WO2011050373A1

WO2011050373A1 - Metatarsal guard

Info

Publication number: WO2011050373A1
Application number: PCT/ZA2010/000063
Authority: WO
Inventors: Christopher John Williamson; Roger Ainsley Hardie
Original assignee: Trader Vic (Pty) Ltd
Priority date: 2009-10-22
Filing date: 2010-10-22
Publication date: 2011-04-28
Also published as: AU2010310439B2; AU2010310439A1; ZA201007533B

Abstract

A metatarsal guard (14) made from a shock-absorbing material with a smooth outer surface (18) and an inner surface (24) with a honeycomb structure.

Description

METATARSAL GUARD BACKGROUND OF THE INVENTION

[0001] This invention relates to metatarsal guards which are used with footwear.

[0002] A metatarsal guard protects a metatarsal region of a foot against impact. Typically a metatarsal guard is rigid in order to provide effective protection over a metatarsal area. The rigidity of the guard does however reduce the flexibility thereof. This can limit a user's freedom of movement and can cause discomfort to the user. The bones in the metatarsal region, which run along the top of the foot from just after the ankle to the toes, are delicate and complex. Injuries in this area invariably result in high compensation claims, expensive treatment and rehabilitation costs, extended time off work and varying degrees of permanent crippling.

[0003] US Patent No. 6381876 attempts to address the problem posed by a rigid metatarsal guard and discloses a metatarsal guard which is made from a flexible plastics material and which is incorporated into safety footwear.

[0004] Another consideration is that adequate protection should be provided for both feet. However, in an attempt to provide a single guard which can be used with either foot conflicting requirements occur. The primary consideration is that the guard should protect the metatarsal area. A secondary aspect is that a reasonable degree of protection should be provided on the small toe side of each foot. The guard should also have a neat appearance.

[0005] Although a person's left and right feet are not identically symmetrical they can be considered to be mirror images of each other. If identical guards are applied to the left foot and to the right foot then material that should be protecting part of an outer side of the left foot is extraneous to the inner side of the right foot, and vice versa. Aesthetically the end result is not satisfactory.

[0006] South African Patent No. 2003/9331 describes a metatarsal guard which is bonded to a boot at a toe region. An upper end of the guard can move to some extent over an ankle region when the boot is flexed. This arrangement allows small pebbles and foreign material, which enter a space between the boot and the guard, to cause discomfort to a user.

[0007] Another factor is that flexibility increased by the incorporation of fold lines which divide the guard into a number of raised zones. Each zone offers protection but, along the fold lines, which are of reduced thickness, the degree of protection is substantially reduced.

[0008] An object of this invention is to provide a flexible metatarsal guard which is comfortable and which is able to a substantial extent to absorb and withstand impact. The guard, when attached to footwear, does not unduly hinder or restrict flexing of the foot even in extreme ergonomic positions which might be experienced during active working conditions such as kneeling, bending or squatting. Also the guard should provide uniform protection over the entire metatarsal area.

SUMMARY OF INVENTION

[0009] The invention provides a metatarsal guard which includes a body, which is made from a flexible, resilient, shock-absorbing material, with a first surface and an opposing second surface which includes a plurality of recesses each of which is surrounded by respective walls.

[0010] Each recess may be of any suitable shape, e.g. square, but preferably is hexagonal in outline. [0011] The recesses should face generally in an optimal direction to provide resistance to gravitational forces favouring a direction which is perpendicular to the area which is to be protected. Preferably this objective is achieved by continuing the walls so that each wall is substantially at a right angle to a region which is contacted by the wall when the guard is in position. The flexible and resilient nature of the material from which the body is made helps to provide this characteristic.

[0012] The walls surrounding each respective recess may be positioned so that a portion of a wall of one recess constitutes a portion of a wall of an adjacent recess.

[0013] The second surface of the body may include a solid periphery i.e. the periphery may be devoid of recesses.

