This invention relates generally to hosiery, particularly to hosiery having a gripping means. More specifically, although not exclusively, this invention relates to socks, for example compression socks, having a gripping or slip resistant sole.

Compression socks apply a compressive pressure to the ankle and leg regions of a wearer. Some compression sock designs, for example compression stockings, extend along a substantial portion or nearly the entire length of the leg region of a wearer.

Compression socks or stockings are usually worn by a person whose movement is limited, for example, after an operation or during an airline flight. A reduction in movement can increase the risk of thrombosis or embolism. By applying pressure to the ankle and/or leg, the velocity of blood flow can be increased, reducing the likelihood of thrombosis or embolism occurring.

Compression socks or stockings may be worn with or without shoes. It has been observed that, in both cases, the sock is susceptible to slipping, either between the sock and the floor or between the sock and the sole of a shoe. This can be particularly dangerous in the case of floors which are highly polished and/or in the case of weak or disabled.

In order to prevent such slippage, it is known to apply anti-slip features to the sole of the compression sock or stocking. WO2012/058708 describes an example of a compression stocking that includes such an anti-slip feature.

However, the applicant has observed that the design and application of anti-slip features is sub-optimal, often requiring excessive amounts of anti-slip material, resulting in increased cost to the end user. The applicant has also observed that the effectiveness of the anti-slip features could be improved.

It is therefore a non-exclusive object of the invention to provide a compression sock or stocking with anti-slip features that mitigate the drawbacks of known compression socks or stockings.

Accordingly, a first aspect of the invention provides a sock comprising a sole with a plantar surface, the plantar surface comprising a forefoot region, a midfoot region and a hindfoot region, each region of the plantar surface having a pattern of grip material deposited thereon, wherein the pattern density of the grip material pattern in the midfoot region is less than the pattern density of the grip material pattern in the forefoot and hindfoot regions.

Arranging the grip material pattern such that the pattern density in the forefoot and hindfoot regions is greater than that in the midfoot region optimises the use of grip material. The grip material is concentrated in the main pressure zones that occur when the wearer's foot contacts a floor and is used more sparingly in other areas.

The sock may be non-sided, non-specific or non-foot specific. The pattern of grip material deposited on the plantar surface may be symmetrical, for example about an axis extending along the sock and/or from the centre of the hindfoot region to the centre of the forefoot region. The sock may comprise or be formed of a fabric material, which may be woven or knitted.

For the avoidance of doubt, the terms 'non-sided', 'non-specific' and 'non-foot specific' as used herein in reference to sock or stocking mean that the sock or stocking can be worn on either foot, there being no features of the sock or stocking adapted specifically for the left or right foot of a wearer.

The midfoot region of the plantar surface may comprise a pair of lateral midfoot regions, which may be spaced. The midfoot region may comprise a central midfoot region, which may be between the lateral midfoot regions. At least one or each of the lateral midfoot regions may comprise a grip material or a pattern of grip material thereon, e.g. deposited thereon. The central midfoot region may comprise a grip material or a pattern of grip material thereon, e.g. deposited thereon, or may be free of grip material. The pattern density of the grip material pattern in the central midfoot region may be less than the pattern density of the grip material pattern in the lateral midfoot regions or at least one or each of the lateral midfoot regions.

The pattern density of the grip material pattern in at least one or each lateral midfoot region may be less than the pattern density of the grip material pattern in the forefoot and/or midfoot regions. The central midfoot region may be described or delineated by the grip material pattern(s) in at least one or two or more, e.g. each, of the forefoot, hindfoot and lateral midfoot regions. The central midfoot region may comprise an enlarged area, e.g. a first enlarged area, which may be adjacent the forefoot region. The central midfoot region may comprise an enlarged area, e.g. a second enlarged area, adjacent the hindfoot region. The central midfoot region may comprise a necked area, e.g. a third, necked area, which may join the enlarged areas, e.g. the first and second enlarged areas.

