GB2125272A - Shoe construction - Google Patents

Abstract

A through for footwear comprises a layer of nylon shaped to the outline of the foot and contoured to the last bottom.

Description

SPECIFICATION Improvements in boot construction The present invention relates to improvements in boot construction and more especially to the construction of a general purpose mountaineering and walking boot which may be constructed to Alpine standard and depending upon individual specification may be suitable for rock climbing, hill running, orienteering or cross-country skiing.

A particular problem with which this invention in one aspect is concerned is the formation of an improved sole pattern. Soles for cross-country walking and climbing are conventionally formed with a tread pattern to improve the frictional resistance against the ground. Conventional tread patterns include peripheral formations called "cleats" and internal projections called "points".

These are normally closely spaced and in practice they very quickly clog up with soil within the intervening spaces and the frictional quality of the sole is reduced to the point at which the tread becomes useless.

On the other hand certain tread patterns where the spaces are large e.g. where individual studs are provided as in football boots or golf shoes, have a very deleterious effect upon the grass land, the turf being rapidly scraped away.

Thus one aspect of the invention is directed to an improved sole for cross-country footwear which provides optimal friction properties combined with soil conservation qualities. In general the Inventors have found that the zone of greatest importance both for providing friction and for causing damage to the soil is in the area of the cleats i.e. at the periphery of the sole.

Therefore in accordance with one aspect of the invention there is provided a sole having a tread formation including peripheral cleats, in which the spacing between the edges of the cleats at the sole periphery is from 1 to 3 cm, preferably from 1.25 to 1.75 cm.

Another feature of importance resides in the actual spacing between cleats and points which are hereafter called "studs" to avoid ambiguity. In accordance with another aspect of the invention there is provided a sole having a tread formation comprising projections in the form of cleats and studs in which (measured at the outer surfaces of the projections) the mean distance of any point on the depressed area of the formation from the two closest adjacent projections is from 2.5 mm to 17.5 mm and more preferably from 3 mm to 15 mm.

Another feature of importance is the extent of the surface area in any tread portion covered by projections in the form of cleats or studs. In accordance with another aspect of the invention there is provided a sole having a tread formation comprising peripheral cleats and studs wherein (measured at the outer surfaces of the projections) the ratio of the surface areas of the projections to the surface area of the depressed area within the formation is from 1:3 to 1:1.

It will be appreciated that these aspects of the invention or any two of them may be combined in a preferred sole.

A preferred sole of the invention comprises peripheral cleats which taper inwardly from the periphery. Preferably the cleats are arranged in two rows at the inner and outer edges respectively with the cleats of the two rows arranged generally in opposed relation. The interior space is preferably filled out with studs which may be circular.

It will also be appreciated that parts of the sole may have no tread pattern in certain areas, e.g. at the toe and heel or at the instep and the above defined tread formations relate to parts of the sole which are provided with a tread pattern.

The invention in another aspect relates to the construction of the sole portion of a boot to provide comfort and flexibility. In general boots for rock climbing, and especially of Alpine standard, require extremely rigid soles which are well insulated and resistant to low temperatures. Those for more general purposes such as hill running require much more flexible soles. Thus, this aspect of the invention is directed towards providing a form of integrated sole construction which lends itself to modification according to the rigidity required and which provides adequate comfort and flexibility. The Inventors have found that the construction of the "through" which lies between the insole and the sole is of critical importance. In boots of the kind described these are conventionally formed of wood or metal to provide rigidity and strength.The Inventors have found that by using suitable polymeric material such as Nylon and in particular Nylon 66, considerable strength and controlled rigidity can be provided combined with lightness, particularly if the through is not of flat formation but is generally contoured to the foot.

Thus in accordance with another aspect of the invention there is provided a through for footwear comprising a layer of Nylon shaped to the outline of the foot and contoured to the last bottom In this specification the word "contour" is used not in the sense of outline or peripheral edge but rather to indicate the non-planar configuration of the sheet.

Various preferred forms of through in accordance with the invention comprises one or more layers of Nylon, preferably Nylon 66 and one or more layers of mouldable porous composite insole material. The preferred insole material is that sold under the Trademark "Radoma" which is described as a random structure of interlocked fibers. It is a semi-flexible material of considerable rigidity and of high strength. Used in combination with Nylon sheet material it provides a greatly improved strength and rigidity for a given thickness when compared with convention materials. The combination is amenable to the provision of a-varying grade of flexibility and most importantly, the combination is amenable to moulding to the contour of the foot or the last bottom.

