The present invention relates to footwear, and in particular to one-piece footwear having improved haptic properties while providing technical features for specific fields of application. Furthermore, the present invention relates to a manufacturing device and manufacturing method of such footwear. INTRODUCTION

Walking is a complex mechanism developed by humans over 4 million years of evolution. Hence, the foot is a unique instrument designed by nature to allow the distinctive human form of gait. For example, the human foot has 24 bones, working together in a complex structure designed to lessen the impact of footfall, combined with muscles, tendons and ligaments that store energy during the footstep and release it at the end.

In order to avoid injury and disease, which are genuine hazards, but also to be "civilized", shoes with specific designs are used for different applications. Foot problems that can result from walking barefoot include cuts, abrasions, bruises, puncture wounds from foreign objects. Poisonous plants, animals, or parasites could enter the body through the cuts on an injured bare foot and appropriate footwear can be valuable in protecting the foot. Hence, shoes are generally "purpose-built" in order to provide cushioning and protection, but also to provide a fashionable design for specific occasions.

Conventional shoes generally include a sole portion and an upper formed above and attached to the sole portion. The upper usually extends over the toe area to form a single toe cap that is adapted to receive the toes. The sole portion consists of a relatively thick and stiff sole, which may be made of leather, plastic or rubber, and an inner sole. The inner sole is typically a soft fabric layer that is adapted to absorb moisture in order to keep the foot dry and to prevent rubbing of the skin.

However, bones, muscles, tendons and ligaments of the foot generally do their job more effectively if unrestrained by shoes. For example, research has shown that less energy is needed when walking without shoes, because the foot movement is much more efficient. Also, less jarring is transferred to the rest of the body, particularly to the knees, because the internal movement of the foot spreads out the impact, and because the foot's rich array of nerve endings provides feedback to help the body manage the movement. Furthermore, research has shown that well- functioning toes are an important part in the mechanism of human gait, because the toes are in contact with the ground for about three quarters of the walking cycle and exert pressures similar to those from the metatarsal heads. Therefore, wearing shoes may not only prevent the body to correctly estimate plantar loads, but also restricts important natural movement of the toes and thus affect the overall efficiency of the human walk, run or stand.

In the past, attempts have been made to provide footwear with individual toe portions or improved haptic (refers to the sense of touch) or

proprioceptive (sense that indicates whether the body is moving with required effort, as well as where the various parts of the body are located in relation to each other) properties. However, none of these attempts have been successful in providing all the advantages of a realistic and natural "barefoot walking" while at the same time providing sufficient protection to the foot and improved properties for specific applications and activities.

In addition, conventional shoe designs generally include several parts, such as and upper, sole and/or inner sole, which are either stitched or glued together, therefore, making the manufacture of shoes relatively time consuming and expensive.

Accordingly, it is an object of the present invention to provide footwear that does not restrict the foot's natural movement and functionality while providing sufficient protection and improved features.

SUMMARY OF THE INVENTION Preferred embodiments of the invention seek to overcome one or more of the above disadvantages of the prior art.

According to a first aspect of the present invention, there is provided footwear, comprising an elastomeric, one-piece casing adapted to receive and extend around a human foot, the casing integrally forming a heel portion, a first and second side portion, a sole portion, a central opening portion and a toe portion, wherein the toe portion further comprises individual articulated toe cavities configured to receive and retain corresponding toes of the human foot. This provides the advantage that the footwear provides an intimate fit fully complying with the natural contour of the human foot and allowing free and independent articulation of the toes, while providing sufficient protection and functionality for general or sport specific outdoor use. The one-piece casing extends around at least part of the human foot, which means that the casing covers the entire sole and toe portion, and at least part of the heel, side and top portion of the foot. Furthernnore, the present invention provides the advantage that the restriction to natural foot movement is minimized improving efficiency and comfort. Also, by using an elastomeric material, one predetermined size of the casing can fit a predetermined range of foot shapes and sizes, therefore, reducing manufacturing cost. In addition, the present invention is made of a single piece and not from individually manufactured parts, such as sole and upper portions, minimizing necessary manufacturing steps and therefore further reducing

manufacturing time and cost.

