Patent Description:
An insole reduces the impact by using materials that cushion the force associated with a step. The comfort of an insole for a user may be associated with how each step is cushioned and the force distributed in the insole. In general, the cushioning of an insole is dependent upon how a force is cushioned and the area over which the force is distributed.

Document <CIT> discloses an insole according to the preamble of claim <NUM>.

The present disclosure describes an insole that distributes the force associated with foot strike to provide comfort to the user. The distribution of the force by the insole reduces the peak force on the foot. The insole provides cushioning upon impact over both a sustained period of time and during repeated uses of the insole. The present invention is defined by an insole according to the appended claim <NUM>. Preferred embodiments are defined by the appended dependent claims.

Aspects of the disclosure are also described in detail, by way of example only, with reference to the accompanying drawings, in which:.

Embodiments will now be described with reference to the Figures.

<FIG> shows an illustration of an insole <NUM> having a pod <NUM>. The insole comprises a heel region <NUM>, an arch region <NUM> and a ball of foot region <NUM>.

The pod <NUM> is located in the heel region <NUM>. The positioning of the pod <NUM> in the heel region <NUM> allows the pod <NUM> to cushion the impact of the strike of the heel during a step.

In the example illustrated in <FIG>, the pod <NUM> is located in the centre of insole width and in the region corresponding to a user heel would strike the insole <NUM>.

<FIG> shows an example of an insole <NUM> having a top layer <NUM>, a forefoot portion <NUM>, a % length portion <NUM>, a shell <NUM> and a pod <NUM>.

In the example illustrated, the top layer <NUM> comprises a memory foam material and a fabric top cloth, the forefoot portion <NUM> comprises a TPE gel material, the % length portion <NUM> comprises a PU foam, the shell part <NUM> comprises a thermoplastic polyurethane (TPU) and the pod <NUM> comprises an encapsulated liquid. In this example, the top layer <NUM> comprises a fabric material on the foot facing portion of the insole which bonded to a memory foam below.

According to the invention, the heel region comprises a pod and a PU foam layer and the pod comprises an encapsulated liquid and the pod is at least partially embedded in the PU foam layer.

The memory foam of the top layer <NUM> is formed from a PU material having foam bubbles.

In an example the memory foam has a density of <NUM>/cm<NUM>. The density of the memory foam may be in the range of <NUM>/cm<NUM> to <NUM>/cm<NUM>, for example <NUM>/cm<NUM> to <NUM>/cm<NUM>. The memory foam may have a thickness of <NUM> to <NUM>, for example <NUM> to <NUM>.

In an example, the PU foam of the % length portion <NUM> is selected to have a hardness from <NUM> Asker C to <NUM> Asker C, for example <NUM> Asker C to <NUM> Asker C, for example <NUM> Asker C. The thickness of the PU foam may be increased to provide addition cushioning. For example, the PU foam may have a thickness of <NUM> to <NUM>, for example <NUM> to <NUM>, for example <NUM>.

In an example, the TPU material of the shell <NUM> is selected to have a hardness from <NUM> Shore A to <NUM> Shore A, for example <NUM> Shore A to <NUM> Shore A, for example <NUM> Shore A to <NUM> Shore A, for example <NUM> Shore A. The TPU material of the shell <NUM> may have a thickness of <NUM> to <NUM>, for example <NUM>.

In an example, the TPE gel material of the forefoot portion <NUM> is selected to have a hardness from <NUM> Asker C to <NUM> Asker C, for example <NUM> Asker C to <NUM> Asker C, for example <NUM> Asker C. The TPE gel material of the forefoot portion <NUM> may have a thickness of <NUM> to <NUM>, for example <NUM> to <NUM>.

As illustrated in <FIG>, the ball of foot region <NUM>, arch region <NUM> and heel region <NUM> comprise different materials to provide the appropriate support. In this example, the ball of foot region <NUM> comprises a gel layer and a memory foam layer, the arch region <NUM> comprises a PU foam layer and a memory foam layer. The heel region <NUM> comprises a liquid encapsulated in the pod <NUM> and the pod <NUM> is surrounded by a PU foam and a TPU shell <NUM>. In the example shown in <FIG>, the shell extends to the arch region <NUM> of the insole.

In the example illustrated, the heel region comprises a top memory foam layer, a middle PU foam layer and a bottom pod <NUM> with the top closest to the foot facing part of the insole and the bottom closest to the shoe facing part of the insole.

