INSOLE FOR FOOTWEAR

Abstract

An orthotic insole with a contoured support surface to conform to the underside of a foot. An arch support is provided by an inflatable bladder located within the insole and having a pump in the heel region of the insole to allow adjustment of the bladder. A valve is provided at the side of the bladder to release air from the bladder.

Description

FIELD OF THE INVENTION

The present invention relates to an insole suitable for use with footwear such as shoes, boots or the like.

DESCRIPTION OF THE PRIOR ART

It is common practice to provide an insole for footwear to increase the comfort or utility of the footwear. Typically such insoles are resilient to provide a degree of cushioning for the user in an attempt to reduce fatigue in the foot of the user. The resilient insoles may be planar and provide a layer of cushioning overlying the interior of the sole of the footwear.

It is also known to use an insole to provide support to a user's foot. These insoles, commonly referred to as orthotics, have a contoured upper surface that is complimentary to the underside of the user's foot and so provides support for the foot within the footwear. The insoles are custom made to suit the user and are typically molded from a rigid plastics material to provide the necessary support. The orthotic insole provides a stable platform that maintains the foot in an optimum orientation whilst supporting the underside of the foot.

Whilst the orthotic provides a greater degree of support than a simple resilient insole, it is relatively expensive to make and, once made, is of fixed configuration. As such it is not able to accommodate different situations that might arise, such as use during a high impact sport activity or use in casual footwear where less underlying structure is available to support the orthotic.

There have been a number of proposals to incorporate an inflatable bladder in to a shoe to enhance the fit of the shoe or boot. U.S. Pat. No. 5,416,988 shows an adjustable inflatable bladder incorporated in to a skate. Interconnected inflatable zones are provided for the ankle, arch and heel regions. A pump and valve assembly is incorporated into the rear of the insert. The primary purpose of this arrangement is to provide a snug fit around the ankle area whilst skating.

U.S. Pat. No. 4,417,407 has a sole with interconnected air chambers so that a flow of air is induced through air intakes and exhaust located at the arch area of the shoe as the user walks. The primary purpose is ventilation of the shoe and no support for the underside of the foot is provided.

U.S. Pat. No. 6,782,640 shows an insole which is filled with expanding foam. A check valve is located at the midpoint adjacent the arch and controls air flow in to the foam filled cavity. When the valve is pressed, it opens and allows air in to the cavity to allow the foam to expand. The insole conforms to the shape of the foot. Once released, the valve seals air in the cavity, which retains the shape of the users foot. The cavity extends over the entire foot and the insole relies on the resilience of the foam to conform to the foot. Once sealed, there is still resilience in the foam that allows movement over the entire sole of the foot.

U.S. Pat. No. 7,426,792 shows the use of separate sealed bladders to support the heel and sole and the support provided may be customised by orienting the bladder in the insole.

None of the prior art addresses the need for an insole that can accommodate varying needs of the user.

It is therefore an object of the present invention to obviate or mitigate the above disadvantages

SUMMARY OF THE INVENTION

In one aspect, the present invention provides an orthotic insole with a contoured support surface to conform to the underside of a foot. An arch support is provided by an inflatable bladder located within the insole and having a pump in the heel region of the insole to allow adjustment of the bladder. A valve is provided at the side of the bladder to release air from the bladder.

The contoured support surface provides support over the foot and the inflatable bladder may be adjusted to vary the support in the arch region. Thus where additional support is required, as for example in high impact supports, the bladder may be inflated to provide additional support without disturbing the overall configuration of the insole. The bladder may subsequently be deflated to relieve the support in the arch area.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention will now be described with reference to the accompanying drawings in which:—

FIG. 1 is a perspective view of an insole;

FIG. 2 is an exploded view of the insole of FIG. 1;

FIG. 3 is a plan view of the insole of FIG. 1;

FIG. 4 is a sectional view on the line IV-IV of FIG. 3; and

FIG. 5 is an enlarged view similar to FIG. 3 and partly in section of the insole of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Referring firstly to FIG. 1, an insole 10 has a body 12 with a toe region 14, a heel region 16 and an arch region 18. An upper support surface 20 of the body is contoured to conform to the underside of the user's foot and a bladder 22 is located within the body 12 in the arch region.

As can be seen from FIG. 2, the body 12 has a tray 24 formed from a rigid plastics material with upturned edges 26. The tray 24 extends along the body 12 from the heel region 16 to forward of the arch region 18 and terminating before the toe region 14. The tray 24 has an aperture 28 to receive a resilient heel pad 30 that is attached to the underside of a molded core 32. The heel pad 30 acts as a shock absorber and may be made from a high tensile strength polyurethane sheet material. A similar pad 34 is fixed to the core under the toe region 14 to provide a shock absorber in the toe region.

The core 32 is molded from a flexible plastics, such as EVA, which is relatively inelastic to resist compression. The core 32 is dimensioned to fit snugly in the tray 24 and the underside 36 of the core 32 is planar to be supported on the tray 24. Each core 32 is custom molded to a user and consequently the thickness of the core 32 varies from toe region 14 to heel region 16. The flanks of the core 32 are supported by the sides 26 of tray 24 to inhibit spreading of the core in the heels region.

A liner 40 is secured to the upper surface 42 of the core 32 and is conveniently a polyester with an anti-microbial characteristic.