The various layers of Nylon and/or insole material may be bonded together to provide a laminate using appropriate adhesives or may be moulded together in the construction of a moulded sole unit on to the insole.

One form of through in accordance with the invention may be moulded with screw threaded projections adapted to extend through the outer sole. These are preferably tubular projections which are internally threaded and the through may be sold in combination with a complementary sole having apertures to receive the projections. These screw threaded projections may be utilised for the fitting of interchangeable studs or, where studs are not used, protectors.

Another form of through in accordance with the invention has lateral extension members or wings in the area of the heel which may be, at a subsequent stage, bent upwardly to provide supports for handicapped persons in the ankle area.

Another form of through in accordance with the invention is extended in the toe region to provide a fitting for a cross-country ski binding.

According to a recent orthopedic medical survey, it was found that 75% of ankle fractures sustained in the hills are caused by boots which were too high and hard around the ankles. For hill walking or running a boot is normally too high and a shoe too low, as regards comfort and possibie damage to the ankle and in particular the Achilles tendon.

In accordance with another aspect of the invention there is provided footwear more particularly for hill walking or running in which stiffening material for the heel extends at the rear to a level substantially at the top of the heel bone, the footwear being extended upwardly by means of a gusset of relatively softer material extending forwardly along the sides of the footwear to a position approaching but short of the ankle bone.

The invention is generally inclusive of the aspects above described in any combination and also to a boot or shoe, more particularly a lightweight boot for outdoor pursuits incorporating a sole and/or a through in accordance with the invention as abovedescribed.

Embodiments of the invention are hereinafter described in accordance with the accompanying drawings, in which: Figure 1 is a perspective view of a crosscountry walking boot in accordance with the invention, Figure 2A and Figure 2B are respectively a bottom plan view of a sole in accordance with the invention and a section along the line A-B of Figure 2A, Figure 3 is a view similar to Figure 2A of the toe portion of a modified sole for cross-country skiing, Figure 4 is a longitudinal sectional view (in diagrammatic form) showing the construction of a composite through in accordance with the invention, Figure 5 is a view similar to Figure 4 of a moulded through in accordance with the invention, and Figure 6 is a longitudinal sectional view of a sole fitted to a through or layer thereof having stud receiving projections.

Figure 1 gives a general view of a cross-country boot showing the position of the through in broken lines. This through is shown optionally extended so as to project from the sole for fitting to the binding of a cross-country ski. It is a feature of the invention that throughs and soles in accordance with the invention can be constructed of sufficient flexibility combined with strength for the purpose of cross-country skiing. The sole 10 is formed with a tread pattern which extends substantially the length of the boot but the immediate heel area 11 and toe area 12 are unpatterned and at the level of the outer surfaces of peripheral cleats 13.

The tread pattern is more clearly shown in Figures 2A and 2B.

In Figure 2A it can be seen that the tread pattern is made up of peripheral cleats 1 3 which taper slightly upwardly to their outer surfaces and studs 14 which taper similarly. The studs and cleats in the forepart and instep region have outer surfaces in one plane and those in the heel region in a slightly more elevated plane. The studs 14 are circular in plan view and the cleats 13 taper generally frusto-conically from the periphery towards the interior where they terminate in a circular arc conforming generally to the radius of the studs 14. The cleats 13 are arranged in two rows at respective sides of the sole and are situated opposite one another in pairs rather than in a staggered formation.The studs 14 are generally distributed in the area centrally between the rows of cleats in three generally parallel rows, the studs of the outer rows overlapping partially the ends of the cleats. One stud 14 of the central row is situated between each opposed pair of cleats 1 3 and the studs of the outer rows are situated generally centrally between two adjacent cleats 13.

With this distribution a convenient ratio of projected area to depressed area is provided leading to good friction without leading to undue ground erosion. It will be apparent from Figure 2A that the ratio of projection area to depressed area (measured at the outside surface of the projections i.e. uppermost in Figure 2B) is within the range 1:3 to 1:1 and more generally about 1:2.

