Patent GB-1061058-A (GB)
Title: Improved disc brake
Inventor: HODKINSON HAROLD
IPC: F16D65/52
Filed: 1962-12-08
Abstract: 1,061,058. Disc brakes. DUNLOP RUBBER CO. Ltd. Nov. 29, 1963 [Dec. 8, 1962], No. 46419/62. Addition to 709,305. Heading F2E. A disc brake assembly comprises an annular disc 10 rotatable by a vehicle wheel, a non- rotatable guide member 13 straddling the outer periphery of the disc with limbs 16 located adjacent each radially-extending side of the disc and provided with axially extending apertures 19 therethrough, friction elements 20 being slidably located in the apertures to frictionally engage the disc and an actuating mechanism located remote from the friction pads acts in conjunction with means to urge the friction elements into frictional engagement with the disc, the axially-extending apertures being bounded adjacent the periphery of the disc by a detachable friction element retaining member 24 which, when removed, enables the friction elements to be withdrawn from the apertures 19 in a radial direction. The means to force the friction elements into engagement with the disc comprises a pair of levers 29, 30 axially aligned one on each side of the disc extending chordally across the disc and pivotally secured to a non-rotatable part of the disc brake assembly 11 and an operating rod 33 (Fig. 1, not shown) extending axially adjacent the outer periphery of the disc secured to one end of one of the lever members 29 (Fig. 1, not shown) and pivotally secured at the other end to one end of a bifurcated operating lever pivotally secured intermediate its ends to an associated end of the other lever 30. In operation, actuation of a fluid pressure operated brake cylinder 37 (Fig. 1, not shown) or operation of a lever member 40 effects angular movement of an operating lever 34 (Fig. 1, not shown) towards the disc 10 to cause the lever members 29 and 30 to move towards the disc thereby forcing the friction pads 20 into frictional engagement with the brake surfaces of the disc. The friction pads 20 are mounted on backing plates 21 each formed with an outturned ear 22 which extends axially adjacent the outer periphery of the disc to slidably engage in a groove in the other backing plate and abut against a companion ear 22 on the other backing plate to prevent tilting of the friction elements relative to the braking surfaces of the disc 10. A pair of springy but deformable retractor fingers 43 (Fig. 1, not shown) extend from the caliper housing 11 and engage in holes 44 in the lever members. The retractor fingers have sufficient resilience to retract the lever members 29, 30 after each brake application but are capable of being progressively deformed as wear of the friction pads takes place. A pair of springy retaining clips 46 (Fig. 1, not shown) are riveted one to each pad backing plate 21 such that they engage on a peg 47 (Fig. 1, not shown) attached to the respective lever members 29, 30 to ensure that the friction elements are withdrawn from the disc after each brake application. An automatic adjuster mechanism may be provided between the bifurcated arms of the operating member 34 to shorten the effective length of the operating rod in order to maintain the friction pads 20 at the desired clearance in the inoperative condition of the brakes as wear of the friction surface occurs. Reference has been directed by the Comptroller to Specifications 883,417 and 818,077.