COMPRISING SUCH APPARATUS

FIELD

The invention relates to electrical-cable storage apparatus and to a vehicle, such as an electric or hybrid electric vehicle, that comprises such apparatus.

BACKGROUND

Whilst vehicles that are powered solely by internal combustion engines have become be phenomenally popular, there is increasing interest in and demand for vehicles that are more environmentally friendly. An example of vehicles that are more environmentally friendly are those in which some or all of the motive power is provided by an electric motor. Such vehicles fall in to two main categories: electric vehicles in which there is no internal combustion engine and in which all motive power is provided by an electric motor or motors; and hybrid electric vehicles in which both an internal combustion engine and an electric motor are used. In both types of vehicle, it can be necessary to connect the vehicle to a high-current external supply of electricity in order to recharge batteries, or other electricity storage means, of the vehicle. This is particularly the case with purely electric vehicles, which, in most configurations, are unable to recharge their batteries, other than perhaps during regenerative braking.

In order to connect the vehicle to a high-current external supply of electr icity, the vehicle may be provided with a length of electrical cable. In order to be useful in a variety of situations, the cable must usually be of substantial length. This however creates a problem: if the full length of the cable is not needed during connection for recharging, the remainder of the cable would usually remain un-deployed and wound around a storage device. When a high current flows in the cable, the strong magnetic field set up around the portion of the cable that is still wound around the storage device results in heating of that portion of the cable. The level of heating can be such that insulation of the cable may melt, resulting in a safety hazard. The cable may even catch fire.

This problems might be avoided by always fully deploying the cable from the cylinder, but this is inconvenient and may also have safety implications in presenting a trip hazard.

In an alternative approach, the vehicle may be provided without an integral cable and may instead be provided with a socket to which an external cable can be connected. This, however, is problematic in that not all charging points may include a cable.

According, it is an object of at least some embodiments of this invention to address these problems.

SUMMARY

In general terms, embodiments of the invention provide a solution in which a cable can be conveniently, efficiently and safely stored in an electric or hybrid electric vehicle without generating a strong magnetic field and overheating the cable. According to a first aspect of this invention, there is provided electrical-cable storage apparatus, the apparatus comprising: an electrical cable substantially fixed at a fixed end thereof relative to a fixed body of the apparatus, and free at a free end thereof for connecting to an electricity supply; and at least one moveable pulley, moveable by being mounted for substantially radial translation relative to the fixed body, wherein the electrical cable is wound around the at least one moveable pulley to give at least two overlapping portions of the cable, wherein pulling on the free end of the cable moves the pulley to reduce the length of those overlapping portions and expose a greater length of the cable adjacent the free end.

By threading the cable around at least one moveable pulley, overlapping lengths of the cable are stored without forming coils and so do not set up strong magnetic fields that would overheat the cable. Pulling on the cable moves the moveable pulley to shorten the overlapping lengths and so allows the cable to be deployed.

Embodiments of the invention are in some ways reminiscent of a block-and-tackle arrangement, but with important differences: in a block-and-tackle arrangement, the purpose is to gain a mechanical advantage in lifting a load, whereas here, the purpose is storage of electrical cable; and in a block-and-tackle arrangement, the pulleys on the block or blocks are co-axially mounted and so cable passing around those pulleys forms coils that would defeat the very purpose of the present arrangement. The at least one moveable pulley may be mounted such that it is resiliently biased against substantially radial translation that reduces the length of the overlapping portions. Thus, releasing the free end of the cable can result in the at least one moveable pulley moving to increase the length of the overlapping portions and so retracting the cable, thereby shortening the portion of the cable adjacent the free end.

The apparatus may comprise a plurality of pulleys. The cable may be wound around each of the plurality of pulleys. The pulleys may be arranged such that the wound cable does not form overlapping coils. Each of the plurality of pulleys may be arranged with their axes spaced from each other.

One or more of the plurality of pulleys may be mounted such that they are relatively moveable towards and away from one or more other of the plurality of pulleys. One or more of the pulleys may be mounted such that they are relatively moveable towards and away from the or each pulley to which they are immediately coupled by the electrical cable.