<FIG> shows a further example of an insole <NUM> having a pod <NUM>. In this example, the shell part <NUM> differs from the example illustrated in <FIG> with the shell located in the heel region <NUM> and the arch region <NUM>.

<FIG> illustrates the position of the pod <NUM> in the insole <NUM>. As illustrated, the pod is surrounded by the PU foam on the bottom surface of the insole. For example, the pod <NUM> is bound laterally by the PU foam of the % portion <NUM> and the PU foam of the % portion <NUM> is surrounded by the TPU material of the shell <NUM>. This concentric type structure allows the liquid in the pod <NUM> to move as pressure is applied by the foot during foot strike. For example, as a force is applied to the pod <NUM> by the foot the pod expands laterally to accommodate the movement of the liquid in the pod <NUM> and redistribute the force applied to the pod <NUM> by the foot. For example, as the pod <NUM> is compressed vertically by the foot the liquid moves so that the pod expands laterally. The concentric type structure described above provides lateral resistance to the movement of the pod so that the liquid is able to move sufficiently to provide a redistribution of the force during impact whilst restricting that movement to provide sufficient stability.

In the example illustrated, the TPU material of the shell <NUM> is relatively stiff to inhibit the movement of the PU foam of the % portion <NUM>. The PU foam compresses between the pod and the shell as the pod expands laterally. This compression provides resistance to the expansion of the pod.

In the example shown in <FIG>, there is a gap of <NUM> between the pod and the PU foam on the bottom surface of the insole. This gap allows the pod to expand without the resistance of the PU foam inhibiting the movement. In accordance with the present invention as defined in claim <NUM> as appended hereto, the gap ranges from <NUM> to <NUM>, for example from <NUM> to <NUM>.

The size of the pod is selected to target areas of pressure on the foot during impact. In the examples illustrated above, the pod is located in the heel region and the size of the pod is selected to redistribute the force from the heel during foot strike over a wider area. In general, the force from the heel during foot strike peaks in the heel area of the insole and forms a peak force area. Selecting a pod size to be larger than the area of the force from heel during foot strike allows the force to be redistributed to areas away from the peak force area and therefore increases comfort to the user.

The pod illustrated has an elliptical shape with a major axis (i.e. the longest distance from the centre to the edge of the ellipse) measures <NUM> and a minor axis (i.e. the shortest distance from the centre to the edge of the ellipse) measures <NUM>. The pod may have a major axis from <NUM> to <NUM>, for example <NUM> to <NUM>. The pod may have a minor axis from <NUM> to <NUM>, for example <NUM> to <NUM>.

The size of the pod may differ for different sizes of insole. For example, for an insole sized to fit a shoe sized <NUM> UK the elliptical pod may have a minor axis measuring in the range <NUM> to <NUM>, for example from <NUM> to <NUM>, for example from <NUM> to <NUM>. The elliptical pod may have a major axis measuring in the range <NUM> to <NUM>, for example from <NUM> to <NUM>, for example from <NUM> to <NUM>.

The elliptical pod may be larger for an insole to fit a larger shoe. For example, for an insole sized to fit a shoe sized <NUM> UK the elliptical pod the elliptical pod may have a major axis measuring in the range <NUM> to <NUM>, for example from <NUM> to <NUM>. The elliptical pod may have a minor axis measuring in the range <NUM> to <NUM>, for example from <NUM> to <NUM>.

In the example illustrated, the ratio of the major axis to minor axis of the pod ellipse is <NUM>. <FIG> show the pod <NUM> in more detail. As discussed above the pod encapsulates a liquid. The shape of the pod <NUM> and the bonding of the pod walls provides sufficient resistance to the increase in pressure associated with the impact of a user's foot on the pod during heel strike.

<FIG> shows the top view of the pod <NUM>. The pod <NUM> comprises a centre portion <NUM>, a lip <NUM> and a side wall <NUM>. The centre portion <NUM> comprises a cavity for the liquid and impact during a foot strike on the centre portion will displace the liquid. The cavity formed by the centre portion is shown in detail in the cross-sectional view of <FIG>. As illustrated, the liquid <NUM> is located in the cavity in the centre portion.

The side wall <NUM> is shown in detail in <FIG>. In the example illustrated, the side wall <NUM> extends perpendicularly from the bottom of the insole and has a thickness of <NUM>. In the example illustrated the film comprises a thermoplastic polyurethane material (TPU) and the capsule comprises a thermoplastic polyurethane material (TPU).

