Automatic shoe clearance adjustment device for a drum brake
AssigneeNisshinbo Industries, Inc.
InventorSeiji Asai
Life of this patent
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Abstract
It is an object of this invention to provide an automatic shoe clearance adjustment device for a drum brake mechanism designed to improve its durability by eliminating a gap, which is caused due to the manufacturing tolerances between the operating end surface of a brake shoe and the extended portion of an adjustment lever. To that end, a long hole (81) is formed to extend horizontally in the actuating direction of a service brake actuator (50); and the adjustment lever (80) is pivotally supported via a pin (14) with a capacity of making a rotation relative to the brake shoe (20) and a capacity of making a relative slide in approximately the same direction in which the service brake actuator (50) operates.
Claims27
An automatic shoe clearance adjustment device for a drum brake, comprising:
- a pair of brake shoes slidably mounted on a back plate;
- an extendible strut restricting an initial position of said pair of brake shoes;
- and
- an adjustment lever pivotally supported at one of said brake shoes, said adjustment lever being rotatable in response to an excessive opening of said brake shoes upon operation of a service brake actuator and said adjustment lever having an extended portion integrally formed as an extended end thereof, said extended portion being arranged between abutment surfaces of said service brake actuator and one of said brake shoes at an actuating force transmitting section through which an actuating force of said service brake actuator is transmitted to said one of the brake shoes, and said adjustment lever being adapted to stop rotating when said actuating force of said service brake actuator reaches a predetermined value;
- wherein said adjustment lever is pivotally supported with a capacity of making a rotation relative to said one of the brake shoes and a capacity of making a relative slide in approximately the same direction in which said service brake actuator operates so as to maintain a contact between said extended portion and said one of the brake shoes.
An automatic shoe clearance adjustment device for a drum brake, comprising:
- a single brake shoe slidably mounted on a back plate;
- an extendible strut restricting an initial position of said brake shoe;
- a link engaging with said brake shoe so as to depress a central region of said brake shoe;
- and
- an adjustment lever pivotally supported at said link, said adjustment lever being rotatable in response to an excessive opening of said link upon operation of a service brake actuator and said adjustment lever having an extended portion integrally formed as an extended end thereof, said extended portion being arranged between abutment surfaces of said service brake actuator and said link at an actuating force transmitting section through which an actuating force of said service brake actuator is transmitted to said link, and said adjustment lever being adapted to stop rotating when said actuating force of said service brake actuator reaches a predetermined value;
- wherein said adjustment lever is pivotally supported with a capacity of making a rotation relative to said link and a capacity of making a relative slide in approximately the same direction in which said service brake actuator operates so as to maintain a contact between said extended portion and said link.
An automatic shoe clearance adjustment device for a drum brake comprising:
- an extendible strut restricting an initial position of at least one brake shoe relative to a back plate;
- an adjustment lever pivotally supported at one end of a reaction member moves in response to an actuating force of a service brake actuator, said adjustment lever being rotatable in response to an excessive displacement of said at least one brake shoe upon operation of a service brake actuator, said adjustment lever having an integrally formed extended portion having a force transmitting section disposed between abutment surfaces of said reaction member and said service brake actuator to facilitate transmission of an actuator force of said at least one brake shoe, said adjustment lever being adapted to stop rotating when said actuator force reaches a predetermined value;
- wherein said adjustment lever is pivotally supported with a capacity of making a rotation relative to said reaction member and a capacity of making a relative slide substantially parallel to a direction in which said service brake actuator operates so as to maintain a contact between said extended portion and said one of the brake shoes.
Dependencies are inferred from the claim text.