Charging cable for an electric vehicle

Abstract

A foldable charging cable 34 for charging an electric vehicle (EV) comprises: plural, insulated, electrical conductors; a flexible sheath formed around the insulated electrical conductors; and plural elongate members (e.g. rigid plastic, fibre-reinforced plastic, aluminium), each arranged parallel to the conductors. The charging cable may be generally flat. Each conductor has a central axis, orthogonal to a line crossing the central axis of the other conductors, i.e. the conductors are arranged parallel to each other on a plane. The conductors extend in a longitudinal direction between first and second ends of the charging cable. The elongate members define corresponding rigid cable portions 48 of the charging cable. The elongate members are spaced apart in the longitudinal direction to define flexible cable portions 46 between the rigid cable portions. Each flexible cable portion is bendable about transverse axes, parallel to the line, allowing the cable to be folded. Neighbouring flexible cable portions, separated by a common rigid cable portion, may be bendable in opposite directions such that the folded cable forms a stack of rigid cable portions. A vehicle connector 20a and a power source connector 20b may be coupled respectively to the first and second end of the charging cable.

Description

Technical Field The present disclosure generally relates to charging cables for charging an electric vehicle. Background Typical charging cables for electric vehicle (EV) charging are bulky and unwieldly. The large connectors, coupled with the length of large cabling required, result in a charging cable assembly that is difficult for users to handle. Generally, users gather known cables for storage by coiling, but this method requires significant time and effort and often results in an untidy cable bundle which is spatially inefficient and difficult to store. Furthermore, deploying such cables can also be demanding on time and effort since coiled cables are particularly prone to tangling when unravelled. Add-on EV charging cable storage solutions are known but these are typically limited to fabric carry bags or large compartments integrated within the vehicle. Such solutions fail to address the difficulties faced in gathering and deploying EV charging cables during use. It is against this background that the invention has been devised. Summary of the Invention According to the invention, a charging cable for an electric vehicle is provided. The charging cable comprises a plurality of insulated electrical conductors, or wires, arranged parallel to each other on a plane and extending in a longitudinal direction between first and second ends of the charging cable. That is, each conductor has a central axis that is orthogonal to a line crossing the central axis of the other conductors. A flexible sheath is formed around the plurality of insulated electrical conductors. The cable further comprises a plurality of elongate members, each arranged parallel to the plurality of insulated electrical conductors to define corresponding rigid cable portions. Each of the plurality of elongate members are spaced apart in the longitudinal direction to define flexible cable portions between the rigid cable portions. Each flexible cable portion may be bendable away from the plane such that the charging cable is foldable. That is, each flexible cable portion may be bendable about transverse axes parallel the line. Accordingly, the cable may be gathered for storage by folding the cable at the flexible cable portions to arrange the rigid cable portions in a neat stack which can be easily grasped by the user. The electrical conductors may be insulated by the flexible sheath and / or additional insulating tubing. The plurality of elongate members may be integrated within the sheath and may also be arranged in the plane on which the insulated electrical conductors are arranged in parallel. That is, they may each have a central axis coincident with, and orthogonal to, the line joining the axes of the conductors. Additionally, the plurality of elongate members may be cylindrical (i.e. of cylindrical cross-section). The charging cable may have a uniform cross-section in the longitudinal direction, in which case, the uniform cross-section may be substantially rectangular. Neighbouring flexible cable portions separated by a common rigid cable portion may be bendable in opposite directions to each other, relative to the plane, so that the charging cable foldable to form a stack of rigid cable portions. The elongate members may be arranged so that the rigid cable portions are parallel to each other when the charging cable is folded to form the stack. Furthermore, the elongate members may be arranged so that each flexible cable portion defines a corresponding cable loop folded about a corresponding transverse axis when the charging cable is folded to form the stack. More particularly, the elongate members may be arranged so that, when the charging cable is folded to form the stack, a first set of cable loops defines a first side of the stack and a second set of cable loops defines a second side of the stack. According to such an arrangement, the elongate members are further arranged so that the transverse axis of each cable loop of the first set of cable loops is offset relative to the transverse axis of an adjacent cable loop in the first set, and the transverse axis of each cable loop of the second set of cable loops is offset relative to the transverse axis of an adjacent cable loop in the second set. This provides a particularly compact arrangement which allows the folded charging cable to be gathered and held conveniently with one hand. Additionally, the elongate members may be arranged so that the transverse axes of alternate ones of the cable loops in the first set are aligned with one another on the first side of the stack and the transverse axes of alternate ones of the cable loops in the second set are aligned with one another on the second side of the stack, when the charging cable is folded to form the stack. 