The present invention relates to a cable tensioning assembly for controlling the reeling and unreeling of electrical cable from an electric vehicle charging cable reel.

BACKGROUND TO THE INVENTION

Cable reels are commonly used for storing electrical cable. In the case of electric vehicle charging, short lengths of electrical charging cable with a plug for charging electric vehicles are often not reeled up, but allowed to hang from a charging point and can be at least partially draped on the ground.

Where charging cable is reeled, the cable is usually free wheeled off the reel by pulling the free end of the cable and wound back on by means of a handle for rotating the reel .

The cable is either wound or unwound, based on the direction of reel rotation.

It can be desirable to use a motorised reel, to assist particularly in winding cable onto the reel. Furthermore, there is a need to use a motorised reel to dispense cable from a reel, particularly for people, who find it difficult to support the weight of a cable. A user with a disability, injury or restricted movement may not be able to manually pull or wind a reel and may not be able to support the weight of a long length of cable.

However, powering a reel can cause problems of cable management, because the cable needs to be retained in a reasonably tight roll around the reel in order to be dispensed and wound up without jamming. The cable may have a natural reluctance to roll tightly, for example because of its stiffness, which may cause it to expand on the reel.

For example, as the cable reel rotates at a speed to dispense the cable, if insufficient tension is applied to the free end of the cable, it will expand from the surface of the cable reel. This means that the coil radius of the wound cable will increase, i.e. making looser coils, which may cause parts of the cable to contact with unintended parts of the device, such as a housing.

Also, as the cable is retracted back into the wound configuration on the reel it may not be stored in the desired or expected configuration, especially if during unwinding the remaining cable has become loose on the reel. In an example of a known arrangement, as shown in Figure 3, a set of rollers 102, 104 are provided adjacent a reel through which the cable 106 extends. The rollers lie on either side of the cable with the axes of the rollers in line and perpendicular to the cable. These serve to guide the cable and compress the cable sheathing. The rollers tend to enclose and surround the cable, ensuring that it does not slip off the rollers. This does not allow for the cable to be easily removed, for changing, maintenance, or manual unrolling.

It is an object of the present invention to reduce or substantially obviate the aforementioned problems.

STATEMENT OF INVENTION

According to a first aspect of the present invention, there is provided a cable tensioning assembly for an electric vehicle charging cable reel, the cable tensioning assembly comprising: a first roller and a second roller for interacting with a cable from a cable reel, wherein both rollers include a first end, a second end, a cable contact portion disposed between the first end and the second end, and a rotational axis extending through the first end and second end; wherein the rotational axis of the first roller and the rotational axis of the second roller are disposed to either side of a plane, in use the first roller being spaced apart from the second roller with the second roller being further from the reel; and wherein a serpentine cable path extends through the cable tensioning assembly, the serpentine cable path crossing the plane and interfacing with the cable contact portions of the first and second rollers.

The cable tensioning assembly may be used for dispensing and/or retracting the cable from or onto the cable reel such as an electric vehicle charging cable reel.

Advantageously, the cable tensioning assembly allows sufficient tension to be provided to the cable when dispensing and/or retracting the cable from or onto the cable reel. In particular, the cable tensioning assembly prevents the cable from expanding from a surface of the cable reel when the cable is being dispensed from the cable reel.

The combined effect of the reluctance of the cable causing the cable to push against the rollers as it makes a serpentine path coupled with the weight of the cable, causes the cable to grip the first and second rollers. The cable tensioning assembly allows the cable to return to a specific or desired configuration around the cable reel when being retracted back onto the cable reel and prevents loose winding of the cable.

The cable tensioning assembly is suitable for use for all types of electric vehicle users including people with physical difficulties and/or disabilities. This is because users do not need to manually dispense and/or retract the cable from or onto the cable reel. This means that they do not need to pull or push the cable from or onto the cable reel, and they do not need to apply force to provide sufficient tension to the cable.

The cable tensioning assembly is able to provide constant tension to the cable at the cable reel when a portion of the cable is extended through the assembly and is located in the serpentine cable path.

