Boot Insert

Abstract

A low friction boot insert 1 that is positioned around the lower leg surrounding a sock 2 and on the inside of a boot 4 such as those worn for skiing. Rotational movement 5 and longitudinal movement 6 of the skin 3 relative to the boot surface is minimised by reducing friction at the interface of the insert and boot or the interface of the insert and sock or both. The reduction in friction transferred to the interface between sock and skin helps to reduce the chafing of the skin which can cause blisters or sores.

Claims

1. A ski boot insert for positioning around a user's lower leg between a sock outer surface and a boot inner surface to reduce the transfer of friction to the skin of a user arising from movement of the boot; the boot insert comprising a deformable panel having smooth major surfaces; two panel ends; and mutually interlockable elements extending from each panel end; wherein each smooth major surface has a static coefficient of friction against cotton fabric of 0.5 or less.

2. A ski boot insert according to claim 1, wherein the deformable panel has an arcuate-oblong shape when in a non-deformed condition.

3. A ski boot insert according to claim 2, wherein the shorter lateral ends of the arcuate-oblong shaped deformable panel are convexly curved.

4. A ski boot insert according to any preceding claim, wherein the deformable panel is formed from a plastic or composite material having a thickness of between 0.1 mm and 4.0 mm.

5. A ski boot insert according to any preceding claim, wherein aeration apertures extend through the deformable panel between the major surfaces.

6. A boot insert assembly comprising: (i) a ski boot insert according to any preceding claim; (ii) a sock; and (iii) a strip of relatively high friction elastomeric material; wherein said elastomeric material is for positioning around a user's leg between said sock's outer surface and a boot's inner surface, and above said deformable panel.

7. A boot insert assembly comprising: a ski boot insert according to any of claims 1 to 5; and (ii) a sock; wherein at least part of the sock is provided with a second ply defining a space within which the deformable panel can be accommodated.

8. A boot insert assembly comprising: a ski boot insert according to any of claims 1 to 5; (ii) a boot; and (iii) a sock; wherein at least part of an upper portion of said sock and at least part of an upper portion of said boot are provided with releasable fastening means.

9. A method of reducing the transfer of friction between a boot and a user's skin comprising the steps of: providing a ski boot insert having a deformable panel according to any one of claims 1 to 5; (ii) positioning said deformable panel around a user's lower leg between a sock outer surface and a boot inner surface; and (iii) interlocking the elements extending from each panel end.

10. A method according to claim 9, wherein the step of positioning said deformable panel around a user's lower leg involves heating the deformable panel and moulding it around the user's sock.

11. A method according to claim 9 or 10 comprising the further step of positioning a strip of relatively high friction elastomeric material around a user's leg between an outer surface of the sock and an inner surface of the boot, and above said deformable panel.

12. A method according to claim 9 or 10 comprising the further step of providing a sock having a second ply defining a space within which the deformable panel can be accommodated.

13. A method according to claim 9 or 10 comprising the further step of providing releasable complementary fastening means on at least part of an upper portion of the sock and at least part of an upper portion of the boot.

Description

[0032] Embodiments of the present invention will now be described by way of example only, with reference to the following diagrams, in which:

[0033] FIG. 1 shows a cross-sectional view of a user wearing an insert between sock and ski boot and differentiates between the principal forces acting between a ski boot and a user's lower leg.

[0034] FIG. 2 shows a cross-sectional view of a user wearing an insert according to the present invention which differs from that illustrated in FIG. 1 insofar as the insert is shaped to include extending elements which substantially interlock or overlap where the ends of said insert meet.

[0035] FIG. 3 shows a cross-sectional view of a user wearing an insert according to an alternative embodiment of the invention where the insert is kept in place by applying a band of high-friction material around the circumference of a user's sock just above the insert.

[0036] FIG. 4 shows a cross-sectional view of a user wearing an insert according to a further alternative embodiment of the invention where the insert is placed between an inner and outer sock ply, all situated within a ski boot.

[0037] FIG. 5(a) shows an enlarged view of the corresponding layers with a graphical representation of the magnitude of shear forces being transferred from ski boot surface to skin for a user wearing a conventional sock and ski boot as represented in FIG. 5(b).

[0038] FIG. 6(a) shows an enlarged view of the corresponding layers with a graphical representation of the magnitude of shear forces being transferred from ski boot surface to skin for a user wearing an insert between sock and ski boot as represented in FIG. 6(b).

[0039] FIG. 7 shows a plan view of a low friction insert laid out flat and before wrapping around a user's leg.

[0040] FIG. 8 shows a plan view of an insert according to the present invention which differs from that illustrated FIG. 7 insofar as the insert is shaped to include extending elements which substantially interlock or overlap where the ends of said insert meet after wrapping around a user's leg.

[0041] FIG. 9 shows a perspective view of a low friction insert as it is being positioned but before it is wrapped around a user's leg.

[0042] FIG. 10 shows a low friction insert once positioned around a user's leg and before being fitted within a ski boot.

[0043] In FIG. 1, an insert 1 is placed around the lower leg to substantially surround a user's sock 2 which is in turn in contact directly with the user's skin 3 and all of which are worn within a ski boot 4. The insert is positioned around a portion of the lower leg between ankle and upper calf or a portion thereof in order to have a freedom of rotation around and longitudinal movement along the axis of the leg to substantially reduce shear forces being transferred from ski boot to the user's skin via the sock. The insert may be formed from a strip of deformable material wrapped around the user's leg whereby the ends meet to substantially surround the lower leg.

[0044] The insert 1 is intended to substantially reduce friction arising from shear forces acting in the rotational direction 5 around the axis of the extended leg as well as shear forces acting in the longitudinal (i.e. upward/downward) direction 6 relative to the extended leg. However, the reduction or absorption of compressive and tensile forces 7 is not a primary concern of the present invention.

[0045] The insert is formed from a thin layer of semi-rigid deformable material such as a plastic or a composite with low friction surfaces on one or both sides. The low friction surface or surfaces reduce shear forces acting at the user's skin by reducing friction at either the interface between ski boot inner surface and insert outer surface or at the interface between insert inner surface and sock outer surface or both.

[0046] The insert may incorporate small holes or channels to improve aeration of the skin surface so that moisture from sweat collecting at the user's skin is wicked away through said holes or channels.

[0047] The insert is shaped to include extending elements or fingers which substantially interlock or overlap where said insert ends meet after being wrapped around the leg, as illustrated in FIG. 2.

[0048] FIG. 3 shows an alternative embodiment in which a band of material is placed above the insert and displaced between the sock and the boot to prevent the insert moving vertically out of the intended position. Said bands of material may be attached to either the sock outer surface, the boot inner surface, or to both. These bands may be formed from any material which substantially impedes unwanted movement of the insert such as a rubber, sticky rubber-like material or a plastic. Alternatively, the insert may be kept in position by the use of a temporary attachment between sock and ski boot inner or outer surface such as bands of hook and loop fastener tape positioned between the ski sock and boot surface or a strap which is tightened around the outside of the ski boot after the ski fabric has been extended over it.

[0049] FIG. 4 shows a further alternative embodiment in which the sock and insert are surrounded by another layer of sock fabric. This fabric may be an additional single sock worn on top of the skin-contacting sock as represented here. Alternatively, it may be a second sock ply attached to the skin-contacting sock either below or above the position of the insert.