GB2245145A - Ventilated footwear - Google Patents

Abstract

A sole unit comprising an air-pump chamber 30 whose volume is altered by movement of a movable member 32 on the underside of the sole unit. Valves 36, 40 cause air to be passed from the atmosphere into a chamber 28 and then through holes 42 in an insole to cool the foot. <IMAGE>

Description

FOOTWEAR VENTILATION This invention relates to footwear ventilation, more particularly to an arrangement for ventilating the interior of shoes, boots and the like.

It is well known that problems may arise from perspiration of the feet when wearing shoes, particularly where the shoes are training shoes, sneakers or the like. These problems include odour, discomfort and even foot disease.

There have been several proposals aimed at promoting ventilation within shoes, so as to minimise foot perspiration. Conventionally, one or more holes are provided in the arch portion of the shoe so that air can flow into and out of the shoe. However, the air flow through the holes is often too small to give any significant benefits. Other, more sophisticated arrangements exemplified by U.S. Patent Nos.964482 and 2003646 employ a protruding elastic-walled bulb in the upper (interior) portion of the shoe heel. The bulb is arranged to force air through ventilation channels within the shoe, in response to changes in the pressure exerted by the wearer's feet uring walking or running.

In the arrangements outlined above, the bulb must be compressed to a considerable degree to force an adequate quantity of air through the ventilation channels. This means that when the wearer lifts his foot and thereby releases pressure from the bulb his heel may lift away from the interior of the shoe because the bulb may remain compressed for a short time after the foot is lifted.

It is important that shoes are a close fit at all times if wearing comfort is to be assured. This means that a shoe should not leave excessive space about the foot, particularly about the heel. Otherwise, there can be an uncomfortable feeling of looseness in use as the shoe moves relative to the foot. Clearly, the prior art arrangements conflict with this requirement and therefore tend to be uncomfortable in use. Moreover, attempts to enhance comfort by reducing the movement necessary to compress the bulb suffer the drawback that insufficient airflow is generated at each step. Thus, the prior art fails to resolve the conflict between wearing comfort and ventilating efficacy.

This invention aims to overcome or at least to mitigate the disadvantages of prior art arrangements.

According to this invention, a sole unit for ventilated footwear comprises an air-pump chamber whose volume may be altered in use by movement of a movable member situated on the underside of the sole unit.

In a presently preferred embodiment, the movable memberis a flexible membrane of resilient construction, formed as an integral part of the sole unit. The flexible membrane may be shaped as a part-spherical bulb protruding from the sole unit to be compressed n use at each stride. Advantageou1, , the bulb hSF - shallow shape curving gently from the protruding centre to the edge, so as to deform progressively and to return quickly to its uncompressed state when allowed.

It is preferred that the air-pump chamber is situated in a heel portion of the sole unit and draws atmospheric air via non-return valve means. Preferably the movable member is a portion of the chamber wall.

Air compressed in the air-pump chamber may be passed into the interior of the shoe, via further non-return valve means, through holes in an inner sole. The compressed air may flow from the heel portion to a sole portion of the sole unit before entering the interior of the shoe through the inner sole.

Embodiments and aspects of this invention will now be described, by way of example, with reference to the accompanying drawings In which: Figure 1 is a part-sectioned side view of a preferred embodiment Figure 2 Is an exploded perspective view showing components of the preferred embodiment in detail; Figure 3 is a top plan view showing a component of the preferred embodiment Figure 4 is a bottom plan view corresponding with Figure 3; Figures 5 (a) and 5 (b) are part-sectioned side views corresponding with Figute 1, showing the operation of the preferred embodiment.

Referring to the drawings, a shoe 10 includes a moulded outer sole 12 to which an upper 14 is attached.

As -best shown in Figure 2, the outer sole 12 includes a lower web 16 which has an upstanding peripheral wall 18.

The wall 18 surrounds upstanding internal features moulded in one piece with the web 16, the features being a transverse partition 20 and a plurality of support blocks 22. The support blocks are spaced apart from one another to define interconnecing channels. An inner sole 24 overlies the outer sole 12 and lies on top of the wall 18, partition 20 and support blocks 22, to define a hollow sole unit 26, as shown in Figures 3 and 4.

The transverse partition 20 divides the sole unit 26 into a sole chamber 28 and a heel chamber 30. The heel portion of web 16 forming part of the heel chamber 30 has an outwardly-protruding bulb 32 which is arranged to be first compressed and then released on each stride as the wearer walks. The bulb 32 is resilient so as to return to its protruding uncompressed state when pressure is released.

The heel chamber 30 is connected to the sole chamber 28 by an opening 34 in the transverse partition 20. A resilient flap 36 positioned on the sole chamber side of the partition 20 coveys the opening 34 to block air flow from the sole chamber 28 to the heel chamber 30. Conversely, the flap 36 allows air to flW ifl the opposite direction from the heel chamber 30 to the sole chamber 28 and therefore acts as a non-return valve.

Another opening 38 in the peripheral wall 18 around the heel chamber 30 connects the heel chamber 30 to the atmosphere. A flap 40 positioned on the inner side of the peripheral wall 18 covers the opening 38 to block air flow from the heel chamber 30 to the atmosphere while allowing air flow in the opposite direction, thereby acting as another non-return valve.

As the bulb 32 moves during walking, the pressure of air within the heel chamber 30 rises and falls. When the bulb 32 is compressed as shown in Figure 5 (b), the air pressure in the heel chamber 30 rises and air is forced into the sole chamber 28 through the opening 34.

Conversely, when the bulb 32 is released and returns to its uncompressed state as shown in Figure 5 (a), air is drawn into the heel chamber 30 through the opening 38.

At the next stride, this air is compressed and is forced into the sole chamber 28, and so on.

Air entering the sole chamber 28 flows through the channels between the support blocks 22 before passing into the interior of the shoe through a number of holes 42 in the inner sole. In the illustrated embodiment, the holes 42 are positioned to direct air around the wearer's toes although other positions may be selected if desired. After passing around the foot, the air leaks out of the shoe 10.

The effect as the wearer walks is that a substantially continuous flow of fresh air passes through the interior of the shoe, thereby ventilating the foot and preventing build-up of moisture and odour.

It is preferred that the bulb 32 has a smooth shallow shape as illustrated, with a gently curving profile from the protruding centre to the edges. This allows the bulb 32 to deform progressively, thereby improving comfort and stability when walking. Moreover, the shape of the bulb 32 is such that the bulb will deflect readily in response to changes in pressure during a stride. In particular, the bulb 32 will return quickly to its uncompressed state when pressure is released, and will not 'lock' in its compressed state.

The arrangement of this invention resolves the conflict between comfort and efficacy suffered by the prior art. This is because the bulb 32 is not installed as taught by the prior art, in the interior of the shoe.

Consequently, the shoe can be a close fit around the wearer's foot so that, in use, the wearer's heel stays in close contact with the interior of the shoe at all times. This allows the-bulb 32 to be of a size suitable for generation of substantial air flow while avoiding the uncomfortable feeling of looseness suffered by the prior art.

Claims (3)

1. A sole unit for ventilated footwear comprising an air-pump chamber whose volume may be altered in use by movement of a movable member situated on the underside of the sole unit.

2. A sole unit according to Claim 1 in which the movable member is a flexible membrane of resilient construction, formed as an integral part of the sole unit.

3. A sole unit according to Claim 2 wherein the flexible membrane is of part-spherical form and protrudes from the sole unit so that in use compression and ventilation takes place at each stride.