GB2462100A

GB2462100A - Footwear sole containing pellet-filled air-tight bladder

Info

Publication number: GB2462100A
Application number: GB0813513A
Authority: GB
Inventors: Mark Herron
Original assignee: Foot & Ankle Clinic Ltd
Current assignee: Foot & Ankle Clinic Ltd
Priority date: 2008-07-24
Filing date: 2008-07-24
Publication date: 2010-01-27
Also published as: GB0813513D0

Abstract

An article of footwear that includes an air-tight bladder 15 in a sole portion 1 and where the bladder 15 contains a plurality of pellets (23, figure 4), the bladder 15 having a valve 17 by which means air is able to pass in and out of the bladder 15. More than one PVC bladder 15 may be provided, and the pellets may be spherical with a 3mm diameter and fabricated from a nitrile material. The footwear may be suitable for use in convalescence or health recovery of the wearer.

Description

AN ARTICLE OF FOOTWEAR AND RELATED METHODS

This invention relates to an article of footwear and related methods.

More particularly it concerns a type of footwear design that can be adapted to the shape of a wearer's foot. The invention may have particular application in the field of orthopaedics but it need not be limited to this use.

There are various designs of post-operative boots available for rehabilitation after injury or operation to the foot and ankle. Most designs incorporate a stiff through-rocker' type sole and design elements to support, offload and irnmobilise the foot and ankle. These current systems work well for a period of approximately three months after an injury and/or operation. During this time the foot and/or ankle and/or lower leg may need maximum protection from knocks and maximum support to maintain the foot and/or ankle and/or lower leg in a set position.

After approximately three months however (when the foot and/or ankle and/or lower leg are usually more robust) currently available orthopaedic boots may become less useful. Their large size and inflexibility become unnecessary and may be frustrating for the patient; who may be made to feel like an invalid for longer than is necessary. The inflexibility of the boot may even prolong muscle atrophy beyond what is necessary as the patient may be unnecessarily prevented from exercising' the foot by the rigidity of the boot.

After some procedures a patient is rarely ready, after a period of three months, to resume normal walking with normal footwear and would benefit from continued augmented support. Currently orthopaedic consultants sometimes resort to suggesting sturdy walking boots, which may be an improvement.

According to a first aspect of the invention there is provided an article of footwear that includes a gas impermeable bladder in a sole portion, the bladder containing a plurality of pellets and having a valve by which means a gas is able to pass in and out of the bladder.

An advantage of such an article of footwear is that it can be contoured to a wearer's foot thereby providing customised support. The shape, contours and volume of a patient's foot many vary significantly both day to day and over the course of a single day in up to the first six months after surgery/trauma. The design allows this to be catered for dynamically as required.

The article of footwear may be any kind of footwear, such as a shoe, boot, sandal or the like. In some embodiments, the article of footwear is suitable for use in convalescence of a wearer and in such embodiments, the footwear may comprise a shoe or boot.

The pellets are generally of a semi-rigid and elastic nature; that is it they might deform slightly when a force is applied and return to substantially their original size and shape when the force is removed. An advantage of such a material selection is that it can provide cushioning to a wearer of the footwear and may make the footwear more comfortable.

A suitable material for the pellets may be a nitrile material.

The pellets may generally be in the range of between roughly 1mm and 5mm in diameter. In other embodiments, the pellets may be roughly in the range of 2mm to 4mm. In one embodiment, the pellets are substantially 3mm in diameter. The skilled person will appreciate that other diameters may be suitable and that diameters within the ranges specified may also be suitable. Additionally it may be advantageous to provide pellets of various sizes.

Conveniently, the pellets are substantially spherical in shape but this need not be the case. In other embodiments, the pellets may be other shapes such as substantially any of the following: cylindrical, ovoid, rugby ball or the like. It is believed that it is convenient if the pellets have rounded surfaces in order that the footwear is comfortable to wear and there is a reduced risk of damage to the bladder.

Whilst the bladder is fabricated from any suitable gas impermeable membrane, it is thought that convenient materials may be PVC (Poly Vinyl Chloride) and/or silicone. PVC is believed to be suitable since it is durable and shows good impermeability. Other materials are also likely to be suitable.In some embodiments, the bladder may be fabricated from a plurality of materials. For example, an upper portion of the bladder may be fabricated from a more flexible material than a bottom portion of the bladder. For example the top portion may be fabricated from silicone.

Such an arrangement is believed to be advantageous as is may aid moulding of the bladder to a wearer's foot.