The sock may comprise a portion or surface, for example a vamp or upper portion or surface, which may be opposed or opposite or above the sole or plantar surface. The portion or surface may comprise an instep region, which may comprise a pattern of grip material, e.g. thereon or deposited thereon.

Another aspect of the invention provides a sock comprising a vamp portion or surface having an instep region with a pattern of grip material, e.g. thereon or deposited thereon. The sock may comprise a sole, which may have a plantar surface. The plantar surface may comprise a forefoot region and/or a midfoot region and/or a hindfoot region. The plantar surface, for example one or more or each region thereof, may comprise a pattern of grip material deposited thereon.

The application of grip material to the instep region in the critical area of contact between the instep and footwear is advantageous in that it reduces the likelihood of relative movement between the sock and a shoe. By having a grip material pattern on the plantar surface and on the instep region of the vamp portion or surface, two areas of anti-slip contact between the shoe and the sock are provided.

In embodiments, the grip material pattern of at least one of the regions may comprise at least one ridge, which may be curvilinear and/or may extend about at least part of its periphery. The sock may comprise first and second curvilinear ridges. The second curvilinear ridge may be offset or offset from and/or parallel to the first curvilinear ridge.

The grip material pattern may comprise discrete deposits, which may be spaced from one another. The pattern density may comprises the proportion of surface area covered by the grip material. In some embodiments, the grip material pattern may comprise two or more nested ridges, e.g. curvilinear ridges. At least one of the ridges, e.g. the nested ridges, may describe a closed form, for example a polygon, circle or closed free-form. The closed form may be interrupted. Alternatively, the closed form may be uninterrupted.

It will be understood by the skilled person that the use of parallel or nested curvilinear ridges can increase the traction between the floor and the sock.

In embodiments, the closed form or nested ridges are only located in the forefoot region and/or the hindfoot region and/or the instep region. The midfoot region, e.g. the central midfoot region and/or the lateral midfoot regions, may be free of closed form or nested ridges.

In embodiments, one or more closed form or nested ridges are located at or adjacent portions of the forefoot and/or hindfoot region corresponding to or aligned with one or more particular areas of a wearer's foot. The particular areas may include the ball of a wearer's foot or the tibial sesamoid or fibular sesamoid or first metatarsal phalangeal joint of a wearer's foot. The particular areas may include the second, third, fourth and/or fifth metatarsal and/or metatarsal head of a wearer's foot. The particular areas may include the plantar medial tubercle of the calcaneus of a wearer's foot.

It is believed that traction between a sole and floor is greatest when tread and groove designs of soles extend in a direction perpendicular to the walking direction of the wearer.

Therefore, the polygonal or circular curvilinear ridge is advantageous, inter alia, in that it provides traction in all directions.

The grip material pattern of at least one of the regions may comprise one or more curvilinear ridges. The grip material pattern of at least one of the regions may comprise one or more bosses. The grip material pattern of at least one region may comprise one or more ridges, e.g. curvilinear ridges, and one or more bosses. In some embodiments, the grip material pattern of each region comprises one or more ridges and one or more bosses. In embodiments, the grip material pattern of the region(s) having a higher pattern density comprise more ridges than those having a lower pattern density. In embodiments, the grip material pattern of the region(s) having a lower pattern density comprise more bosses than those having a higher pattern density. In embodiments, the grip material pattern of the region(s) having a higher pattern density comprise bosses and/or ridges that are closer together or less spaced than those having a lower pattern density.

The grip material may comprise material having a higher coefficient of friction than the material, e.g. the fabric or bulk material, of the sock. The grip material may comprise a polymer, for example, an elastomer such as a synthetic or natural rubber or other rubberlike material. In embodiments, the grip material comprises a silicone-based polymer or polysiloxane.

The grip material may comprise a bead or beading on the plantar surface and/or the vamp region or surface. The ridges may be less than 10mm in width and/or the bosses may have a maximum dimension, e.g. diameter, that is less than 10mm. Preferably, the ridges are less than 8mm in width and/or the bosses have a maximum dimension, e.g. diameter, that is less than 8mm. More preferably, the ridges are less than 6mm in width and/or the bosses have a maximum dimension, e.g. diameter, that is less than 6mm. The ridges may be 5mm or less in width and/or the maximum dimension of the bosses may be 5mm or less.