The first roller may be regarded as an inner roller, ie closer to the reel than the second roller, which may be regarded as an outer roller.

The first roller may have a substantially frustoconical portion between the first end and second end of the roller. The substantially frustoconical portion may form at least a portion or the whole of the cable contact portion of the first roller.

The substantially frustoconical portion may include a smaller end and a larger end. This means that the diameter and/or radius at one end of frustoconical portion may be smaller than at the other end. The smaller end may have a smaller diameter and/or radius than the larger end.

The smaller end may be disposed proximate to the first end of the first roller and the larger end may be disposed proximate to the second end.

The substantially frustoconical portion allows the first roller to guide the movement of the cable as it is dispensed and/or retracted from or onto the cable reel. This means that the cable can move along the length of the frustoconical portion to follow the movement or path of the cable from or onto the cable reel.

The substantially frustoconical portion may be a substantially curved funnel shape.

The curved funnel shaped may substantially exponentially increase in diameter towards the second end of the first roller. The shaped first roller provides a means in increases the interface area between the cable and roller and provides an aligning means.

A flange may be provided at the first end of the first roller. The flange may have a curved surface which curves up from the smaller end of the frustoconical portion. The flange of the first roller prevents the cable from moving or sliding away from the substantially frustoconical portion. The curved surface of the flange allows the flange to guide the cable back towards the smaller end of the frustoconical portion or the central part of the first roller.

The second roller may be substantially bobbin shaped. In other words, the second roller may include a first flange, a second flange and a central part. The first flange may be provided at the first end of the second roller and the second flange may be provided at the second end of the second roller. The first and second flanges may extend away from the second roller by substantially the same distance. The diameter of the central part of the outer roller may be smaller than the diameter of the flanges.

The first and second flanges allow the outer roller to maintain the cable on the central part. They prevent the cable from sliding off from the first end and/or the second end of the second roller when being dispensed and/or retracted from or onto the cable reel.

The central part of the second roller may from at least a part of the cable contact portion of the second roller.

The central part of the bobbin-shaped second roller may be concave. This allows the second roller to complement the shape of the cable, thereby providing a great area of contact between the roller and the cable.

The length of the central part of the second roller may be equivalent to or larger than the diameter of the cable. This prevents the cable from sliding along the length of the central part and allows the second roller to provide better control of the movement of the cable as it is guided through the assembly and dispensed and/or retracted from or onto the cable reel.

At least one of the first roller and the second roller may include a cable grip for increasing friction between the cable and the roller. The cable grip may comprise material for increasing friction. The cable grip may be disposed along the whole or part of the length of the frustoconical portion of the first roller and/or the central part of the second roller. The cable grip may be disposed to the cable contact portion of the first roller and/or second roller.

The cable grip increases friction between the cable and first roller and/or second roller.

The cable contact portion of the inner roller may be disposed to a bottom of the first roller. The cable contact portion of the second roller may be disposed to a top of the second roller.

The serpentine cable path may be disposed below the first roller and above the second roller.

In use, the cable contact portion of the first roller may interface with an upper surface of the cable, and the cable contact portion of the second roller may interface with a lower surface of the cable.

Advantageously, this arrangement of below the first roller and above the second roller in combination with the reluctance of the cable to bend increases friction between the rollers and the cable because the cable pushes against the rollers.

The first roller and the second roller may counter rotate with respect to each other. For example, the first roller may rotate in an anti-clockwise direction and the second roller may rotate in a clockwise direction, or vice versa, when in use.

The first roller and second roller may be adapted to rotate at substantially the same speed. This allows the cable to be properly dispensed and/or retracted from or onto the cable reel since both portions of the cable interfacing with the first and second rollers are being gripped or pulled by the rollers towards or away from the cable reel at the same speed.

A motor may drive rotation of at least one of the first roller and the second roller. The motor allows for automatic dispensing and/or retracting of the cable from or onto the cable reel. This is advantageous as it means that people with disabilities, injuries, restricted movement or similar are able to dispense and/or retract the cable without needing assistance.