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. 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. Brief Description of the Drawings So that it may be more fully understood, the invention will now be described, by way of example only, with reference to the following drawings in which like features are assigned like reference numerals, in which: Figure 1 a is a schematic view of a typical known system for charging an electric vehicle; Figures 1b and 1c are a cross-section and perspective view respectively of a typical known charging cable for use in the system shown in Figure 1a; Figure 2 is a perspective cross-sectional view of a flexible cable portion of a charging cable according to an embodiment of the invention; Figure 3 is a schematic view of the charging cable shown in Figure 2; Figures 4a to 4c are perspective cross-sectional views of a rigid cable portion of charging cables embodying different arrangements in accordance with the invention and as shown in Figures 2 and 3; Figure 5 is a side view of a folded length of the charging cable shown in Figures 2 to 4c; Figure 6 is a perspective view of a charging cable according to an embodiment of the invention in a folded configuration; Figure 7 is a perspective view of a charging cable according to another embodiment of the invention in a folded configuration; and Figure 8 is a perspective view of a charging cable according to yet another embodiment of the invention in a folded configuration. Detailed Description In general terms, embodiments of the invention provide an electric vehicle charging cable which can be easily folded into a neat arrangement which is convenient for handling and storage. The cable is configured as a flat-type cable and is provided with alternating rigid and flexible portions along its length which serve to guide the user to draw in the cable by gathering the rigid portions in a pre-defined concertina manner. In this way, the cable is configured so that it can be repeatably folded into a spatially efficient shape for storage and handling. To provide context for the invention, Figure 1a shows an electric vehicle 10 in the form of a car which comprises a battery 12 and is connected to a power supply or charging terminal 14 via a conventional charging cable assembly 16. As is typical, the charging cable assembly 16 comprises a cable 18 which extends between two connectors 20a and 20b; a first connector 20a for connecting to a corresponding charging port 22a on the vehicle 10, and a second connector 20b for connecting to a corresponding charging port 22b on the charging terminal 14. When both connectors 20a and 20b of the charging cable assembly 16 are connected to the corresponding charging ports 22a and 22b and the charging terminal is initiated and the vehicle is in a charge-receptive mode, the cable 18 is configured to transmit electrical power from the charging terminal 14 to the electrical vehicle 10 so as to charge the vehicle battery 12. As shown in Figure 1b, a typical charging cable 16 comprises a plurality of individually insulated electrically conductive wires 24 bundled together and surrounded by a protective sheath 26 to form a flexible cable having a substantially circular cross section. In this example, the cable 16 also includes a packing core 28 disposed along the centre of the cable 16 and configured to ensure that a substantially circular cross section is maintained along the cable’s length. The protective sheath 26 is typically formed from a flexible thermoplastic material to allow the cable 16 to be coiled for storage, as shown in Figure 1c. Each insulated electrically conductive wire 24 comprises an electrically conductive core 28 sheathed by insulating tubing 32. The electrically conductive core 30 of each wire 24 may be solid but more typically comprises a bundle of conducting strands twisted together to render the wire more flexible. The core material is typically copper and the insulating tubing 30 is typically made from a flexible thermoplastic material. In the example shown, the plurality of insulated electrically conductive wires 24 include three live wires, a neutral wire, a ground wire, and a communications wire. The live wires, the neutral wire and the ground wire have substantially the same diameter, while the communications wire is of a smaller diameter. Thus, as the skilled person will appreciate, this example cable 16 is suitable for charging the electric vehicle 10 from a three-phase alternating current (AC) power supply 14. Alternatively, the plurality of insulated electrically conductive wires 24 may be configured for charging the electric vehicle 10 from a direct current (DC) power supply 14. In any event, the thickness of the conducting wires must be such that they are capable of handling the current supplied by the charging terminal, which may be significant. This results in a cable 16 of substantial overall diameter, possibly 25-30 mm in diameter, rendering the cable relatively inflexible and perhaps not capable of a bending radius of much less than 200 mm. This results in a coil (when the cable is to be stored) of at least this diameter, which