GB1207327A - Disc brakes and friction pad assemblies therefor - Google Patents

Abstract

1,207,327. Disc brake pad assemblies; disc brakes. R. L. MOSSINO, and H. E. AINE. 10 Oct., 1967, No. 43810/67. Heading F2E. In a friction pad assembly for a disc brake, a friction pad assembly 17 including a friction member 21 is supported wholly spaced apart from a base-plate 18 by rigid interconnecting spacer means 26, 27 to define an air space 19 through which atmospheric air can freely flow without the necessity of a pump or compressor when the brake disc in in rotation so as to air cool the friction member. Pad assemblies.-Fig. 4 shows one end of a pad 21, backing plate 22 and base-plate 18 secured together by a rivet 33 and spaced apart by pedestals 26, 27. The backing plate 22 may be of stainless steel and may be bonded during sintering to a metallic pad 21. Alternatively, the pad 21 may be of organic or ceramic material. The pedestals 26, 27 may be welded to the base-plate 18 in triangular arrays (Fig. 3, not shown), and may have projections (42, 46, Figs. 5 and 6, not shown) for projection welding. In alternative pad assemblies (Figs. 7 and 8, not shown), the pad assembly 17 and base-plate 18 are separated by a rectangular frame (47) having holes (48) to vent the pad or by bars (49) at the ends of the pad. In an alternative pad assembly (Fig. 9, not shown), the pedestals 26 (54) are welded to the base-plate 18 and the inner pedestals (54) are also welded to the backing plate 22. In further pad assemblies (Figs. 10 and 11, not shown), the pedetals are welded to the base-plate 18 and the pedestals may have projections (57) which engage in slots (58) in the backing plate 22 or may fit into socket connectors (59) secured as by welding to the backing plate 22. The pad assembly 17 may include spots (52, Fig. 12, not shown) of pad material bonded to the backing plate 22 or alternatively can be constructed in the form of a ring for use in aircraft or heavy duty machinery. The pad assemblies may be used in automobiles. Disc brake construction.-The pad assemblies 14 (Fig. 2) are maintained in light contact with the brake disc 13 by springs 81 and are actuated by pistons 16. Hydraulic fluid from a master cylinder is fed to the brake cylinders 69 via an inlet 72. Rubber boots 78 connected to the pistons 16 serve to retract the pistons after braking is terminated and prevents entry of foreign matter. The pad assemblies 14 are held in by pins 63 and may move circumferentially to engage the sides 87 or 88 depending on the direction of rotation of the disc. To avoid shear forces arising between the base-plate 18 and the pad assembly 17, the end 91 of the pad assembly 17 is arranged to project further or the same as the end 89 of the base-plate 18. Alternatively, a projection may be provided at the sides 87, 88 to engage the ends 91 of the pad assembly 17. Cooling.-Although air enters the housing 61 carried by the rotating disc 11 preferably passageways are provided for the entry of air. Air enters the brake casing 61 at a top opening (92, Fig. 1, not shown), and from an opening at the bottom. --The pedestals and supports for spacing the pad assembly 17 from the base-plate 18 provide a turbulent flow of air. The vane structure 11 of the disc may enhance the flow of air through the pad assemblies.