GB961155A - Improvements in or relating to the manufacture of shoes - Google Patents

Abstract

961,155. Moulding micro-cellular rubber soles on to footwear uppers. BRITISH UNITED SHOE MACHINERY CO. Ltd. Sept. 23, 1960 [Sept. 25, 1959], No. 32590/59. Heading B5A. [Also in Division F2] In a machine for vulcanizing micro-cellular rubber soles on to footwear uppers of the construction described in Specification 922,401, valve means is provided to decompress the pressure fluid before it is withdrawn from each piston and cylinder applying pressure to a sole mould, such withdrawal being regulated to produce a controlled expansion of the mould cavity. The withdrawal of the pressure fluid may be regulated by a metering device associated with a control valve incorporating temperature compensating means for providing a substantially uniform fluid flow rate through the control valve independently of variations in the viscosity of the fluid due to temperature changes. In the fluid pressure system illustrated the pressure fluid in the cylinder 8 beneath the piston 6 carrying the sole mould support 2 is decompressed by allowing a part thereof to flow to a sump S through conduits 34, 32, 76, non-return valve V5, conduit 82, non-return valves V15, V16, and a valve V14. When the pressure beneath the piston 6 has fallen sufficiently to decompress the fluid (which may comprise oil having air absorbed therein) the valve V14 is actuated by a spring 80, against the action of the fluid pressure operating through a pilot H4, into a position to interrupt the pressure fluid supply through lines 90, 88 to the non-return valve V15 so that the latter closes to stop the flow from the cylinder 8 through the valve 14. When the valve 14 has been so actuated pressure fluid is supplied via conduit 90, valve 14 and conduits 87, 60, 62, and 64 to open non-return valves V7, V8, and to change over valve V10 to supply pressure fluid from the high pressure pump P2 to the cylinder 8 above the piston 6. The piston 6 and sole mould thus descend, the fluid beneath the piston passing into the metering device M at a rate determined by the flow of fluid from beneath the piston 44 to a sump S through the non-return valve V8 and the control valve V9. The control valve V9 incorporates a temperature compensating means for the purpose stated above, and its construction is described in detail (see Division F2). Specification 859,671 is referred to.