Rotation of one roller may be mechanically couple to rotation of the other roller. For example, the rotation of the second roller may be mechanically coupled to rotation of the first roller. The mechanical coupling may comprise a gear train. The mechanical coupling may comprise a pulley.

A first motor may drive the first roller and a second motor may drive the second roller. This allows the rotation of the inner roller and the second roller to be controlled or operated separately or individually.

A connecting assembly may be provided for mounting the first roller and the second roller of the cable tensioning assembly to the cable reel. The connecting assembly may include at least one substantially triangular plate.

The connecting assembly may comprise an axle for each of the rollers.

A roller mounting surface may be provided. The roller mounting surface may be provided on the connecting assembly. The mounting surface may be provided proximate the first ends of the first and second rollers.

A cable receiving cavity may be provided between the first roller and second roller. The serpentine cable path may extend through the cable receiving cavity between the first and second rollers.

The cable receiving cavity may include a closed side disposed to the first ends of the inner and outer rollers. The cable receiving cavity may include an open side defined by a cable threading aperture. The cable threading aperture may be defined between the second ends of the first and second rollers for allowing a cable to be removed from or inserted within the cable receiving cavity.

This improves maintenance because the cable may be located in or removed from the cable tensioning assembly with ease. This is advantageous when the cable is a removable cable, for example when the cable has electrical connectors at each end, as the cable may be received into the cable receiving cavity.

The roller mounting surface, or the connecting plate, may define the closed side of the cable receiving cavity.

A means to cause the cable to hang after the outer roller may be provided. This allows the free end of the cable to hang under gravity which increase friction between the cable and the roller. A cable reel may be provided with the cable tensioning assembly. This may be considered a cable reel assembly. The cable reel may be suitable for an electric vehicle charging cable. This allows the cable tensioning assembly and the cable reel to be provided together.

The speed of rotation of the first and/or second rollers may be controlled so as to ensure that the cable is dispensed or retracted at a constant speed.

According to a second aspect of the present invention, there is provided an electric vehicle charging cable reel assembly for dispensing an electric vehicle charging cable, the cable reel assembly comprising: a cable reel rotatable about a first axis for storing cable in a coiled configuration ; a cable tensioning assembly, the cable tensioning assembly comprising a first roller rotatable about a second axis for interfacing with a portion of the cable, a second roller rotatable about a third axis for interfacing with a different portion of the cable, the first and second rollers each include a cable contact portion disposed between a first end and a second end, the second axis and the third axis being spaced apart from each other and the first axis; and a serpentine cable path defined between the cable reel, the inner roller and the outer roller.

The cable tensioning assembly in the second aspect of the present invention may include features of the first aspect of the present invention. For example, the serpentine cable path.

A connecting assembly may be provided on the cable reel to connect, fix or attach the cable tensioning assembly to the cable reel.

According to a third aspect of the present invention, there is provided a cable tensioning assembly for an electric vehicle cable reel, the cable tensioning assembly comprising: a first roller and a second roller, each roller includes a first end, a second end, a cable contact portion disposed between the first end and the second end, and a rotational axis extending through the first end and second end; and a cable receiving cavity being provided between both the first and second rollers, wherein the cable receiving cavity has a closed side disposed to the first ends of the rollers and an open side defined by a cable threading aperture between the second ends of the rollers for allowing a cable to be removed from within the cable receiving cavity.

The cable tensioning assembly in the third aspect of the present invention may include features of the first aspect and/or second aspect of the present invention. For example, the serpentine cable path or the positioning of the rollers and cable reels, i.e. the rotational axis of the first roller and the rotational axis of the second roller may be disposed to either side of a plane, in use the first roller may be spaced apart from the second roller with the second roller being further from the reel.

A roller mounting surface may define the closed side of the cable receiving cavity.

An electric vehicle may be provided.

The electric vehicle may comprise a cable tensioning assembly according to any aspect of the present invention. That is to say, a cable tensioning assembly according to any aspect of the present invention may be disposed in or on the electric vehicle.

