Abstract: A boosted brake having a booster with a decompression arrangement wherein an output push rod has a head with a plurality of openings that extend into a stem and create a plurality of arcuate grooves. The openings receive a plurality of projections that extend from a piston retained in a sleeve held in a movable partition. A spring acts on the projections and urges the piston into engagement with a reaction disc through which an actuation force is supplied a master cylinder. A predetermined reaction force from the master cylinder acts on piston and overcomes the spring to allow the reaction disc to expand and thereby modify the reaction force. The arcuate grooves in the stem allow for a maximum diameter for spring with a minimum diameter for stem that corresponds to a diameter of piston in order to creates a desired braking in response to an emergency brake application.

Abstract: A backing plate assembly for a drum brake includes a first part adapted for attachment to a vehicle frame and a second part releasably coupled to the first part. The second part is made of a material that effects substantial noise reduction in the assembly and the second part is tightly frictionally coupled to the first part. The second part sees no braking torque and is coupled to a reinforced portion of the first part.

Abstract: A self-centering brake assembly in which the leading shoe 12 and the trailing shoe 14 are connected in a duo servo braking mode. The connected ends of the shoes have an automatic adjuster comprising an adjuster lever return spring 70, an adjuster lever 74, a wire form link 76 and a pretension caged spring 78. The force of the adjuster lever return spring 70 and the placement of the wire form link 76 together with its pretension cage spring 78 develop a balanced force so that the moments about each anchored end of the shoe is substantially equal to 0. Shoes 12, 14 thus maintain concentricity of the brake shoe ring in relation to the brake drum 28.

Abstract: A torque plate construction (50) comprises two stamped parts (58, 60) which are fastened together at central planar portions (62, 63) thereof and to a wheel axle housing (20) of a vehicle. Each torque plate part (58, 60) includes housing portions (77) spaced axially from the central planar portion (62, 63) of the respective plate part, the portions (77) providing a wheel cylinder housing (78). A piston cylinder (90) is disposed within the wheel cylinder housing (78), with a pair of bolts (100) and nuts (87) connecting together the portions (77) and securing the cylinder (90) within the housing (78). Each torque plate part (58, 60) has a pair of circumferentially spaced-apart notched portions (37) providing seats for a pin (40) extending from an associated brake shoe web (34), one web having an extension (39) extending between the torque plate parts to engage the piston (92).

Abstract: A duo-servo drum brake (10) includes an adjusting mechanism (40) for effecting brake shoe (18, 20) adjustment during application of the brake. The brake (10) includes a cable (42) connected to the anchor pin (28) and one of the brake shoes (20), and to an adjuster connector (46) attached at its end. The adjuster connector (46) contains an elongated slot (49) receiving therein an end (61) of an opposing force clutch spring (60) mounted upon the adjusting pivot nut (56) of an extendible strut (50). The adjuster connector (46) is connected to a resilient return spring (70) anchored to the one brake shoe (20). A second opposing force clutch spring (62) is secured at one end (63) to the one brake shoe (20) and is mounted about the adjusting pivot nut (56) in order to prevent retraction rotation of the nut (56).

Abstract: An adjuster assembly for a nonservo drum brake includes a pawl (44) cooperating with a star wheel (30) of an extendible strut (22). The pawl (44) includes more than one (56, 58) edge cooperating with the star wheel to control extension of the extendible strut (22).

Abstract: A leading trailing drum brake with an improved strut and adjusting pawl mechanism. The adjusting pawl comprises a single piece which is mounted in a shaped aperture within one of the brake shoes to provide a structure which can be easily assembled. The pawl has an arm which contacts the strut in an off-set position from the longitudinal axis of the strut and applies a force to the strut parallel to its longitudinal axis.