is not very efficient in terms of space utilisation. Turning to embodiments of the present invention, Figure 2 shows a cross-sectional view of a charging cable 34 for an electric vehicle 10. As shown, the cable 32 comprises the same electrically conductive wires 24 as in the prior art example shown in Figure 1a. However, instead of being bundled together around the packing core, the wires 24 are arranged side by side and parallel to each other so that a central axis of each conductor is coincident with an orthogonal line 36 which bisects the cable across its length. When the cable 32 is flat, the line 36 along the length ofthe cable defines a plane 36. In other words, the insulated electrically conductive wires 24 (or wires as referred to herein) are arranged parallel to each other on a longitudinal plane 36 in a longitudinal direction between first and second ends ofthe cable 34. The cable 34 comprises a flexible outer sheath 38 formed around the arrangement of wires 24 to provide a generally flat or flat-type of cable 34, as opposed to a generally cylindrical or cylindrical-type cable 16. As such, the outer sheath 38 comprises an upper surface 40 and an opposing lower surface 42, both of which lie parallel to the longitudinal plane 36 described above. The upper and lower surfaces 40, 42 are connected by opposing side surfaces 44 such that the total cross-section ofthe wires 24 surrounded by the outer sheath 38 is substantially rectangular. That is to say, the width (w) ofthe cable 34 from one side to the other is greater than the thickness (t) ofthe cable 34 between the upper and lower surfaces 40, 42. As shown, the outer sheath 38 may be radiused around the corners ofthe rectangular profile so that the cable 34 is more ergonomic to handle. In some embodiments, the outer sheath 38 may be moulded directly around the electrically conductive cores 28 of each wire 24 so that separate insulating tubing 32 is not required. The outer sheath 38 may be made from a mouldable elastomer such as silicone rubber. It will be appreciated that, fora moulded sheath, the surfaces 40, 42 and 44 are thus all part of one continuous surface. Because the cable 34 is generally widerthan it is thick or deep, it is more flexible in a direction perpendicular to the longitudinal plane 36 (represented by arrow A), that is, about axes defined by any line 36, than in a direction parallel with the longitudinal plane (represented by arrow B), that is, about axes perpendicular to the plane 36. Generally, the ratio of cable thickness to width is such that the cable 34 always tends to bend in the direction A perpendicular to the longitudinal plane 36. As shown in Figure 3, generally, the flexibility of the cable 34 is varied along its length to provide flexible cable portions 46 and comparatively rigid cable portions 48 arranged alternately along the length of the cable 34. More specifically, the cable 34 comprises a series of elongate members 50 disposed along its length in a longitudinally spaced arrangement. Each elongate member 50 is longitudinally aligned with the longitudinal direction of the cable 34 and is configured to be stiffer, at least in the direction A perpendicular to the longitudinal plane, than the plurality of insulated electrically conductive wires 24 and the outer sheath combined 38. In this way, each elongate member 50 defines a corresponding rigid cable portion 48 which is stiffer in the direction A perpendicular to the longitudinal plane than portions of the cable length in which such elongate members 50 are not comprised. The absence of elongate members 50 in these portions where elongate members 50 are not comprised thereby defines the flexible cable portions 46. It should be noted that the rigid cable portions 48 are termed as such because they are comparatively stiffer in at least the direction A perpendicular to the longitudinal plane 36 than the flexible cable portions 46. This does not mean to say that the rigid cable portions 48 do not bend at all in that direction and it is expected that they will be able to flex to a degree. The elongate members 50 may be made from rigid plastic, fibre-reinforced plastic, or aluminium, for example, and may have a minimal degree of flexibility. Likewise, the elongate members 50 have a stiffness in the direction B which adds to the stiffness in that direction of the remainder of the cable 34, rendering the cable even less bendable in that direction. Nevertheless, there remains some flexibility even in that direction. Figures 4a to 4c show alternative examples as to how an elongate member 50 may be formed as part of the cable 34 to define a rigid cable portion 48. In the example shown in Figure 4a, the elongate member 50 takes the form of a thin plate which is attached to the upper surface 40 of the outer sheath 38 using an adhesive. The plate extends along the length of the cable to define a length for the rigid cable portion 48 in the longitudinal direction of the cable. The elongate member 50 is thin compared with the thickness of the sheathed wires such that the overall thickness of the cable 34 remains small compared with its width. The elongate member 50 is no wider than the width of the cable 34 so that the cable 34 as a whole maintains a substantially rectangular cross-section. As shown in the example of Figure 4b, the elongate member 50 in the form of a plate may alternatively be integrated within the cable 34 such that the outer sheath 38 is formed around the plurality of electrically conductive wires 24 as well as the elongate member 50. In other words, each elongate member 50 may be integrated within the