The electric vehicle may comprise a cable reel assembly according to any aspect of the invention. That is to say, a cable reel assembly according to any aspect of the invention may be disposed in or on the electric vehicle.

The cable tensioning assembly or cable reel assembly may be removable from the electric vehicle.

This allows the cable reel assembly or cable tensioning assembly to be moved between the interior and exterior of the vehicle, for example between a storage compartment, such as a car boot, to a pavement or road surface. This is especially useful when the charging cable includes a first plug at one end for connection to the electric vehicle and a second plug at the other end for connection to an electric vehicle charger.

A means to detachably attach the cable reel assembly or cable tensioning assembly to the electric vehicle may be provided. This means may be a mounting means. This is particularly useful for retrofitting a cable reel assembly to an electric vehicle.

A portion or surface of the electric vehicle may be the roller mount surface. An electric vehicle charging cable may be provided. The electric vehicle charging cable may be provided with any aspect of the present invention.

An electric vehicle plug for connecting to a socket in an electric vehicle may be disposed at an end of the electric vehicle charging cable.

A charger plug for connecting to a socket in an electric vehicle charging station or a power outlet may be disposed at an end of the electric vehicle charging cable. This arrangement may be provided with the electric vehicle.

The electric vehicle charging cable may comprise a plug at each end of the cable. The first plug may be an electric vehicle plug for connecting to a socket in an electric vehicle. The second plug may be a charger plug for connecting to a socket in an electric vehicle charging station or a power outlet. This type of electric vehicle charging cable can be considered a removable cable because it is entirely removable from the cable reel. This is advantageous as it provides a charging cable which can be connected between the electric vehicle and electric vehicle charger or power outlet meaning that the electric vehicle user does not need to rely on the electric vehicle charger having an installed charging cable. It also allows for the cable reel assembly or cable tensioning assembly to be removable from the electric vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings, in which:

Figure 1 shows a perspective view of a cable tensioning assembly;

Figure 2 shows a schematic cross-sectional view of the cable tensioning assembly in Figure 1 ; and

Figure 3 shows a schematic cross-sectional view of a prior art cable tensioning assembly.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to Figures 1 and 2, a cable tensioning assembly for an electric vehicle charging cable reel is indicated at 10. The cable tensioning assembly 10 comprises a first roller 12 and a second roller 14. In the current embodiment, the first roller 12 is referred to as an inner roller and the second roller 14 is referred to as an outer roller.

A connecting assembly 16 provides a means to mount the inner roller 12 and the outer roller 14 to the cable reel 18. The connecting assembly 16 provides a means to space the inner and outer rollers 12, 14 from a rotatable element of the cable reel 18.

The cable reel 18 has a drum-shaped body, preferably cylindrical, that extends along a longitudinal axis. The drum-shaped body being the rotatable element.

An electric vehicle charging cable 56 is stored in a coiled configuration around the drum-shaped body of the cable reel 18.

In some embodiments the cable 56 has electrical connectors, such as plugs, disposed at either end of the cable, one connector for connection to the electric vehicle and one connector for connection with an electric vehicle charger or power outlet. In such cases, one plug is stored in a recess on the drum-shaped body while the other cable at the dispensing end, i.e. the end not stored on the cable reel. This can be considered a removable cable as it can be removed entirely from the device.

In other embodiments, the cable has one electrical connector, such as a plug, at the free end of the cable, i.e. the end not stored on the cable reel.

The drum-shaped body is rotatable about the longitudinal axis. In other words, the drum-shaped body is rotatable about a central rotational axis. This provides a means for dispensing and/or retracting the cable 56 from or onto the cable reel 18.

In the current embodiment, a motor is provided which drives rotation of the drumshaped body. In other embodiments, the drum -shaped body may freely rotate.

A serpentine cable path is provided for cable 56. This is provided by the cable 56 extending from the upper region of the cable reel 18 below the inner roller 12 and over the outer roller 14.