In some embodiments a liner or coating may be provided on an outer region of the bladder. The liner or coating may in particular be provided on top of the outer region of the bladder, such that it would be situated, in use, between the bladder and the wearer's foot. The liner may have properties that make it more suitable for contact with the wearer's foot than the material from which the bladder is made. The liner or coating may for example offer better grip than the bladder material. Silicone is one material that may be suitable for the liner or coating, but many others may also be suitable.

In some embodiments, the sole portion may comprise a cavity arranged to receive the bladder. Such an arrangement is thought to be advantageous as it may provide positive location of the bladder relative to the sole portion.

A fastener may or may not be provided in order to secure the bladder to the sole portion. That is in some embodiments the bladder may simply rest on the sole portion and/or within the cavity. However, in other embodiments, a fastener may be provided in order to assist in location of the bladder relative to the sole portion.

Suitable fasteners may comprise an adhesive (such as a glue), press studs, a hook and eye system (such as VelcroTM), a strap or the like.

The cavity may be provided over substantially the entire area of the sole portion. In other embodiments, the cavity may be provided in a region of the sole portion, such as the heel region, or the ball of the foot region.

Indeed, in some embodiments, more than one bladder may be provided.

For example, one bladder may be provided in a heel region and a further bladder may be provided in a ball of the foot region.

The sole portion may be provided with a channel arranged to have the valve of the bladder passed therethrough. Such an arrangement is convenient as it can allow the bladder to be readily inflated and/or deflated whilst in situ within the footwear.

The channel may be sealed around the valve. Such an arrangement can help to prevent the ingress of water into the footwear. The seal may be effected by any suitable means such as an adhesive, 0-rings or other seals, or the like.

In other embodiments the channel may be dimensioned so that it is substantially sealed by the presence of the valve therein. Such sealing may be enhanced if the sole portion is fabricated from a resilient material.

In some embodiments, a rigid or semi-rigid casing may be provided for the valve. Or indeed, the valve itself may be made from a rigid or semi-rigid material. Such arrangements may advantageously allow gas to be passed through the valve even when a wearer is applying his/her weight to the footwear by helping to prevent the valve from being squashed by the applied weight. The casing may for example be a tube or at least a portion of a tube through which the valve is passed.

Conveniently, the channel is provided in a medial side of the sole portion.

Such a location is believed to facilitate user access of the valve in order to add or remove gas from the bladder. However, the skilled person will appreciate that other locations on the sole portion may be suitable, including locations on the lateral side of the sole portion.

In some embodiments, the channel is provided in a heel region of the sole portion. Such a location may be convenient, particularly if the heel is of greater depth than other regions, such as a ball of the foot region.

Conveniently the valve does not extend beyond the sole portion in order to prevent it being a trip hazard and in order that the aesthetics of the footwear may be improved. In other embodiments the valve may be extendable for user operation and retractable once user operation is complete.

The sole portion may comprise a through-rocker' sole portion which may be advantageous for helping ambulation where the footwear is used for a convalescing wearer.

The sole portion may be provided as a single member. In alternative embodiments, the sole portion may be provided by a plurality of members and a through rocker member may be one such member. In some embodiments, the through rocker member may be substantially rigid.

The footwear generally comprises an upper arranged to hold the footwear onto a user's foot. The upper may be arranged to give support to a user's foot.

According to a second aspect of the invention there is provided a kit comprising footwear according to the first aspect of the invention and a pump arranged to be used with the valve.

Generally, the pump is a hand held pump.

The pump may comprise a bellows arrangement, perhaps arranged to be squeezed by a user's hand. Such an arrangement is convenient as it allows a pumping action to be performed without the need of a power source.

The pump may be arranged to withdraw gas, typically air, from within the bladder so as to evacuate the bladder.

The pump may also be arranged to re-fill the bladder with gas, typically air, so as to return the bladder to substantially atmospheric pressure or above when required. The valve may be arranged to close automatically whenever the pump is not in use.

The valve may be provided with a user operable means arrangeable to allow gas to flow, substantially freely, from outside of the bladder to the inside of the bladder. Such an arrangement is convenient to allow the bladder to be refilled with gas. However, the valve will generally be arranged to prevent the flow of gas from outside of the bladder to the inside of the bladder and/or vice versa.

According to a third aspect of the invention there is provided a method of customising an item of footwear to a wearer's foot comprising: 1. inserting a foot into the footwear; 2. using a pump to substantially evacuate a bladder provided within the sole portion of the footwear and filled with a plurality of pellets.

Conveniently, the footwear is the footwear of the first aspect of the invention.

Such a method is advantageous since the pellet filled bladder becomes substantially rigid once it has been evacuated and as such the bladder moulds itself to the wearer's foot.

The method may further comprise opening the valve to allow gas, such as air, to enter the bladder thereby allowing the pellets to move relative to one another. Such a step may allow the bladder to be re-moulded to the wearer's foot.

