摘要 |
An electro-pneumatic brake system for a railroad freight car is integrated with the existing pneumatic freight brake system by utilizing the air stored in the emergency reservoir to supply brake cylinder pressure via the exhaust passage of the pneumatic control valve, which is maintained in release position during electro-pneumatic brake operation. The electro-pneumatic brake system fails to a release mode, so that the brakes on an individual car that experiences a power loss do not apply. In the case of a power loss in the electro-pneumatic system, due to a train break-in-two, the pneumatic brake system is automatically operated by the consequent loss of brake pipe pressure to provide a back-up brake, while at the same time interrupting the control valve exhaust path via which the electro-pneumatic brake is communicated with the brake cylinder. |