The present invention relates to roulette wheels and, in particular, to roulette wheels which include an inductive power transfer arrangement to transmit power from a base of the roulette wheel to a rotor rotatably coupled to the base.

Roulette wheels have been known for decades. They rely upon a rotor spinning freely in respect of a static base. Any features or components of the wheel which disrupt or interfere in the rotation of the rotor about the base are undesired, as they may bias the wheel in some way.

Roulette wheels in which the rotor and an associated turret can be illuminated are also known. In practice, the illumination provided by shining a light through the rotor from a stationary light source, typically located within the base of the wheel. The illumination may be used to provide visual feedback or information to the players.

Similarly, it is known to provide power to a rotary component from a stationary base. However, such known apparatus typically rely upon a physical connection, such as a slip ring arrangement, to transfer the power from the base to the rotary component. As noted above, such physical connections are undesirable in roulette wheels, as they affect the randomness of the wheel.

By providing a powered rotor (i.e. a rotor which receives electrical power), it is possible to locate electronic components and/or display screens in the rotor, which provide a significant increase in what can be displayed to users. For example, the rotor may be illuminated and/or it may display images, such as static images or videos. Similarly, the winning number pocket may be illuminated or otherwise highlighted. Finally, digital serial numbers and calibration data pertaining to the rotor may be stored internally in the rotor, for example in a memory storage component located within the rotor.

According to a first aspect of the invention, there is provided a roulette wheel comprising a base and a rotor which is rotationally coupled to the base, wherein the rotor rotates relative to the base about a rotational axis, wherein the base includes a first inductive coil connected to an electrical power source which generates an alternating current; the rotor includes a second inductive coil; wherein when the second inductive coil is located within the alternating magnetic field of the first coil, an electrical current or an EMF is generated in the second coil; and the rotor includes at least one electrical device which is powered by the second coil.

The skilled person will appreciate that the first and second coils together form an inductive coupling, which wireless transmits or transfers power from the first coil to the second coil. An alternating current passing through the first coil creates an alternating magnetic field around the coil in accordance with Ampere's Circuital Law. The alternating magnetic field induces an electromotive force (EMF or voltage) in a second coil, when the second coil is located within the magnetic field of the first coil, in accordance with Faraday's law of induction. This EMF may be used to power electrical components carried by the rotor, either directly or via a rechargeable power storage component, such as a rechargeable battery.

Accordingly reference to "at least one electrical device which is powered by the second coil" as used herein means that the or each electrical device is powered by the EMF generated in the second coil as a result of the inductive coupling between the coils.

The inductive coupling may generate an EMF in the second coil all the time that the first inductive coil is connected to an alternating current source or it may generate an EMF only when the rotor is spinning relative to the base. Accordingly, the rotor may include a power storage component, such as a rechargeable battery, which may store the electrical energy generated by the second coil.

In an embodiment of the invention, the first inductive coil is arranged in a circular or annular configuration around the rotational axis and is co-axial therewith. The circular/annular arrangement may define a continuous circle around the rotational axis. It may be a flat arrangement in which the coil lies in a plane, which is suitably perpendicular to the rotational axis. In such an arrangement, an inner coil or portion of a coil may be spaced from the rotational axis by a first radius, R1 and an outer coil or portion of a coil may be spaced from the rotational axis by a second radius, R2, where R2 is greater than Rl.

Alternatively, the circular configuration may be discontinuous, wherein the coil comprises a plurality of spaced apart windings arranged in a circular or annular configuration about the rotational axis. In a further embodiment of the invention, the second inductive coil is arranged in a circular or annular configuration around the rotational axis and is co-axial therewith.

As with the first inductive coil, the circular arrangement of the second coil may define a continuous circle around the rotational axis or it may define a discontinuous circular configuration. The second coil may be a flat arrangement in which the coil lies in a plane, which is suitably perpendicular to the rotational axis. In such an arrangement, an inner coil or portion of a coil may be spaced from the rotational axis by a first radius, R3 and an outer coil or portion of a coil may be spaced from the rotational axis by a second radius, R4, where R4 is greater than R3.

It will be appreciated that the rotational axis is typically a vertical axis and the rotor typically rotates about the axis in a substantially horizontal plane.

In order to achieve a maximum power transmission from the base to the rotor, the second inductive coil may be aligned with the first inductive coil. In embodiments in which the rotational axis is vertical, the second inductive coil may be aligned above the first inductive coil such that they are vertically spaced from each other. In such embodiments, the radius R1 may be substantially equal to the radius R3 and the radius R2 may be substantially equal to the radius R4.

The skilled person will be aware that an alternating magnetic field may generate eddy currents in adjacent metal components. In order to prevent or minimise this effect, the first inductive coil is suitably electrically insulated from the base. Similarly, the second inductive coil may be electrically insulated from the rotor. The electrical insulation may be formed from any electrical insulation material. However, it is desired that the electrical insulation should not interfere with the alternating magnetic field generated by the first inductive coil.

In an embodiment of the invention, the first inductive coil is located within a first channel defined by or carried by the base, wherein the first channel includes a layer of electrically insulating material. Similarly, the second inductive coil may be located within a second channel defined by or carried by the rotor, wherein the second channel includes a layer of electrically insulating material.

The or each channel is suitably a U-shaped channel. In such embodiments, the open side of the channel suitably faces the other channel or inductive coil arrangement. For example, the base may include or define and upwardly-facing U-shaped channel and the rotor may include or define a downwardly-facing U-shaped channel.

