!NSOLE

FIELD OF THE INVENTION

This invention relates to an insole More particularly, this invention relates to an tnsole to be used with water and air impermeable footwear, to prevent or limit direct contact of a foot of a wearer of the footwear to moisture accumulated inside said footwear

BACKGROUND TO THE INVENTION

Water and air impermeable footwear, such as rubber shoes or boots or so-called Wellington boots, do not allow moisture accumulated inside the shoe, owing to perspiration of the foot, to evaporate from the inside of the shoe It has been shown that feet perspire approximately half a cupful per foot in a working day This perspiration thus accumulates in the shoe and surrounds the foot of the wearer A disadvantage of perspiration accumulated in the shoe and to which the feet are exposed, is that it causes a condition known as 'trench foot ¹ which makes the skin of the foot rot because it is waterlogged A further disadvantage of wearing these shoes is that wearers of these shoes are at high risk of suffering from fungal infections on their feet, as the environment tnside the shoe provides ideal conditions for the growth of fungi

A still further disadvantage of such impermeable footwear is that they are usually made having a certain width only and do not easily stretch to conform to the width of the wearer's feet Wearers with wider or narrower than average feet are thus not able to comfortably wear such footwear, as their feet fπctionally rub against the insides of the footwear or are compressed by the footwear

Insoles for footwear are widely known and commonly found Known tnsoles are usually designed to alleviate foot pain, by providing soft and pliable insoles which are contoured to support the feet. Such insoles are generally made of a soft material or gel-like substance and have contours to massage the feet

A disadvantage of conventional insoles is that when they are used in impermeable footwear, such as those descnbed above, they are soaked with liquid inside the footwear, which is usually absorbed into the insole still wetting the foot in contact therewith

US6681500 discloses a vapour-permeabie waterproof sole for shoes having a lower flat eiernent, the lower flat element having a hollow upper region delimited by a border with air passage openings which extend laterally with respect to the ground resting plane, an upper element, a membrane made of waterproof and vapour-permeabSe material, which is interposed between said lower and upper elements at said hollow region, said lower and upper elements and said membrane being joined hermetically in penmetπc regions of mutual contact The sole may include one-way valves arranged in channels formed peπmetπcally by a coupling between the lower element and the upper element

Moisture inside the shoe is thus expelled from the shoe to the outside environment as the channels open on the outside of the shoe These shoes do not provide a suitable replacement for rubber shoes or boots for workmen in hazardous environments as hazardous substances may enter such a shoe through these channels

OBJECT OF THE INVENTION

It is accordingly an object of the present invention to provide an insole with which at least some of the aforesaid disadvantages can be overcome or at least minimised

SUMMARY OF THE INVENTION

According to the invention there is provided an insole for footwear to support a foot of a wearer of the footwear, the insofe comprising an insole body having draining means with valve means for draining liquid through the body of the insole from an operatively upper side of the insole to an operatively lower side of the insole

The insole body may elevate the foot of the wearer from the sole of the footwear

The draining means may be in the form of a plurality of passages passing through the insole body, to allow passage of liquid or liquid vapour produced by foot perspiration inside the footwear, from the operatively upper side of the insole to the operatively lower side of the insole

The valve means may be a one-way valve provided in each passage of the draining means, such that liquid is passed only from the operatively upper side of the insole to the operatively lower side of the tnsσfe

The insole body may include a plurality of projections projecting from the operativeSy lower side of the insole

Adjacent projections may define collection spaces in which the liquid may be accumulated

The insofe may be made from a liquid impermeable material, such as rubber or a plastics material, to permit passage of water, water vapour and other liquids through the passages, such that the liquid is not absorbed by the insole

The length of the projections, and thus the amount of elevation provided by the insole body, could be varied, such that higher elevations elevate the foot in the footwear such that the footwear fits around the foot tighter and lower elevations elevate the foot less such that the footwear fits around the foot less tightly

The insole may further be contoured to fit to the shape of the foot and the specific footwear with which it is used

