IE44687B1 - Imrovements in or relating to sole moulds for footwear - Google Patents

Description

This invention relates tc sole moulds for use in the manufacture of footwear.

According to this invention there Is provided a sole mould for moulding a sole unit on to a lasted upper on a last, comprising a first member having an open-topped cavity therein, a sealing second member made from a resilient material and sealingly clamped against a face of the first member which extends laterally from the edge of the cavity, said second member overhanging the edge of the cavity (so as to define the form of the upper surface of the sole unit where it projects laterally from tha upper) and pressing against the uppar on the last over a zone of the upper extending upward from the edge of the cavity to form a seal with the upper in said zone (even when the cavity is empty of the material' which is to form the sole unit).

The second member may incorporate portions adapted to press down on the ankle region of the last and on the fore part of the lasted upper. The inner surface of the second member above said zone is, save for the said portions thereofs in this case preferably relieved so as not to press against the upper or the last. In an alternative construction, the second member is sealingly clamped against said face of the first member by a third member which has portions thereof adapted to press down on the ankle region of the last, on the fore part of the lasted upper and on the upper surface· of the second member, and in this case the inner surface of the third member is, save for said portions thereof, preferably relieved so as not to press against the upper or the last.

The second member and, where provided, the thord member may conveniently be split along the longitudinal central plane of the mould to assist in placing the mould about the lasted Upper and in removing the finished article of footwear from the mould. - 2 44687 The invention will now be described in more detail with reference to the accompanying diagrammatic drawings in which: Figure 1 shows a mould according to the invention in longitudinal section, and Figure 2 illustrates an alternative method of using the mould shown in Figure ?.

Referring to the drawing, the shoe upper 10 is disposed on a wooden last, the cone or ankle region of which is indicated at 11. The mould in which the lasted upper on the last is placed is formed by three members 12, 13 and 14.

The first member 12 has a mould cavity 15 in its upper surface. The second mould member 13 is made in this instance from polyurethane and is arranged to form a seal with the upper surface of member 12 about the lip of the mould cavity. The member 13 clamps the upper against the last in a zone 13a along the full periphery of the upper. In the illustrated arrangement the zone extends over the full thickness of member 13. The inner edge part 16 of the member 13 overhangs the edge of the mould cavity and may be shaped to form imitation stitching or any other desired pattern on the upper surface of the outer edge portion of the sole unit.

The third member 14 rests on the second member 13, and except for a part 17 which is adapted to engage an area of the fore part of the upper the inner surface of the member 14 is relieved so as to be out of contact with the upper. Member 14 has an aperture 18 through which the top parts of the upper of a boot can project. A bridge piece 19 has its sides 20 secured to the member 14 and has a bolt 21 with a knurled head engaged in a threaded hole in the top horizontal element of the bridge. The end of the bolt presses on the cone 11 of the last. If preferred, the material of the member 14 itself may be arranged to engage the cone on the last.

The three members of the mould are clamped together and polyurethane - 3 4468? or other suitable material is injected into the mould cavity to form a sole unit moulded on to the lasted upper. The part 17 of the member 14 and the bolt 21 prevent the upper and last from being pressed upward by the pressure of the injected sole unit material.

Alternatively the last with its shoe upper 10 is assembled with members 13, 14 positioned away from member 12 as shorn in Figure 2. A suitable material such as polyurethane is then poured or cast into the cavity 15 of member 12. - When the pouring is complete the assembly of last and members 13 and 14 is positioned on member 12 as shown in Figure 1 and clamped.

If desired, the second and third members 13 and 14 may ba formed'integrally, and in either case the members are preferably split along the vertical plane containing the longitudinal centre line of the mould to facilitate the insertion of the upper and last and the removal of the finished hoot or shoe.

The second and third members may conveniently be made by being moulded about a master shoe or boot. The resilience of the polyurethane then enables the mould members to take up minor variations among the lasted uppers on their ’making’ lasts, whilst still forming a zonal seal therewith. The aperture 18 enables the member 14 to be used for boots as well as shoes.

One advantage of forming the member 14 separately from the member 13 is that uppers of differing patterns can he accommodated provided that the zones gripped by the member 13 are of substantially the same shape.

Another advantage Is that different members 13 may be provided for use with member 14 to form different patterns on the upper surface of the outer edge portion of the sole unit.

Overall, the chief advantage of the illustrated arrangement is that the use of metal lasts and metal knife edge members to form a seal with the upper about - 4 14 6 8 7 the cavity» all of which are expensive, is avoided, and the relatively inexpensive nature of the present mould members permits a greater variety of moulds to be employed than has hitherto been customary.

Claims (7)

1. A sole mould for moulding a sole unit on to a lasted upper on a last, comprising a first member having an opentopped cavity therein, a sealing second member made from a resilient material and sealingly clamped against a face of the first member which extends laterally from the edge of the cavity, said second member overhanging the edge of the cavity (so as to define the form of the upper surface of the sole uriit where it projects laterally from the upper) and pressing against the upper on the last over a zone of the upper extending upward from the edge of the cavity to form a seal with the upper in said zone (even when the cavity is empty of the material which is to form the sole unit).

2. A sole mould as claimed in claim 1, wherein the second member incorporates portions adapted to press down on the ankle region of the last and on the fore part of the lasted upper.

3. A sole mould as claimed in claim 2, wherein the inner surface of the second member above said zone is, save for the said portions thereof, relieved so as not to press against the upper or the last.

4. A sole mould as claimed in claim 1, wherein the second member is sealingly clamped against said face of the first member by a third member which has portions thereof adapted to press down on the ankle region of the last, on the fore part of the lasted upper and on . the Upper surface of the second member.

5. A sole mould as claimed in claim 4, wherein the inner surface of the third member is,save for said portions thereof, relieved so as not*to press against the upper or the last.

6. A sole mould as claimed in any one of claims 1 to 5, wherein the second member and, where provided, the third member are split along the longitudinal central plane of the mould.

7. A sole mould substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.