The present invention relates to improved outsoles for footwear and improved methods for their production. More particularly, but not exclusively, it relates to outsoles for footwear providing improved comfort, flexibility and ease of fit.

Much development has been carried out on outsoles and the like for footwear. Outsoles are routinely produced by moulding processes (such as injection moulding, vulcanising rubber, and so forth), and have been made from a range of polymeric materials, including natural and synthetic rubbers, TPR (thermoplastic rubber), polyurethanes, PVC (polyvinyl chloride, usually plasticised), TPU (thermoplastic polyurethane), EVA (ethylene vinyl acetate) and mixtures of these materials. A wide range of high-performance outsole structures have been produced, but there are still problems which have as yet not been fully resolved.

It is common for a wearer's feet to swell up, for example having been standing or walking for long periods. Others may experience swelling once footwear has been removed, but for most people, their feet are measurably smaller on waking than they are at the end of the day. (For this reason, one should normally purchase shoes later in the day). Conventional outsoles generally extend all across an underside of footwear, and in many cases part-way up the sides. This provides excellent wear surfaces and foot protection. However, materials that are sufficiently tough, hard-wearing and mouldable for outsole use do not expand sufficiently with an expanding foot for the wearer to benefit. Uppers, particularly of leather, may well provide a small amount of "give", but conventional outsoles are substantially rigid, and tend to restrict and confine the foot, in particular providing almost no expansion across the forefoot. This can rapidly lead to foot fatigue and even pain if the footwear was not a particularly good fit to begin with.

A related issue is that most people's feet are not symmetrical; their left and right foot sizes may differ significantly, but footwear is always provided in identically-sized pairs (barring extremely expensive bespoke lasted footwear, of course). Feet change with age, tending to become longer and wider, and major weight gain or loss can affect foot size.

During pregnancy, female shoe sizes tend to change. A hormone called elastin is produced to soften ligaments around the pelvis, to assist delivery. However, the hormone also affects other ligaments and connective tissues, and the ligaments of the feet are particularly affected. This, coupled with the increase in body weight and change of centre of gravity as pregnancy progresses, leads to changes in the size and shape of the feet.

A more recently-identified problem is how one's legs and feet may react to long journeys, particularly in the case of long-haul flights. A minority may risk problems such as DVT (deep vein thrombosis) but for many more the experience of swollen legs and feet on landing is a routine but significant problem. It is very well known that children's feet grow so rapidly that new shoes must be purchased at frequent intervals. However, this situation is found to be more complex. The bones of children's feet are not just smaller than those of adults, but are developing in form, structure and rigidity. The growth plates in children's bones generally do not finish closing until the age of 15 to 17 in boys and 13 to 15 in girls, and until this point the sites of growth are not fully rigid and are potentially deformable. Because children's feet are (relatively speaking) soft and pliable, abnormal pressures over long periods may cause deformities. Tight, restricting footwear may lead to serious, possible irreversible abnormalities of the feet. It is hence important that children's footwear, whether for "first walkers", infants or young teenagers, should be able to accommodate growth without restricting the foot.

In all cases, although the behaviour of the outsole is most important, it is also important that the upper of the footwear should not be restrictive.

It is hence an object of the present invention to provide an outsole for footwear that provides improved expansibility in wear, while still supporting and protecting the wearer's foot. It is also an object of the present invention to provide a method for the production of such outsoles. A further objection of the invention is to provide an upper compatible with such expansible outsoles.

According to a first aspect of the present invention, there is provided outsole means for an item of footwear comprising an outsole body provided with at least one inset panel means comprising a flexible extensible lamina having a plurality of fibrous elements extending from a lower, in use, surface thereof and at least one ground contact body moulded or cast directly to said lower surface of the lamina. Preferably, the or each ground contact body comprises a mouldable or castable plastics material.

Preferably, the outsole means has at least one said inset panel means extending, in wear, generally beneath a forepart of the foot, optionally only one.

Advantageously, said inset panel means extends across at least half of a width of the outsole means, optionally at least two-thirds thereof.

The outsole body may define frame means extending around the or each inset panel means.

Preferably, said outsole body comprises a moulding of plastics material.

Advantageously, the outsole body comprises a resilient plastics material, optionally an elastomer.

In a first embodiment, said lamina comprises a leather material having a nap on said lower surface, such as a suede or nubuck leather.

Said leather material may alternatively comprise a natural leather or may comprise a synthetic leather material.

In a second embodiment, said lamina may comprise a sheet of a woven textile fabric. In either embodiment, the or each ground contact body may comprise a thermoplastics material.

Preferably, said thermoplastics material is substantially resilient.

Advantageously, said thermoplastics material comprises an elastomer.

The thermoplastics material may comprise natural rubber, synthetic rubber, TPR, polyurethane, plasticised PVC, EVA or mixtures thereof.

Most preferably, the thermoplastics material comprises TPU.

Preferably, the lamina is provided with a plurality of said ground contact bodies.

Advantageously, one said ground contact body extends circumferentially adjacent a margin of the lamina.

Said ground contact bodies may advantageously be linked, each to the others, by the lamina alone.