outer sheath 38. As in the example of Figure 4a, the plate extends along the length of the cable to define a length for the rigid cable portion 48 in the longitudinal direction of the cable. Alternatively, as shown in the example of Figure 4c, an integrated elongate member 50 may take a rod-like form having a diameter which is no larger than the diameter of the largest wire 24 and arranged at each end of the cable profile. The rod-like elongate members 50 are arranged on the longitudinal plane 36 to align with the wires 24 such that the overall thickness of the cable 34 is unaffected by the inclusion of the elongate members 50. In this way, the outer sheath 38 may be formed around the wires 24 and the elongate members 50 to provide a cable 34 with the minimum thickness required for sufficiently protecting the wires 24 within. Similarly to the previous examples, the rod-like elongate members extend along the length of the cable to define a length for the rigid cable portion 48 in the longitudinal direction of the cable. Feasibly, only one elongate member is provided on just one side of the cable. Feasibly, the side of the cable on which the single elongate member is disposed could alternate between adjacent rigid cable portions 48. As just described, each rigid cable portion 48 may be defined by more than one elongate member 50. As shown in the example of Figure 4c, two identical rod-like elongate members 50 are provided within the outer sheath 38; one arranged to the left of the plurality of wires 24, and one arranged to the right of the plurality of wires 24, in the orientation of the figures. They could be arranged between the wires 24. Turning now to Figure 5, which shows, in a folded configuration, a side view of a length of the cable 34 comprising a first rigid cable portion 48a, a second rigid cable portion 48b, and a flexible cable portion 46 between the two rigid cable portions 48a, 48b. The length of cable 34 is folded whereby the flexible cable portion 46 is bent or folded in the direction A about axes parallel the lines 36 and perpendicular to the longitudinal plane 36a of the first rigid portion 48a so that the upper surface 40b of the second rigid cable portion 48b contacts the upper surface 40a of the first rigid cable portion 48a, whereby the two upper surfaces 40a, 40b are facing and parallel. In this way, the flexible cable portion 46 forms a closed loop 52 around a transverse axis 54 that is parallel all the lines 36 through the cable, and the first and second rigid cable portions 48a, 48b form a stacked arrangement whereby the second rigid cable portion 48b is on top of and vertically aligned with the first rigid cable portion 48a. The rigid cable portions 48a, 48b and the intervening flexible cable portion 46 are configured so that the two rigid cable portions 48a, 48b can remain in the stacked arrangement without the application of an external force holding them together. That is to say, the second rigid cable portion 48b (i.e. the uppermost rigid cable portion) is sufficiently weighted to resist the elastic tendency of the flexible cable portion 46 to unbend. As will be appreciated by the skilled person, electrical cables have a minimum bend radius which defines a measurement of the smallest radius the cable can be bent around without damaging the cable. Thus, in Figure 5, the flexible cable portion 46 is sufficiently long to allow the first and second rigid cable portions 48a, 48b to be arranged in the stacked arrangement while forming a closed loop 52 with a radius (r) which is no smaller than the minimum bend radius. This length of the flexible cable portion 46 may be referred to as the minimum flexible cable portion length. Generally, the larger the diameter of a cable having a circular cross section (such as that shown in Figure 1b), and thus the stiffer the cable, the larger its minimum bend radius. Thus, for the cable 34 shown in Figure 5, the minimum bend radius of the flexible cable portion 46 is defined, at least in part, as a multiple of the flexible cable portion 46 thickness. Thus, it follows that the minimum flexible cable portion 46 length is also defined, at least in part, as a multiple of the flexible cable portion 46 thickness. In other words, the minimum longitudinal spacing of the elongate elements 50 defining the first and second rigid cable portions 48a, 48b is defined by the flexibility of the sheathed wires in the direction A perpendicular to the longitudinal plane. As shown in Figure 5, the thickness of the flexible cable portion 46 is the same as the thickness of the rigid cable portions 48a, 48b such that the cable 34 has a uniform thickness along its length. Accordingly, when in the folded configuration, the cable loop 52 has an outer diameter which is larger than the thickness of the two rigid cable portions 48a, 48b stacked together. Therefore, when oriented as shown in Figure 5, the maximum vertical dimension of the folded cable 34 is defined by the outer diameter of the cable loop 52. Figure 6 shows the whole length of the cable 34 in a folded configuration. As can be seen, the cable 34 comprises a series of rigid cable portions 48, each being the same length as the others. The rigid cable portions 48 are spaced apart so that the flexible cable portions 46 are all the same length, that length being at least equal to the minimum flexible cable portion length. In other words, the elongate members 50 are evenly spaced in the longitudinal direction and the flexible cable portions 46 are all of equal length. For the purposes of the following description, the rigid cable portion nearest to a first end 