The sole portion may further comprise an interior surface and an exterior surface, wherein the interior surface may comprise a plurality of

indentations adapted to displace moisture such that grip between the human foot and the interior surface is maximized. Also, the indentations may be embossed into the interior surface of the sole portion. This provides the advantage that there is no need for an inner sole in order to minimize foot slippage within the casing. In particular, the indentations inhibit the formation of a continuous fluid film between the foot and the interior surface of the sole portion so that the foot will always be in contact with at least part of the interior surface of the sole, therefore, providing sufficient gripping traction between the foot and the interior surface of the sole portion.

The casing may be made of silicone rubber. Silicone rubber is a highly inert material which does not react with most chemicals making it highly tolerant to human skin. Therefore, silicone rubber is used in many medical applications and in medical implants.

Each of the toe cavities may comprise at least one perforation adapted to allow fluid exchange. This provides the advantage that trapped fluid such as air or water can either escape or enter the casing through the

perforations when inserting or removing the foot, respectively. Fluid pockets may be formed when inserting the foot into the casing of the present invention due to the snug fit of the footwear. Also, when using the footwear for water sports, water may be trapped within the casing of the footwear compromising the secure fit of the footwear. When moving the foot out of the casing, it is possible that a vacuum is formed in the toe cavities, therefore providing a resistance to the foot movement and making it more difficult to remove the footwear from the foot. The additional perforations in the toe cavities will prevent any formation of fluid pockets or vacuum.

The heel portion of the casing further comprises an integral tag located at a rear end of the central opening portion. The integral tag provides the advantage that the footwear can be easily put on and removed by simply pulling the heel portion off the heel of the wearer's foot.

The exterior sole may further comprise a surface texture. The surface texture may further resemble a human foot print pattern. The human foot print has been perfected by millions of years of evolution and therefore provides maximised grip for many surface types.

The exterior sole may further comprise a plurality of integral studs arranged such that grip between said exterior surface and a ground surface is maximized. This provides the advantage that the footwear may also be used in rougher terrain.

The first and second side portion and/or heel portion and/or sole portion may comprise at least one perforation adapted to allow fluid exchange. The sole portion may be of substantially uniform thickness and intimately follows the contour of the received human foot. A uniform thickness of the sole portion allows an improved haptic response of the foot relative to the ground, because the information about the ground is transmitted to the foot directly and undistorted due to a uniform sensitivity across the sole of the foot.

The footwear may further comprise a strapping means adapted to secure said casing to said human foot. The strapping means may be located at the central opening portion releasably coupled to the first and second side portion. The strapping means may be releasably coupled to the inside of the first and second side portion. This provides the advantage that the footwear is securely fitted to the foot. Coupling the strapping means to the inside of the side portions allows the foot to securely hold the releasable strapping means in place by pressing the releasable ends of the strapping means against the side portions of the casing.

According to a second aspect of the present invention, there is provided a casting mould comprising a top plate, a first and second side plate, a bottom plate and an interchangeable core coupled to the bottom plate, enclosing a cavity adapted to reproduce previously disclosed, wherein the first side plate is pivotably coupled to the second side plate and the top plate is pivotably coupled to the bottom plate such that the first and second side plate and the top and bottom plate open from the same side. This provides the advantage that the moulding material can be easily placed and the finished product removed from the casting mould reducing manufacturing time and cost. The casting mould may further comprise locking means adapted to lock the top plate, the first and second side plate and the bottom plate into place when closed. The casting mould may further comprise leverage means adapted to open the top plate individually, and the first and second side plate at the same time. Being able to open first and second side plates simultaneously allows a further reduction of manufacturing time and consequently manufacturing cost.

The top plate, the first and second side plate, the bottom plate and the core may be made of heat conducting material.

The casting may further comprise a heat source adapted to heat the cavity to a predetermined temperature.

