GB2131277A

GB2131277A - Inner sole for footwear

Info

Publication number: GB2131277A
Application number: GB08314472A
Authority: GB
Inventors: Tanzi Giancarlo
Original assignee: ASOLO SPORT Sas
Current assignee: ASOLO SPORT Sas
Priority date: 1982-12-09
Filing date: 1983-05-25
Publication date: 1984-06-20
Also published as: EP0111256B1; EP0111256A1; GB8314472D0; DE3376289D1; IT8259342V0

Description

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SPECIFICATION Inner sole for footwear

5 This invention relates to an inner sole suitable for a wide range of footwear types.

An object of the present invention is provision of an accurately shaped inner sole which will maintain its shape for a considerable period of time and is 10 also simple to secure into an appropriate item of footwear. The shape of the inner sole is, of course, all-important in determining the fit of an item of footwear and its orthopaedic and functional characteristics. Ease of assembly of footwear items is 15 obviously important to footwear manufacturers as regards the cost of production of same.

With this object in view, the present invention provides an inner sole which is pre-formed in a mould by a method of synthetic resin injection and 20 has areas of differing thickness and pliability depending on the foot region to be supported and the type of footwearto which the inner sole is intended to be applied.

The invention will be described further, by way of 25 example, with reference to the accompanying drawing, in which:

Figure 1 is a perspective view showing the upper surface of a preferred embodiment of the inner sole of the invention;

30 Figure 2 is a perspective view showing the underside of the same inner sole; and

Figure 3 is a cross-section along the line Ill-Ill shown in Figure 1.

A preferred embodiment of the inner sole 1 of the 35 invention, as illustrated in the drawing, is preformed in a mould by a method of synthetic resin injection. This method ensures production of durable inner soles of consistant accurate shape. Moreover the shape of each inner sole is maintained 40 for a long period of time. The shape of the inner sole 1 is particularly important for the fit of the item of footwear, whether boot or shoe, and the orthopaedic and functional characteristics of the boot or shoe also depend on the shape of the inner sole 1. 45 A suitable material for the inner sole 1 has been found to be thermoplastic nylon No. 6, but, of course, other materials may be equally suitable. The overall shape of the inner sole 1 includes predetermined areas of differing thickness so as to guarantee 50 differing degrees of pliability in different areas according to the foot region to be supported and the type of footwear-for example, walking shoes, sports shoes and orthopaedic shoes require inner soles of different degrees of pliability.

55 In the region of the sole, the inner sole 1 is thicker in the central area and at the extreme edge, while a peripheral band of diminished thickness in the form of a groove 2 in the upper surface is provided. This groove 2 is intended to receive stitches (not shown) 60 which will secure the inner sole 1 in an appropriate item of footwear. The material of the stitches will lie in the groove 2 and will not protrude above the level of the upper surface of the inner sole 1 so that no discomfort is likely to be caused to a wearer's foot. 65 Although it is faster and easier to glue inner soles into position in items of footwear rather than to stitch same in position, it is preferable to secure same by stitching as this leads to a much more durable product. Accordingly, provision of a special peripheral band of diminished thickness (such as the groove 2) for reception of stitches facilitates production of good quality, long-lasting items of footwear. Moreover, the thin peripheral band guides the stitching needle and facilitates piercing of the inner sole 1 by the needle.

As mentioned, it is possible, within certain limits, to vary the pliability of differing areas of the inner sole 1 by varying the thickness thereof, taking into account the elasticity ofthe chosen inner sole material. However, in certain types of footwear, it is not possible to provide the required pliability and durability in this way, particularly in the arch area which has to undergo most stress. To this end, in the illustrated embodiment of inner sole 1 an elongate steel leaf spring 3 of appropriate thickness and springiness is accommodated in a slot 6 in the underside ofthe inner sole 1. This slot 6 extends between the region ofthe heel and the arch area of the inner sole 1. The spring 3 is attached in the slot 6 at each end by means of rivets 4, 5 extending through the inner sole 1 and the spring 3. This inner sole 1 is substantially rigid and is suitable for certain types of footwear such as skating boots, cycling shoes etc., in which the sole ofthe boot or shoe itself is relatively stiff. In other words provision of a spring 6 makes the inner sole 1 sturdier and also more resilient.

The invention is not, of course, limited to the details ofthe above-described embodiment and many variations are possible. For example, the peripheral band of diminished thickness may in some case be formed by a groove on the underside instead ofthe upper surface ofthe inner sole. Also the spring may be attached in the slot only at the end disposed in the heel region, the free end in the arch region being capable of sliding slightly within the slot, thereby endowing the inner sole with a particular springiness required in certain shoes and boots. In other embodiments for other types of footwear, of course, the presence of a slot and/or a spring is not essential.

Claims

1. An inner sole which is pre-formed in a mould by a method of synthetic resin injection and has areas of differing thickness and pliability depending on the foot region to be supported and the type of footwear to which the inner sole is intended to be applied.

2. An inner sole as claimed in claim 1 having, at least in the region ofthe sole, a peripheral band of diminished thickness which is intended to receive stitches to hold the inner sole in position in an appropriate item of footwear.

3. An inner sole as claimed in claim 2 wherein the peripheral band is in the form of a groove in the upper surface ofthe inner sole so that the material of the stitches does not protrude above the level of said upper surface, thereby avoiding discomfort to a

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wearer's foot.

4. An inner sole as claimed in claim 1,2 or 3 wherein an elongate leaf spring is accommodated in a slot provided in the underside ofthe inner sole.

5 5. An inner sole as claimed in any preceding claim wherein one end of an elongate leaf spring is attached to the underside of the inner sole in the region ofthe heel so as to allow some sliding ofthe free end ofthe spring towards the region ofthe sole. 10

6. An inner sole as claimed in claim 4 wherein the leaf spring is attached in the slot at both ends and thereby enhances the sturdiness ofthe inner sole.

7. An inner sole substantially as hereinbefore 15 described with reference to and as illustrated in the accompanying drawing.

Printed for Her Majesty's Stationery Office, by Croydon Printing Company Limited, Croydon, Surrey, 1964.

Published by The Patent Office, 25 Southampton Buildings, London, WC2A1 AY, from which copies may be obtained.