The core 32 has a triangular opening 44 extending between the underside 36 and upper surface 42 in the arch region 18. The opening 44 is surrounded by the core 32 so the opening is delimited laterally by a portion of the core 32 between the opening 44 and the sides 26 of the tray 24. A circular hole 46 is formed in the core 32 to the rear of the opening 44 and extends between the underside 36 and the upper surface 42. The liner 40 is similarly formed with openings 48 and 50.

The bladder 22 is received in the opening 44 and hole 50, as can best be seen in FIGS. 3 and 4. The bladder 22 is formed from a flexible plastics material and has an expandable chamber 52 and a pumping chamber 54. A passageway 56 interconnects the chambers 52, 54. A valve assembly 60 is mounted to one side of the expanadable chamber 52 and connected to it by a conduit 58.

Referring to FIG. 5, valve assembly 60 has an inlet 62 with a check valve 64. The check valve 64 has a ball 66 biased by a spring 68 in to engagement with a seat 70. The check valve 64 controls flow of air to an internal duct 72 that connects to the conduit 58. The duct 72 extends to an outlet 76 which has a poppet valve 78 biased in to engagement with a seat 80 by a spring 82. The poppet valve 78 has an actuator in the form of a stem 84 that projects laterally from the valve assembly 60 and is aligned with an access hole 86 in the edge 26 of tray 24.

The expandable chamber 52 has strengthening ribs 88 molded in to the upper surface to provide stability to the surface as the chamber is expanded.

The underside of bladder 22 is supported on the tray 24 and is positioned so that the expandable chamber 52 extends through the opening 44 and the pumping chamber 54 extends though the circular hole 46. As can be seen in FIG. 4, the pumping chamber 54 is slightly recessed from the upper surface 42 of the core 32, whereas the expandable chamber 52 may project above the core 32. The tray provides support for the valve assembly 60 when the bladder is located in the opening 44.

In use, the insole 10 is placed within the footwear of the user with the core uppermost. To provide support to the arch region 18, the expandable chamber 52 is inflated using the pumping chamber 54. The pumping chamber 54 is accessible from above the insole 10 and by applying repetitive pumping forces to collapse and expand the chamber 54, air is drawn in to the bladder. Collapsing the chamber 54 causes air to be expelled in to chamber 52 and release of the pumping chamber 54 draws air in through the check valve 64. The pumping continues until the chamber 52 is expanded to the required size. The poppet valve 78 prevents air from flowing out of the bladder 22 and so maintained inflation of the chamber 52.

The chamber 52 provides support for the arch region 18 and generally conforms with the contour of the upper surface 42 of the core 32. If further support is required, the user exposes the pumping chamber 54 by lifting the heel or removing the footwear and further air is pumped in to the chamber 52. It will be noted that the overall configuration of the upper surface is not affected so that the user's foot is [properly supported on the insole, but additional localised support is provided in the arch region 18.

When the additional support is no longer required, the poppet valve 78 is accessed at the side of the insole 10 and the stem 84 pushed to move the poppet away from the seat 80. Air is released from the chamber 52 allowing the bladder to retract and relax the arch region 18.

The stem 84 is located at the side of the insole and so protected by the tray 24 to inhibit accidental actuation of the poppet valve 78. Similarly, the recessing of the chamber 54 ensures that air is not pumped in to the expandable chamber in use.

Although the invention has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art without departing from the spirit and scope of the invention as outlined in the claims appended hereto. The entire disclosures of all references recited above are incorporated herein by reference.

Claims

1. An orthotic insole having a contoured support surface to conform to the underside of a foot, an arch support including an inflatable bladder located within the insole, a pump in the heel region of the insole to allow adjustment of the bladder, and a valve at the side of the bladder to release air from the bladder.

2. The orthotic insole of claim 1 wherein said pump is located in an aperture in said heel region.

3. The orthotic insole of claim 2 wherein said aperture extends from said support surface.

4. The orthotic insole of claim 3 wherein said pump is recessed in said aperture below said support surface.

5. The orthotic insole of claim 1 wherein said inflatable bladder is located within an opening in said support surface.

6. The orthotic insole of claim 5 wherein said pump is located in an aperture in the heel region.

7. The orthotic insole of claim 6 wherein said pump and said bladder are connected by a passage located beneath said support surface.

8. The orthotic insole of claim 6 wherein said support surface is provided on a core and said opening and said aperture are formed in said core.

9. The orthotic insole of claim 8 wherein said core extends about said bladder to encompass said bladder.

10. The orthotic insole of claim 8 wherein a valve is connected to said bladder to control efflux of air from said bladder.

11. The orthotic insole of claim 10 wherein said valve is located to one side of said bladder.

12. The orthotic insole of claim 11 wherein an actuator is provided to open said valve and release air from said bladder.

13. The orthotic insole of claim 12 wherein said actuator projects to one side of said core.

14. The orthotic insole of claim 13 wherein said actuator lies within said insole to inhibit unintentional actuation of said actuator.

15. The orthotic insole of claim 14 wherein said core is supported on a tray and said tray extends over said actuator.

16. The orthotic insole of claim 5 wherein reinforcing ribs are formed on an upper surface of said bladder.

17. The orthotic insole of claim 8 wherein said core is supported on a tray.

18. The orthotic insole of claim 17 wherein said opening and said aperture extend through said core and said bladder and said pump are supported on said tray.

19. The orthotic insole according to claim 18 wherein a valve assembly is connected to said bladder to control efflux of air from said bladder, said valve assembly located laterally of said bladder and supported on said tray.