Abstract: A brake system and a valve device for a brake system are provided which provide at least partial front brake actuation in the event of a failure in the front brake pneumatic supply circuit. The valve device may be configured as a biased orifice double check valve which permits compressed air flow from the front brake pneumatic supply circuit to a front brake actuator during normal brake operation, but in the event of lack of sufficient front brake pneumatic pressure permits compressed air to be supplied to the front brake actuator from a rear brake pneumatic supply circuit, as well as permitting compressed air in the front brake actuator to be ventilated back through the rear brake pneumatic supply circuit when the brake is released.

Abstract: A brake system and a valve device for a brake system are provided which provide at least partial front brake actuation in the event of a failure in the front brake pneumatic supply circuit. The valve device may be configured as a biased orifice double check valve which permits compressed air flow from the front brake pneumatic supply circuit to a front brake actuator during normal brake operation, but in the event of lack of sufficient front brake pneumatic pressure permits compressed air to be supplied to the front brake actuator from a rear brake pneumatic supply circuit, as well as permitting compressed air in the front brake actuator to be ventilated back through the rear brake pneumatic supply circuit when the brake is released.

Abstract: An arrangement for securing a carrier for a brake to an axle housing of a vehicle includes a torque plate having an attachment portion securable to the carrier and an annular mounting section securable to a backing plate on the axle housing. The annular mounting section is provided with pluralities of alignment holes and mounting slots, permitting adjustment of a torque plate clocking angle. By way of a torque plate configured in accordance with this invention, clocking angle adjustments can be made in increments of under three degrees.

Abstract: A mid-power spring brake actuator includes first, second, and third actuator housing portions, with the first actuator housing portion interposed between the second and third housing portions. A parking brake release actuator is received within the third housing portion, and a connecting shaft is attached at a first end to the parking brake release actuator and extends through a dividing wall defined by the first housing portion. A service brake apply actuator is received within at least one of the first and second housing portions. Between the dividing wall defined by the first housing portion and a second end of the connecting shaft, a brake actuator spring is provided, and a service brake actuation chamber is interposed between the brake actuator spring and the service brake apply actuator. A parking or emergency brake de-actuation chamber is defined between the parking brake release actuator and the first housing portion.

Abstract: A spring-type brake actuator for a pneumatically-operated vehicle brake is provided, with a brake actuator spring located on a front side of the actuator's intermediate flange, between a service brake actuator and a parking brake release actuator. The spring is captured between the intermediate flange and a retaining plate which is connected to the parking brake release actuator via a shaft through the intermediate flange. Because the retaining plate and parking brake release actuator are connected to one another on opposite sides of the intermediate flange, spring expansion is checked, thereby increasing safety during actuator production and servicing by virtually eliminating the potential for uncontrolled spring energy release. The actuator configuration also reduces structural loads on the rear portion of the housing and shifts spring and housing weight closer to the vehicle brake, permitting simpler designs and use of alternative materials, such as plastic or aluminum to lower costs.

Abstract: A mid-power spring brake actuator includes first, second, and third actuator housing portions, with the first actuator housing portion interposed between the second and third housing portions. A parking brake release actuator is received within the third housing portion, and a connecting shaft is attached at a first end to the parking brake release actuator and extends through a dividing wall defined by the first housing portion. A service brake apply actuator is received within at least one of the first and second housing portions. Between the dividing wall defined by the first housing portion and a second end of the connecting shaft, a brake actuator spring is provided, and a service brake actuation chamber is interposed between the brake actuator spring and the service brake apply actuator. A parking or emergency brake de-actuation chamber is defined between the parking brake release actuator and the first housing portion.

Abstract: In an actuator for a brake system or a method for making a brake actuator, an attachment mechanism for attaching a diaphragm to a piston includes a plurality of protrusions on one of the piston and diaphragm and a plurality of cavities on the other of the piston and diaphragm, each protrusion being insertable into a corresponding cavity to attach the diaphragm to the piston. Alternatively, a retaining ring is provided that need not be precisely made and yet can attach the diaphragm to the piston securely and sealingly.