TECHNICAL FIELD

This description relates to sport shoes having interchangeable inserts to adjust the height of a portion of the sole. BACKGROUND

Specialist shoes are used in many sports to help improve performance. In particular, sports which require a swinging or throwing action require the person taking the swing to have an optimum biomechanical posture, and specialist sports shoes can be used to adjust and correct biomechanical deficiencies of the user. A typical sports shoe is comprised of several parts. The shoe upper is the body of the shoe. This can be made from a variety of materials including but not limited to: synthetic mesh, nubuck, leather, suede or combinations thereof. The shoe can be made waterproof by adding a coating to the exterior of the shoe or the addition of a lining material such as Gore-Tex® or polyester. The exact construction of the shoe depends on its intended purpose. In an example, a sports shoe intended to be used for golf may have an upper made primarily from leather, with or without a waterproof lining. A shoe intended to be used for cricket may be made primarily from synthetic materials.

The sole of the shoe is the base portion of the shoe. This can be made of a variety of materials including but not limited to: carbon rubber, blown rubber or leather. The sole may include grooves which increase the flexibility of the sole. Spikes, cleats, studs or other traction-enhancing devices can be used in order to reduce slipping and provide anchoring for the foot.

A sports shoe may in addition comprise a midsole. The midsole is a layer of shock absorbing material between the sole and the upper. The construction of the midsole can include elements directed toward cushioning the foot, constructed of materials such as EVA or polyurethane. In addition the midsole may comprise additional structural elements designed to stabilize the foot, for example to reduce over-pronation. It is difficult to tailor the biomechanical characteristics of a sports shoe specifically to an individual user, due to the mass produced nature of the shoes. This can be done to an extent through the use of insoles inserted within the interior of the shoe, for example as described in JP9028401 , US5212894, and US4682425.

However, the insertion of insoles change the fit of shoe, requiring a broader shoe upper than would otherwise be necessary. The expansion range of the upper limits range of adjustment that can be achieved with an insole combined with a mass-produced shoe. The use of insoles can therefore cause discomfort due to excessive tightness over some or all of the foot. Furthermore, a particular insole will only fit a particular size of shoe, requiring the insoles to be produced in many different sizes. In addition, the padding material that insoles are made from also tends to compress over time, making them less effective relatively quickly once they are used. Therefore, a shoe comprising an insole cannot be easily adjusted for a variety of users.

SUMMARY

According to one aspect of the invention, there is provided a sports shoe, comprising: a sole; an insert removably attached to an external underside portion of the sole, such that, in use, the height of the underside portion of the sole above a supporting surface is dependent on the thickness of the insert; and at least one traction-enhancing projection mounted on the insert.

Because the height of the underside portion of the sole is dependent on the thickness of the insert, and the insert is removably attached, the insert can be interchanged for one having a thickness that sets the height of the underside portion of the sole (and hence the length of the leg of the user when wearing the shoe) to a preferred position.

In an embodiment, the traction-enhancing projection is removably mounted on the insert. A portion of the at least one traction-enhancing projection may be arranged to pass through an aperture in the insert and affix to the external underside portion of the sole, such that the traction-enhancing projection secures the insert to the external underside portion of the sole.

Because the insert is secured using the traction-enhancing projection, the insert can be manufactured in a simple and cost effective way that does not require complex molding. This enables a large variety of inserts to be produced in varying thicknesses, without increasing manufacturing complexity. In an embodiment, the portion of the at least one traction-enhancing projection is a threaded portion, and the at least one traction-enhancing projection is arranged to affix to the external underside portion of the sole by screwing into a threaded hole in the external underside portion of the sole. In an embodiment, the aperture in the insert comprises a complementary thread to the threaded portion. The complementary thread in the aperture results in a continuous threaded hole being formed from the opening of the aperture, through the insert, and into the underside portion of the sole. This reduces the strain on the threaded portion of the traction-enhancing projection and increases the fixing strength of the insert.

The aperture in the insert may have an annular toothed portion arranged to increase rotational friction on the traction-enhancing projection when affixed to the external underside portion of the sole. The annular toothed portion bites into the traction-enhancing projection, thereby ensuring that the traction-enhancing projection does not work loose, and hence loosen the insert.