According to a third aspect of the present invention, there is provided a method of manufacturing the previously disclosed footwear using the previously disclosed casting mould, comprising the steps of:

closing and locking the first and second side plates and the bottom plate;

placing a predetermined amount of polymer material onto the core of the casting mould;

closing and locking the top plate;

providing heat of a predetermined temperature and a

predetermined pressure suitable to process the polymer material to the cavity for a predetermined period of time;

opening the top plate, and the first and second side plate;

cooling down the cavity for a predetermined period of time;

removing the core from the bottom plate, and removing the footwear from the core.

The polymer material may be silicone rubber.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention will now be described, by way of example only and not in any limitative sense, with reference to the accompanying drawings, in which: Figure 1 shows a perspective view of a preferred embodiment of the present invention,

Figure 2 shows the embodiment of Figure 1 from (A) the side, (B) the bottom and (C) the rear,

Figure 3 shows the embodiment of Figure 1 from (A) the top and (B) a close-up view of a section of the interior surface including

indentations,

Figure 4 shows (A) a side view of another embodiment of the present invention including a strap and (B) a single strap,

Figure 5 shows (A) a side view and (B) a bottom view of a further embodiment of the present invention including a plurality of integral studs arranged on the exterior surface of the sole,

Figure 6 shows a five-piece casting mould for the footwear disclosed in Figures 1 to 4 in an open position, and

Figure 7 shows typical steps (A) - (D) of manufacturing the footwear disclosed in Figures 1 to 5.

DETAILED DESCRIPTION OF EMBODIMENTS

Referring to Figures 1 , 2-A and 2-B, a preferred example of the footwear embodying the present invention comprises an elastomeric, one-piece casing 100 integrally forming a heel portion 102, a first side portion 104 and a second side portion 106, a sole portion 108, a central opening portion 110 and a toe portion 112. Preferably, the one-piece casing 100 extends around at least part of the human foot, which means that the casing covers the entire sole and toe portion, and at least part of the heel, side and top portion of the foot. However, in another embodiment of the present invention, the one-piece casing 100 may extend around the whole of the foot up to the ankle area enclosing the whole foot and part of the ankle. The casing 100 is made of a non-fabric material, and is preferably made of a relatively soft silicone rubber. However, any other suitable non- fabric, rubber-like material may be used. The advantage of using silicone rubber is that it is generally non-reactive, stable, and resistant to extreme environments and temperatures from -55°C to +300°C while still maintaining its useful properties. In order to manufacture silicone rubber into the desired shape, heat is required to vulcanize (set or cure) the silicone into its rubber-like form and then post-curing it in a prolonged process. Silicone rubber may also be injection molded.

As disclosed in Figures 2-A, 2-B, 3-A and 3-B, the sole portion 108 further comprises an interior surface 114 and an exterior surface 116. The interior surface 114 includes a plurality of indentations 118 which allow the displacement of moisture between the foot and the interior surface 114 such that grip between the sole of the foot and the interior surface 114 is maximized. In particular, when the foot is placed into the casing 100 of the footwear, any moisture trapped between the sole of the foot and the interior surface 114 is evenly distributed between the small-volumed cavities of the indentations 118 such that the sole of the foot is in contact with the protruding edges of the indentations 118, therefore providing enough grip to prevent possible slippage between the foot and the footwear. Figure 3-B shows a close-up view of a section of the interior surface 114. In this particular example, the indentations 118 may be of hexagonal shape arranged in a honeycomb pattern. In a preferred example, the indentations may have a diameter in the region of 2 mm covering the whole of the interior surface 114 of the sole portion 108. However, any other suitable shape, size and pattern may be used. For example, the indentations 118 may be of circular or annular, oval or rectangular shape, symmetrical or asymmetrical, of the same size and depth or of varying size and depth, as long as the indentations and their arrangement allow displacement of moisture such that grip between the sole of the foot and the interior surface 114 is maximized. In particular, the indentations 118 may be of smaller diameter and may be arranged closer together in high- pressure regions of the sole portion 108 in order to minimize the risk of damage to the sole portion 108 through wear and to avoid unwanted markings to the skin of the foot. In addition, the indentations may also be allocated across the whole of the interior surfaces defined by the heel portion 102, the first and second side portion 104 and 106, respectively, the sole portion 110 and the toe portion 112. The indentations 118 may be embossed onto the interior surface 114 of the sole portion 108, but may also be created from a cast during manufacture of the footwear.