In the current embodiment, the cable tensioning assembly 10 is fixed to a non-rotating portion of the cable reel 18 by the connecting member 16. The non-rotating portion is a flange 82 proximate an end of the drum-shaped body. In other embodiments, the tensioning assembly 10 can be spaced in a position away from the drum-shaped body such that it is a fixed position relative to the drum-shaped body. The assembly 10 may be attached to a housing, enclosure or similar.

In other embodiments, the connecting assembly 16 can be releasably attached to the cable reel 18. The assembly 16 can be attached to the cable reel 18 when in use and be removed when not in use. This allows the cable reel 18 to be stored in a more compact storage space.

In the current embodiment, the connecting assembly 16 includes two substantially triangular plates 20, 22, which are spaced apart by a connecting member 24. The plates 20,22 are substantially similar or identical in shape and are aligned with each other i.e. , the corners of the first substantially triangular plate 20 are aligned or in-line with the corners of the second substantially triangular plate 22.

An axle 44 is provided for the inner roller 12. An axle 46 is provided for the outer roller 14. The axles 44, 46 provide a means for rotationally mounting the inner and outer roller 12, 14. The axles 44, 46 may extend through the connecting assembly 16.

The axle 44 is provided proximate an upper portion of the connecting assembly 16. Axle 44 is disposed proximate an upper corner of the connecting assembly 16. The axle 46 is provided proximate a lower portion of the connecting assembly 16. The lower portion being below the upper portion in use. Axle 46 is disposed at a corner of the connecting assembly 16 diagonally opposite the axle 44.

The inner roller 12 includes a first end 32, a second end 34 and a cable contact portion 36 disposed between the first end 32 and the second end 34. The first end 32 of the inner roller 12 is proximate the connecting assembly 16. A rotational axis of the inner roller 12 extends along the axle 44 and through both ends 32, 34 of the inner roller.

The outer roller 14 includes a first end 38, a second end 40 and a cable contact portion 42 disposed between the first end 38 and the second end 40. The first end of 38 of the outer roller 14 is proximate the connecting assembly 16. A rotational axis of the outer roller 14 extends along axle 46 and through both ends 38, 40 of the outer roller.

The rotational axes of the inner roller 12, the outer roller 14 and drum-shaped body of the cable reel 18 are parallel to each other.

In use, the inner roller 12 is disposed closer to the drum-shaped body than the outer roller 14. That is to say, that the inner roller is spaced apart from the second roller with the second roller being further from the drum-shaped body, in use. The rotational axes of the inner and outer rollers are disposed to either side of a plane.

Preferably, the rotational axis of the inner roller 12 is disposed to one quadrant formed by two planes substantially orthogonal to each other, for example a substantially vertical plane and a substantially horizontal plane, while the rotational axis of the outer roller 14 is disposed to a diagonally opposite quadrant. Put another way, rotational axes of the inner and outer rollers 12, 14 are disposed to either side of a first plane and either side of a second plane, the first plane being substantially orthogonal to the second plane.

The distance between inner roller 12 and outer roller 14, and inner roller 12 and drumshaped body may vary based on at least one cable property, for example, the diameter of the cable, weight of the cable, stiffness of the cable, or similar.

A substantially frustoconical portion 48 is provided between the first end 32 and the second end 34 of the inner roller 12. The substantially frustoconical portion 48 is a substantially curved funnel shape. The substantially curved funnel shape produces a smaller end 50 and a larger end 52 with a substantially exponentially increasing diameter.

The smaller end 50 is disposed proximate the first end 32 of the inner roller 12 and the larger end 52 is disposed to the second end 34 of the inner roller 12.

The first end 32 of the inner roller 12 includes an inner roller flange 54 having a curved surface which curves up from the smaller end 50 of the frustoconical portion 48.

A cable grip 58 is provided on the inner roller 12. In the current embodiment, the cable grip 58 is provided by a piece of material extending around the inner roller 12 proximate the smaller end 50 of the frustoconical portion 48. In other embodiments, it may be an over mould, textured surface or similar.