[0014] The body may be attached to footwear by securing a solid lip of a first end of the second surface of the body to the footwear in any appropriate way, e.g. by using a suitable adhesive, so that a second end of the body is movable relative to the footwear. Preferably the first end is located at an upper end of the metatarsal guard.

[0015] The body may be generally saddle-shaped and curved in cross section.

[0016] The body may, at least partly, extend over and beyond a toe region of footwear to which it is secured.

[0017] The invention also provides a kit of a first metatarsal guard and a second metatarsal guard, wherein each metatarsal guard is of the kind described hereinbefore, and wherein the first metatarsal guard is substantially a mirror image of the second metatarsal guard. This approach allows one metatarsal guard to be used satisfactorily on footwear on the left foot, and the other metatarsal guard to be used satisfactorily on footwear on the right foot, of a user. [0018] The invention further extends to a combination of footwear and a metatarsal guard of the aforementioned kind over a metatarsal region of the footwear. The metatarsal guard is preferably separately formed and then attached to the footwear. However it does fall within the scope of the invention for the metatarsal guard to be formed integrally with the footwear.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The invention is further described by way of example with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a boot and a metatarsal guard according to the invention;

Figure 2 is a perspective view of the metatarsal guard showing a first surface of the guard;

Figure 3 is a perspective view of the metatarsal guard showing a second surface of the guard;

Figure 4 is a cross-sectional side view of the arrangement of Figure 1 ; and

Figure 5 shows two metatarsal guards, each according to the invention, which comprise a composite kit.

DESCRIPTION OF PREFERRED EMBODIMENT

[0020] Any reference made to a boot in the specification, and any illustration of a boot in the accompanying drawings, is made for convenience only and does not limit use of the metatarsal guard of the invention to a boot. This invention extends any footwear which requires a safety device for the metatarsal region of the foot.

[0021] Figure 1 illustrates an arrangement 10 which comprises a boot 12 and a metatarsal guard 14. The guard includes a body 16 with an outwardly facing first surface 18, a first, upper end 20 and an opposing second, lower end 22. [0022] The body 16 is made from a flexible, resilient, shock-absorbing material such as rubber or polyvinyl chloride (PVC).

[0023] Figure 3 shows a second surface 24 of the body 16. The second surface forms an inner surface of the body for in use it directly opposes an outer surface of the boot. The surface has a plurality of recesses 26, 28, 30, 32, Each recess is surrounded by respective walls 34.

[0024] The walls 34 surrounding each recess generally form respective hexagons. The walls may form other shapes and for example each recess may be surrounded by walls which are in the shape of a square. The invention is not limited in this respect. The walls are positioned in a regular array and portions of the walls surrounding one recess form corresponding portions of adjacent recesses. This results in a honeycomb effect.

[0025] Referring to Figure 2 the body 16 has what may be referred to as a saddle shape. In a longitudinal direction the first surface 18 is concave while, in a transverse direction, the first surface 18 is convex. The second surface 22 is convex in a longitudinal direction and concave in a transverse direction. The body 16 is shaped so that it conforms to an outer surface of the boot 12 and closely embraces and covers the metatarsal region of the boot.

[0026] The second surface 24 is bounded by a solid periphery 46.

[0027] The body 16 may be integrally bonded to the boot. Preferably though the body is adhesively secured to the boot. A solid lip 48 of the first end 20 is adhesively secured to the boot above an ankle region. The opposing second end 22 is not secured to the boot 12. This has a twofold effect. Firstly, there is no upwardly facing gap between the metatarsal guard and the boot through which foreign material could enter into a space between opposing surfaces of the metatarsal guard and the boot. Secondly, if debris does enter the region between the boot and the second surface, there is a self-cleaning action in that the debris readily falls free due to gravitational, ergonomic or mechanical actions. The cleaning of the recessed formations takes place generally automatically when a user is walking for this action causes the walls of the recesses to flex and material which may be held in the recesses is thereby loosened and can fall free. Alternatively the user can pull the second end slightly away from the boot surface and the debris can be removed with ease.