The insole includes an anti-microbiai substance The anti-microbsal may be an anti-fungal substance and/ or an antibacterial substance The anti-microbiai substance is silver

There is provided for the operatively upper side of the insole body to include a silver mesh matenal

The footwear may be any impermeable footwear, such as those selected from the group consisting of sport shoes, work boots, such as gumboots or Wellington boots safety boots incorporating protective toe mechanisms and leisure shoes

The insoie body may include an attachment means on the operatively lower side of the insote for attaching the insole to the sole of the footwear The attachment means may be a sucker or suckers

The insole body may include an absorbent material for absorbing fiquid from the operativefy lower side of the insole

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described below by way of non-limrting examples with reference to the accompanying drawings wherein

Figure 1 is a perspective view from the top of an insole according to one embodiment of the invention,

Figure 2 is a perspective view from the bottom of the insole of figure 1 ,

Figure 3 is a sectional side view of the insole of figures 1 and 2, in use,

Figure 4 is a perspective view of the bottom of the insole and an enlarged view of part of the bottom of the msole of a second embodiment, and Figure 5 is a sectional side view of the insole and an enlarged view of part of the insole of figure 4, in use

DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

Referring to the drawings, in which like numerals refer to like features, an insole according to one embodiment of the invention is generally designated by reference numeral 10

The insole 10 is used with water and air impermeable footwear, such as a rubber boot 12, shown in figures 3 and 5 The impermeable boot 12 does not allow air and/or liquid to pass into or out of the boot 12 Liquid and liquid vapour thus caused by foot perspiration accumulates inside the boot 12

The insole 10 is placed in the boot 12 resting on an upper inner surface of the sole 14 of the boot 12, to support a foot 16 of a wearer of the boot 12 The insole 10 has an fnsole body 18 for elevating the foot 16 of the wearer from the upper inner surface of the sole 14 of the boot 12 The insole body 18 has draining means, in the form of a plurality of passages 20 to allow passage of liquid or liquid vapour produced by foot perspiration inside the boot 12 to pass from an operatsvefy upper side of the insole 10 to an operattvely lower side of the insole 10 The liquid thus accumulates between the operatively lower side of the insole body 18 and the upper snner surface of the soie 14 of the boot 12 After use, the liquid can be drained from the boot 12 and the boot 12 may be cleaned

Referπng to figures 1 to 3, moisture collection spaces 24, between the operatively iower side of the insole body 18 and the upper inner surface of the sole 14 are achieved by a number of projections 22 projecting from the operatively lower side of the insole body 18 The projections 22 are in the form of elongate πbs, which rest on the upper inner surface of the sole 14 of the boot 12, as shown in figure 3 Liquid thus passes through the passages 20 and accumulates in the moisture collection spaces 24 The insole 10 is made from a liquid impermeable material, such as rubber or a plastics material, to permit passage of liquids through the passages 20, so that the liquid is not absorbed by the insole 10 The insole 10 is further contoured to comfortably fit to the shape of the foot 16, so that the insole 10 provides comfort to the wearer

The length of the projections 22, and thus the amount of elevation of the foot 16 provided by the insole body 18, could be vaned to conform to the shape of a foot Furthermore, higher elevations (and thus longer projections 22) would elevate the foot 16 in the boot 12 such that the boot 12 fits around the foot 16 tighter Higher elevations are thus typically used in the case of a wearer with narrower or flatter than average feet Lower elevations (and thus shorter projections 22) would elevate the foot 16 less, such that the boot 12 fits around the foot 16 less tightly A wearer with broader or higher bridged than average feet would thus use lower elevated msotes such that the shoes fit looser around his feet.

