GB2435396A

GB2435396A - Cushioning element for heel of footwear

Info

Publication number: GB2435396A
Application number: GB0604025A
Authority: GB
Inventors: Jack Stuart Kishk
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-02-28
Filing date: 2006-02-28
Publication date: 2007-08-29
Anticipated expiration: 2026-02-28
Also published as: GB0604025D0; GB2435396B

Abstract

The sole (20) for footwear has a cushioning element 60 incorporated into the heel portion (50) of the sole. A recess is formed in the sole in the heel area. A cushioning element 60 is closely fined into the recess. The cushioning element (60) comprises a hollow container having flexible walls and filled with gas. The cushioning element (60) comprises a horseshoe shaped tube 61 with cross tubes 62 moulded into a heel block 50.

Description

I

M&C Folio: GBP93845 Document: 1145229

HEEL CONSTRUCTION

Field of the Invention

The invention relates to soles having a cushion in the heel and a method for making them and a cushioning element for a sole.

Background of the Invention

Cushioning heels in sneakers and shoes are well known in the art. Cushions provide shock absorption and comfort for the wearer, especially during physical activity such as hiking, physical labour and sports such as basketball. Typically, a cushion is put in the mould and the plastic sole is injection moulded about the cushion. The sole then is incorporated in the manufacture of the shoe.

Heavy boots present a problem when trying to incorporate cushions into the heel. Manufacturer of such boots require the heavy sole to be trimmed to fit the undersole. If a cushion is incorporated into the heel, it quickly becomes separated from the thick sole as there is nothing to hold the two together against the stress and flexing of the sole.

There is a need in the art for heel construction for shoes or boots having a cushion able to withstand stress and flexing of the sole without the heel becoming separated from the thick sole.

It is also desired to provide a heel construction in which a high degree of cushioning can be obtained within a simple design. It is desired that the heel construction should be straight forward to manufacture.

It is particularly desired to provide a heel construction for footwear aid using a Goodyear welt.

Summary of the Invention

The present invention provides a sole for footwear comprising a heel portion, having a cushioning element for providing comfort to the user, the cushioning element comprising a hollow container having flexible walls and filled with gas.

The present invention further provides a cushioning element for the heel portion of footwear, the cushioning element comprising a hollow container having flexible walls and filled with gas.

The present invention further provides a method of making a sole comprising forming a heel, having a cushioning element therein, the cushioning element comprising a hollow container having flexible walls and filled with gas.

The cushioning element used in the present invention provides a particularly reliable form of cushioning which can be integrated into a sole relatively simply.

In a preferred embodiment, said cushioning element comprises a hollow member spaced inwardly from the periphery of the heel and extending around at least 50% of the periphery of the heel. The cushioning element may be located in a recess in the heel.

By spacing the cushioning element inwardly from the periphery of the heel, the heel can be trimmed when necessary. It also places the cushioning element in a position where it is able to provide the most effective support for the user. By extending around at least 50% of the periphery of the heel, a high degree of support can be provided.

Preferably, the cushioning element extends around at least 75% of the periphery of the heel. The cushioning element may have a generally U-shaped or horseshoe shaped outer boundary. This allows the cushioning element to match the general shape of the heel and provides support over a large area. The cushioning element may comprise elements having a generally circular section when viewed in a plane which extends generally normal to the sole. The circular section elements provide good cushioning effect. By making the cushioning element out of plurality of circular section elements connected together, extensive cushioning effect can be obtained, with the cushioning element integrated into the heel so that good bonding between the surfaces of the cushioning element and the heel can be obtained.

Preferably, the cushioning element comprises a U-shaped member having a pair of arms which are connected together, at least one cross-structure being provided extending between the arms. The cross-structure suitably comprises at least one hollow member and may comprise a plurality of tubes. This allows a good integration of the cushioning member into the heel, having a large contact surface area between the members and the heel material. Preferably, air can flow between the arms and the tubes of the cross-structure. This allows rocking or other movements of the heel to be cushioned by allowing some parts of the cushioning member to be compressed when others are not under load. Preferably, the cushioning element comprises one or more structural elements, a web being provided extending between structural elements or between a structural element and the arms of the cushioning element. Preferably, the or each web comprises an aperture. These measures provide good bonding between the cushioning element and the material of the heel.

The cushioning element may be fixed to the heel material by adhesive.

Windows may be provided in the side of the heel extending to the periphery of the cushioning element. This means that at least one surface of the cushioning element is not constrained by the material of the heel, so that it deforms more easily, increasing the cushioning effect. Preferably, there is a window on each side of the heel, each window extending to the recess, so that the enhanced cushioning effect is provided on both sides of the heel.

Preferably, the cushioning element is integrally moulded in place in the heel block, to obtain a strong bond between the cushioning element and the heel, to prevent parts of the heel coming apart from one another under stress during use.