It will be appreciated that Figure 2A is not to scale. However a point P, which is chosen as representative of a point lying midway between two most closely approaching projections, is situated in this embodiment about 4 mm from the closest point on each adjacent projection measured at the outer extremity. Likewise a point Q chosen as representative of a point lying at the greatest distance from any adjacent projection, measured at the outer extremity, is in this embodiment about 12.5 mm from the two closest projections. The peripheral extremities of the cleats 13 are in this embodiment about 2 cm apart.Naturally all of these dimensions may vary somewhat from one size of boot to another, but one advantage of the pattern is that in order to move through size alterations, it is only necessary normally to enlarge or diminish the outline leaving the centre part of the pattern unchanged. This will primarily affect the distance between the cleats at the periphery, but only by a relatively small amount.

The sole may be moulded from various mouldable soling materials, e.g. rubber having a high content of natural rubber giving good friction properties and low wear characteristics, synthetic rubbers, blown or unblown with a higher carbon black content, giving long wear characteristics but reduced friction qualities, or polyurethane. In the latter case the sole may be moulded directly onto the footwear in a known manner, with varying degrees of blowing agent to control strength and flexibility.

There is shown in broken lines in Figures 2A and 2B a modification in the sole in which the forepart of the sole part as far back as the rearward broken line is formed without projections (Figure 2B). This may be useful in footwear which has more than one function e.g. for use partly in road walking or for cross-country skiing, where the footwear needs to be fitted to bindings.

Figures 4 and 5 show different forms of inner sole incorporating a through. In Figure 4 the through 20 is formed of a laminate consisting of a lower layer 21 of Nylon 66 e.g. as sold under the Trademark "Nylatron" e.g. of 2 to 3 mm thickness.

This is bonded to a layer 22 of Radoma insole material which may be of similar thickness. it will be appreciated that Figures 4 and 5 are generally diagrammatic. Preferably prior to attachment to the remainder of the inner sole parts, the laminate 20 is moulded to conform to the last bottom, so that it takes the contour of a normal foot. This may be carried out by formers under the action of heat and pressure. The Nylon layer could be directly injection moulded from moulding powder and then used alone or bonded to a layer of Radoma.

In the heel area a heel wedge 23 is cut and fitted by adhesive. It may be of a resilient material such as polyurethane foam. After the shoe welt has been fitted at 24 around the edges of the through 20 a base material 25 is secured by adhesive. This is adapted for bonding to the sole unit and may be e.g. of polyurethane or rubber or it may incorporate a further layer of Nylon for stiffness.

Figure 4 is only illustrative of one type of through. The through could consist of a single layer of Nylon 66 of 1.5 mm to e.g. 4 mm thickness, depending upon the stiffness required and for greater rigidity or stiffness a laminate of two or three individual layers of Nylon could be used with or without a further layer of composite insole material. By making the through in this way a close control is available of the rigidity of the boot. Other suitable materials for the layer 25 are E.V.A., microcellular rubber, resin rubber, polyurethane foam and leather.

Figure 5 illustrates an insole construction formed by direct moulding on the last. The lower layer 26 consists e.g. of 2 mm hard moulding compound e.g. of polyurethane foam. Over this is moulded or placed the through 20 which in the embodiment illustrated can be a substantially thick layer of Nylon 66, e.g. 5 mm thickness.

Around this is moulded in situ the portion 27 e.g.

of soft polyurethane foam which acts as the heel wedge and welt.

Naturally other forms of through in accordance with the invention could be substituted as already described.

Figure 6 illustrates a form of sole to which can be attached Nylon or steel crampon fixing plates or alternatively interchangeable studs or protectors. A through 20 of Nylon is moulded with a pattern of tubular projections 28 which have screw threaded bores 29. Naturally the through 20 could have further layers of Nylon or composite insole material such as Radoma overlying it as in Figure 4. The tubular projections 28 are adapted to extend through the outer sole 30 which is suitable bored or punched to receive the projections before being secured in place.

Studs or crampon fixing plates of suitable form provided with matching screw threads may be simply screwed in place where desired. Where no such attachments are fitted, the bore is preferably filled by means of a grub screw to prevent ingress of soil.