In an embodiment, the insert is arranged to be secured to the external underside portion of the sole using a releasable clip. In another embodiment, the insert comprises a keyed protrusion and is arranged to be secured to the external underside portion of the sole by sliding the keyed protrusion into a correspondingly keyed slot in the external underside portion of the sole. The insert may comprise a threaded aperture into which the at least one traction-enhancing projection is screwed.

The traction-enhancing projection may comprise at least one of: a spike; a stud; and a cleat. The external underside portion of the sole may comprise at least one of: an external underside heel portion of the sole; an external underside toe portion of the sole; and an external underside ball portion of the sole. The external underside portion of the sole may comprise substantially the whole underside surface of the sole.

In an embodiment, the external underside portion of the sole and the insert have complementary chamfered edges such that the insert can be positioned accurately with respect to the sole. The chamfered edges increase the ease of insertion of the insert into the underside portion of the sole and the accuracy of alignment. In an embodiment, the external underside portion of the sole comprises at least one aperture and the insert comprises at least one complementary member arranged to mate with the at least one aperture. The mating aperture and member reduce twisting of the insert when the shoe is in use, and hence increase stability.

According to another aspect of the invention, there is provided a kit of parts, comprising: a sports shoe having a sole; and a plurality of inserts, each having a different thickness and arranged to be removably attachable to an external underside portion of the sole, such that, in use, the height of the underside portion of the sole above a supporting surface is dependent on the thickness of a selected attached insert.

In an embodiment, the kit of parts further comprises a plurality of traction- enhancing projections arranged to be removably attachable to the plurality of inserts. In an embodiment, each of the traction-enhancing projections comprises a threaded portion arranged to pass through an aperture in the insert and screw into the external underside portion of the sole, such that the traction-enhancing projection secures the insert to the external underside portion of the sole, and different ones of the a plurality of traction-enhancing projections have different lengths corresponding to the different thicknesses of the inserts.

By providing a plurality of traction-enhancing projections having different lengths, an appropriate length can be selected for use with an insert of a given thickness. This ensures that the traction-enhancing projections screws sufficiently deeply into the underside portion of the sole to provide sufficient fixing strength. In an embodiment, each of the traction-enhancing projections having a threaded portion of a given length are colour coded to match the colour of the inserts having a thickness corresponding to the given length. This ensures that the correct length of traction-enhancing projections can be readily and rapidly matched to a given insert. According to another aspect of the invention, there is provided a sports shoe substantially as described herein with reference to, and as shown in, the accompanying drawings. According to another aspect of the invention, there is provided an insert for adjusting the sole height of a sports shoe substantially as described herein with reference to, and as shown in, the accompanying drawings.

Many of the attendant features will be more readily appreciated as the same becomes better understood by reference to the following detailed description considered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present description will be better understood from the following detailed description read in light of the accompanying drawings, wherein: Fig. 1 illustrates an exploded view of the underside of an example sports shoe having interchangeable inserts;

Fig. 2 illustrates the underside of an example heel insert;

Fig. 3 illustrates a top-down view of the example heel insert;

Fig. 4 illustrates the underside of an assembled example sports shoe; Fig. 5 illustrates a series of heel inserts of varying thickness;

Fig. 6 illustrates the effect of different heel insert thicknesses in use;

FIG. 7 illustrates an insert secured to the sole using traction-enhancing projections;

Fig. 8 illustrates an insert is secured to the sole using a keyed protrusion; Fig. 9 illustrates an insert is secured to the sole using a clip; and

Fig. 10 illustrates a kit of parts.

Like reference numerals are used to designate like parts in the accompanying drawings.

DETAILED DESCRIPTION The detailed description provided below in connection with the appended drawings is intended as a description of the present examples and is not intended to represent the only forms in which the present example may be constructed or utilised. The description sets forth the functions of the example and the sequence of steps for constructing and operating the example. However, the same or equivalent functions and sequences may be accomplished by different examples. Although the present examples are described and illustrated herein using the example of a golf shoe, this is provided as an example and not a limitation. As those skilled in the art will appreciate, the present examples are suitable for application in a variety of different types of sports shoes.

For example, it will be readily understood that this is merely an illustrative application of the bio-mechanical correction technique, and the technique could also be used with sports shoes for different sports. This includes, but is not limited to, swing-based sports such as golf, cricket and baseball, throwing-based sports such as bowls and field athletics, or any other sport requiring rotation of the spine.

