IE33963B1 - Improvements in and relating to shoe making - Google Patents

Abstract

1300931 Boots &c SHOE & ALLIED TRADES RESEARCH ASSOCIATION 29 Jan 1970 [29 Jan 1969 (2) 27 Feb 1969 31 Oct 1969 (3) 10 Dec 1969] 4864/69 5076/69 10625/69 53625/69 53628/69 53629/69 and 60291/69 Heading A3B A method of preforming a shoe upper or upper component preparatory to assembly of a shoe includes the steps of conforming a sheet or blank of stretchable and settable shoe uper material to a mould having a flattened last shape, the mould surface corresponding to the whole or part of the upper, said conforming being achieved by applying a fluid pressure differential to the material so that it stretches into conformity with the mould surface, and setting the resultant distortions in the upper material at least temporarily. Preferably the mould has a male moulding surface corresponding to the whole of the shoe upper and has a shape which is substantially that which would be arrived at by forming a shell of thin resiliently bendable material to the last shape required and partially flattening the shell by outwardly displacing the side portions. In making the mould unplasticised PVC is vacuum moulded to a last to form a shell (Fig. 33) which is trimmed along the top line 301 and feather edge 22. In a first embodiment the shell is cut at one side along line 300 and is opened out and flattened and the J-shaped mould shown in Fig. 1 is made using the flattened shell as a pattern. In a second embodiment the shell is cut down the back line 302 to form the U-shaped mould shown in Fig. 5. In a third embodiment (not shown) the shell is cut down both sides 300, 303 to form a two part mould, one part for the quarters and the other for the fore part. The shell is flattened to such an extent that the draw ratio B/A (see Fig. 23) of any protuberance (e.g. the toe, heel or vamp cone) is in excess of 1, Furthermore the distance between two points of the feather edge (e.g. points 211 and 212 in Fig. 23) measured along the mould surface must not be more than 35% greater than the distance between the two points as measured in a straight line. The moulds (see Fig. 1, 5) include surfaces 21 for forming the lasting margin, surfaces 22 for forming a seam allowance and surfaces 20 for forming a top-line folding margin. In a modification (not shown) the centre of the mould shown in Fig. 5 is filled in level with the feather edge and the top line is cut after moulding. The shape of the cut top line can be varied to form different styles of shoe e.g. oxford, gibson or casual shoes. The upper material may be poromeric material or P.V.C. and is vacuum moulded to the mould shapes shown. Leather uppers may be similarly formed but must be covered with an impervious sheet, e.g. of rubber, to permit vacuum moulding. [GB1300931A]