The gas in the cushioning element may be air or any other suitable gas.

By "flexible walls" it is meant that the walls of the container can flex under the loads applied to the container in normal use.

Preferably, the walls of the container are made of an oil resistant material. This will allow the footwear to be used in environments in which the heel is exposed to oil, without damage.

The cushioning element may comprise gas at a pressure above atmospheric pressure. For example, the cushioning element may comprise an injection moulded component which is subsequently inflated with gas and sealed.

The footwear may be any suitable footwear, for example a shoe or boot.

The present invention is particularly suitable for use in footwear manufactured using a Goodyear welt.

The present invention will be further described by way of example only, with reference to the accompanying drawings, in which:

Brief Description of the Drawings

Figure 1 is a side view of a boot incorporating a sole according to the invention.

Figure 2 is a cross sectional view of the forefoot portion of the boot of Figure 1.

Figure 3 is an exploded view of the sole of the boot of Figure 1.

Figure 4 is a view from underneath of the sole of figure 3.

Figure 5 is a cross sectional view along the line VV of the sole of Figure 4, showing the sole part and heel block in more detail.

Figure 6 is a plan view of a cushioning element according to the invention within the heel block Figure 7 is a cross sectional view along line Vil-Vill of figures 4 and 5, in exploded view.

Detailed description of the invention

Figure 1 shows a conventional boot 10 having a sole 20, a mid sole 30 and upper 40. The upper 40 is attached to the mid-sole 30 by a welt 31. The welt 31 may be made of durable material such as PVC or leather. The welt 31 sits on the top of the sole and is connected to the upper by stitching 32 in a conventional manner.

Figure 2 shows a sketch cross section of the forefoot portion of the boot 10 showing the stitching 32 through the welt 31 in more detail.

The construction shown is commonly referred to a Goodyear welt, which is known to the skilled person, and will not be described further.

Figure 3 shows an exploded schematic isometric view of the sole 20. It comprises a forefoot portion 21 and a heel portion 22. The heel portion 22 comprises a step 23 for receiving a heel block 50. This it to allow the heel block to be manufactured separately and then united with the heel portion 22 abutting step 23. It may be fixed in position, for example by adhesive.

The sole 20 can then be manufactured out of a material which is commonly used for a sole, for example natural or synthetic rubber or polyurethane or PVC, with a tread 24 formed on an underside thereof for grip.

The heel block 50 comprises a cushioning element which will be described further below and which is not visible in figure 3 except through a window 51 which will be described further below.

Figure 4 shows a view of the sole 20 of Figure 3 from the top. The position of the welt 31 is shown in dotted lines. The heel block 50 is shown in position adjacent to the step 23. Profiling 25 is formed on an upper surface of an instep portion of the sole 20, to enhance bond to an insole and to provide more comfort for the wearer.

Figure 5 shows a cross sectional view along the line VV in figure 4 Only the heel portion 22 and adjacent instep portion 26 are shown. A tread pattern 24 can be seen on the tread side of the sole 20. This will be of conventional design and will not be described further.

The line a-a shown in Figure 5 defines a notional contact plane between the sole and the ground, which may be taken to be the horizontal direction. It can be seen that the face of the step 23 is not normal to the horizontal direction but slightly inclined. The heel block 50 is shown disconnected from the sole portion 22 in figure 5. Tn practice, it will be fixed in place by adhesive. It can be seen that the heel block 50 comprises a cushioning element 60 which will be described further below.

The heel portion 22 is suitably injection moulded from natural or synthetic rubber, polyurethane or PVC.. The heel block 60 preferably comprises a polyurethane block with the cushioning element 60 moulded in situ.

Figure 6 is a plan view of the cushioning element 60, showing its position within the heel block 50.

The cushioning element is formed in a recess in the heel block 50. This is achieved, for example by moulding the heel block 50 in situ around the cushioning element 60.

The cushioning element comprises a hollow polyurethane container having flexible walls. It comprises a grid of interconnected tubes filled with gas, for example air. As a result, it defines a hollow container having flexible walls. The walls will deflect under the weight of a wearer of the boot, to provide a cushioning effect.

The walls are oil resistant.

The cushioning element is spaced inwardly from the periphery of the heel by a distance of about 1cm. It extends around nearly 90% of the outer periphery of the heel, so that a very large proportion of the area of the heel is cushioned by the cushioning element. It can be seen that it has a generally U-shaped outline with a pair of arms 61, one on either side, the arms being continuous with one another. The arms 61 are of generally circular cross-section, as can be seen in figure 5 and figure 7. Cross structures are provided in the form of hollow tubular members 62. There are four of these, extending from one side to the other. The connection between the tubes 62 and the arms 61 is unobstructed, so that gas can flow freely from one side of the cushioning element to the other, enhancing the cushioning effect.