In the example described below, the shoe is a golf shoe which corrects biomechanical deficiencies of the user during a golf swing by adjusting the height of a selected portion of each foot separately. As an example of a biomechanical deficiency, a large proportion of people have a leg length discrepancy, so that one leg is slightly longer than the other. This discrepancy prevents the user's spine rotating cleanly around an axis during a swing, which increases the risk of injury and prevents an ideal swing being attained. The sports shoe described hereinafter is adjustable so that the leg length discrepancy correction can be provided for a variety of different users. Each foot, and separate portions of each foot, can be adjusted separately.

Reference is first made to FIG. 1 , which illustrates an exploded view of the underside of a sports shoe having interchangeable inserts. The sports shoe comprises an upper 100 and a sole 102. The upper 100 is similar to known sports shoe uppers. The sole 102 of the shoe can be constructed of rubber, leather or any other appropriate material. The sole 102 comprises a first external underside portion 104 that forms a shallow cavity in the sole 102. In this example, the first external underside portion 104 is located in the heel region of the sole 102. The example of FIG. 1 also shows a second external underside portion 106 forming a shallow cavity in the ball region (i.e. in the area beneath the ball of the foot of the user when worn), and a third external underside portion 108 forming a shallow cavity in the toe region of the sole 102. Note that, in other examples, only one, two or more than three external underside cavities can be formed in the sole 102. In addition, these can be located at different positions on the sole 102 to that illustrated in FIG. 1 . For example, an alternative sports shoe can have only a heel cavity, only a toe cavity, only a ball cavity, or any combination thereof. In a further example, a cavity can be formed covering substantially the whole of the external underside of the sole 102.

An insert is arranged to fit into each of the external underside portions of the sole 102. For example, FIG. 1 illustrates a first insert 1 10 (a heel insert in this example) arranged to fit into the first external underside portion 104, a second insert 1 12 (in this case a ball insert) arranged to fit into the second external underside portion 106, and a third insert 1 14 (in this case a toe insert) arranged to fit into the third external underside portion 108. The inserts are arranged to be removably attachable to the sole 102. In other words, the inserts can be repeatedly removed and replaced by the end-user. Optionally, the edges of the cavities at each of the external underside portions (104, 106, 108) of the sole 102 and the edges of the respective inserts (1 10, 1 12, 1 14) are chamfered. The chamfered edges aid the insertion of the inserts into the cavities, as the user does not need to align them as precisely as would otherwise be required. In addition, the chamfered edges guide the inserts into an accurate alignment with the cavities.

Each of the inserts (1 10, 1 12, 1 14) has one or more traction-enhancing

projections 1 16 mounted thereon. These can be removable traction-enhancing projections 1 16 as shown in FIG. 1 , or, alternatively, integrally formed with the inserts. The traction-enhancing projections 1 16 can be in the form of spikes (such as the golf spikes shown in FIG. 1 ), cleats or studs, for example. In the example shoe of FIG. 1 , the traction-enhancing projections 1 16 comprise a threaded portion 1 18 that passes through an aperture 120 in the inserts and screws into a corresponding threaded hole 122 in the external underside portion of the sole 102. However, in other examples, other methods of attachment can be used, as outlined hereinafter.

Reference is now made to FIG. 2, which illustrates an underside view of the heel insert 1 10 shown in FIG. 1. The heel insert 1 10 is merely an example, and other inserts can comprise similar features. The view in FIG. 2 is from the toe-end of the shoe. The insert 1 10 comprises the aperture 120, into which the traction- enhancing projection 1 16 is inserted. In some examples, the aperture 120 can be in the form of a straight hole, or in alternative examples the aperture 120 can be threaded. If the aperture 120 is threaded, then, when inserted into the cavity, a continuous threaded is formed by the aperture 120 and the threaded hole 122. This enables the traction-enhancing projection 1 16 to be screwed through the insert aperture 120 and into the threaded hole 122. This reduces the strain on the threaded portion of the traction-enhancing projection.

