop valve device for vehicle brake systems

摘要

An automatic stop valve device adapted to be mounted in the fluid pressure brake system of a vehicle and having a valve mechanism capable of being shifted between an open and a closed state and operative by closing to maintain fluid pressure in the system to hold the brakes in an applied condition. An electromagnetic mechanism having a coil and an armature actuated by the coil is capable of shifting the valve mechanism to its closed state. The electromagnetic mechanism is arranged to be energized to hold the brakes in the applied condition when a moving vehicle is brought to a stop, to maintain the valve mechanism closed while the vehicle remains stopped to hold the brakes in the applied condition and to open the valve mechanism when the operation of the vehicle resumes to release the brakes. Provision of a bypass around the valve mechanism permits the fluid pressure transmitted to hold the brakes to be increased even when the electromagnetic mechanism is energized to actuate the valve mechanism to its closed state.