Dual cct. hydraulic brake system - has spring brake actvator fed from both ccts. via lines with press responsive protection valves

摘要

The dual circuit hydraulic braking system has a spring brake actuator which is fed from both service circuits through separate lines each incorporating a pressure responsive protection valve operable in the event of a failure in the related service circuit to cut off that circuit from the spring brake circuit whereby the latter continues to be fed from the other service circuit. The protection valves may also be operable to shut off fluid flow to the spring brake circuit in the event of lowering of fluid level in the system reservoir, whilst provision may also be made for relieving possible build-up of pressure in the reservoir return line from the spring brake control valve.