The grip material may be included, deposited or applied to the plantar surface and/or vamp region or surface of the sock as an ink, for example, a plastisol ink. The grip material may be applied to the plantar surface and/or vamp surface of the sock via a printing technique, for example a screen printing technique, or any other suitable depositing or application technique.

The sock may comprise a foot portion, which may comprise the sole and/or the vamp region or surface. The sock may comprise a leg portion, which may be configured to extend from the foot portion to or adjacent a calf of a wearer. In embodiments, the sock comprises a stocking, wherein the leg portion is configured to extend to or adjacent a knee or thigh of a wearer and/or over a calf of a wearer and/or over a thigh of a wearer. The stocking may comprise a knee high stocking or a thigh high stocking.

The sock may comprise a compression sock or stocking, for example an anti-embolism sock or stocking. The sock or fabric material may comprise or be configured to provide a graduated compression, for example along at least the leg portion thereof. In embodiments, the sock or leg portion may comprise or be configured to provide a graduated compression that decreases from the foot portion toward an opposite or free end of the sock or leg portion, e.g. opposite to the foot portion. The sock or fabric material may comprise or be configured to provide a compressive pressure of between 1.0-3.0 kPa (7.5-22.5 mmHg), preferably between 1.5-2.5 kPa (11.3-18.75 mmHg), for example between 1.9-2.4 kPa (14- 18 mmHg), to an ankle of a wearer when in a supine position. The sock or fabric material may comprise or be treated with an antimicrobial agent.

The sock or fabric material may be stitched or woven to provide compression or graduated compression to the foot and/or leg of the wearer. The sock or fabric material may comprise a stitching or weaving pattern and/or pattern density. The sock or fabric material may comprise an elastomeric or elastane material, e.g. formed into elongate member(s) or thread(s). The sock or fabric material may comprise an aliphatic or semi-aromatic polyamide or nylon, e.g. formed into elongate member(s) or thread(s). In embodiments, the sock or fabric material comprises about 20-30%, e.g. about 25%, elastane and/or about 70- 80%, e.g. about 75%, aliphatic or semi-aromatic polyamide material.

The sock may comprise an aperture or opening, for example a toe aperture or opening. The aperture or opening may be located adjacent a portion of the sock corresponding to or aligned with one or more toes of a wearer's foot. The aperture or opening may be located in or on the sole or plantar surface. The aperture or opening may be expandable or stretchable to enable insertion of one or more toes therethrough and/or to enable the aperture or opening to engage with one or more toes inserted therethrough. In embodiments, the aperture or opening may be expandable or stretchable around one or more toes to enable inspection thereof, e.g. while the sock is worn. The aperture or opening may comprise or be described or defined by a welt, which may be resilient or elastic.

For the avoidance of doubt, any of the features described herein apply equally to any aspect of the invention. Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. For the avoidance of doubt, the terms "may", "and/or", "e.g.", "for example" and any similar term as used herein should be interpreted as non-limiting such that any feature so-described need not be present. Indeed, any combination of optional features is expressly envisaged without departing from the scope of the invention, whether or not these are expressly claimed. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a plan view of the bottom of a left foot showing the areas that experience the highest pressures when a user walks;

Figure 2 shows a view of the main pressure areas of a right foot;

Figure 3 shows the main pressure areas of right and left feet superimposed;

Figure 4 shows the superimposed main pressure areas of Figure 3 mapped onto a sole of a sock;

Figure 5 shows a pattern of grip material on a plantar surface of a sock according to an embodiment of the invention;

Figure 6 shows a pattern of grip material on a vamp surface of a sock according to an embodiment of the invention;

Figure 7 shows a pattern of grip material on a plantar surface of a sock according to another embodiment of the invention;

Figure 8 shows a pattern of grip material on a vamp surface of a sock according to another embodiment of the invention; and

Figure 9 shows a pattern of grip material on a plantar surface of a sock according to yet another embodiment of the invention.

