Automatic wear adjuster for drum brakes
AssigneeAutomotive Products plc
InventorsJohn P. Burke, Alastair J. Young
Life of this patent
Estimating the term…
Abstract
An internal drum brake of the kind including a strut between a hand brake lever pivoted on one shoe and the other shoe, has a wear adjuster comprising a pair of screw-threaded members with a pawl and pawl wheel for relative rotation thereof on operation of the service brake system, the axis of the screw-threaded members intercepting the line of action between the shoe and an abutment which limits return movement of the shoe to a brake-released position, one of the members having a spacer between the shoe and the abutment, the spacing effect of the spacer being changed on relative rotation of the screw-threaded members.
Claims7
In a drum brake:
- a brake drum;
- a pair of brake shoes each having a wearable friction lining;
- a fixed abutment between two adjacent ends of the brake shoes;
- actuating means between the other adjacent ends of the brake shoes for urging said shoes against the drum;
- a handbrake lever pivoted to one brake shoe adjacent the actuating means;
- a strut between the handbrake lever and the other brake shoe for urging the brake shoes against the drum on actuation of said handbrake lever;
- and
- self adjusting means for increasing the effective length of the strut on wear of the friction linings;
- said adjusting means comprising a pair of screw-threaded members and step by step means for relative rotation thereof on operation of said actuation means, said screw-threaded members being arranged substantially at right angles to the strut and one of the members having spacer means dirrectly interposed between the strut and one of the handbrake lever and other brake shoe, the position of the spacer means being variable by relative rotation of the screw-threaded members to change the spacing effect of the spacer means and thus the effective length of the strut.
Dependencies are inferred from the claim text.