| 主权项 |
1. A vehicle air valve brake system having a source of air pressure, an air pressure actuator for normally applying a vehicle brake, a spring operated air pressure released actuator for mechanically applying the brake when the air pressure from said source is below a predetermined pressure, a manually operable valve having an inlet port connected with said source, a pressure regulated outlet port and an exhaust port both connected to the atmosphere, said valve manually moveable to said first position to preserve system air pressure and to said second position to deplete system air pressure, said valve also automatically movable to said first position when system pressure is depleted to desired p.s.i. |
