GB190424778A - Improvements relating to the Vulcanisation of Rubber Soles to Boots and Shoes - Google Patents

Abstract

24,778. Butterfield, G. F. Nov. 15. Moulding boots and shoes.-Relates to a shoe-holding apparatus for use between the platens of a shoe-sole vulcanizing press, the object being to make the solemould and the last removable together from the apparatus so that they can be left to cool slowly while duplicates are introduced into the press. The top and bottom plates 13, 14 of the apparatus are adjustably bolted to the platens 10, 11 respectively of the press, the lower platen, which is formed hollow to receive live steam, being capable of a slight vertical movement with its shaft. The mould 15, cast in soft metal which expands on cooling, has a sole and heel shaped recess in which is placed the unvulcanized or partially vulcanized rubber 16. The shoe is mounted on a metal last 18 having a broad flanged top portion 19, and the mould and last are connected together by adjustable and detachable hook-shaped links 33 which can be tightened by means of thumb-screws 37, Fig. 3. The two are then placed in the press by sliding the upper portion 19 of the last into grooved ways formed in a casting 20, which is cast with, or secured to, the plate 13, the proper positioning of the last and mould being effected by the engagement of projections 38 on the plate 14 with tapered recesses in the bottom of the mould. Pressure is then applied to the last so as to force the shoe on to the uncured surface of the rubber, while, in addition, the forward ends of four adjustable clamps 21 carried by the plate 14 enter between the upper and welt and assist in holding the shoe in position and also in keeping the rubber 16 confined within the mould. The downward pressure on the clamps is applied through extensible braces, each of which comprises a hinged tubular portion 28, fitted with a spring 32, and two rods 29 reversely threaded and joined by a right and left handed nut 30, the rods being held in place and kept from rotating by a pin-and-slot connection 31. Each of the clamps 21, which are stayed by guides, has at its extreme tip a slight downward extension, as shown in Fig. 5, so that the rubber can cover the top and outer edge of the welt. In addition, each of them has a depending foot 26 to keep it from dropping down when the mould and last are withdrawn. These depending feet are sometimes fitted with a button 27 of non-conducting material. Fillings 39 of non-conducting material are also fitted into the plate 14 to lessen the liability of injury to the upper of the shoe by the radiation of heat from the platen 11.