GB1424769A - Disc brake friction pad assembly - Google Patents

Abstract

1424769 Disc brake wear detectors SUMITOMO ELECTRIC INDUSTRIES Ltd and TOYOTA JIDOSHA KOGYO KK 19 Oct 1973 [21 Oct 1972] 48871/73 Heading F2E A friction pad assembly for a disc brake comprises a back plate supporting a brake lining, a loop of insulated electric wire presenting, at a point in the thickness of the brake lining corresponding to a lower limit of its working thickness, a portion to be worn through by contact with the periphery of a brake disc, and spring means mounted on the back plate and arranged to place a tension on the loop of wire whereby, when the portion is worn through an adjacent end of the wire is removed radially from the periphery of the brake disc. As shown in Figs. 1 and 2, a wire spring 8 has one end located in a hole 17 in a back plate 7, has a U-portion accommodated in a hole 12, has a further U-portion straddling an edge portion 15 of the back plate, and has its other end formed into a loop 11. A loop of insulated electric wire 5 is threaded through hole 12 and a further hole 10 in such a manner that part 13 extends from the lining bearing face through hole 12 to the plain face, while part 9 issuing from hole 10 (which hole extends into a recess 18 in a brake lining 2) lies entirely on the lining bearing face and passes through loop 11 of wire spring 8. A sleeve 14 is then arranged about the two parts 9, 13 and engages loop 11 to apply flexure to the adjacent end of the spring 8. Then, when the right-angled wearable portion 6 of the electric wire loop is worn and broken by frictional contact with brake disc 1, loop 11 of spring 8 springs upwards, removing wire 5 from the vicinity of the disc 1. In Fig. 3, the electric wire 5 is located wholly at the lining-bearing face of back plate 2, and is partly embedded in a moulding 19 of synthetic resin. Hole 17 is omitted, the one end of wire spring 8 being located in hole 12. In Figs. 4, 5, a coil spring 8 located in hole 12 has a loop 11 at each end, and two sleeves 14 are located on wire 5-one adjacent each loop.