The method may repeat step 2. above in order to re-evacuate the bladder thereby re-moulding the bladder to the wearer's foot.

The skilled person will appreciate that features discussed in relation to any one aspect of the invention may be provided with any other aspect of the invention.

An embodiment of the invention will now be described in more detail by way of example only with reference to the accompanying drawings in which: Figure 1 is an exploded perspective view of one embodiment of the invention, showing a sole portion and a bladder of an article of footwear; Figure 2 shows a longitudinal cross-section through the sole portion of Figure 1 along line XX; Figure 3 is a cross-section through the bladder of Figure 1 along line YY thereof; and Figure 4 is a cross-sectional view through the sole portion of Figure 1 along line ZZ, also showing a portion of an upper of the article of footwear.

Referring first to Figure 1 a shoe sole portion 1 of an article of footwear is provided having what is commonly referred to as a through-rocker' base formation 3, designed to allow a wearer to tilt forwards and backwards more easily, while still maintaining weight on the foot. This type of base formation is widely known in the orthopaedic field. Such sole portions have a curvature along their length which allows this tilting to occur and this curvature can most readily be seen in Figure 2.

On top of the base formation 3 is a body 5 of the sole portion 1. which defines the perimeter sole portion side wall 7. The sole portion side wall 7 is shaped so as to provide support to the foot of a wearer.

In a top region of the body 5 is a cavity 9 which has a bottom wall 11 and a side wall 13. In the embodiment of Figure 1 the cavity 9 is provided over substantially the whole top surface of the body 5. In other embodiments the cavity 9 may be of any suitable size and shape as required. For example the cavity may be provided in a ball of the foot region 14.

In use there is positioned in the cavity 9 a bladder 15. For ease of reference the bladder is shown separately with tracking lines to show positioning relative to the sole portion 1. The bladder 15 rests on the bottom wall 11 of the cavity 9 and may be secured by a suitable adhesive such as a glue, but any other suitable securing means may be used.

Indeed, in other embodiments, the bladder 15 may be retained in position by engagement with the side walls 13 of the sole portion 1.

A valve 17 is provided on the bladder 15 which allows air in and out of the bladder 15. The valve 17 is fitted to the side of the bladder to be used on the medial side of the shoe sole portion 1.

A channel 19 is formed through a heel region 21 of the body 5 on the medial side of the sole portion 1. To accommodate the channel 19 a dip is formed in the bottom wall 11, in other embodiments this may not be necessary.

The channel 19 extends from the cavity side wall 13 to the sole portion side wall 7 and as such allows communication between the cavity and the outside of the shoe. The channel 19 is designed to receive an outer part of the valve 17 which protrudes far enough through the channel 19 to be operated by a wearer or someone else from the outside of the shoe.

Referring to Figure 2 the through-rocker' base formation 3 can be clearly seen. The through-rocker' feature comprises a curvature in the base formation 3 along the length of the sole portion 1. This curvature facilitates easier walking in a heel to toe manner. In the case where the wearer has an injury the through-rocker' feature may reduce stress on the bones, joints and soft tissues of the foot and ankle in question by automatically tilting the foot with the momentum of walking as weight is transferred over it.

Referring to Figure 3, a plurality of semi-rigid pellets 23 are provided inside the bladder 15, which substantially fill the bladder 15. For ease of reference the pellets 23 are shown larger than might be used.

The pellets 23 comprise a nitrile material, but any other suitable material may be used.

In this embodiment the pellets 23 are substantially spherical and are of approximately 3mm in diameter. The bladder 15 is shaped to fit the cavity 9, but may also be shaped with particular orthopaedic objectives in mind. The outer surface of the bladder 15 comprises a non-porous material, in this case PVC, although many other suitable materials may be used.

The bladder 15 itself is substantially air-tight with passage for air in or Out of the bladder being controlled by the valve 17. When air at substantially atmospheric pressure, or above, is present inside the bladder 15 the pellets are relatively free to move about in response to external forces placed on the bladder 15. When the bladder 15 is substantially evacuated the pellets are substantially retained in position and do not move substantially relative to one another.

The valve 17 is of a suitable design to allow removal of air from the bladder 17 while also allowing injection of air back into the bladder 15 when the valve 17 is open. The valve closes automatically when the pump is not in use. The valve is provided with an outer casing that enables it to function even when the sole portion 1 is weight bearing.