[0028] As relative movement between the boot and the second end is possible the body of the guard does not limit the mobility or adversely affect the comfort of the metatarsal guard user.

[0029] The metatarsal guard is well able to fulfil its primary function of protecting the metatarsal region. The walls 34, due to the resilient nature of the material from which the guard is made, are closely positioned against the outer surface of the boot. Each wall substantially at a right angle to a surface of a region on the footwear which is contacted by the wall. This means that the wall is orientated to absorb impact in a direction which is generally coincident with a plane in which the wall is positioned. The capability of the guard to absorb impact is thus enhanced. The walls act to cushion the effect of impact on the guard by moving, bending and distributing the resulting force across the outer surface of the boot. This is achieved without materially affecting the mobility of the user.

[0030] The second end 22 of the body extends, at least partly, over and beyond the toe region of the boot thereby to protect the toe region 50 and adjacent portions 52 at the sides of the boot - see Figure 4. The extended section of the second end 22 is able to absorb and distribute impact on the section. When flexing of the boot takes place the second end 22 which is not directly adhered to the boot is capable of sliding over the boot surface as is indicated by means of a double-headed arrow 54. Thus the guard does not hinder or restrict the foot when it is flexed even in extreme ergonomic positions experienced, for example, during active working conditions such as kneeling, bending or squatting. This goal is achieved whilst maintaining uniform protection over the entire metatarsal area.

[0031] It is observed in this respect that protective footwear typically incorporates protective steel toe caps. These toe caps do not normally provide protection to the small toes and the capability of the metatarsal guard in this respect is significant.

[0032] The metatarsal guard, which neatly saddles the area between the shin and the toe cap of the boot, is a fixed component which cannot easily be removed. It thus offers permanent built-in protection. An impact on the honeycomb structure is distributed and the impact force is diluted as more of the honeycomb formations come into play. The metatarsal guard is lightweight, typically only 200g, and is fully waterproof.

[0033] Figure 5 shows a kit 56 of first and second metatarsal guards 14A and 14B respectively. In all material respects each guard is of the kind described hereinbefore with reference to Figures 1 to 4. The metatarsal guard 14A is however a mirror image of the metatarsal guard 14B. Each guard is respectively designed to provide adequate protection for the left foot and for the right foot of a user. The protection is such that the small toe of the foot and an adjacent surface of the foot are afforded a reasonable degree of protection. This is done in an aesthetically acceptable manner.

Claims

1. A metatarsal guard which includes a body which is made from a flexible, resilient, shock-absorbing material, with a first surface and an opposing second surface which includes a plurality of recesses each of which is surrounded by respective walls.

2. A metatarsal guard according to claim 1 wherein each recess is hexagonal in outline.

3. A metatarsal guard according to claim 1 wherein the walls surrounding each respective recess are positioned so that a portion of a wall at one recess constitutes a portion of a wall at an adjacent recess.

4. A metatarsal guard according to claim 1 wherein the second surface has a periphery which is devoid of recesses.

5. A metatarsal guard according to claim 1 wherein the body has opposing first and second ends and the first surface is generally concave in a longitudinal direction between the first and second ends and is generally convex in a direction which is transverse to the longitudinal direction.

6. A combination of footwear and a metatarsal guard according to claim 5 wherein the second surface of the body opposes the footwear and the first end of the body, which is uppermost, is secured to the body so that the second end of the body is movable relative to the footwear.

7. The combination of claim 6 wherein the body extends at least partly over and beyond a toe region of the footwear. A metatarsal kit which includes a first metatarsal guard and a second metatarsal guard, each metatarsal guard being according to claim 1 , and wherein the first metatarsal guard is substantially a mirror image of the second metatarsal guard.