The electrically insulating material may be a ferrite material, which is electrically non-conductive, but which may be magnetised. Ferrite materials are ceramic materials which comprise iron oxides, typically iron(lll) oxide. It will be appreciated that ferrite insulators are electrically non- conductive, but may act as conductors of magnetic fields.

In addition to wirelessly transmitting power from the base to the rotor, the inductive coupling may further be utilised to wirelessly transfer data between the two components. For example, by providing voltage and/or current modulation to the inductive coils, it is possible to provide bi directional wireless communication between the electrical/electronic components of the base and the electrical/electronic components of the rotor.

Accordingly, in an embodiment of the invention, the base includes a signal transceiver; the rotor includes a signal transceiver and signals are wirelessly transmitted between the base and the rotor via the inductive coupling between the first and second inductive coils. It will be appreciated that the transmitted signals comprise data. As such, data may be transmitted from the base to the rotor and/or from the rotor to the base via the inductive coupling.

As noted above, the electrical power (EMF) wirelessly transmitted from the base to the rotor may power the or each electrical/electronic component carried by the rotor, either directly or indirectly. For example, the rotor may include a rechargeable battery, wherein the rechargeable battery is charged by power transmitted to the second inductive coil from the first inductive coil and the rechargeable battery powers the or each electrical device carried by the rotor. Such an arrangement provides the powered components carried by the rotor with a power source that has a constant voltage. Additionally or alternatively, the rotor may include a power conditioner which is electrically coupled between the second inductive coil and the rechargeable battery or the or each electrical device carried by the rotor. In this way, the power conditioner may condition the input received from the second inductive coil to provide an electrical output with the desired voltage and/or current properties to charge the battery or for the powered components. The skilled person will appreciate that the features described and defined in connection with the aspects of the invention and the embodiments thereof may be combined in any combination, regardless of whether the specific combination is expressly mentioned herein. Thus, all such combinations are considered to have been made available to the skilled person.

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

Figure 1 shows a cross-sectional view through both a base portion and a rotor portion of a roulette wheel according to the invention;

Figure 2 shows a perspective view of part of a base of a roulette wheel according to the first aspect of the invention; and

Figure 3 shows a cross-sectional view through the base portion shown in Figure 1.

For the avoidance of doubt, the skilled person will appreciate that in this specification, the terms "up", "down", "front", "rear", "upper", "lower", "width", etc. refer to the orientation of the components as found in the example when installed for normal use as shown in the Figures.

Figure 1 shows part of a roulette wheel 2 according to the invention. The roulette wheel 2 is mostly a conventional roulette wheel and comprises a base 4 and a rotor 6, wherein the rotor 6 rotates relative to the base 4 about a spindle 8. Such an arrangement is conventional in the field of roulette wheels and as such, the conventional associated components such as bearings and the like are not shown or described herein.

The base 4 defines an annular recess 10 about the spindle 8 which is U-shaped and lined with a U- shaped layer 12 of a ferrite material. The U-shaped annular layer of ferrite 12 includes an inner upstanding circular wall 14 which is spaced from a rotational axis A defined by the spindle 8 by a distance Rl, an outer upstanding circular wall 16 which is spaced from the rotational axis A by a distance R2, and a planar floor portion 18 which joins the first and second circular walls 14, 16.

A first metal coil 20 formed from copper wire is located within the U-shaped annular layer of ferrite 12 such that the first coil 20 is arranged in a substantially planar configuration upon the floor portion 18, with an inner winding of the coil arranged adjacent to the inner circular wall 14 and an outer winding of the coil arranged adjacent to the outer circular wall 16. The free ends of the first coil 20 are connected to an alternating current electrical source located within the base 4, such that an alternating electrical current may be passed through the coil 20.

The rotor includes a corresponding arrangement. Thus, the rotor 6 carries an inverted U-shaped element 26 on a downwardly facing surface 22. The U-shaped element 26 is annular and arranged to be co-axial with and spaced from a bearing portion 24 of the rotor 6. The U-shaped element 26 is formed from a ferrite material and includes an inner downwardly projecting circular wall 28 which is spaced from the rotational axis A defined by the spindle 8 by a distance R3, an outer downwardly projecting circular wall 30 which is spaced from the rotational axis A by a distance R4, and a planar ceiling portion 32 which joins the first and second circular walls 28, 30.

The distance R3 is substantially equal to the distance R1 and the distance R4 is substantially equal to the distance R2, such that the U-shaped element 26 of the rotor 6 is vertically aligned with the U-shaped annular recess 10 of the base 4 and the two annular channels face each other.

A second metal coil 34 formed from copper wire is located within the U-shaped element 26 such that the second coil 34 is arranged in a substantially planar configuration upon the ceiling portion 32, with an inner winding of the coil arranged adjacent to the inner circular wall 28 and an outer winding of the coil arranged adjacent to the outer circular wall 30.

The free ends of the second coil 34 are connected to a power regulator (not shown) located within the rotor 6. The power regulator conditions the electromotive force generated by the second coil 34 when an alternating magnetic field is generated in the first coil 20 as a result of the alternating current being passed through the first coil. The electromotive force is conditioned to provide a substantially constant voltage output from the regulator, which may be used to power electrically-powered components carried by the rotor.

The skilled person will appreciate that the wireless power transmission resulting from the inductive coupling arrangement of the present invention means that no significant additional external forces operate between the rotor 6 and the base 4 that may impact the freedom of rotation of the rotor 6 about the base 4.