Shoe With Sole That Includes Inflatable Passages to Provide Cushioning and Stability

This invention relates to shoes, and more particularly to the soles of shoes.

An object of the invention is to provide a shoe with an improved sole for contact with the ground by providing the sole with inflatable passage means.

In general the invention provides a shoe having a sole which includes inflatable passage means comprising respective continuous passages extending lengthwise of the sole adjacent each side thereof, and means for enabling fluid to be supplied to the passage means for the inflation thereof. Preferably, the underside of the sole is provided with a lengthwise extending recess bounded by the continuous passages extending on each side of the sole.

The passage means may extend completely around the periphery of the sole, such an arrangement being particularly advantageous for orthopaedic shoes, where, in use, the inflated passage means provide both a cushioning effect and stability for the user.

Alternatively, the passage means may comprise two spaced continuous passages which extend one on each side of the shoe to respective closed ends at or adjacent the toe end portion of the shoe, the other ends being interconnected to allow the transfer of the fluid therebetween. Such an arrangement is particularly advantageous for sports shoes, especially athletics shoes.

In such an arrangement, the passages are preferably interconnected by a reservoir disposed in the heel. end portion of the shoe. The reservoir may comprise chamber disposed in a heel portion of the sole. Alter natively, the reservoir may comprise a U-shaped passage at the heel end portion of the shoe. The means for enabling fluid to be supplied to the passage means for inflating the latter preferably comprises a valved inlet to the reservoir.

Preferably the passage are provided with means preventing or at least restricting their inflation at the portions thereof adjacent the reservoir.

The passages may comprise inflatable tubing, and in such a case, the wall of the tubing may be tthickened or reinforced at the portions thereof adjacent the reservoir to prevent or restrict inflation of the tubing. The tubing may be contained within a protective covering therefore which is disposed for contatct with the ground when the shoe is being used. In this case, the covering may be dimensioned to prevent or restrict inflation of the tubing at the portions thereof adjacent the reservoir.

As an alternative to using inflatable tubing for the passages, the passages may be formed by cavities in one or more mouldings forming the sole. In this case, the wall thickness of the cavities of the portions of the passages adjacent the reservoir may be made greater than the wall thicknesses of the cavities remote from the reservoir, at least on the underneath of the sole to restrict inflation of the first mentioned portion of the passages.

In order that invention may be well understood, some embodiments thereof, which are given by way of example only, will now be described, with reference to the accompanying drawings in wnhich:

FIG. 1 is a sketch showing the underside of an athletics shoe;

FIGS. 2 and 3 are respectively sketches of cross-sections of the shoe taken along the lines II--II and III--III in FIG. 1;

FIG. 4 is a side view of the same shoe;

FIG. 5 is a sketch showing the underside of another athletics shoe; and

FIG. 6 is a sketch showing the underside of an orthopoedic shoe.

Referring first to FIGS. 1 to 4, there is shown an athletics shoe 10 comprising essentially an upper 12 and a sole 14.

In this connection, it is to be understood that in this specification the term `sole` refers to the whohle of the bottom of the shoe including any heel which may be provided.

The sole includes inflatable passage means formed as two spaced passages 16 extending lengthwise of the sole adjacent each side 18 thereof. The passages 16 are continuous along their length. As illustrated the underside of the sole 14 is provided with a lengthwise extending recess 20 bounded by the two spaced passages 16. The passages 16 have closed ends 22 at, or as illustrated adjacent, the toe end portion 24, wherat, in the illustrated embodiment the sole is provided with two sppikes 26. The other ends 28 of the passages 16 are interconnected to allow the transfer of fluid therebetween. These ends 28 are interconnectetd via a reservoir disposed at the heel end portion of the shoe and formed as a chamber 30 in a heel portion 32 of the sole. A valved inlet 34 to the resevoir forms a means for enabling fluid to be supplied to the passages 16. For example the valved inle may be of the type which is connectable via an adapter to a hand operated pneumatic pump.

The passages are provided with means preventing or restricting their inflation at the portions 36 thereof disposed bettween the ball porttion and heel end portion of the shoe adjacent the reservoir and corresponding to that part of the sole which flexes in use. In the embodiment the passages 16 are formed from inflatable tubing and this tubing is thickened or reinforced (for example by a winding of tape) at the portions 36 to prevent or at least restrict the inflation of the tubing at these portions. The tubing forming each passage 17 is secured to the underside of a body portion 38 of the sole and is contained within a covering 40 also secured to the underside of the body portion 38 of the sole and disposed for contact with the ground. The covering 40 is made of a substantially non-stretchable material of good grip and wear characteristics and may for example comprise a canvas material impregnated with a rubber or flexible plastic material.

