Patent GB-817235-A (GB)
Title: Apparatus and method for finally shaping and curing brake lining blanks
IPC: B29C65/48
Filed: 1957-05-06
Abstract: 817,235. Finally shapi n g and curing brake lining blanks. HARDIE & CO. PTY Ltd., J. May 6, 1957 [May 7, 1956], No. 14336/57. Class 87(2). In a method of finally shaping and curing brake lining blanks, heated formers 15, Fig. 3, and partially cured blanks 17 are added alternately to the bottom of a stack 21, and are removed from the top of the latter at the same rate, the stack being raised between each addition of a former and a blank by a distance at least equal to the combined height of the added former and blank, and the formers 15 are returned from the top to the bottom of the stack 21, e.g. by an endless chain conveyer 119, for re-addition to the stack, and while so returning are heated, e.g. by gas flames 25, sufficiently to effect final curing of the blanks 17 while they are in the stack 21. Each former 15, Fig. 14, has cylindrical upper and lower faces 16, 18 of the required radii of curvature of the outer and inner faces, respectively, of a blank 17, an upstanding flange 92 at one edge of the face 16, and a projecting lug 50 on each side face. The stack 21 is raised intermittently by means of an anvil 29 having an arcuate upper surface conforming with the lower face 18 of a former 15, and reciprocated vertically through a hole in a platform 28, by mechanism including a main shaft 45 having keyed thereto a crank plate 43 connected by a pitman 44 to an arm 41 of a bell crank keyed to a shaft 39. The bell crank comprises also a pair of arms 38 carrying rollers 35 which raise and lower a beam 32 beneath the anvil 29 when the shaft 45 is rotated by a motor 46 through reduction gearing (not shown). The movement of the rollers 35 is such that during each rotation of the shaft 45 the anvil 29, is stationary for a period when shoulders 31 thereon rest on the platform 28. When the anvil 29 is thus paused a heated former 15 is placed thereon by a pusher plate 66 operated by a pneumatic ram 72 through a linkage 69, 68. A blank 17 is then placed on the heated former 15 by means of a cradle 84 in which a blank 15 may be placed by hand from a tray 89. The cradle 84 is fixed to two rods 85 slidable in runner tubes 82 fixed to a plate 80. The latter is slid on rails 81 towards the stack 21 linkage 78, 79 actuated by a pneumatic ram 77, and carries the cradle 84 with it until a bar 86 carried by the rods 85 engages a bumper 88 (not shown) to halt the cradle. The plate 80 continues to move and a plate 83 carried thereby pushes the blank 17 from the cradle 84 on to the heated former 15. An alternative feeding mechanism is described in which means is provided for feeding blanks to the cradle 84 at the desired rate. When the blank 17 and former 15 are in position on the anvil 29 the latter rises and lifts the stack 21 until the lugs 50 on the newly added former 15 pass the tips of hooks 51 of pawls carried by the frame in which the stack is guided. The anvil 29 then descends leaving the stack elevated by the engagement of the lugs 50 by the pawl hooks 51. The top former 15 is now entered between removal jaws 93, 94, Fig. 13. The jaw 93 is fixed to the piston rod 96 of a pneumatic ram 97 mounted on a bar 98, Fig. 8, carried by the piston rods of rams 100 mounted on a pivoted bracket 101. The jaw 94 is fixed to a tube 104 through which the piston rod 96 extends. The rod 96 is raised by the top former 15 to disengage an arm 115 carried by a counterweighted lever 112 from a microswitch 116, so that an electric circuit is completed for actuating the rams 97, 100. The jaw 93 is first moved by the ram 97 to engage one side of the former 15, and the rams 100 move the jaws 93, 94 to push the former 15 over rails 109 on to carrying prongs 117 of the conveyer 119. The ram 97 then operates to free the former 15 which is then lowered beneath the jaws 93, 94 by the conveyer 119. The rams 100 then retract the jaws 93, 94 so that a shoulder 108 of a wedge 107 fixed to the tube 104 pushes the top blank 17 from the stack 21 into a shoot 118 for disposal as required. The chain conveyer 119 is driven by a sprocket 123 intermittently rotatable by a ratchet 125 actuated by a pawl 126 carried by a lever 127. The latter is oscillated by the shaft 39 through a crank web 129 and link 128. The weight of the stack 21 may be sufficient to provide the moulding pressure, but it is preferred to apply additional pressure to the top of the stack by a loading member 146 carried by a lever 144 actuated by a pneumatic ram 138 (not shown). This additional pressure is applied only during the periods when the stack is stationary. Various safety devices are described for preventing jamming of the apparatus. It is also stated that the pneumatic rams may be replaced by mechanical linkages connected to the driving motor, and that the formers may be lowered by a gravity feed shoot.