58 of the cable 34 is referred to as the first rigid cable portion 48a. The next rigid cable portion along from the first end 58 of the cable 34 is referred to as the second rigid cable portion 48b, and so on. The flexible cable portion between the first and second rigid cable portions 48a, 48b is referred to as the first flexible cable portion 46a. The flexible cable portion between the second and third rigid cable portions 48b, 48c is referred to as the second flexible cable portion 46b, and so on. It will be appreciated that the cable may comprise any number of rigid cable portions 48 and intervening flexible cable portions 46 as is suitable for the total length of the cable 34. However, in the example shown in Figure 6, the cable 34 comprises eight rigid cable portions, 48a to 48h, and seven intervening flexible cable portions 46a to 46g. The cable 34 further comprises a first end flexible cable portion 46h which extends between the first rigid cable portion 48a and the first connector 20a (not shown in Figure 6); and a second end flexible cable portion 46i which extends between the eighth (i.e. the last) rigid cable portion 48h and the second connector 20b (also not shown in Figure 6). The first and second end flexible cable portions 46h, 46i are excluded from the below description of flexible cable portions. As shown, in the folded configuration, consecutive or neighbouring flexible cable portions 46, which are separated by a common rigid cable portion 48, are bent in opposite directions to each other so that the rigid cable portions 46 form a stacked arrangement with cable loops 56 formed on either side of the stack. In other words, the charging cable is thereby foldable to form a stack of rigid cable portions 48. In more detail, the first rigid cable portion 48a defines the bottom-most rigid cable portion in the stack. As described with reference to Figure 5 above, the first flexible cable portion 46a is bent clockwise (in the orientation of the figures) about a first transverse axis 54a, thus forming the first cable loop 56a, so that the second rigid cable portion 48b is arranged on top of the first rigid cable portion 48a in the stack with the upper surfaces of the two rigid cable portions 48a, 48b contacting each other in a facing and parallel manner. Conversely, the second flexible cable portion 46b is bent anti-clockwise about a second transverse axis 54b, thus forming the second cable loop 54b, so that the third rigid cable portion 48c is arranged on top of the second rigid cable portion 48b in the stack with the lower surfaces of the two rigid cable portions 48b, 48c contacting each other in a facing and parallel manner. This pattern of bending consecutive folding flexible cable portions 46 in alternate directions is repeated so that the cable 34 is folded in a concertina manner with all the rigid cable portions 48 arranged on top of each other in the stack in vertical alignment. Since the rigid cable portions 48 are all of equal length, and the flexible cable portions 46 are also of equal length, the alternating cable loops 56 are also vertically aligned. That is to say, the first, third, fifth and seventh cable loops define a first set of cable loops which are vertically aligned on the left side of the stack, and the second, fourth, and sixth cable loops define a second set of cable loops which are vertically aligned on the right side of the stack. Therefore, the maximum vertical dimension of the folded cable 34, in the orientation of the figures, is defined as the sum of the outer diameters of the cable loops 56 aligned in the set having the most cable loops 56. However, it is apparent from Figure 5 that the overall thickness of the stack may thereby be defined by the minimum radius r of the loops 52 at each end, since they overlap one another, which may result in a thickness of the stack greater than the combined thickness of the stacked rigid cable portions 48. That is, the rigid cable portions 48 may not be lying face-to-face against one another. It will be appreciated that, in order to ensure the rigid cable portions 48 are able to be stacked on top of the other in a parallel arrangement, each of the flexible cable portions 46 must be longer than the minimum flexible cable portion length that is necessary to avoid damage to the cable 34. Providing longer flexible cable portions 46 will allow the flexible cable portions 46 to be flexed in the vertical direction so that the additional vertical dimension of the stacked cable loops 56 can be accommodated without causing the rigid cable portions 48 to angle away from the parallel plane. Alternatively, the rigid cable portions 48 may be provided with additional thickness to compensate for the additional vertical dimension of the stacked cable loops 56 and to ensure that the rigid cable portions 48 lie in a parallel arrangement when stacked on top of each other. In an alternative embodiment, shown in Figure 7, the rigid cable portions 48 are arranged with dissimilar lengths so that, when the cable 34 is arranged in the folded configuration, the cable loops 56’ in the first set are vertically misaligned and the cable loops 56” in the second set are similarly misaligned. That is to say, the first set of cable loops 56’ defines a first side of the stack of rigid cable portions, and the second set of cable loops 56” define a second side of the stack of rigid cable portions. As in the example of Figure 6, each of the flexible cable portions 46 is of equal length, that length being at least equal to the minimum flexible cable portion length. Thus, as will be understood, the outer diameter of