Additionally the valve 17 is designed to be relatively discreet and does not protrude beyond the channel 19 so as to ensure that it is not a trip hazard As can be seen in Figure 4, the shoe also comprises an upper 25 allowing a wearer to retain the shoe on his/her foot. An outer region 27 of the bladder is in contact with the sole 1 and (when the shoe is worn) the wearer's foot In use, the valve 17 is opened such that the air inside the bladder 15 is at approximately atmospheric pressure or above. A wearer places his or her foot inside the shoe and puts his or her weight on that foot and therefore the bladder 15. As the air in the bladder 15 is at approximately atmospheric pressure the pellets 23 are substantially free to move about within the bladder 15 and therefore form to the shape of the underside of a wearer's foot.

The user then uses a hand held pump (not shown) to substantially evacuate the bladder 15 thereby substantially retaining the pellets 23 in position such that they do not move relative to one another. Thus, the bladder remains substantially rigid under a wearer's foot.

The pellets 23, which are semi-rigid provide cushioning while also providing substantially rigid support following the contours of a wearer's foot.

The positioning of the valve 17 on the medial side of the heel of the sole portion 1 facilitates operation of the pump (not shown) by a wearer. The body 5 of the sole portion 1 also provides additional support around the lower sides of the foot. The through-rocker' base formation promotes ease of ambulation, especially where the foot in question is damaged in someway.

Referring to Figure 4, the bladder 15 is shown in its substantially evacuated configuration. It can be seen that the bladder 15 has been shaped before evacuation to follow the contours of a wearer's foot (not shown). Additionally the shoe upper 25 can be seen.

Claims

CLAIMS1 An article of footwear that includes an air-tight bladder in a sole portion and where the bladder contains a plurality of pellets, the bladder having a valve by which means air is able to pass in and out of the bladder.
2 An article of footwear according to claim 1 suitable for use in convalescence of a wearer.
3 An article of footwear according to claim 1 or claim 2 where the pellets are of a semi-rigid nature.
4 An article of footwear according to any preceding claim where the pellets are fabricate from a nitrile material.
An article of footwear according to any preceding claim where the pellets are substantially 3mm in diameter.
6 An article of footwear according to any preceding claim where the pellets are substantially spherical in shape 7 An article of footwear according to any preceding claim where the bladder is fabricated from PVC (Poly Vinyl Chloride) and/or silicone.8 An article of footwear according to any of claims 1 to 7 where the bladder is fabricated from a plurality of materials.9 An article of footwear according to any preceding claim where a liner or coating is provided on an outer region of the bladder.An article of footwear according to claim 9 where the liner or coating is provided on top of the bladder such that it would be situated, in use, between the bladder and the wearer's foot.11 An article of footwear according to any preceding claim where the sole portion includes a cavity arranged to receive the bladder.12 An article of footwear according to claim 11 where the cavity is provided over substantially the entire area of the sole portion.13 An article of footwear according to claim 11 where the cavity is provided in a region of the sole portion, such as the heel region, or the ball of the foot region.14 An article of footwear according to any preceding claim where more than one bladder is provided.An article of footwear according to any preceding claim where the valve is arrangeable to allow gas to flow, substantially freely, from outside of the bladder to the inside of the bladder.16 An article of footwear according to any preceding claim where the sole portion is provided with a channel arranged to have the valve of the bladder passed there through.17 An article of footwear according to any preceding claim where one of a rigid or semi-rigid casing is provided for the valve.18 An article of footwear according to claim 16 or 17 where the channel is provided in a medial side of the sole portion.19 An article of footwear according to any of claims 16 to 18 where the channel is provided in a heel region of the sole portion.An article of footwear according to any preceding claim where the sole portion possesses a through-rocker' formation.21 An article of footwear according to any preceding claim where the footwear has an upper arranged to give support to a user's foot.22 A kit comprising footwear according to any preceding claim and a pump arranged to be used with the valve.23 A kit according to claim 22 where the pump is a hand held pump.24 A kit according to claim 22 or claim 23 where the pump comprises a bellows arrangement arranged to be squeezed by a user's hand.A kit according to claim any of claims 22 to 24 where the pump is arranged to withdraw gas, typically air, from within the bladder so as to evacuate the bladder.26 A method of customising an item of footwear to a wearer's foot comprising: 1. inserting a foot into the footwear; 2. using a pump to substantially evacuate a bladder provided within the sole portion of the footwear and filled with a plurality of pellets.27 A method of customising an item of footwear according to claim 26 further comprising opening the valve to allow gas, such as air, to enter the bladder thereby allowing the pellets to move relative to one another.28 A method of customising an item of footwear according to claim 27 further comprising repeating step 2. of claim 30 in order to re-evacuate the bladder thereby refitting the bladder to the wearer's foot.29 An Article of footwear substantially as described herein with reference to the accompanying drawings.A kit substantially as described herein with reference to the accompanying drawings.31 A method of customising an item of footwear substantially as described herein with reference to the accompanying drawings.