In another embodiment of the invention, as shown in figure 4, the insole body 18 includes projections 22 which project from the operatively lower side of the insole 10 The projections 22 are in the form of ribs which intersect each other to form a lattice Each intersection of the πbs defines a cylindrical projection 26 The cylindrical projections 26 terminate at their operatively lower, free ends, in suckers for attaching the insole 10 to the upper, inner surface of the sole 14 of the boot 12 The suckers allow the insole 10 to adhere to the sole 14 of the shoe and prevent the insole 10 from moving relative to the sole 14 of the boot

Moisture collection spaces 24, between the operativeiy lower side of the insole body 18 and the upper inner surface of the sole 14 are formed in between the πbs and projections 26

The operatively lower side of the insole body also 18 includes drainage protrusions in the form of frusto-contcal projections 30 extending from the operatively lower stde of the insole body 18 into the moisture collection spaces 24 These protrusions effectively lengthen the passages 20 making it more difficult for moisture or fluid to pass upwards in the passages Each frustro-

conical projection 30 is surrounded by the πbs 22 such that one frustro-comcal projection 30 projects into one moisture collection space 24

The draining means are a plurality of passages 20 Each passage 20 drams liquid from the operatively upper side of the insole body 18, through a frustro-conical projection 30, to the operatively lower side of the insole body 18 into a moisture collection space 24

Each space is not, however, closed or sealed off The sucker projections 26 extend further away from the lower side of the insole body 18 than operatsvely lower edges of the πbs, such that fluid may flow freely around the sucker formations underneath the ribs

The insole 10 could yet further include an absorbent mateπal (not shown) on the operatively lower side of the insole body 18 to absorb moisture that accumulates in the channels 24

In a further embodiment, the insole 10 could include silver strands woven into an upper layer of the inside body 18 The silver may have cooling properties and anti-microbial properties

The length of the cylindncal projections 26, and thus the amount of elevation of the foot 16 provided by the insole body 18, could be vaπed Higher elevations (and thus longer cylindrical projections 26) would elevate the foot 16 in the boot 12 such that the boot 12 fits around the foot 16 tighter Higher elevations are thus typically used in the case of a wearer with narrower than average feet Lower elevations (and thus shorter cylindrical projections 26) would elevate the foot 16 less, such that the boot 12 fits around the foot 16 less tightly A wearer with broader than average feet would thus use lower elevated insoles such that the shoes fit looser around his feet

It is foreseen that the insole 10 would alleviate direct contact of the foot of the wearer of the shoe 12 to moisture accumulated inside the shoe, to thus promote healthier conditions inside the shoe The insole 10 would further prevent, as a result of the silver in the top of the body 18 microbes such as fungi and bacteπa from growing in the shoe, even if moisture is accumulated in the shoe, owing to the presence of the anti-mtcrobial It will thus prevent fungi and/or bactenal infections of the feet of a wearer It is further foreseen that the insole 10 would aid comfort of the wearer of the shoe stnce the tnsole would be available in different thicknesses, for different widths of feet If a person for example, has a size 8 shoe but with very broad feet, he could wear a size 8 with lower or thinner insoles, so that the shoe fits properly

It is also foreseen that an insole having suction devices 26 will not experience excessive displacement of the insole body 18 relative to the sole 14 of the boot 12 due to movement of the foot during use It is yet further foreseen that the absorbent material in the insole would absorb moisture, thereby drawing moisture away from the foot of the wearer of the shoe and keeping the foot dry It is still further foreseen that an insole 10 incorporating silver threads or a silver mesh material would prevent the growth of microbes in the shoe when the silver is present in the mateπal at higher proportions (weight/weight) At iower proportions of silver (weight/weight), the silver mesh material will also have a cooling effect on the foot of the wearer of the shoe It is further foreseen that the insole 10 could be used with any impermeable footwear, such as sport shoes, work boots including gumboots or Wellington boots, safety shoes having protective toe devices or leisure shoes

It will be appreciated that vanations in detail are possible with an insole according to the invention without departing from the scope of this disclosure For example, the insole 10 may include valve means consisting of a one-way valve (not shown) provided in each of the passages 20 The one-way valve may be a type of duckbill valve The one-way valve allows liquid to pass only from the operativeiy upper side of the insole 10, to an operatively lower side of the insole 10