GB1375513A - - Google Patents

Abstract

1375513 Brake shoe assemblies JURID WERKE GmbH 6 June 1973 [7 July 1972] 26953/73 Heading F2E A drum brake lining comprises an arcuate metal backing plate defining opposite concave and convex surfaces, and a friction liner secured by an adhesive layer to the convex surface, the concave surface being adapted to have a coefficient of friction at least equal to that of the convex outer surface of the friction liner. The adaptation of the concave surface may be effected by roughening it or coating it with a friction layer. In the lining shown in Fig. 1 a perforated metal backing plate 11 has had bonded to it by an adhesive layer 13 a friction liner 12 containing fibres (e.g. of asbestos) metal, metal oxides or hydroxides and thermosetting resins or rubbers, the adhesive layer 13 being cured and set in an oven. The friction layer 14 on the "shoe" side of the backing plate 11 consists of metals, metal oxides or hydroxides and abradants in comminuted form bound by rubber and/ or a phenolic resin: it is applied to the backing plate by rolling, pressing or sticking. Fig. 5 shows part of a complete shoe where holes 55 in backing plate 51 allow bonding between friction interlayer 54 and friction liner 52 (and optionally adhesive layer 43). The interlayer 54 is contained by a step 112 in the backing plate, and the backing plate is fixed to a base 57 on shoe 56 by spot welds 511 or by wedge or screw devices. In Fig. 4, the lining is secured by turning down the leading end 45 of a metal backing plate 41 into a slot 46 in brake shoe 47 and anchoring it by a wedge 48 and screws 49. Liner 42 is grooved at 421 to improve contact with the drum. Preferably, where there is a preferred direction of rotation of the brake drum, only the leading end (i.e., that end first encountered by a given point on the drum) of the backing plate is secured to the shoe body. The liner 12 may be applied to a metal backing plate previously provided with bonding layer 13, and the assembly then heated, pressed and cured. The backing plate may be steel or light metal alloy.