Prior to use of the shoe, air is pumped into the reservoir and the tubing 16 connected thereto via the valved inlet 34. The portions 36 of the tubing whose inflation is restricted remain flexible so as not to unduly stiffen the sole in this region, but the portions of the tubing remote from the reservoir and extending over that part of the sole which supports the ball of the foot can inflate into engagement with the covering 40 thereat. The air pressure in the tubing determines the degree of hardness or softness of the contact of the sole with the ground over these portions and can be adjusted to suit the user's preference. The above-described shoe has been found to have advantageous characteristics in use since the air in the passages 16 is transmitted lengthwise thereof into and out of the reservoir 30 each time the shoe contacts the ground during running and also between the passages 16 via the reservoir when more load is exerted on one side of the sole than the other, for example when the user is running around a bend.

A shoe 50 whose underside view is shown in FIG. 5 is an athletics shoe designed for sprinting where the sole 52 is not provided with a heel portion. Parts of the sole 52 which correspond to parts of the sole 14 in FIGS. 1 to 4 have been given like reference numerals. The sole 52 differs from the sole 14 primarily in that the two spaced passages 16 which extend on each side of the shoe with the recess 20 therebetween have their portions 36 interconnected by a U-shaped passage 54 at the heel end portion of the shoe forming a reservoir corresponding to reservoir chamber 30.

A single piece of inflatable tubing provides the passages 16 and passage 54. The covering 40 which covers the tubing is dimensioned to prevent or at least restrict the inflation of the tubing at portions 36 of the passages 16 and additionally at the passage 54 forming the reservoir but to allow inflation of the portions of the tubing remote from the reservoir and extending over that part of the sole which supports the ball of the foot. Thus, as in the first embodimentn the air prssure in the tubing determines the degree of hardness or softness of the contact of the sole with the ground over these latter portions, the portions 36 remaining flexible so as not to unduly stiffen the sole in the region where they are located.

It will be appreciated that the sole 52 functtions in the same way asa the sole 14 in that air in the passages 16 is transmitted lengthwise of these passages into and out of the reservoir each time the shoe contacts the ground during running and also between the passages 16 via the reservoir when more load is exerted on one side of the sold than the other.

Referring now to FIG. 6, the orthopoedic shoe 60 illustrated is provided with a sole 62 which includes inflatable passage means 64 which extend not just lengthwise of and on each side of the shoe but around the entire periphery of the sole. This passage means 64 bounds a lengthwise extending recess 60 on the underside of the sole.

The passage means 64 comprises an inflatable tubuler member (not shown) which is provided with a valved inlet 68 at the heel end portion of the shoe. The tubular member is secured to the underside of a body portion 78 of the sole and contained within a covering 80 also secured to the underside of the body portion 78 of the sole and disposed for contact with the ground. The covering 80, like the covering 40 previously referred to is made of a substantially non-stretchable material of good grip and wear characteristics. In this shoe however, the covering 80 does not selectively restrict the inflation of the tublar member and accordingly when the tubular member is inflated into engagement with the covering 80 a uniform degree of hardness or softness of the contact of the sole with the ground is obtained. Thus, by adjusting the degree of inflation of the tubular member a desired cushioning effect can be obtained. Stability is also provided by arranging for the tubular member to extend around the entire periphery of the sole.

Whilst the above described embodiments utilise inflatable tubing for providing inflatable passages it is to be understood that these passages may instead be formed by cavities defined in or by one or more mouldings forming the sole. Further, as indicated hereinabove, when the passages are so formed, the wall thickness of the cavities of the portions corresponding to the portions 36 in the first and second embodiments may be made greater than the wall thicknesses of the cavities of the portions of the passages extending over that part of the sole which supports the ball of the foot so that whilst the latter portions are able to inflate, the former portions are not.

It will be apprciated that whilst certain materials have been specified above in the embodiments, these are given by way of example only and other suitable materials could be used instead.

Further it is to be understood that the valved inlet in the embodiments may be of any suitable known type, for example such as that conventionally used for cycle inner tubes or such as that conventionally used for soccer balls. The latter type is presently preferred since it is adapted to be housed within the sole structure.