Abstract: An automatic slack adjuster assembly is provided in or for a vehicle internal shoe drum brake of the duo-servo type having primary and secondary shoes located within a rotatable drum so that the primary shoe is carried round with the drum when the brake is applied, the slack adjuster assembly being located in a housing between adjacent ends of the shoes and including a thrust member which engages the ends of the shoes and transmits thrust on the primary shoe to the secondary shoe when the brake is applied. The adjuster assembly includes a sensing mechanism which senses relative movement between the thrust member and the housing and controls an energy-storing clutch mechanism which is connected to an adjuster and operates the adjuster to increase the effective length of the thrust member when the torque generated by the stored energy force is greater than the torque generated by the force applied to the thrust member from the shoe ends.

Abstract: A disc brake comprises a fluid pressure-operated actuator for urging two pressure plates carrying friction pads to opposite faces of a disc. In the actuator a piston movable in a housing is detachably engaged with a draw-bar which acts on one of the pressure plates, the housing acting directly on the second pressure plate. A seal between the housing and the draw-bar contacts an enlarged portion of the draw-bar. Apparatus is provided to prevent the draw-bar from rotating.

Abstract: A disc brake comprises a fluid pressure-operated actuator for urging two pressure plates carrying friction pads to opposite faces of a disc. In the actuator a piston movable in a housing is detachably engaged with a draw-bar which acts on one of the pressure plates, the housing acting directly on the second pressure plate. A seal between the housing and the draw-bar contacts an enlarged portion of the draw-bar. A screw-driver slot is provided to prevent the draw-bar from rotating.

Abstract: A reaction type disc brake is provided with a mechanical actuator in the form of a helical thrust bearing whose nonrotatable cam component is part of or fixed relatively to the caliper. The rotatable cam component is housed in the caliper and is axially displaceable as well as rotatable therein. The rotatable cam component acts on the directly operated brake pad assembly via an axial thrust bearing and the reaction thrust is received directly by the caliper and applied to the indirectly operated brake pad assembly. The rotatable cam component is turned by means of a laterally flexible member which extends into the housing and which is placed under tension. The lateral flexibility accommodates the axial travel of the rotatable cam component. The helical thrust bearing comprises bearing needles disposed between helical cam tracks on the rotatable and nonrotatable components.

Abstract: In a disc brake assembly of the type including first and second fluid pressure-operated actuators for applying friction pads to opposite faces of first and second axially spaced rotatable discs respectively, the first and second actuators are both disposed on the same one side of a disc diameter, and the actuators are both located adjacent to the outer face of an outer disc.

Abstract: A thrust transmitting assembly, particularly useful as a shoe tip abutment for an internal shoe drum brake, has a cylindrical output member and a slidable input member in the form of a piston, the members being transmissively coupled by a fluent material, such as an elastomeric material, which transmits input thrust in one direction to the output member in the same direction but at a higher velocity.

Abstract: A vehicle wheel spring brake actuator has a service braking piston and cylinder assembly and an auxiliary parking or emergency braking piston and cylinder assembly, the emergency braking piston being spring biassed towards a brake-applying position and normally held off by an opposing fluid pressure, upon release of which the spring force is transferred through the emergency braking piston and a force transferring member to the service braking piston to apply the brake. A quick release device is movable through a small distance to permit relative movement between the force transferring member to release the applied brake, the release device and the force transferring member extending through the emergency braking piston freely and with clearance.

Abstract: The invention concerns shoe drum brakes and provides for such brakes, a replaceable shoe lining component which is detachably secured to the shoe platform or backplate, the latter remaining permanently in position in the brake assembly. The lining component preferably comprises a thin carrier plate and a lining of friction material secured to the carrier plate; the shoe platform and the carrier plate having detachably inter-engageable means such as tongues and slots by which they are capable of being securely connected together in the brake assembly.