each cable loop 56 (whether in the first set or the second set) is the same as for the other cable loops 56. In more detail, each rigid cable portion 48 is configured with one of three longitudinal lengths; a ‘short’ length, a ‘medium’ length, or a ‘long’ length. The ‘medium’ length is approximately equal to the ‘long’ length minus the outer diameter of a cable loop 56, and the ‘short’ length is approximately equal to the ‘medium’ length minus the outer diameter of a cable loop. Every other rigid cable portion 48 along the length of the cable 34 is configured with the ‘medium’ length. The intervening rigid cable portions 48 are alternately configured with the ‘short’ and ‘long’ lengths. In other words, the rigid cable portions 48 are configured from the first end 58 of the cable 32 to the second end 60 of the cable 34 to have lengths in the repeating sequence of ‘medium’, ‘long’, ‘medium’, ‘short’. As will be appreciated, the sequence may begin with any length rigid cable portion 48 and may be fully or partially repeated for the total number of rigid cable portions 48 defined in the cable 34. Configuring the rigid cable portions 48 to have dissimilar lengths in this way allows for the cable 34 to be arranged in a folded configuration in which the transverse axes 54 of each of the cable loops 56’ of the first set are alternately aligned along two distinct and horizontally offset vertical planes to the left of the stack of rigid cable portions 48. Similarly, the transverse axes 54 of the cable loops 56” of the second set are alternately aligned along two distinct and horizontally offset vertical planes to the right of the stack of rigid cable portions 48. In this way, the first and second sets of cable loops 56’, 56” each comprises a set of outer loops and a set of inner loops. In other words, the elongate members 50 defining the rigid cable portions 48 are configured so that the transverse axis 54 of each of the cable loops 56’ of the first set is offset relative to the transverse axis 54 of an adjacent cable loop 56’ in the first set and, similarly, so that the transverse axis 54 of each of the cable loops 56” of the second set is offset relative to the transverse axis 54 of an adjacent cable loop 56” in the second set Offsetting the cable loops 56 in this way provides a maximum vertical dimension of the folded cable 34 which is less than the sum of the outer diameters of the cable loops 56 aligned in the set having the most cable loops 56. That is to say, the vertical dimension of the embodiment of Figure 7 has a maximum dimension which is smaller than the maximum vertical dimension of the embodiment of Figure 6. As such, this configuration provides a cable which folds into a more spatially efficient and stable arrangement, meaning that the cable will maintain a folded arrangement without additional support or retention means.. Another way of achieving this effect is by providing a cable 34 in which the rigid cable portions 48 are of equal length but the flexible cable portions 46 are of dissimilar length, as shown in Figure 8. In this embodiment, alternate flexible cable portions 46,46 are configured with a long length and a short length respectively. Both lengths are no shorter than the minimum flexible cable portion length discussed above. Thus, when the rigid cable portions 48 are gathered and aligned in the stacked arrangement, the long flexible cable portions 46’ provide the outer cable loops, while the short flexible cable portions 48” provide the inner cable loops. In use, the user may retrieve and return the cable 34 in a folded configuration to and from a storage location. The storage location may be in the boot of the vehicle or near to the charging terminal 14, for example. The storage location may comprise a box or bag specially configured to hold or retain the cable in the folded configuration. Additionally or alternatively, the cable itself may comprise a retainer (not shown) configured to hold the cable in the folded configuration. For example, a strap may be coupled to one of the rigid cable portions 48 and be configured to extend around the stack of rigid cable portions 48 and secure back on itself so as to hold the rigid cable portions 48 together in the stacked arrangement. To connect the two connectors 20a, 50b to their corresponding charging port 22a, 22b, the user will unfold the cable 34 by carrying one end of the cable away from the other. As will be appreciated, when both connectors 20a, 50b are connected for charging, the cable 34 may be in a fully unfolded, partly folded, or fully folded configuration, depending on the distance between the two charging ports 22a, 22b in relation to the length of the cable 34. To refold the cable 34 after charging, the user may take the rigid cable portion 48 nearest an end 58, 60 of the cable 34 in one hand and then place consecutive rigid cable portions 48 on top of each other to form the stack of rigid cable portions 48 described above. The cable 34 is configured so that the user can hold the entire folded cable 34 by grasping the stack of rigid cable portions 48. Thus, in accordance with typical ergonomics, each rigid cable portion 48 is preferably no wider than approximately 40mm and no thicker than 7mm. From a practical perspective, the minimum viable thickness and width of each rigid cable portion 28 will be driven by the requirements for the internal wires and the durability of the outer sheathing. It will be appreciated that various modifications may be made to the aforementioned embodiments without departing from the scope of the invention as set out in the accompanying claims.

