Abstract: In order to safely and conveniently assemble and service new design spring brake actuators having power springs located in the middle of the actuator, the actuator's rear chamber cover must be able to withstand high localized forces from tools such as power spring compression rods. A reinforcement and method for its installation is provided, in which a plurality of reinforcement plates is stacked on the rear chamber cover about a tool-insertion aperture, and the outermost plate is crimped about the aperture, thereby securing the plates to the rear chamber cover in a cost- and time-efficient manner. Preferably, the lip of the rear chamber cover aperture is stamped when the cover is formed such that the lip protrudes axially outward to help assure that the lip is captured between the crimped reinforcing plate on one side and the remaining reinforcing plates on the other side.

Abstract: A brake assembly includes a brake, an actuator, and an automatic slack adjuster for adjusting the clearance between the brake shoes and the brake drum. The actuator includes a housing, a piston moveably disposed in the housing, a yoke disposed outside of the housing, and a pushrod extending through the housing. The pushrod is connected to the piston, and an end portion of the pushrod forms a rivet that attaches the yoke to the end portion of the pushrod.

Abstract: A power spring arrangement of a spring-type brake actuator for a vehicle brake, in which the actuator's power spring is located between the service brake actuator and parking brake release actuator, and the power spring comprises a plurality of concentric springs. The power spring is captured between the actuator's intermediate flange and a spring retainer. The use of two or more concentric springs allows higher parking brake actuator force to be generated than with a standard single power spring, without the need to enlarge the actuator housing or to use more costly spring materials or spring configurations.

Abstract: An improved seal/bearing arrangement employs an O-ring type seal which has segmented fingers. The seal ring has a recess which is sized to mate with a corresponding projecting lug of a bore use, for example, in brake actuator mechanisms. The seal ring can be made from synthetics such as polyamides and polyethylenes. The fingers are so arranged that locking of the seal rings in the bore occurs with insertion of a sliding, oscillating and/or rotating shaft or the like through the rings.

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.