The plurality of pulleys may comprise two groups of pulleys: a first group and a second group. There may be one or more pulleys in each group. The first group may be mounted such that their axes are fixed relative to the fixed body. The second group may be mounted such that their axes are moveable relative to the fixed pulleys and the fixed body. The second group may be mounted such that they can be translated in a substantially radial direction. The second group may be mounted on a moveable member that is moveable relative to the first group and the fixed body. The direction of movement may be perpendicular to the axes of the pulleys thereon. The second group may be mounted so as to be moveable towards and away from the first group, thereby, respectively, shortening and lengthening the distance therebetween.

Alternatively, the first group may, like the second group, be mounted such that their axes are also moveable relative to the fixed body. The second group may be mounted on a second moveable member (the moveable member referred to above being the first moveable member) that is moveable relative to the fixed body and also the first moveable member. The first and second moveable member may be arranged to move together and to move apart. The direction of movement may be substantially

perpendicular to the axes of the pulleys mounted thereon.

Each group of pulleys may be mounted such that their axes are spaced apart, substantially in-line with each other (where there are three or more pulleys in the group). The pulleys of the first group may be staggered relative to the pulleys of the second group. The cable may extend between the pulleys of the first group and the pulleys of the second group, alternating between the two to form a plurality of overlapping portions of cable. The arrangement may be such that the overlapping portions of the electrical cable lie substantially in the same plane. The arrangement may be a substantially zig-zag arrangement

The or each moveable member may be resiliently biased to maximise the distance between the two groups. Resiliently deformable means may be coupled to the or each of the moveable members.

The or each moveable member may be an arm, pivotably mounted to the fixed body at one end and free to move at the other. The two moveable members may be pivotably coupled together and mounted to the fixed body at their pivotably mounted ends.

The apparatus may also include a cable arrestor. The arrestor may be positioned to engage the cable between the plurality of pulleys and the free end of the cable. The arrestor may be arranged automatically to prevent retraction of the cable when the free end of the cable is released. The arrestor may be arranged such that it can be manually operated to allow retraction. According to a second aspect of this invention, there is provided a vehicle comprising the apparatus defined hereinabove. The vehicle may be an electric vehicle; it may be a hybrid-electric vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

Specific embodiments in which the invention is embodied are described below by way of example only and with reference to the accompanying drawings, in which:

Figure 1 is a plan view of apparatus forming a first embodiment, the apparatus shown mainly in a position in which a cable is retracted and stored;

Figure 2 is a rear view of the apparatus of Figure 1;

Figure 3 is a perspective view of the apparatus of Figure 1 and Figure 2; and

Figure 4 is a simplified plan view of certain components of the apparatus, showing those components in a position in which the cable is deployed.

SPECIFIC DESCRIPTION OF CERTAIN EXAMPLE EMBODIMENTS

It should be noted that, in the drawings, certain moveable parts are shown

simultaneously in two different positions in order to shown how those part move during operation. This is to aid understanding.

Figure 1 shows electrical-cable storage apparatus 10. The apparatus 10 is for incorporating into an electric car or hybrid electric car (not shown) to store an electrical cable that can be used to connect the car to an external supply of electrical power, such as a domestic electricity socket. The apparatus is arranged to deploy a length of the cable when needed; and to store the cable when it is not needed, or when only some of the deployable length is needed. The apparatus 10 is made up of a body portion 20, a first pivotable arm 40, a second pivotable arm 60, an electrical cable 80, a tensioning arrangement 90 and an arrestor unit 100. These will be described in turn.

The body portion 20 forms a base for the apparatus 10, with most other components of the apparatus 10 being mounted thereon. The body portion 20 is made up of a generally rectangular base plate 22 that has integral projecting, and generally triangular, lug portions at each corner and also one 24 at the middle of a front edge of the base plate 22. Each of the lug portions is generally co-planar with the remainder of the base plate 22. The two lug portions 26 that are at either end of the rear edge of the base plate 22 each have a triangular cut-out 27 therethrough, with a apex of the triangular cut-out 27 being outermost. The base plate 22 also includes three circular cut-outs in the middle of the base plate 22 in order to save material, and hence weight, where not needed.