Claims

1. A charging cable for charging an electric vehicle, the charging cable comprising:a plurality of insulated electrical conductors, each conductor having a central axis orthogonal to a line crossing the central axis of the other conductors, the conductors extending in a longitudinal direction between first and second ends of the charging cable;a flexible sheath formed around the plurality of insulated electrical conductors; anda plurality of elongate members, each arranged parallel to the plurality of insulated electrical conductors to define corresponding rigid cable portions of the charging cable, wherein each of the plurality of elongate members are spaced apart in the longitudinal direction to define flexible cable portions of the charging cable between the rigid cable portions; whereineach flexible cable portion is bendable about transverse axes parallel the line such that the charging cable is foldable.

2. The charging cable of claim 1, wherein neighbouring flexible cable portions separated by a commonrigid cable portion are bendable in opposite directions to each other, relative to the line, such that the charging cable is foldable to form a stack of rigid cable portions.

3. The charging cable of claim 1 or claim 2, wherein the elongate members are arranged so that the rigid cable portions are parallel to each other when the charging cable is folded to form the stack.

4. The charging cable of claim 3, wherein the elongate members are arranged so that each flexible cable portion defines a corresponding cable loop folded about a corresponding one of said transverse axes when the charging cable is folded to form the stack.

5. The charging cable of claim 4, wherein the elongate members are arranged so that, when the charging cable is folded to form the stack, a first set of cable loops defines a first side of the stack and a second set of cable loops defines a second side of the stack; wherein the transverse axis of each cable loop of the first set is offset relative to the transverse axis of an adjacent cable loop in the first set; and the transverse axis of each cable loop of the second set is offset relative to the transverse axis of an adjacent cable loop in the second set.

6. The charging cable of claim 5, wherein the elongate members are arranged so that the transverse axes of alternate ones of the cable loops in the first set are aligned with one another on the first side of the stack and the transverse axes of alternate ones of the cable loops in the second set are aligned with one another on the second side of the stack, when the charging cable is folded to form the stack.

7. The charging cable of any preceding claim, wherein the plurality of elongate members are integrated within the sheath.

8. The charging cable of claim 7, wherein each of the plurality of elongate members each have a central axis coincident with and orthogonal to the line.J'9.      The charging cable of claim 8, wherein each of the plurality of elongate members are cylindrical.

10. The charging cable of any preceding claim, wherein the charging cable has a uniform cross-section5 in the longitudinal direction.

11. The charging cable of claim 10, wherein the uniform cross-section is substantially rectangular.

12. A charging cable of any preceding claim, comprising:10           a vehicle connector coupled to the first end of the charging cable; anda power source connector coupled to the second end of the charging cable.

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