Flanges 60, 62 extend from both the first end 38 and the second end 40 of the outer roller 14. This provides a substantially bobbin shaped outer roller 14. The cable contact portion 42 is provided around a central part of the outer roller 14 between the first 60 and second 62 flanges.

A central part of the outer roller 14, i.e. the cable contact portion 42, is sized to allow the cable 56 to be disposed between flanges 60, 62. For example, the distance between the flanges 60,62 are substantially the same or greater than the diameter of the electric vehicle charging cable 56.

The central part or the cable contact portion 42 of the outer roller 14 is concave. This allows the cable contact portion 42 to complement the shape of the cable sheathing and thereby create a better contact or interface between the outer roller 14 and the cable 56.

A cable grip (not shown) may be provided around the central part or cable contact portion 42 of the outer roller 14. In other embodiments, the cable grip may only be provided on one of the inner 12 and outer 14 rollers.

In the current embodiment, a motor 64 drives the rotation of the inner roller 12 through axle 44. The motor 64 is position orthogonal to axle 44 and drives a gear which meshes with a gear on axle 44. Outer roller 14 may freely rotate about its rotational axis due to the movement of the cable 56 through the serpentine path.

In other embodiments, a mechanical coupling may be provided which will cause the motor 64 to drive rotation of both the inner and outer rollers. In other embodiments, a second motor is provided which drives rotation of the outer roller 14 while motor 64 rotates the inner roller 12. In other embodiments, the inner and/or outer roller may be motorised while the drum-shaped body is not.

The motors are controllable and synchronised so as to control the speed of dispensing and retracting of the cable 56.

In use, the inner roller 12 and the outer roller 14 counter rotate with respect to each other. For example, the inner roller 12 rotates clockwise and the outer roller 14 rotates anti-clockwise, or vice versa.

As best shown in Figure 2, a substantially serpentine cable path is provided between the inner roller 12, outer roller 14 and drum-shaped body of the cable reel 18.

In use the cable 56 is coiled around the drum-shaped body with one portion extending from an upper region of the drum-shaped body under the inner roller 12 and over the outer roller 14. The end of the cable 56 after the outer roller 14 hangs or is directed down in use. This end may be considered the dispensing end, the end not stored on the cable reel or free end. As the cable 56 follows the serpentine path it forms a substantial S-shape portion. An upper surface of the cable 56 interfaces with the inner roller 12 at a bottom portion of the cable contact portion 36, for example around point 74 in Figure 2, and a lower surface of the cable 56 interfaces with the outer roller 14 at a top portion of the cable contact portion 42, for example around point 78 in Figure 2.

While the cable 56 moves the serpentine cable path by rotation of the or each roller, the combined effect of the reluctance of the cable causing the cable to push against the inner and outer rollers with the weight of the cable, cause the cable to grip the inner and outer rollers.

A cable receiving cavity 78 is provided between the inner and outer rollers 12, 14. The serpentine cable path extends through the cable receiving cavity 78.

The cable receiving cavity 78 has a closed side disposed to the first ends 32, 38 of the inner and outer rollers 12, 14. The closed side being provided by a surface 68 of the connecting assembly 16.

A cable threading aperture 80 is provided in an open side of the cable receiving cavity 78. The cable threading aperture 80 is provided between the second ends 34, 40 of the inner and outer rollers 12,14.

The cable 56 can be removed from and inserted into the cable receiving cavity 78 through the cable threading aperture 80. This allows users to quickly remove and insert the cable 56 from the cable reel. This can be beneficial for maintenance.

The cable tensioning assembly 10 of the present invention allows cable 56 to be dispensed and/or retracted from or onto the cable reel 18 without preventing easy access for the cable 56 to be inserted or removed from the cable tensioning assembly 10. This means that the cable tensioning assembly 10 can also be easily used with different sizes and types of cable 56.

The embodiments described above are provided by way of example only, and various changes and modifications will be apparent to persons skilled in the art without departing from the scope of the present invention as defined by the appended claims.