Referring now to Figure 1 , there is shown a bottom plan view of a left foot 10 having a bottom surface 11 with a forefoot region F, a midfoot region M and a hindfoot region H. The bottom surface 1 1 of foot 1 is the inferior aspect, sole or bottom of the foot, much of which is in contact with the ground when a person is standing or during gait. When the bottom surface 11 is in contact with the ground there are a number of critical areas 12 at which the pressure applied to the bottom surface 11 is greatest. Surrounding the critical areas 12 are pressure zones 13 which are the areas of the bottom surface 1 1 that come into contact with the ground when standing or during gait, but which experience less pressure than the critical areas 12.

The critical areas 12 occur in the forefoot and hindfoot regions F, H. The critical areas 12 in the forefoot region F, referred to herein as forefoot critical areas 14a, 14b, 14c, 14d, include a first, largest area 14a corresponding to the tibial sesamoid, fibular sesamoid, first metatarsal phalangeal joint and second metatarsal head of the foot. Further critical areas 14b, 14c, 14d correspond to regions of the foot adjacent the third, fourth and fifth metatarsals of the foot respectively. The critical areas 12 in the hindfoot region H, called hindfoot critical areas 15a, 15b, include a first, main area 15a, corresponding to the heel and the plantar medial tubercle of the calcaneius, and a second area 15b, corresponding to the chopart's joint of the foot.

The applicant has determined that identifying the location of the critical areas 12 and pressure zones 13 enable footwear to be designed such that friction with a substrate on which the wearer stands or during gait is optimised. Locating grip material in the location of the critical areas 12 and pressure zones 13 will provide the greatest amount of friction between the footwear and the ground.

Figure 2 shows the critical areas 12 of a right foot (not shown) corresponding to those described above in relation to the left foot 10 and Figure 3 shows the critical areas 12 and pressure zones 13 of the left and right feet 10 superimposed on one another. This superimposition creates two, combined critical regions 12a, 12b and single combined pressure region 13a. The first combined critical region 12a, corresponding to the forefoot region F of the foot, includes a pair of spaced flanks 12a' surrounded by corresponding portions of the combined pressure region 13a, which extend into the midfoot region M of the foot. The combined critical region 12b corresponding to the hindfoot region H is spaced from the first combined critical region 12a and the combined pressure region 13a. When the combined critical regions 12a, 12b and the combined pressure region 13a are superimposed onto the sole of a sock S, their location shows the key areas in which grip material should be deposited in order for the sock S to be worn on either foot of a person whilst optimising grip. More particularly, the combined critical regions 12a, 12b and combined pressure region 13a identifies the key areas in which the grip material can be applied to the sole of the sock S in a single pattern for every sock S. This eradicates the need for different patterns of grip material for a left foot and right foot and hence simplifies the manufacturing process.

Referring now to Figure 5, there is shown a bottom view of a compression sock 1 according to an embodiment of the invention. The sock 1 is formed of a fabric base material in this embodiment, which is woven or knitted. The sock 1 is configured to apply a graduated pressure to the wearer's foot, to reduce the wearer's risk of suffering an embolism. In this embodiment, the fabric material is configured to provide a compressive pressure of between 2.0-2.5kPa to the ankle of a wearer when in a supine position and gradually decreases toward the upper end of the leg (not shown) of the sock 1. The fabric material of the sock 1 is a blended weave or knit formed of approximately 25% elastane material and approximately 75% nylon.

The sock 1 has a plantar surface 2 that contacts, in use, the ground or any other support surface the wearer may stand on. The plantar surface 2 has a forefoot region F, a midfoot region M and a hindfoot region H corresponding to the forefoot, midfoot and hindfoot regions F, M, H of the foot. Each region F, M, H of the plantar surface 2 has a respective pattern of grip material 3 deposited thereon to provide friction between the ground and the sock 1. The sock 1 also has toe opening 4 provided on the plantar surface 3 in the forefoot region F.

