DISC BRAKES

1355959 Spot-type disc brakes; caliper supports; automatic adjusters AUTOMOTIVE PRODUCTS Ltd 9 Nov 1971 [23 Nov 1970 8 March 1971] 55611/70 and 47921/71 Divided out of 1355960 Heading F2E In a spot-type disc brake where application is by applying means on one part of a sliding caliper and caliper reaction, and where the caliper slides on a fixed support, the fixed support comprises an attachment portion 12, 13, Figs. 3 and 5, or 43, Figs. 8, 9, and two pairs of limbsa first pair, 14 or 44, extending across the periphery of the brake disc 16 and having their inner edges located at a greater distance radially outwardly from the disc axis than the inner edges of the second pair 15 or 46. As shown in Figs. 1, 3, 5, two sheet metal members 10, 11 each of generally U-shape, are secured, e.g. by bolts (not shown) to a fixed anchorage on a vehicle (not shown) so that limbs 14 of member 10 overlie brake disc 16, Fig. 3, while limbs 15 of member 11 extend in the opposite direction. The left-hand side of Fig. 1 shows the brake in elevation from the right-hand side of Fig. 3. Caliper 17 at the "reaction" end is provided at each side with two guide surfaces 28, 29, Fig. 1, at right angles, which engage respectively surfaces 31, 32, Fig. 5, provided on limbs 14. The caliper at the "cylinder" end is provided with two oppositely-located longitudinal ribs 22, (one only shown in Fig. 1), the under surface 23 of each rib being urged into contact with one of the limbs 15 by bolt 26, clamping plate 24 and blade spring 27 so as to permit longitudinal sliding of the caliper. These bolts and components are removed, together with the caliper, to permit pad replacement (see below). Directly-operated pad 34, Fig. 3, located between the piston (not shown) and disc 16, includes a backing plate 35, Fig. 1, whose edges 36 slide in contact with inwardly-directed surfaces of limbs 14. Reaction-operated pad 37 is secured by studs 39 to projections 21, Fig. 1, extending downwards from the end of the caliper. Brake torque on pad 34 is taken directly by support 10, 11, while that on pad 37 is transmitted thereto by the caliper 17. In Fig. 8 the fixed support for the caliper is in the form of a one-piece metal casting 41, limbs 44 (corresponding to the limbs 14 of Fig. 3) being provided with flat surfaces 49, 51 (see also Fig. 9) and limbs 46 being provided with flat surfaces 47, 48. Caliper 52 has surfaces 54, 56, co-operating respectively with support surfaces 49, 51 and surfaces 57 co-operating with support surfaces 48. Surfaces 55 on caliper 52 are urged into contact with support surfaces 47 by bolts 59, clamping plates 58 and blade springs 62, Fig. 9. Fig. 10 reverts to a brake construction including the caliper support of Figs. 1, 3, 5, but including also an automatic wear-compensating adjuster associated with mechanical applying means 71. Plunger 82, pressed down by a lever 85 mounted on a pivot (not shown) and operated by a cable or linkage (not shown), urges component 75 to the right by means of roller 83, component 75 in turn urging piston 66 to the right by means of the adjuster mechanism. Parts 72 to 79 and 81 are analogous in structure and function to the wear-compensating adjuster of Specificaton 1,240,222. Piston 66 is accommodated in cylinder 65 for fluid pressure operation.