Alternatively, the ground contact bodies may be linked by relatively narrow linking elements extending across the lamina, and/or by a skin of the plastics material extending thereacross.

The lamina may be adhesively bonded to the outsole body. Additionally or alternatively, the lamina may be stitched adjacent its margin to the outsole body.

Said stitching may extend through a ground contact body thereof.

Alternatively or additionally, a margin of the lamina may be embedded within the outsole body, optionally extending laterally into the frame means thereof.

According to a second aspect of the present invention, there is provided an item of footwear comprising outsole means as described in the first aspect above.

According to a third aspect of the present invention, there is provided a method of producing outsole means for footwear, comprising the steps of providing panel means comprising a lamina of a flexible, extensible material having a plurality of fibrous elements extending from a first surface thereof and at least one ground-contact body moulded or cast directly to said first surface, providing a moulded outsole body and mounting said panel means to the outsole body.

Preferably, the or each said ground contact body comprises a mouldable or castable plastics material.

The panel means may be mounted to the outside body by stitching a margin thereof to the outsole body.

The panel means may alternatively or additionally be mounted by adhesive means. Preferably, said outsole body is formed in a moulding step around the panel means, the panel means being so disposed that a margin of the lamina becomes embedded in the outsole body.

Embodiments of the present invention will now be more particularly described by way of example and with reference to the accompanying drawings, in which:

Figure 1 is a transverse cross-section of a forepart of a first outsole embodying the present invention;

Figure 2 is a transverse cross-section of a forepart of a second outsole embodying the present invention;

Figure 3 is a transverse cross-section of a forepart of a third outsole embodying the present invention;

Figure 4 is a scrap cross-sectional view of a first upper for use with any of the outsoles shown in Figures 1, 2 or 3;

Figure 5 is an plan view from below of the first upper shown in Figure 4;

Figure 5A is a plan view from below of a second upper having an alternative construction;

Figure 6 is a plan view from below of any of the outsoles shown in Figures 1, 2 or 3; and

Figure 7 is a side elevation of the outsole shown in Figure 6.

Referring now to the Figures and to Figure 1 in particular, a first outsole 1 embodying the present invention comprises an outsole moulding 2 of a synthetic rubber composition having an aperture 10 formed in a forepart thereof (see Figure 6 for details). A lamina 3 of sueded natural leather extends completely across this aperture 10, with a fibrous surface of the suede leather aligned downwardly, in use. An array of ground contact lugs 4 is moulded to the fibrous surface of the lamina 3, together with a marginal strip 7 extending circumferentially around an outer edge of the lamina 3. In this particular embodiment, the lugs 4 and the marginal strips 7 are moulded from a rubber composition. A range of other materials may be used (see below for details). A series of very thin parallel strips 9 of outsole material extend longitudinally across the aperture 10.

The lamina 3 is bonded to the outside moulding 2 and to the strips 9 with adhesive. Security stitching 6 through the marginal strip 7, lamina 4 and outsole moulding 2 helps to secure the lamina 3 in place. Waterproof seam sealing cement is preferably applied around the stitching 6 and between the marginal strip 7 and the outsole moulding 2. (NB: the security stitching 6 may alternatively be applied when the outsole 1 is mounted to an upper, in which case it is preferably for the security stitching 6 to pass through the upper also).

The outsole moulding 2, lugs 4 and marginal strip 7 may each be moulded from alternative plastics materials (ideally elastomers). Natural rubber, TPR, polyurethanes, plasticised PVC, TPU and EVA are all believed to be highly suitable.

Note: for the purposes of this description, the terms "moulding" and "moulded" will be considered to include casting a settable composition into a mould, as well as moulding a thermoplastic composition.

The lamina 3 may alternatively comprise a nappa or nubuck leather rather than a full suede, and may comprise natural or artificial leather, as long as it has a fibrous surface to receive the moulded lugs 4 and marginal strip 7. The lamina 3 may also be made from a textile material, such as a woven synthetic textile, as long as it has at least one fibrous surface capable of receiving the moulded lugs 4 and marginal strip 7. The lamina must be flexible and capable of stretching. It is beneficial in most applications that the lamina 3 is waterproof, although there may be applications in which it is not essential. It is also beneficial if the lamina 3 is breathable, allowing water vapour to escape (and hence reducing sweat build-up within a shoe, etc). Again, this is usually considered subsidiary to the flexibility and expandability. Suede, particularly pigskin suede, appears to provide the best combination of properties of materials tested so far.

In use, the outsole moulding 2, marginal strip 7 and lugs 4 each contact a ground surface beneath the outsole 1. Expansion channels 8 defined between the lugs 4, and between the marginal strip 7 and adjacent lugs 4, allow the lamina 3 to flex, improving comfort in wear, and also allows the lamina 3 to stretch locally to accommodate the particular foot of the wearer. The expansion channels 8 are ideally at least three or four millimetres wide in the design shown; where there are more, smaller lugs 4 and hence more channels, this minimum width may be lowered. Elongate slots 5 between the strips 9 are aligned with the expansion channels 8. The strips 9 are sufficiently thin that they do not hinder the flexibility of the lamina 3, but these slots 5 obviate such a risk, and also provide a through path for water vapour to pass downwardly through a breathable lamina 3. In an alternative embodiment (not shown) the strips 9 are replaced by a thin, flexible, stretchable skin of outsole material having a series of perforations aligned with the expansion channels 8.