The grip material 3 is a silicone-based polymer in this embodiment and has a higher coefficient of friction than the fabric material of the sock 1. The grip material 3 is formed by depositing a plastisol ink on the fabric material using a screen printing technique. The patterns of grip material 3 are symmetrical about an axis A extending from the centre of the hindfoot region H to the centre of the forefoot region F. The symmetry of the grip material 3 enables the sock 1 will provide the same amount of grip whether worn on a left foot or a right foot of a person. In this embodiment, the pattern density of grip material 3 in the forefoot F and hindfoot H regions is greater than the pattern density of grip material 3 in the midfoot region M. The pattern density of the grip material 3 is therefore greatest where the combined critical regions 12a, 12b and the combined pressure region 13a are located, as shown in Figure 4. Increasing the pattern density in these areas increases the coefficient of friction between the sock 1 and the ground.

In this embodiment, the midfoot region M of the plantar surface 2 also includes a pair of spaced lateral midfoot regions LM and a central midfoot region CM therebetween. The lateral midfoot regions LM include a respective pattern of grip material 3 deposited thereon, whilst the central midfoot region CM is free of grip material 3. The central midfoot region CM is described or delineated by the pattern of grip material 3 in each of the forefoot F, hindfoot H and lateral midfoot LM regions. The central midfoot region CM includes a first enlarged area 5a adjacent the forefoot region F, a second enlarged area 5b adjacent the hindfoot region H and a third, necked area 5c joining the first and second enlarged areas 5a, 5b.

The grip material 3 of each of the lateral midfoot regions LM bridges the pattern in the forefoot region F to that of the hindfoot region H. The reduction on pattern density of grip material 3 in the midfoot region M relative to the frontfoot region F and hindfoot region H results in more efficient use of grip material 3. The central midfoot region CM is absent of critical areas 12 and pressure zones 13, therefore applying grip material 3 in this region would not increase substantively the coefficient of friction between the sock 1 and the ground during conventional gait or standing.

The presence of grip material 3 in the lateral midfoot regions LM also provides friction between the sock 1 and the ground when the wearer is walking up or down stairs. In this case, the corner of a step may contact the midfoot region M and therefore having grip material 3 present, although less than in the frontfoot region F and hindfoot region H, can be advantageous.

The grip material 3 is deposited as curvilinear ridges 30, 31 , 32 and as bosses 33. Some curvilinear ridges 30 describe a continuous or uninterrupted closed form, which is a hexagon with rounded corners in this embodiment but it will be appreciated that any suitable closed form may be used. Some curvilinear ridges 31 describe an interrupted closed form and some curvilinear ridges 32 describe part-closed forms. The bosses 33 are illustrated as rounded hexagonal deposits in this embodiment, but these may be circular, square, elliptical or any other suitable shape.

Each of the forefoot and hindfoot regions F, H includes a pair of nested continuous closed form curvilinear ridges 30 in a central region thereof. The forefoot region F also includes, adjacent the toe opening 4, a continuous closed form curvilinear ridge 30 that is nested within a pair of interrupted closed form curvilinear ridges 31. Each lateral side of the forefoot region F includes three nested part-closed form curvilinear ridges 32, the outermost of which ridges 32 corresponds substantially to the periphery of one of the aforementioned first, largest critical area 14a. The other part-closed form curvilinear ridges 32 are distributed across the forefoot, hindfoot and lateral midfoot regions F, H, LM in series of two or more offset ridges 32 in various orientations believed to provide improved grip between the sock 1 and the ground.

The presence of the aforementioned parallel and spaced curvilinear ridges 30, 31 , 32 provides both improved grip in multiple directions and creates a channel for water evacuation in the event that a wearer is walking on a wet surface. The bosses 33 are distributed between the curvilinear ridges 30, 31 , 32 and along the lateral midfoot regions LM to make up the grip material patterns whilst providing a lower pattern density. The presence of bosses 3 in combination with parallel curvilinear ridges 30, 31 , 32 also aids in the aforementioned water evacuation from beneath the plantar surface 2 of the sock 1.