Figure 2-B shows the exterior surface 116 of the sole portion 108 of a preferred embodiment of the present invention. In this particular example, the exterior surface 116 comprises a surface texture that resembles a human footprint pattern, therefore providing sufficient grip between the footwear and the ground. However, in another embodiment of the present invention as shown in Figure 5-A and 5-B, the exterior surface 108 may comprise studs 122 in order to improve grip on a specific ground surface composition. The studs 122 may be of different shapes, height and diameter and may be arranged in different patterns depending on the ground surface composition the footwear is used for. For example, longer and a smaller number of studs may be advantageous for a muddy surface, wherein shorter and a larger number of studs may be advantageous for a grassy or stone surface. The studs 122 may be an integral part of the sole portion 108 and may be created from the cast during manufacture of the footwear. However, the studs may also be an additional part that is releasably attached to the exterior surface 116 of the sole portion 108.

As shown in Figure 2-C, the heel portion 102 includes an integral tag 120 which is located at the rear end of the central opening portion 110 of the casing 100. The integral tag provides an easily accessible gripping section for the wearer allowing the wearer to hold the footwear when either slipping the foot into the casing 100 of the footwear or when removing the footwear from the foot. The integral tag may include a gripping profile to increase friction between the tag 120 and the wearer's fingers and may be of varying thickness to add strength and/or an easily accessible gripping surface. The profile may have a typical human fingerprint pattern, but any other patterns suitable to improve the grip may be used. Furthermore, the toe portion 112 comprises individual articulated toe cavities 124 suitable to receive and retain the corresponding toes of the wearer's foot. Preferably, the toe cavities 124 are suitable to individually house the toes of the human foot. However, in another embodiment, the toe cavities 124 may be suitable to house two or more of the foot's toes. Each of the individual toe cavities 124 includes at least one perforation 126 at the tip of the toe cavity 124. The perforation 126 is a simple hole that allows fluid exchange between the interior and the exterior of the footwear. In particular, because of the snug and intimate fit of the footwear, air or water may be trapped in the toe cavities 124 when the foot moves into the casing 100 of the footwear, providing a resistance to the foot movement and therefore making it difficult to pull the footwear over the foot. Also, when the wearer attempts to pull the footwear from the foot, a vacuum may be created within the toe portion of the footwear, again, providing a resistance to the foot movement. In this respect, the

perforations 126 provide a respective outlet or inlet allowing fluid to either escape or enter the casing 100 of the footwear. Further perforations may be added to any one of the other portions of the casing 100 in order to allow fluid exchange between the interior and exterior of the footwear. The sole portion 108 of the footwear is preferably made of substantially uniform thickness. In a preferred example the thickness may be in the region of 2 mm, however, any other thickness may be used depending on the application of the footwear and varying levels of protection required relative to the terrain. The uniform thickness of the sole portion 108 allows an equal sensitivity of the foot therefore improving haptic and

proprioceptive response of the foot. For example, a sole portion 108 having different padding at different parts of the sole does not allow the wearer to feel with the same sensitivity across the foot providing distorted feedback which may alter the wearer's gait. A substantially uniform thickness of the sole portion 108 includes slight thickness variations at high-wear areas of the footwear. For example, the material may be made slightly thicker at the ground-touching part of the toe portion, or at the ground-touching part of the heel portion in order to minimize damage through a higher wear and tear.

