GB1370261A - Bonding brake blocks to brake shoes - Google Patents

Abstract

1370261 Shoes for internal drum brakes L FRIEDMAN 15 Jan 1972 2005/72 Heading F2E A device for use in clamping opposed brake blocks 112 (for large vehicles) to brake shoes prior to a heat-bonding process, in which device the brake blocks are to be confined under pressure against brake shoe tables 110 having struts 144, includes a spreader element comprising a pair of spaced parallel pressure plates 124 each having an arcuate edge to fit and bear against the inside surface of one of the brake shoe tables outside the struts 144 on the table, spaced means 126, secured to and extending between the pressure plates to space them and each having an inner surface 142 facing away from the arcuate edges to serve as a load-bearing surface, leaf-spring means 130, 134, spanning and overlying the load-bearing surfaces 142, and means 136, secured to the leaf spring means to co-operate with another such spreader element to maintain a relative position between the spreader elements when in a clamped position. As shown, an expander platform 100 has fixed expander unit 102 and movable expander unit 104, these units being notched at 106 to permit a spreader screw 108 and the tube 136 to be slid into place. The assembly is surrounded by a stainless steel band 114 overlapped and welded together at the bottom 115, and reinforced by a welded plate 116 at the top. Each of the spaced means 126, in the form of a plate, extends beyond the chordal edges of pressure plates 124 and forms a loop 132 with a U-shaped rod 128 to accommodate the leaf spring 130. On the left, tube 136 and spring-retaining plate 138 are fastened to the spring, while on the right screw 108 and a similar retaining plate are similarly secured. When hydraulic pressure is applied to a piston and cylinder unit 154, the expander unit 104, connected to the piston-rod (not shown), is forced to the right, thereby flattening the righthand springs 130, 134, and causing band 114, via the left-hand shoe table assembly, to flatten the left-hand springs against fixed expander unit 102. Then a nut 137 on spreader screw 108 is run up against the end of tube 136 to hold the parts in this position. When the assembly is placed in an oven (not shown) and the temperature is raised, the springs will retain some tension despite expansion of band 114.