Omnidirectional Wheel Apparatus The present invention relates to a new wheel assembly which is particularly applicable to wheels omnidirectional wheels. Although the following description refers to an wheel omnidirectional wheels and wheel assemblies the skilled person will appreciate that the current invention could be used on other omnidirectional wheels incorporating discs or rollers such as Mecanum wheels and the like. Omnidirectional wheels, also known as omni-wheels, poly- wheels, are wheels that incorporate rollers or discs around the circumference so the wheel can be driven forward or backward, but can also be easily moved sideways or laterally on the passive rollers. Often the rollers comprise rubber material such that when the wheels are driven conventionally their rubber rollers offer superior grip. Conventional omni-wheels are used in robotics, trolley systems, transfer conveyors, shipping carts and lifters, luggage and many other applications. Omni-wheels are also frequently integrated with convention wheels systems. For example, a six wheeled vehicle incorporating two conventional wheels on a centre axle and a pair of omni-wheels on the front and rear axles allow the vehicle to move and rotate conventionally, whilst enabling increased manoeuvrability and speed with precise direction control. Omni wheels can be formed in a single ring around the circumference of the wheel, however rollers can be mounted on separate parallel plates forming two rings on the wheel. The later double arrangement has the advantage that the rollers can be staggered such that there are no ‘dead’ areas between the respective rings. Omni-wheels however are costly to produce mainly because of the time required to assemble the relatively large number of parts. In addition, omni-wheels provide very little vibration or shock absorption. Any shock absorption provided is limited to the elastomeric nature of the rubber roller material. It is therefore an aim of the present invention to provide an omni-wheel and wheel assembly that addresses the abovementioned problems. It is a further aim of the present invention to provide a vehicle incorporating omni-wheels and assemblies incorporating one or more omni-wheels that address the abovementioned problems. In a first aspect of the invention there is provided a omnidirect ional wheel apparatus, said apparatus including; at least one outer ring or mounting means located substantially around the circumference of the wheel onto which are rotatably mounted a plurality of rollers or discs, one or more anchor means that depend inwardly from the outer ring or mounting means characterised in that at least part of the anchor means is received or embedded in at least one polymeric material layer located below and/or within outer ring or mounting means. In a preferred embodiment of the invention the polymeric layer includes at least one thermosetting polymer. Typically the thermosetting polymer is at least one polyurethane. As such the layer of polyurethane material provides additional shock absorbing properties. In one embodiment the at least part of the outer ring and/or anchor means comprises a thermoplastic polymer. Further typically the thermoplastic material is nylon. In one embodiment the outer ring or mounting means includes a plurality of axle members. Typically the axle members are substantially linear lengths. Further typically the axle members function as axles on which the discs or rollers are mounted. In one embodiment the axle members extend through the centre of the discs or rollers. Typically the axle members are linear sections of the outer ring or mounting means about which the rollers can turn or rotate. In one embodiment the axle members are linked or connected to form a substantially circular ring or annular mounting means. In one embodiment the axle members are connected via one or more spacer members. Typically adjacent rollers or axle members are separated by one or more spacer members. In one embodiment the anchor means extend inwardly into the polymeric layer from the spacer means. In one embodiment adjacent anchor means are connected together. Typically connected parts of adjacent anchor means for a second inner ring. Further typically the inner ring is embedded within the polymeric layer. In one embodiment the apparatus includes two outer ring or mounting means positioned substantially parallel and or adjacent to each other and substantially around the circumference of the wheel. Typically the anchor means depend inwardly from each outer ring or mounting means characterised in that at least part of the anchor means is received or embedded in a layer of polymeric material. In one embodiment of the invention the polymeric material layer is of suitable thickness and/or diameter to form the body of the wheel. In one embodiment the wheel apparatus includes a hub member. Typically said hub member is located substantially at the centre or the wheel. In one embodiment the hub member includes one or more project ions that extend radially outwardly. Typically the project ions can be embedded or received in the polymeric layer. In one embodiment the hub member includes a plurality of web or rib members. Typically said