There is a centre tube 63 which extends from the apex of the U and intersects all of the cross tubes 62. In this way, a rectangular grid is defined. Further, there is free flow of gas between the cross tubes 62 and the centre tube 63, to allow gas to move from front to back of the cushioning element. An inflation point 64 can be seen at one end of the cushioning element. The cushioning element may for example be formed by injection moulding with an opening at the inflation point 64 to allow gas to be fed under pressure to the cushioning element to ensure that it is inflated. Once it is inflated, the inflation point 64 can be closed, for example by a stopper or by heat sealing.

A web 65 is formed between the tubes 61, 62, 63 within the grid, to provide additional strength. This web 65 is pierced by one or two holes 54, 55. The holes allow the material of the heel block 50 to penetrate through the components of the cushioning element 60, allowing a good bond between upper and lower parts of the heel block 50 and preventing delamination at the cushioning element.

Figure 7 is a sketch section along line Vu-Vu of figures 5 and 4. It should be noted that figure 7 shows a side wall 65 of one of the cross tubes 62.

The heel block 50 is shown disconnected from the heel portion 22. In practice, they would be fixed together with adhesive.

Figure 7 shows a pair of wedge shaped windows 51 which extend inwardly from the periphery of the heel block 50 to the outer periphery of the cushioning element 60.

This allows the cushioning element to be readily deformed under load, as the respective part of the element 60 adjacent the windows 51 can be deformed without being constrained by the material of the heel block 50.

The windows 51 have a limited extent from front to back. Typically, they extend for about 4-5 cm.

Claims

CLAIMS: 1. A sole for footwear comprising: a heel portion; at least one

recess in said heel portion; the recess comprising a cushioning element for providing comfort to the user, the cushioning element comprising a hollow container having flexible walls and filled with gas.

2. The sole of claim 1, wherein said cushioning element comprises a hollow member spaced inwardly from the periphery of the heel and extending around at least 50% of the periphery of the heel.

3. The sole of claim 2, wherein the cushioning element extends around at least 75% of the periphery of the heel.

4. The sole of any of claims 1 to 3, wherein the cushioning element has a generally U-shaped or horseshoe shaped outer boundary.

5. The sole according to any of claims 1 to 4, wherein the cushioning element comprises structural elements having a generally circular section when viewed in a plane which extends generally normal to the sole.

6. The sole according to any of claims 1 to 5, wherein the cushioning element comprises a U-shaped member having a pair of arms, at least one cross-structure being provided extending between the arms.

7. The sole of claim 6, wherein the cross-structure comprises at least one hollow member.

8. The sole of claim 16 or 7, wherein the cross-structure comprises a plurality of tubes.

9. The sole of claim 8, wherein gas can flow between the arms of the cushioning element and the tubes of the cross-structure.

10. The sole of any of claims 6 to 9, wherein the cross-structure comprises one or more structural elements, a web being provided extending between structural elements or between a structural element and the U-shaped member.

11. A sole according to claim 10, wherein the web comprises an aperture.

12. A sole according to any of claims 6 to 11, wherein the cushioning element comprises a centre member extending in the same general direction as the arms of the U-shaped member, the centre member comprising a hollow tube.

13. The sole of claim 1, wherein the cushioning element is located in a recess and is fixed thereto with adhesive.

14. The sole of any of claims 1 to 13, further comprising a window in the side of said heel extending to the periphery of the cushioning element.

15. The sole of claim 14, further comprising a window on each side of the heel, each extending to the periphery of the cushioning element.

16. A sole according to any claims 1 to 15, wherein the heel comprises the cushioning element and a sole block which is moulded in place around the cushioning element.

17. The sole of any preceding claim, wherein the gas in the cushioning element is at a pressure above atmospheric pressure.

18. Footwear, comprising a sole according to any preceding claim.

19. Footwear of claim 18, wherein the footwear is manufactured with a Goodyear welt.

20. A cushioning element for a sole for footwear, comprising a hollow container having flexible walls and filled with gas.

21. The cushioning element of claim 18, wherein the cushioning element is as set out in any of claims 2 to 12.

22. A method of making a sole, comprising forming a heel, having a cushioning element therein, the cushioning element comprising a hollow container having flexible walls and filled with gas.

23. The method of claim 22 wherein the cushioning element is as defined in any of claims 2to 11.

24. The method of claim 22 or 23 further comprising securing said cushioning element in a recess formed in the heel.

25. The method of claim 24, further comprising using adhesive to secure said cushioning element.

26. The method of claim 22, further comprising forming the heel by integrally moulding a heel block around the cushioning element.

27. A sole, substantially as herein described with reference to the accompanying drawings.

28. A method of forming a sole, substantially as herein described with reference to the accompanying drawings.

29. A cushioning element for a sole, substantially as herein described with reference to the accompanying drawings.