Patent GB-277719-A (GB)
Title: Improvements in or relating to the stiffening of shoe upper parts
IPC: A43B23/08
Filed: 1926-03-22
Abstract: 277,719. British United Shoe Machinery Co., Ltd., Silvester, R. H., Bancroft, W. H., Ricks, F., Hill, M. G., and Bristow, T. H., (United Shoe Machinery Corporation). March 22, 1926. Stiffeners. - Thermoplastic toe stiffeners and the like upper stiffeners are rendered resilient either by the embodiment therein of rubber, gutta percha &c., or of a material distinct in the stiffener from the thermoplastic material. The improvements aimed at relate to the bodies of toe puffs, or to the margins, or to both. Felt or equivalent fibrous material may be dipped into a rubber suspension in water and dried. The suspension may be natural latex or a dispersion of crude or reclaimed rubber in water, as described in Specifications 217,612 and 233,370, [both in Class 70, Indiarubber &c.]. The rubber-treated fabric is dried. One or more vulcanizing agents and an accelerator are preferably incorporated in the rubber suspension. The treated fabric may be heat cured, or the rubber may be dissolved in a solvent and then cold cured. Rubber-treated fabric forms a base which may be cut into puff blanks for treatment with thermoplastic material. The rubber is only slightly attacked by the thermoplastic material owing to the short time interval. The puff is rendered flexible without cracking. In a modification, crumbed rubber, such as scrap rubber motor tyres and rubber gas tubing, are incorporated in molten colophony. Similar results are obtainable by mixing solutions of colophony and of rubber in the. same volatile solvent, removing the solvent, and adding the dried broken down material to the molten colophony. In dealing with plain vamp shoes, a suitable back margin, as described in Specifications 210,161 and 236,600, is provided by using two layers of woven cotton material, one being a highly raised twill, such as swansdown, and the other being a very thin weave only slightly raised. The slightly raised plain cloth is then cemented to the unraised side of the swansdown and the combined fabric is impregnated with thermoplastic material. The rear margin is then skived, preferably in a machine as described in Specification 14725/02. The skived blank can be treated for expulsion of impregnant as described in Specification 236,600. The treatment gives an exceedingly flexible back margin. In another modification, a thermoplastic stiffener may be edged with rubber where the margin is shielded by a stencil from impregnant. Impregnation of the puff margin may be made by dipping in a. suitable rubber suspension. The margin may be hot rolled. Celluloid or the like may be applied to a puff blank rear margin either as paste or solution and, if dry, becomes appreciably plastic when treated in a press, as described in Specification 244,507, [Class 17 (i), Boots and shoes, Apparatus for making &c.]. A puff may be formed of two layers united by rubber and may have along its back margin a narrow band of dried celluloid. The back margin may however be dipped in celluloid solution. Specifications 18174/13, 6014/15, 112,663, 114,398, 115,770; 163,909, [Class 17 (i), Boots and shoes, Apparatus for making &c.], 197,351, 210,849, 236,988, and 258,351 also are referred to.