web or rib members comprise flexible or resilient material. Preferably at least the web or rib members comprise a thermoplastic material. Typically the material is a thermoplastic polymer. Further typically the thermoplastic material is nylon. In a one embodiment the hub member includes a band member. Typically the band member is an annular ring formed around the distal ends of the first inner web or rib members. In one embodiment the wheel assembly includes a core means forming at least part of the wheel hub member. Typically the web members depend outwardly from the core means or hub. In one embodiment the web or rib members extend outward from the wheel hub to the band member. Typically the web or rib members are non-linear in shape. Further typically the web members are C-shaped or preferably S-shaped. Typically the web or rib members comprise a series of resilient or flexible fingers. Preferably the web or rib members include at least one bend or curve in the region where the web member meets or attaches to a band member. Typically the web or rib members are deformable. Further typically the shock absorption performance of the web or rib members can be tuned or selected by varying any of or any combination of length, thickness, curvature of the same. In one embodiment the web or rib member properties may be preselected to provide a required cushioning effect to the wheel in use by selecting from web material, length, width or thickness, rib inclination or curvature between the bands. In one embodiment the web members or ribs are encapsulated or encased in the polymeric material layer. Typically the encapsulation prevents the outer ribs from going beyond their elastic limit. In one embodiment the outer surface or the band member is wrapped or completely encapsulated by the layer of polymeric material. Preferably the layer of polymeric material is foamed polymeric material. Typically the foam is polyurethane foam. Further typically the foam forms a ring or annular around the hub and/or band member. Further typically at least part of the anchor means is embedded, encapsulated or received in the polymeric material. This arrangement provides; stability, potential to vary the spring rate, ensures a mechanical retention of the outer ring to the apparatus. In one embodiment the polymeric material can be applied in one or more layers. In one embodiment the properties of the polymeric material layers can be different. Typically the density and/or rigidity of the polymeric material can be adjusted to provide layers of different properties. Optionally the web or rib members can be encased or encapsulated in polymeric material. In one embodiment the polymeric material can form one or more bands around the edge or towards the outer surface, or tread, of the tyre in contact with the ground in use. In one embodiment the polymeric material is or includes at least one ring or layer of less dense or foamed polyurethane. Typically polymeric material forming at least part of the web or rib members and/or band members is harder or less flexible than the polymeric material coating or over moulding the same. Further typically the polymeric material forming the rib members and/or the band member is nylon. In one embodiment the web or rib members are inclined in the same direction. In one embodiment the discs or rollers are formed from polyurethane. In one embodiment the hub includes first inner web or rib members and one or more second outer web or rib members. In one embodiment at least one set of inner or outer web members includes substantially straight web or rib members. Typically the inner web or rib members are straight. In one embodiment the outer ring or mounting means including the anchor means depending from the same are made to form a single unit or unitary body. Typically the unitary body or single unit comprises a thermoplastic polymer. Further typically the polymer is nylon. In a second aspect of the invention there is provided a vehicle equipped with one or more wheels, wherein at least one of the wheels is a omnidirectional wheel comprising at least one outer ring or mounting means located substantially around the circumference of the wheel onto which are rotatably mounted a plurality of rollers or discs, one or more anchor means that depend inwardly from the outer ring or mounting means characterised in that at least part of the anchor means is received or embedded in at least one polymeric material layer located below and/or within outer ring or mounting means. In a third aspect of the invention there is provided an omnidirectional wheel said wheel comprising a number of rollers movably attached or mounted to an annular frame, at least part of said frame located or received within a layer or body of thermoset polymer. Preferably the polymer is polyurethane. In one embodiment the axles are mounted or disposed in line with or parallel to the circumference of the wheel, or a tangent thereof. In one embodiment at least some or all of the axles are mounted or disposed at an angle to or non-parallel to the circumference of the wheel, or a tangent thereof. Typically this angled or non- parallel arrangement ensures that the rollers wear evenly as most of the