| 摘要 |
<p>Electro-pneumatic parking brake assembly, comprising a brake cylinder (10) which is operated by electro-pneumatic valve means, including a protection valve (3) for providing a bi-stable safe state function, wherein an input port (3.1) of the protection valve (3) is connected to a supply pressure source (1), an output port (3.2) is connected to the brake cylinder (10) and an exhaust port (3.3) is connected to the ambient pressure, wherein the protection valve (3) is a pivot-controlled bi-stable 3 by 2 valve containing two independently movable spring-retracted pistons (A and B), wherein the first piston (A) corresponds to an input valve seat (C) and the second piston (B) corresponds to an exhaust valve seat (E), and both valve seats (C and E) are closed together independently of the output pressure at output port (3.2) if the control piston (B) is charged by a pressure equal or higher than the supply pressure (1) coming in control input port (3.4).</p> |
