Brake control valve device for an air pressure brake system of a railway vehicle

摘要

The present invention discloses a maximum pressure control device for the brake cylinder pressure that is to be supplied to a brake cylinder and this device can consist of two separate pressure control devices or be constructed as a unified, reversible pressure control device. The selection of one of the active pressure control devices or changeover of the switchable maximum pressure control device results from a main brake line pressure acting against a spring loaded control piston which, depending on the main brake line pressure, can switch off the pressure control function of the maximum pressure control device for the low (service) or high (emergency) brake cylinder pressure. The control piston when functioning as an actuated cut off device can be mechanically coupled with a pressure control device by means of a stop coupling or pneumatic coupling. As a result, the control piston is not able to exert any negative effect on the control precision of the maximum pressure control device.