The toe opening 4 is surrounded by an elastic welt 40 in this embodiment. The toe opening 4 and welt 40 can be stretched open to surround one or more of the wearer's toes to allow inspection of the toes while the compression sock 1 is worn.

Referring now to Figure 6, there is shown a top view of the compression sock 1 of Figure 7 showing a vamp surface 6 with an instep region 7. The instep region 7 of the vamp surface 6 includes a pattern of grip material 3 deposited thereon. The grip material 3 deposited on the instep region 7 of the vamp surface 6 is also symmetrical about the axis A and includes continuous closed form curvilinear ridges 30, interrupted closed form curvilinear ridges 31 , part-closed form curvilinear ridges 32 and bosses 33. The pattern of grip material 3 deposited on the instep region 7 of the vamp surface 6 includes a continuous closed form curvilinear ridge 30 nested within a pair of interrupted closed form curvilinear ridges 31 and a series of part-closed form curvilinear ridges 32. The part-closed form curvilinear ridges 32 are distributed across the instep region 7 in series of two or more offset ridges 32 in various orientations and the bosses 33 are distributed between the curvilinear ridges 30, 31 , 32 to fill the grip material pattern.

The grip material 3 deposited on the instep region 7 of the vamp surface 6 provides friction between the sock 1 and the internal surface of a shoe worn over the sock 1. This friction helps prevent rotation of the sock 1 about a wearer's foot whilst inside a shoe.

Referring now to Figures 7 and 8, there is shown bottom and top views of a compression sock 100 according to another embodiment of the invention. The compression sock 100 according to this embodiment similar to that of Figures 5 and 6, wherein like features are denoted by like references with a preceding T.

The sock 100 according to this embodiment differs from the previous embodiment in that the grip material 103 is deposited in different patterns. For example, the only nested curvilinear ridges 130 include a first pair of nested closed form curvilinear ridges 130 adjacent and between the forefoot and midfoot regions F, M and a second pair of nested closed form curvilinear ridges 130 at the centre of the instep region 107 of the vamp surface 106. There are no interrupted closed form curvilinear ridges 31 and the remainder of the patterns of grip material 103 are made up of part-closed form curvilinear ridges 132 and bosses 133.

Referring now to Figure 9, there is shown a bottom view of a compression sock 200 according to yet another embodiment of the invention. The compression sock 200 according to this embodiment similar to those of the previous embodiments shown in Figures 5 to 8, wherein like features are denoted by like references with a preceding '2'.

The sock 200 according to this embodiment differs from the previous embodiment in that the grip material 203 is deposited in a different pattern. For example, the pattern includes three groups of nested, interrupted closed form curvilinear ridges 231 , each surrounding a closed form curvilinear ridge 230, located in the forefoot region F in a side-by-side relationship. The outer groups 230, 231 correspond substantially to the position 14a corresponding to the tibial sesamoid, fibular sesamoid, first metatarsal phalangeal joint and second metatarsal head of the foot of each of the left and right foot. The central group 230, 231 is slightly lower, at a position 14b corresponding to the third metatarsal region of the foot.

The pattern also includes nested closed form curvilinear ridges 230 in the lower portion of the forefoot region F, between a pair of nested part-closed form curvilinear ridges 232 each surrounding a further closed form curvilinear ridge 230. The hindfoot region H includes a pair of nested closed form curvilinear ridges 230 in a lower portion thereof, and a series of part-closed form curvilinear ridges 132. The remainder of the pattern of grip material 203 is made up of part-closed form curvilinear ridges 232 and bosses 233.

It will be appreciated by those skilled in the art that several variations to the aforementioned embodiments are envisaged without departing from the scope of the invention. It will also be appreciated by those skilled in the art that any number of combinations of the aforementioned features and/or those shown in the appended drawings provide clear advantages over the prior art and are therefore within the scope of the invention described herein.