摘要 |
A brake interface circuit (50) for use with a hybrid drive system (10) includes a brake interface circuit (50) for selectively enabling and disabling the operation of a brake (45) that is actuated by an actuator (64). The brake interface circuit (50) includes a brake cylinder (52) and an actuator control valve (63) that is adapted to selectively enable and disable the operation of the brake (45) by the actuator (64). First and second control valves are connected between the brake cylinder (52) and the actuator control valve (63). The brake interface circuit (50) is operable in a first operating mode to cause the actuator control valve (63) to enable the operation of the brake (45) by the actuator (64), a second operating mode to cause the actuator control valve (63) to disable operation of the brake (45) by the actuator (64), and a third operating mode to cause the actuator control valve (63) to enable the operation of the brake (45) by the actuator (64) even though a portion of the brake interface circuit (50) is operated in the second operating mode. |