A second outsole 201, shown in Figure 2, is substantially similar to the first outsole 1. In this case, however, the outsole moulding 202 defines an aperture 210 under the forefoot without any strips 9 or the like extending thereacross. The lamina 3 has a plurality of lugs 4 moulded to its lower, fibrous surface, but no marginal strip 7.

The lamina 3 is adhesively bonded along its margin into a rebate 212 in an upper surface of the outsole moulding 202 adjacent the aperture 210, and then is secured with stitching 6 extending through an inner edge portion 211 of the outside moulding 202 and a margin of the lamina 3. Waterproof sealing cement is then applied along an upper, in use surface of the outsole 201 along the line of the stitching 6.

The second outsole 201 may be made from the same materials as the first outsole 1. It performs in the same manner, and provides the same benefits.

A third outsole 301 is shown in Figure 3. The lamina 3 in this case is substantially identical to that shown in Figure 2, with a plurality of lugs 4 moulded directly to its lower, fibrous surface. While the first 1 and second 201 outsoles are made from a preformed outsole moulding 2, 202 and a preformed lamina 3, the third outsole 301 comprises a preformed lamina 3 which is located in a mould, and an outsole moulding 302 is then formed around it, in this case by pouring and curing TPU in the mould. Alternatively, the outsole moulding 302 may be moulded from plastics materials, typically elastomers. Natural rubber, TPR, polyurethanes, PVC and EVA are all believed to be suitable.

A margin of the lamina 3 is thus embedded in the outsole moulding 302 of TPU, etc. Its fibrous lower surface bonds with an edge portion 311 of the outsole moulding 302, and a flap 312 of the outsole moulding 302 also extends across an upper surface of a margin of the lamina 3 (which may also be sueded for added bonding). This forms an excellent seal around - l i the margin of the lamina 3. In the example shown, security stitching 6 is used, extending through the edge portion 31 1 , the margin of the lamina 3 and the flap 312. hi some versions, the stitching 6 may not be required, as bonding between the fibrous lamina 3 and the outsole moulding 302 is sufficiently strong.

Suitable uppers 401, 501 for mounting to such outsoles 1, 201, 301 are shown in Figures 4, 5 and 5 A. This construction allows the upper 401, 501 to expand in line with expansion of the outsole 1, 201, 301. It is preferable not to use an upper that would restrict expansion. Since the particular outsoles 1, 201, 301 described have expandable laminae 3 across in their foreparts alone, the first upper 401 shown in Figures 4 and 5 is designed mainly to be expandable across its forepart, too.

The first upper 401 is stroble stitched in its forepart, while towards its heel part it may be stroble stitched or board-lasted as preferred. Where a built-up heel is required, and particularly if a supportive shank is to be used, a board-lasted heel part is probably required. The example shown in Figures 4 and 5 is fully stroble-stitched.

An inner section 409 of the stroble insole comprises a material with good stretching properties, to comply with the lamina 3 to be located in the outsole 1, 201, 301 below. Thin leather, synthetic leather or a man made textile may be suitable. A remainder 410 of the stroble insole is preferably of a textile that does not stretch appreciably, as this facilitates stitching the insole 410 to the actual upper material and lining 411. The second upper 501, shown in Figure 5 A, has a forepart 509 which is stroble-stitched to a respective upper and lining 411, and a backpart which is board lasted on to an insole board 511. Again, the forepart 509 comprises a material with good stretching properties.

The upper 401 is then force-lasted on to a last, and the outsole 1, 201, 301 is mounted thereto by conventional means to form an item of footwear.

An underside of a finished outsole 301 is shown in Figures 6 and 7 (for simplicity, this will be described in terms of the third outsole 301, but the first 1 and second 201 outsoles should appear almost identical).

The outsole moulding 302 extends beneath a wearer's heel and arch, but there is a zone beneath a forepart of the wearer's foot which is underlaid solely by the lamina 3, to which is mounted an array of moulded lugs 4 separated by expansion channels 8. Stitching 6 extends around the edge portion 311 of the outsole moulding 302 and through the embedded margin of the lamina 3.

There are hence a plurality of independently moveable lugs 4 beneath the wearer's forefoot, increasing immediate comfort while walking. Furthermore, the portions of the lamina 3 revealed by the expansion channels 8 may expand where necessary (either temporarily or permanently, depending on whether the foot within expands temporarily or permanently) to alter the fit of the footwear to comply with the current shape and size of the foot. Usually, the lamina 3 will expand with the foot in wear during the day, then recover during the night (like the foot). However, for a continually growing foot (such as a child's), the lamina 3 will gradually stretch permanently, avoiding pinching or crushing of the feet. Testing has shown that such an outsole is capable of stretching laterally by three width fittings. No other practical outsole is known that can do this.