direction of travel of the wheel will be in a straight line or forward direction. Specific embodiments of the invention are now described with reference to the following figures wherein; Figure 1 shows a wheel assembly in accordance with one embodiment of the invention; Figure 2 shows a wheel assembly in accordance with one embodiment of the invention; Figure 3 shows a roller support structure in accordance with an embodiment of the invention; Figures 4 shows a roller support structure and hub arrangement in accordance with one embodiment of the invention; Figure 5a and 5b show a roller support structure in accordance with one embodiment of the invention; and Figure 6 shows a roller support structure embedded in the polymeric material in accordance with one embodiment of the invention. Omni Wheels (omni-directional wheels) have a series of rollers mounted on axles on the outside diameter of the wheel. When the wheel is subjected to side-loads the rollers greatly reduce the effect of the side-load as their axles are mounted perpendicular to the main wheel axle. The wheel is therefore able to move sideways. Omniwheels are costly to produce due to the high number of components and time required for assembly. An Omniwheel typically requires two rows or bands of rollers to ensure a reasonably smooth ride. Depending upon the size of the wheel a total of 24 rollers is not uncommon. Each roller needs an axle, some have bearings and all components need to be fixed to the wheel. Typically, the connection of the rollers and axles to the wheel is with a large number of separate components and fixing screws, which is time consuming and costly. The number of components also increases the risk of quality, durability and/or performance concerns. In current designs, the wheels offer very little suspension or vibration absorption, due to all the required fixings. The shock absorption is limited to the elastomeric nature of the rollers. The present invention reduces the number of components and cost, it also provides shock absorption that can be varied to suit the application. Turning to figure 1 there is shown a wheel assembly 2, comprising two annular bands 4a, 4b of rollers 6. The rollers are equally spaced around the bands and are mounted onto a support frame 8a, 8b which provides an axle on which the rollers turn, providing sideways or lateral displacement to the wheel, which can still be driven or rotated in the conventional manner. Although two rings of rollers are provided in this example, the skilled person will appreciate that the present invention will be suitable for a single band or ring of rollers. Underneath the annular bands is a layer or band of polymeric material 10, which in this preferred example is polyurethane. The polymeric material 10 can form the body of the wheel or can be formed around a hub 16 as shown in the examples provided here. The hub 16 in these examples is formed from a central plate 18 with a first set of fingers 20 extending from the same followed by a ring and a second set of curved fingers 22. Figure 2 shows the same wheel with the polymeric material removed to illustrate the tabs or anchor project ions 12 that depend inwardly from the support frames 8a, 8b. The tabs can be T-shaped, as shown in figures 2-4 and 5a or can be joined together to form an anchor ring 14 as shown in figures 5b and 6 The hub 16 and the annular bands 4 comprising the support frames 6 and anchor project ions 12 or rings 14 are usually made from a thermoplastic polymer, such as nylon. Figure 3 and 5b show the arrangement of the axles 24 and the tabs 12 or inner ring 14 which are encapsulated within the polymer layer. In particular, the axles 24 from a suitable durable, low friction material, typically injection moulded nylon or similar. This single piece acts as axles for each of the rollers and has inner tab features to assist with attaching to the wheel. Typically in manufacture one or two sets of roller assemblies 8 are located into a mould. The wheel is fitted into the centre of the mould. A polyurethane elastomer and/or microcellular elastomer is injected into the mould between the axle assembly and the wheel. The polyurethane elastomer/foam cures and bonds the axle to the wheel. Both the axle and wheel can also incorporate features to achieve a mechanical bond as well as chemical bond. The wheel can have flexible spokes or fingers 20, 22 to further increase shock and vibration absorption. The polyurethane elastomer/foam layer 10 not only fixes the roller assembly 8 to the wheel, but also provides suspension and/or shock absorption. This polyurethane layer can be adjusted in both material hardness and density, thus providing a very wide range in potential shock absorption/suspension performance. A complete wheel assembly with 24 rollers can actually be constructed by using only 6 components/manufacturing stages: 1. Axle 1 produced 2. First 12 rollers over-moulded 3. Axle 2 produced 4. Second 12 rollers over-moulded 5. Wheel produced 6. Wheel & two sets of axle assemblies located into final mould & PU foam/elastomer is injected. Three very significant benefits versus current designs: 1. Far fewer components 2. Much reduced cost 3. Much quicker to produce