Patent GB-766011-A (GB)
Title: Improvements in or relating to apparatus suitable for moulding tread members on to shoes
IPC: B29D35/00
Filed: 1954-02-06
Abstract: 766,011. Shoe moulding apparatus. BRITISH UNITED SHOE MACHINERY CO., Ltd. (United Shoe Machinery Corporation). Feb. 4, 1955 [Feb. 6, 1954], No. 3550/54. Class 87(2). A shoe upper 10, on which a tread member or sole is to be moulded, is mounted on a last 12 and has margins 14 which, sewn between an insole and a rand 18, form an extension 19 round the edge which engages the surface 24 of a mould member 20 around the mould cavity 22, the surface 24 being suitably contoured, and resilient members 40, 60, 70, 99, 102 and 104 are carried by a support 30 and engage the edge 19, as the support approaches the mould, to press the edge against the surface 24 and form a seal around the mould cavity. The mould 20 rests on the lower platen of a press, (not shown), and the support 30 is attached to the upper platen. When the press is closed, and therefore the mould also, plastic material in fluid form is introduced through a passage 26 and heat is applied to the mould to cause the resin to set and adhere to the upper as a tread member. The resilient members 40, 60 engage the heel of the shoe upper and are mounted for adjustment in an arcuate path. The member 40 is attached to two struts 44, the upper ends of which are fixed to a plate 48 which is adjustably secured to a plate 32 attached to the support 30 by bolts 34 passing through spacers 36. The plate 48 has a tab 50 by which it is held to the plate 32 by a bolt 52 which also passes through the end of a finger 54. Another bolt 58 passes through the finger 54, through a slot 56 in the plate 32, and is threaded into the plate 48. The slot 56 is arcuate and thus provides for the required adjustment. The member 60 is similarly mounted in relation to an arcuate slot 64. The resilient members 70, 99 engage the waist of the shoe, on opposite sides. Struts 44 connect the member 70 to a plate 72 which is fixed to a slide plate 76 by bolts 74, 96, these bolts passing through a wide slot in the plate 32. The plate 76 is slidable in one arm of a cruciform member 80, of which the arms 84, 92 at right angles are slidable in guideways in blocks 86, 94 screwed to the plate 32. The member 70 is thus adjustable lengthwise and transversely. The member 99 is similarly mounted. The resilient members 102, 104 engage the toe of the shoe. Struts 44 connect the member 102 to a plate 110 which is attached by a bolt 106 to a finger 108, the bolt passing through a long and wide slot 112 in the plate 32. The finger 108 is also pivoted to a sliding plate 116 by a bolt 120 which passes through a slot 122 in the plate 32 and into a tab on the plate 110. The member 102 is thus adjustable rotatably and lengthwise. The member 104 is similarly mounted. Each of the resilient members comprises a block of soft material, e.g. synthetic rubber or a silicone rubber adhesively attached to a rigid L-shaped backing member. The struts 44 are long enough for the range of lasts required. Before the tread member is moulded on the upper, the insole thereof is preferably coated with a suitable fluid such as polyvinyl chloride latex, which is then dried. Examples of suitable moulding materials are (a) a dispersion of a copolymer of vinyl chloride and vinyl acetate containing 85-88 per cent vinyl choride in an equal weight of dioctyl phthalate ; (b) a dispersion of 50 parts of such a copolymer in 45 parts of dioctyl phthalate; or (c) a dispersion of 50 parts of a similar copolymer in 45 parts of an ester type plasticizer. The mould is heated from 5 to 20 minutes, a suitable temperature to cause solution and/or gelling of the resin by the plasticizer, in the solutions mentioned by 270‹-325‹C. The heating may be by means of a high frequency electric field. Specification 681,969 is referred to.