Referring now to Figure 4-A and 4-B, which shows another embodiment of the present invention, the footwear may comprise strapping means 128 providing a secure fit of the footwear to the foot. The strapping means is preferably made of the same material as the casing and is releasably attached to the first side portion 104 and second side portion 106, respectively. The strapping means 128 may be of a simple band shape or of a more complex shape, as shown in Figure 4-B. In one example, the end portions of the strapping means 128 are secured to the side portions 104, 106 of the casing 100 via a press-stud button mechanism. However, a simple shank button mechanism or Velcro fastener may be used instead. When using a shank button mechanism, the buttons are preferably located at the end portion of the strapping means 128. The corresponding holes 130 are located at the respective first and second side portion 104, 106 which may be thickened around the holes 130 to add strength and integrity. In order to allow tightness adjustment of the strapping means 128, additional holes may be provided at the respective first and second side portions 104 and 106. The buttons of the end portion of the strapping means 128 may be fitted through the holes 130 of the first and second side portion 104, 106 from the inside. This allows a more secure fit, because the foot is pressing the end portion of the strapping means 128 towards the holes 130 of the first and second side portion 104 and 106. In another example, the strapping means 128 may be integrally formed with the casing 100 allowing an "all-in-one" manufacturing process through casting mould or injection moulding. In yet another example, the strapping means 128 may be adapted to fully cover the central opening portion 110.

It is understood that, even though the Figures only disclose either a left or right foot version of the footwear, the footwear of the present invention includes casings 100 for the right and left foot.

Figure 6 shows an example of a casting mould 200 suitable for the manufacture of the previously disclosed footwear. The casting mould 200 comprises a top plate 202, a first side plate 204 and a second side plate 206 and a bottom plate 208 having an interchangeable core 210. The first side plate 204 is pivotably coupled to the second side plate 206 and the top plate 202 is pivotably coupled to the bottom plate 208. The first pivot joint 212 and the second pivot joint 214 are located at the same side of the casting mould 200 so that the plates open from the same side allowing easy access to the core 210 of the casting mould 200. The top plate 202 includes an imprint of the surface texture used for the exterior surface 116 of the sole portion 108. In this particular example a typical foot print pattern is used. Accordingly, the core 210 comprises a profile that is suitable for creating the indentations 118 of the interior surface 114 of the sole portion 108. Preferably, the casting mould 200 comprises locking means suitable to secure the side plates 204, 206, top plate 202 and bottom plate 208 into place when the casting mould 200 is closed. The first side plate 204 and the second side plate 206 may be coupled to a leverage system allowing to simultaneously open the side plates 204 and 206. By simultaneously moving away from the core 210 and moulded footwear potential damage to the footwear through sticky material may be avoided. Furthermore, at least the portion of the plates enclosing the cavity of the cast and the core 210 are made of heat conducting material, such as metal, so that the heat generated by a heat source is efficiently and uniformly distributed in the cast cavity and core portion providing a predetermined temperature throughout.

An example of a typical manufacturing process is described with reference to Figures 7-A, 7-B, 7-C and 7-D. The Figures only disclose the

manufacture of footwear for the right foot using the previously described casting mould for a right-foot footwear. However, it is understood that the casting mould and manufacturing method include casting moulds for the left and right foot of various shape and size. In the first step, silicone rubber material is ground and mixed with a colorant providing a predetermined colour to the silicone rubber material. As shown in Figure 7-A, a predetermined amount of the dyed silicone rubber is placed onto the core 210 of the casting mould 200 and the side plates 204, 206 and top plate 202 are closed and sealed by the locking means. The locking of the top and bottom plate 202, 208 may be provided by a hydraulic press (not shown) which provides a suitable pressure to the top and bottom plate 202, 208. The cavity enclosed by the side-, bottom-, top plates and core 201 is then heated to a temperature in the region of 250 °C transforming the silicone rubber material into a molten state to thereby allow the material to flow over and around the core 210 within the enclosed cavity. During the heating process the enclosed cavity is subjected to a predetermined pressure suitable for processing silicone rubber. In a preferred example, this pressure may also be provided by the hydraulic press (not shown) applying pressure to the top and bottom plate 202, 208 of the casting mould 200. After approximately 20 min, the pressure is removed and the top plate 200 is opened as shown in Figure 7-B, further allowing the product to cool down. In the next step, as shown in Figure 7-C, the side plates 204 and 206 are opened, either

simultaneously or individually, allowing the removal of the core 210 and moulded article. After removing the moulded article from the core 210, the cavity portions and core 210 of the casting mould 200 are sandblasted to remove any residues of the silicone rubber material. It will be appreciated by persons skilled in the art that the above embodiment has been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departing from the scope of the invention as defined by the appended claims.