Patent GB-1322324-A (GB)
Title: Shoemaking
IPC: B29C33/38
Filed: 1969-06-17
Abstract: 1322324 Boots &c SHOE & ALLIED TRADES RESEARCH ASSOCIATION 17 June 1970 [17 June 1969 31 Oct 1969 10 March 1970] 30597/69 29500/70 and 11494/70 Divided out of 4864/69-Cog 1300931 Heading A3B [Also in Divisions B5 and B6] A method of preforming a patterned upper or part thereof from synthetic upper material preparatory to assembly of the shoe includes the steps of heating the material to render it stretchable, conforming the heated material to a mould having a moulding surface whose shape is substantially that which would be arrived at by forming a shell of resiliently flexible material at the last shape required and partially flattening the shell by outwardly displacing the side portions thereof, the upper material being so held during the conforming thereof that the upper material stretches in conforming to the mould, contacting the upper material with a flexible embossing member while the upper material is still on the mould and is still hot to form the pattern on the upper and cooling the upper material before removing it from the mould. Suitable synthetic upper materials are poromeric materials e.g. those consisting of a layer of microporous polyurethane which may include a base layer of non-woven fibrous material and/or a woven fabric interlayer, or synthetic plastics material such as polyvinyl chloride. In a first embodiment (Figs. 1, 2) a sheet of upper material 514 is held in a clamp 506 which is movable along rails 508 between a first position (Fig. 1) in which the sheet 514 is held between radiant heaters 510, and a second position (Fig. 2) in which the sheet 514 is held over a vacuum box 502. The box 502 contains male moulds 518 mounted on a platform 504 which can be raised by a ram (not shown). In use the heated sheet 514 is held over the box 502, the moulds 518 are raised and vacuum is applied to the box 502 to stretch the sheet 514 and conform it to the shape of the moulds 518. Flexible embossing members 522 (Fig. 2) which are mounted in a matrix 524 of metal strips in a frame 520 are then pressed against the upper material 514 by ram 526 to form the pattern on the upper. The embossing members 522 are cast from elastomeric material e.g. rubber, and have a shape corresponding to that of the mould and have a negative of the desired pattern on their inner surfaces. When it is not essential to avoid distortion of the pattern due to stretching of the embossing member, e.g. for a random pattern such as a crocodile skin pattern, the shaped embossing member 522 may be replaced with a diaphragm (not shown) which is flat in its unstressed condition and which has the desired pattern on its lower surface. The embossing member is held against the upper until it is cool and the mould 518 may be provided with cooling means e.g. fluid coolant may be circulated through the moulds. The material 514 is then removed from the apparatus and the preformed uppers are cut from the material. In a second embodiment (Figs. 17, 18) a piece of heated upper material 102 is clamped between upper and lower housings 104, 106, mould 518 is raised to stretch the material 102 and high pressure fluid is applied through conduit 118 to cause a flexible embossing diaphragm 114 to conform the upper material to the mould 518 and form the pattern on the upper. The lower chamber 106 may be vented to atmosphere at 112 or may be connected to a source of vacuum. In a modification (not shown) fluid is permanently locked within the embossing diaphragm 114 to form a sack or bag and the lower housing 106 is omitted.