ELECTROPNEUMATIC FEDERAL AND OPERATIONAL RESTRICTION DEVICES.

摘要

An electro-pneumatic braking system includes a tandem brake actuator including a service brake actuating section and an emergency/parking spring actuated section. Hold-off pressure is communicated to the emergency/parking section through a three-way solenoid valve from a pressure reservoir, and communication to the service actuator is controlled by an electro-pneumatic modulator. Service pressure is taken both from the branch of the conduit communicating with the air reservoir, and from the hold-off pressure in the emergency/parking reservoir. Accordingly, only a single line communicates fluid pressure from the reservoir to the brake, and service brake response time is improved because the hold-off pressure and the emergency/parking section of the actuator is used as a small reservoir immediately adjacent the service actuator.