Patent GB-897587-A (GB)
Title: An improved machine for moulding and vulcanising microcellular rubber or other elastomeric soles to the undersides of shoe uppers
Inventor: WEBB CHARLES ERNEST
IPC: B29C35/00
Filed: 1958-10-30
Abstract: 897,587. Moulding microcellular rubber soles on to footwear uppers. C.I.C. ENGINEERING Ltd. Oct. 30, 1958, No. 31294/60. Divided out of 895,981. Class 87(2). A machine for moulding and vulcanising a microcellular rubber or other elastomeric sole to a shoe upper has a moulding cavity formed by a last 50 and relatively movable side moulds 51 and sole mould 152, mechanical means being provided to automatically displace the sole mould 152 by a pre-arranged amount to increase slightly the volumetric capacity of the moulding cavity during the vulcanising stage of the machine cycle, while still maintaining controlled pressure on the vulcanising mass to ensure undirectional controlled expansion thereof. Figs. 1 and 2 illustrate respectively fluid circuitry and electrical circuitry of a twinhead machine in which the side moulds 51 are opened and closed by paired, horizontal fluid cylinder units 53, the fluid flow to which is controlled by a common solenoid-operated valve 54, Fig. 1, electro-magnetically controlled by a timer 55 Fig. 2. Valve 54 is also connected to two diaphragm valves 56 and thence to two vertical fluid cylinder units 57 adapted to raise and lower the sole moulds 152 which are mounted on rams 52. The valves 56 are also associated with solenoid-operated control valves 58 adapted to direct fluid via a solenoidoperated clamp control valve 59 to a pair of fluid-operated clamps 60 (referred to below). Valve 59 receives fluid direct from the pressure main, fluid at reduced pressure being supplied through a reducing valve 62 to the side mould cylinder units 53 via control valve 54 and to the sole mould cylinder units 57 via a solenoidoperated control valve 63 and diaphragm valves 56. The vulcanisation portion of the machine cycle is in three stages, the first stage being effected at high pressure and initiated by operation of a microswitch 68-1 connected to the field circuit 69 of an electric motor 70 and to the timer 55. Depression of the " start " button 67 results in energisation of solenoid 54A of valve 54 with consequent inward movement of the side moulds 51 which operate microswitches 73 and thus energise the solenoid 63A of the sole ram control valve 63 whereupon the sole mould rams 52 are raised. The rising sole rams 52 operate switches 65 to bring the timer 55 into circuit, whereupon the field circuit 69 is energized and motor 70 begins to turn disc cam 80. Cam 80 has a trip pin 79 which trips microswitch 68-1 to commence the first vulcanisation stage. When microswitch 68-2 is tripped to commence the second vulcanisation stage, the coil of self-holding relay 72 is energized and the closing of this relay results in energization of solenoid 59A of clamp control valve 59, accompanied by deenergizing of solenoid 63A of sole mould control valve 63. The resulting movement of the spool of valve 63 effects reversal in the direction of flow of the pressure fluid to bring about lowering of the sole rams. The final vulcanisation stage under full pressure is effected. when microswitch 68-3 is tripped. During the second vulcanisation stage, the disc cam 80 operates through a follower roller 81 to depress a rockable beam 83, Fig. 9, supported on compression springs 87. The beam 83 is of U-shape in plan and the two fluid-operated clamps 60 referred to above are mounted in its side limbs. During the second vulcanisation stage, tapes 89 connected to the sole ram piston rods 127 are held by the clamps 60 which are depressed by the action of cam 80. The contour of cam 80 thus determines the rate of retraction of the sole rams 52 to control the unidirectional expansion of the vulcanising mass. Specification 895,982 also is referred to.