Optionally, the insert 1 10 comprises an annular toothed portion 200 located at the rim of the aperture 120. The annular toothed portion 200 engages with the traction-enhancing projection 1 16 when it is screwed tightly against the insert and increases rotational friction. In other words, the annular toothed portion 200 bites into the traction-enhancing projection 1 16, thereby ensuring that the traction- enhancing projection does not work loose, and consequently allow the insert 1 10 to become loose. FIG. 2 also shows the insert comprising one or more integral traction-enhancing elements 202, such as integrally molded spikes or treads, but these are optional. In addition, FIG. 2 shows the chamfered edges 204 of the insert 1 10.

Reference is now made to FIG. 3, which illustrates a top-down view of the heel insert 1 10 shown in FIG. 1 and 2 (i.e. the other face of the insert 1 10 in FIG. 2). This view is oriented from the side of the shoe. As with FIG. 2, the insert 1 10 comprises the aperture 120 and chamfered edges 204. In addition, the top of the insert 1 10 comprises one or more members 300. The members 300 of FIG. 3 are in the form of protruding fins. The members 300 are arranged to mate with complementary apertures formed in the external underside portions of the sole 102, such as aperture 124 shown in FIG. 1 . The mating aperture and member reduce twisting of the insert 1 10 when the shoe is in use, and hence increase stability.

The underside of an assembled sports shoe comprising the above-described features is shown illustrated in FIG. 4. In order to provide the biomechanical adjustment, the sports shoe can be provided with a plurality of inserts for each cavity. Each of the plurality of inserts can have a different thickness. This is shown illustrated in FIG. 5, which shows a set of four heel inserts (as an example) having a range of thicknesses. A first, thinnest, heel insert 500 has a relatively small thickness, and can, for example, be used to just fill the cavity of sole where no additional adjustment of height is necessary. A second heel insert 502 is slightly thicker, such that it protrudes slightly from the cavity. A third heel insert 504 is thicker still, and hence protrudes further. A fourth heel insert 506 is thicker again, and protrudes yet further. Note that more or fewer inserts can be provided with the sports shoe than are illustrated in FIG. 5.

Optionally, the sports shoe can also be provided with a plurality of traction- enhancing projections 1 16 having different length threaded portions 1 18. The different length threaded portions 1 18 allow an appropriate length to be selected for use with an insert of a given thickness. For example, a first set 508 of traction- enhancing projections have threaded portions of an appropriate length for the thinnest insert 500, a second set 510 have slightly longer threaded portions of an appropriate length for the insert 502, a third set 512 have yet longer threaded portions of an appropriate length for the insert 504, and a fourth set 514 have yet longer threaded portions of an appropriate length for the insert 506. This ensures that the traction-enhancing projections screw sufficiently deeply into the underside portion of the sole to provide sufficient fixing strength, as described in more detail hereinafter.

Reference is now made to FIG. 6, which illustrates the effect of inserts of different thicknesses when the sports shoe is in use. The top figure in FIG. 6 shows the effect when the thickest heel insert 506 of FIG. 5 is inserted into the external underside portion 104. In this case, when the shoe is on a supporting surface 600 a first height 602 between the supporting surface 600 and the external underside portion 104 (i.e. where the insert meets the cavity base) is obtained. The bottom figure in FIG. 6 shows the effect when the thinnest heel insert 500 of FIG. 5 is inserted into the external underside portion 104. In this case, when the shoe is on a supporting surface 600 a second height 604 between the supporting surface 600 and the external underside portion 104 is obtained. The second height 604 is lower than the first height 602, which in turn changes the

biomechanics of the user due to the shorter length of the user's leg. Note that a similar effect is achieved when a toe insert, ball insert, or combination of toe, ball and heel inserts are used. This illustrates how different inserts can adjust the biomechanics of the user, and the user can select and interchange the inserts in order personalise the biomechanical characteristics of the shoe to their requirements. Reference is now made to FIG. 7, 8 and 9, which illustrate various options for removably securing the inserts to the external underside portions of the sole. Firstly, FIG. 7 illustrates a heel insert 1 10 being secured to the external underside portion 104 by the traction-enhancing projections 1 16, as mentioned hereinbefore. The threaded portions 1 18 of the traction-enhancing projections 1 16 are inserted into the aperture 120 of the insert 1 10, and are either pushed through or screwed through the aperture 120 (depending on whether or not it is threaded). The threaded portions 1 18 are then screwed into the threaded holes 122 in the external underside portion 104 until they tightly clamp the insert 1 10 to the external underside portion 104. Members 300 can engage with apertures 124 to reduce twisting, as mentioned. In this example shown in FIG. 7, a cleat wrench 700 is used to tighten the traction-enhancing projections 1 16.