The boot itself may be constructed generally conventionally. However a novel feature is provided at the heel. In order to provide added flexibility in the region of the achilles tendon, stiffening material 40 at the rear of the foot, extends to a level 41 substantially at the top of the ankle bone, the footwear being extended above this level by means of a gusset 42 of relatively softer material, e.g. soft leather with an internal foam padding. The gusset, as shown in Figure 1, extends forwardly along the sides of the footwear to a level 43 approaching but short of the ankle bone.

In general the footwear of Figure 1 features a soft ankle area, and a wide tongue area for easy removal. The outer material is of soft leather having abrasion resistant and good bonding properties. Lining materials allow perspiration to pass through away from the foot. Internal strength can be provided by thermoplastic toe puffs and board heel stiffeners. Insoles of Radoma or leather-bound cork can be used.

Two one-piece uppers with tongue gussets are preferably used, so that the outer materials require to be soft in order to fold the forepart correctly for maximum comfort and prevent material breakdown. Closure is generally achieved with D rings and hooks with, as shown, the third closure 44 positioned further towards the heel to give a tight fit on the long heel measure. This aids in the reduction of frost bite danger. Additional thermal interlinings can be incorporated. Rubber toe puffs and heel stiffeners can be provided externally. A padded ankle cuff 45 may be provided.

For higher altitude conditions, a padded ankle cuff may be combined with a one-piece vamp, tongue and seat and lined with (Trademark) Damart fleece. Closed or open-cell foam can be incorporated together with space blanket interlinings.

Forspecialised hill running applications a fivepiece upper may be used with added padded ankle cuff and a full gusset tongue. A rubber rand may be used to enclbse the boot covering the feather edge to a height of e.g. 2 cm with contoured sections protecting the toe and heel areas. Closure may be with eyelets.

Claims (18)

1. A through for footwear comprising a layer of nylon shaped to the outline of the foot and contoured to the last bottom.

2. A through as claimed in claim 1 comprising one or more layers of nylon and one or more layers of mouldable porous composite insole material.

3. A through as claimed in claim 2 in which the insole is a random structure of interlocked fibers.

4. A through as claimed in claim 2 or claim 3 in which the various layers are bonded together as a laminate.

5. A through as claimed in any preceding claim which includes lateral extension members in the area of the heel adapted to be bent upwardly to provide supports for handicapped persons in the ankle area.

6. A through as claimed in any of claims 1 to 4 which is extended in the toe region to provide a fitting for a cross-country ski binding.

7. A through as claimed in any of claims 1 to 5 which is moulded with screwthreaded projections adapted to extend through an outer sole.

8. An insole unit comprising a through according to any preceding claim bonded to a base layer and a heel wedge.

9. An insole unit as claimed in claim 8 comprising a through as claimed in claim 2 or claim 3 in which the various components are moulded together to unite them.

10. An insole unit substantially as described herein with reference to Figure 4 or Figure 5 of the accompanying drawings.

1 A boot which is manufactured utilising a through as claimed in any of claims 1 to 7 or an insole unit as claimed in any of claims 8 to 10.

12. A boot as claimed in claim 11 which includes a sole having a tread formation including peripheral cleats, in which the spacing between the edges of the cleats at the sole periphery is from 1 to 3 cm.

13. A boot as claimed in claim 11 or claim 12 in which the sole has a tread formation comprising projections in the form of cleats and studs in which (measured at the outer surfaces of the projections) the mean distance of any point on the depressed area of the formation from the two closest adjacent projections is from 2.5 mm to 17.5 mm.

14. A boot as claimed in any of claims 11 to 13 in which the sole has a tread formation comprising peripheral cleats and studs wherein (measured at the outer surfaces of the projections) the ratio of the surface areas of the projections to the surface area of the depressed area within the formation is from 1:3 to 1:1.

1 5. A boot as claimed in any of claims 11 to 14 in which the sole comprises peripheral cleats which taper inwardly from the periphery.

16. A boot as claimed in claim 15 in which the cleats are arranged in two rows at the inner and outer edges respectively with the cleats of the two rows arranged generally in opposite relation.

17. A boot as claimed in claim 12 or any of claims 13 to 1 6 as dependent thereon in which the interior space is filled out with studs.

18. A boot substantially as described herein with reference to the accompanying drawings.

1 9. A sole for footwear having a tread formation including peripheral cleats, in which the spacing between the edges of the cleats at the sole periphery is from 1 to 3 cm.