Fixed to the top face of the base plate 22 are two end stops 23. Each end stop 23 is positioned towards a respective one of the outside ends of the base plate 23, between the projecting lugs at the front and rear corners thereof.

The body portion 20 also includes a brace 30. The brace 30 is in a plane perpendicular to the plane of the base plate 22 and is fixed to the base plate 22 to extend along the front edge of the base plate 22, so as to project from the top face of the base plate 22. The brace 30 is more easily seen in the rear view of Figure 2. As can be seen in Figure 2, the brace 30 has a cut-out 32 in the middle thereof, such that the brace 30 resembles a bridge over the top face of the base plate 22.

The final component of the body portion 20 that will be described before moving on is a reinforcing skeleton 34. The skeleton is a frame that surrounds and reinforces parts of the brace 30 and the base plate 22 where increased strength and rigidity is needed.

The base plate 22, the brace 30 and the skeleton 34 are all formed of aluminium alloy in this embodiment and are epoxy bonded and riveted to each other. With reference again to Figure 1, the first and second pivotable arms 40, 60 will now be described. Each arm 40, 60 is formed of two spaced-apart parallel plates 42, 62. For each arm 40, 60, the plates 42, 60 are substantially identical and are fixed relative to each other by several spacing elements (not visible in Figure 1). The arms 40, 60 are mounted to the body portion 20 at a front end of each arm 40, 60. The front ends are pivotable mounted to each other and to the body portion 20. The pivotable mounting is at an outer tip of the triangular lug portion 24 that projects from the middle of the front edge of the body portion 20. The arrangement is such that each arm 40, 60 is substantially a mirror-image of the other in a plane passing though the axis of the pivot. The skeleton 34 provides support for the mounting such that the front end of each arm 40, 60 is sandwiched between the skeleton 34 and the base plate 22.

When viewed from above as in Figure 1 (that is, perpendicular to the plane of the base plate 22), the arms 40, 60 together form a V-shape. Each branch of the V is not, however, straight: this is because each arm 40, 60 firstly curves outwards from the pivot point, and then curves inwards at their free ends.

Each arm 40, 60 has a respective pulley arrangement 50, 70 at the free end thereof. These will now be described. In the present embodiment, the two pulley arrangements 50, 70 differ from each ther.

Taking firstly the pulley arrangement 50 that is towards the left side of the apparatus 10 when viewed from above, this arrangement 50 is made up of two pulleys 52 mounted in a first cradle 54. The pulleys 52 are mounted in the cradle 54 so as to have their axes spaced apart and such that the pulleys are co-planar. The cradle 54 is, in turn, mounted in a cradle brace 56 that forms a supporting frame around the cradle 54. The cradle brace 56 is pivotably mounted to the free end of the left arm 40, the pivot point being between the axes of the two pulleys 52. The cradle brace 56 is mounted to the arm 40 so that it, together with the cradle 54 and pulleys 52 therein, are sandwiched between the two plates 42 of that arm 40. Clearances are provided such that the pulley arrangement 50 can move freely between the two plates 42 about its pivot.

Turning now to the pulley arrangement 70 that is towards the right side of the apparatus 10, this arrangement 70 is similar to that just described in having a plurality of pulleys 72 mounted in a cradle 74 that is in turn mounted in a cradle brace 76. However, this arrangement 70 differs in that three pulleys 72, rather than two, are provided in the same plane and with their axes spaced apart in a line. Again, the cradle brace 76 of this pulley arrangement 70 is pivotally mounted to the free end of the respective arm 60 so as to be sandwiched, again with clearances, between the plates 62 of that arm 60. This time, however, the pivot is co-axial with the middle one of the three pulleys 72. In both the pulley arrangements 50, 70 described above, the pulleys and the cradles are formed of plastic; whereas both of the cradle braces 56, 76 are formed of the same material as the arms 40, 60.