Similarly, to remove an insert 1 10, the traction-enhancing projections 1 16 are unscrewed (e.g. using the cleat wrench 700) until the threaded portion 1 18 disengages from the threaded hole 122, and the insert is released. This attachment method makes it easy for the user to interchange the inserts as required, whilst also minimising manufacturing complexity for the inserts, as only a simple aperture 120 is formed in them.

FIG. 8 illustrates an alternative technique for removably attaching the insert 1 10 to the external underside portion 104. FIG. 8 shows a cross-section through the sole 102 and insert 1 10. The insert 1 10 is provided with a keyed protrusion 800. For example, the keyed protrusion 800 in FIG. 8 is a dove-tail member, although other keying shapes can also be used. A complementary-shaped slot is provided in the external underside portion 104 of the sole 102. The keyed protrusion 800 of the insert 1 10 can then be slotted into the complementary slot, and slid into position. The keying of the slot and protrusion ensures that the insert can only be removed by reversing the sliding action.

In the example of FIG. 8, the traction-enhancing projections 1 16 mount directly onto the insert 1 10 (e.g. the threaded portions 1 18 screw into threaded apertures in the insert 1 10) rather than screwing into the external underside portion 104 of the sole 102. In other examples, the traction-enhancing projections 1 16 can still screw into the external underside portion 104, for example if apertures 120 are provided on the insert that line up with the threaded holes 122 when the insert 1 10 is slid into position. FIG. 9 illustrates a further alternative technique for removably attaching the insert 1 10 to the external underside portion 104. FIG. 9 again shows a cross-section through the sole 102 and insert 1 10. The insert 1 10 is provided with a clip 900, which engages with a corresponding catch portion 902 on the sole 102. In other examples the clip 900 can be on the sole 102, and the catch portion on the insert 1 10. The clip 900 can be in the form of a toggle clip, quick release catch, Dzus fastener, or other similar device. The insert 1 10 can be inserted into the external underside portion 104 and then secured in position with the clip 900.

As with FIG. 8, the traction-enhancing projections 1 16 in FIG. 9 mount directly onto the insert 1 10 (e.g. the threaded portions 1 18 screw into threaded apertures in the insert 1 10) rather than screwing into the external underside portion 104 of the sole 102. In other examples, the traction-enhancing projections 1 16 can still screw into the external underside portion 104, for example if apertures 120 are provided on the insert that line up with the threaded holes 122 when the insert 1 10 is clipped into position.

Reference is now made to FIG. 10, which illustrates a kit of parts comprising a sports shoe 1000 having upper 100 and sole 102, and the external underside portion features outlined hereinabove. The kit of parts also comprises a plurality of inserts 1002. In this example, a plurality of toe inserts, a plurality of ball inserts, and a plurality of heel inserts are provided. In other example, any combination of toe, heel and ball inserts can be provided, depending on the adjustment available for the particular shoe. The plurality of inserts 1002 are of different thicknesses, enabling the user to interchange the inserts in order to correct for biomechanical deficiencies. Optionally, also provided are a plurality of traction-enhancing projections 1004 arranged to mount on the inserts 1002. These can have different length threaded portions to correspond to different thickness of inserts, as outlined above. In some examples, the traction-enhancing projections 1004 can be colour coded to match the colour of a given insert, so that the user can readily select the traction- enhancing projection having the correct length of threaded portion for a particular thickness of insert. For example, if the thickest insert is coloured yellow, and the thinnest red, then the traction-enhancing projection with the longest threaded portion can be coloured yellow, and the one with the shortest threaded portion coloured red. This reduces the likelihood of the user mistakenly using a traction- enhancing projection with too short a threaded portion, which consequently reduces the fixing strength of the traction-enhancing projection.

It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. It will further be understood that reference to 'an' item refer to one or more of those items.

It will be understood that the above description of a preferred embodiment is given by way of example only and that various modifications may be made by those skilled in the art. The above specification, examples and data provide a complete description of the structure and use of exemplary embodiments of the invention. Although various embodiments of the invention have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this invention.