Patent GB-1258966-A (GB)
IPC: B29D35/00
Filed: 1967-12-14
Abstract: 1,258,966. Boots &c. BRITISH UNITED SHOE MACHINERY CO. Ltd. 14 March, 1969 [14 Dec., 1967], No. 13506/69. Heading A3B. [Also in Divisions B3 and B5] A mould assembly including, Fig. 3, a recess in the form of a shoe bottom unit defined by a bottom member 10 bounded by a continuous upstanding peripheral wall 12, having an upper surface of the contour of the welt of a shoe, is made from a mould assembly, Fig. 1, comprising a base plate 2 on which is secured a mould member 10a defining the wear surface of the shoe bottom unit, the side surface whereof is defined by inwardly facing surfaces 13a of side mould members 6a, 8a when these are displaced over the base plate into a closed position in abutment with the member 10a. In one embodiment, Fig. 1 and 2, welt plates 7, 9 are removed from the side mould members 6a, 8a which are then welded together along the parting lines of the inwardly facing surfaces 13a thereof and cut, along a line A, at a distance from the surfaces 13a corresponding to the thickness of the upstanding peripheral wall 12, the welt plates 7, 9 then being resecured to the members 6a, 8a which then function as carrier members 6, 8 therefore in the use of the mould assembly. Four series of spaced bores 28 the axes of which intersect a line inclined to the base plate 2, are then provided through the peripheral wall member 12 on each side and at front and rear portions thereof and four series of similarly spaced bores 29, Fig. 4, but in a line parallel to the base plate 2, are then provided in bottom member 10 at similar locations to the bores 28, so that each bore 29 of a series thereof is alignable with a different bore 28 of the corresponding series at different heights of the member 10 within member 12, which member 10 may be secured by pins 30, in the bores 29, 28' to mould varying thickness of shoe bottom unit. In the use of this embodiment the welt plates 7, 8, are closed upon a flat lasted shoe upper assembly mounted on a foot form onto which a shoe bottom unit is then moulded by injection. In an alternative embodiment, Fig. 6, after similarly welding together the side mould members (56a, 58a), Fig. 5 (not shown), these are cut and the welt plates similarly cut to define carrier members 56, 58 carrying welt plate portions 57, 59 which extend around the forepart of the shoe unit mould as far as a breast region of the heel corresponding to a region 62 of the continuous upstanding peripheral wall of uniform thickness, the remainder 78 of the continuous wall being thicker to define a mould part 78 to which a remaining welt plate portion 80 is non displaceably secured, the thickness of the centre portion of plate 80 being reduced so that it extends inwardly of the inner surface of part 78 by a smaller distance than that of portions 57, 59 to produce a narrower welt margin at the rear than at the front of a moulded shoe bottom unit. In the use of this embodiment the backpart of the lasted assembly is positioned against the welt plate portion 80 in a top-closing sealing engagement and the welt plate portions 57, 59 are then closed upon the lasted assembly, whereafter molten polyvinyl chloride is injected into the mould.