Abstract: A parking brake interlock is provided according to the invention. The parking brake interlock includes a parking brake inlet configured to receive a parking brake air supply, a service brake inlet configured to receive a service brake air supply, an exhaust port, and an interlock valve mechanism in communication with the parking brake inlet, the service brake inlet, and the exhaust port. The interlock valve mechanism is configured to exhaust the parking brake air supply if the service brake air pressure is not received. The interlock valve mechanism is further configured to hold the parking brake air supply in order to generate a parking brake air pressure if the service brake air pressure is received.

Abstract: A parking brake interlock is provided according to the invention. The parking brake interlock includes a parking brake inlet configured to receive a parking brake air supply, a service brake inlet configured to receive a service brake air supply, an exhaust port, and an interlock valve mechanism in communication with the parking brake inlet, the service brake inlet, and the exhaust port. The interlock valve mechanism is configured to exhaust the parking brake air supply if the service brake air pressure is not received. The interlock valve mechanism is further configured to hold the parking brake air supply in order to generate a parking brake air pressure if the service brake air pressure is received.

Abstract: A first normally open solenoid valve “A” is connected to passageway (32). A second normally open solenoid valve “B” is connected to a passageway (36). A latching valve (24) includes a valve spool chamber (26) and a valve spool (50) within the chamber. An air-delivery conduit (20) delivers pressurized air to both a first passageway (32) and a second passageway (36). Passageway (32) is connected to one end of the valve spool chamber (26). Passageway (36) is connected to the opposite end of the valve spool chamber (26). The valve spool (50) has two positions. In the first position, passageway (32) is connected with a passageway (40) that extends to an air-operated device (44). Flow through the valve (24) to and from passageway (36) is blocked. In the second position, flow from passageway (32) to passageway (40) is blocked. Also, flow through the valve (24) to and from passageway (36) is blocked.

Abstract: A first normally open solenoid valve “A” is connected to passageway (32). A second normally open solenoid valve “B” is connected to a passageway (36). A latching valve (24) includes a valve spool chamber (26) and a valve spool (50) within the chamber. An air-delivery conduit (20) delivers pressurized air to both a first passageway (32) and a second passageway (36). Passageway (32) is connected to one end of the valve spool chamber (26). Passageway (36) is connected to the opposite end of the valve spool chamber (26). The valve spool (50) has two positions. In the first position, passageway (32) is connected with a passageway (40) that extends to an air-operated device (44). Flow through the valve (24) to and from passageway (36) is blocked. In the second position, flow from passageway (32) to passageway (40) is blocked. Also, flow through the valve (24) to and from passageway (36) is blocked.