The cross-sectional view shown in <FIG> shows the pod being formed by a capsule <NUM> and a film <NUM>. The capsule <NUM> is bonded to the film <NUM> at the lip <NUM>. In this example the film <NUM> and the capsule <NUM> is bonded using a high frequency weld.

The lip <NUM> extends around the perimeter of the pod and provides a large surface area for the capsule <NUM> to bond to the film <NUM>. The large surface area increases the strength of the bond between the capsule <NUM> and the film <NUM>. The bond strength is related to the burst pressure of the pod. In the example illustrated the lip has a length, measured from the edge of the pod to the end of the lip, of <NUM>. The lip length may be from <NUM> to <NUM>, for example <NUM> to <NUM>, for example <NUM> to <NUM>, for example <NUM> to <NUM>.

The lip <NUM> of the pod also allows the pod to be secured in the insole <NUM>. In the example illustrated in <FIG>, the lip <NUM> is bonded to the PU foam of the % portion <NUM>. As illustrated in <FIG>, the lip is enclosed by the % portion <NUM>.

The location of the pod <NUM> in the PU foam <NUM> is illustrated in <FIG>. In this example, the pod is embedded in the PU foam. As illustrated in <FIG>, the PU foam <NUM> is located relative to the pod so that the PU foam is located either side of the lip and therefore embeds the pod by having PU foam on either side of the lip of the pod <NUM>. Embedding the pod in the PU foam <NUM> allows the pod to be secured by the PU foam <NUM> and inhibits the pod from moving within the insole.

In the example illustrated, the capsule <NUM> has a thickness of <NUM> and film has a thickness of <NUM>. The capsule may have a thickness ranging from <NUM> to <NUM>, for example <NUM> to <NUM>. The film may have a thickness ranging from <NUM> to <NUM>, for example <NUM> to <NUM>.

The pod <NUM> comprises a liquid that is sealed within a capsule <NUM> and the film <NUM>. The viscosity and the density of the liquid is selected to provide sufficient cushioning of the force from foot strike whilst also providing stability for the foot. The viscosity and density of the liquid and the encapsulation of the liquid allows the impact of the foot strike to be distributed over a larger area and therefore reduce the peak force on the foot during foot strike. In an example, the liquid has a viscosity of <NUM><NUM>/s (<NUM>,<NUM> cSt) at <NUM> and density of <NUM>/cm<NUM>.

The viscosity of the liquid may range from <NUM> to <NUM><NUM>/s (<NUM>,<NUM> to <NUM>,<NUM> cSt) at <NUM>, for example <NUM> to <NUM><NUM>/s (<NUM>,<NUM> to <NUM>,<NUM> cSt) at <NUM>. The liquid may have a density of <NUM>/cm<NUM> to <NUM>/cm<NUM>, for example <NUM>/cm<NUM> to <NUM>/cm<NUM>.

According to the invention, the insole comprises a pod located in the heel region.

In further examples the pod may be located in other regions of the insole that correspond to areas of high-pressure during foot strike, for example the pod may be located in the ball of foot region.

In the examples illustrated above, the insole comprises a single pod. In further examples, the insole may comprise more than one pod. For example, the insole may comprise a first pod in the heel region and a second pod located in the ball of foot region.

In the examples described above the pod has an elliptical shape, the pod may also be circular.

In the examples above, the shell is made from TPU. In other examples, the shell may be made from hard materials such as Nylon.

In an example, the pod may be sized based on the size of the insole. For example, the pod length may be <NUM>% of the insole length and pod width <NUM>% of the insole width. The pod length may range from <NUM>% to <NUM>% of the insole length, for example <NUM>% to <NUM>% of the insole length, for example <NUM>% to <NUM>% of the insole length. The pod width may range from <NUM>% to <NUM>% of the insole width, for example <NUM>% to <NUM>% of the insole width.

Claim 1:
An insole (<NUM>) comprising a heel region (<NUM>), an arch region (<NUM>) and a forefoot region (<NUM>);
the heel region (<NUM>) comprising a pod (<NUM>) and a PU foam layer;
wherein the pod (<NUM>) comprises an encapsulated liquid, and the pod (<NUM>) is at least partially embedded in the PU foam layer and surrounded by the PU foam on a bottom surface of the insole (<NUM>);
characterised in that the PU foam is separated from the pod (<NUM>) on the bottom surface by a gap of <NUM> to <NUM>.