DISC BRAKE

PURPOSE:To reduce dragging torque, by previously bending the central part of a shim interposed between a piston and the back metal of a brake shoe, so that the central part of the shim extends into the piston. CONSTITUTION:A piston 4 slidably fitted in a cylinder 3 formed at one end of a caliper body 2 has an opening 5. A dust boot 6 is fitted between the cylinder 3 and the open end of the piston 4. Brake shoes 7, 8 are opposed to both the sides of a disc 1 secured on a rotary shaft (not shown in the drawing) and are provided with back metals 9, 10 and linings 11, 12. A shim 14 is secured on the piston 4 by juts 15. The central part of the shim 14 is bent into the piston 4. In braking, the piston 4 is moved leftward to bring the brake shoes 7, 8 into contact with the disc 1 to apply a braking force. In non-braking, the piston 4 is returned to the original position. In that case, the brake shoe 7 pushed on the disc 1 is surely released from it because the cental part of the shim 14 is bent into the piston 4.