The arrangement of the arms 40, 60 and the pulley arrangements 50, 70, is such that, when the arms 40, 60 are moved apart from each other to their greatest extent, structure of the cradle braces 56, 76 that surrounds the respective cradle 54, 76 abuts the end stops 23 to limit that movement.

The tensioning arrangement 90 will now be described. With reference to Figure 2, the tensioning arrangement 90 is made up of a pair of coil springs 92. Each of the springs is anchored at one of its ends to an anchor plate 94. The anchor plate is fitted to the chassis of the car below the read edge of the base plate 22 of the body portion 20. The other end of each spring 92 is attached by a respective length of cable 96 to a respective one of the cradle braces 56, 75. The attachment to the cradle braces 56, 76 is best seen in Figure 1. With reference again to Figure 2, each cable 96 passes around a respective pulley 98 (only one of which is shown) mounted in the adjacent one of the triangular cut-outs 27 formed in the projections 26 at the rear corners of the base plate 22. These pulleys 98 of the tensioning arrangement 90 are mounted such that, as well as allowing rotation about its own axis, each can rotate about a vertical axis at the tip of the respective triangular projection 26, thereby being moveable through an arc within the triangular cut-out 27. Two extreme positions of this movement of the pulley 94 towards the right of the apparatus 10 are shown in Figure 1 and Figure 3, the two positions being shown simultaneously.

The arrangement of the electrical cable 80 will now be described. With reference to Figure 1, a fixed end of the cable 80 that is connected to electrical equipment of the car passes through a cable clamp 82 that is mounted to the front of the brace 32 of the body portion 32, to the left of the cut-out 32 through the brace 32. The cable clamp 82 clamps this part of the cable 80 relative to the body portion 20. From the clamp 82, the cable 80 passes through the cut-out 32 and passes around the pulleys 52, 72 of the two pulley arrangements 50, 70 in a ziz-zag fashion, alternating between the two arrangements 50, 70. More specifically, the cable 80, from the cable clamp 82, passes around a front-most one of the three pulleys 72 of the right-hand pulley arrangement 70, from front to back; then passes around a front-most one of the two pulleys 52 of the left-hand pulley arrangement 50, again from front to back; then passes around the middle one of the right-hand pulleys 72; then the second one of the two left-hand pulleys 52; before finally passing around the rear-most one of the three right-hand pulleys 72, passing through all from front to back. From that last pulley 72, the cable 80 passes through the arrestor unit 100, which will be described below. Thus, the cable 80 is arranged between the arms 40, 60 in a series of generally co-planar, spaced-apart lengths. With reference to Figure 2, the arrestor unit 100 is made up of two co-planar, spaced- apart pulleys 102 mounted in a frame 104. A moveable arrestor head 106 is mounted to the frame 104 and arranged to allow the cable 80 to be drawn therethrough in one direction, but to resist movement of cable 80 in the reverse direction, unless the head 106 is moved temporarily into a position in which reverse movement is allowed. The electrical cable 80 of the present apparatus 10 extends through the arrestor unit 100 by passing around both pulleys 102 in an S-shape before emerging (not shown in the drawings) from a mouth 108 in the head 106. The arrestor unit 100 it mounted to the chassis and so its location is relatively fixed in relation to the body portion 20 of the apparatus 10.

Operation of the apparatus 10, in which the apparatus moves from a position in which the cable is retracted and stored, to a position in which the cable is at least partly withdrawn and deployed, will now be described.

With reference to Figure 3, in the retracted position, tension in the springs 92 of the tensioning arrangement 90 pulls on the cables 98 attached thereto, which in turn pull on the free ends of the arms 40, 60 to pull the arms 40, 60 apart. The cradle braces 56, 76 coupled to each arm 40, 60 abut the end stops 23, which limit further outward movement of the arms 40, 60.

With continued reference to Figure 3, to begin withdrawing and deploying the electrical cable 80, the free end (not shown) of the cable 80 adjacent the mouth 108 of the arrestor arrangement 100 is pulled away from the arrestor unit 100. As the other end of the cable 80 is fixed by the cable clamp 82, pulling the free end of the cable 80 exerts a force on the pulley arrangement 50 of the left arm 40 and the pulley arrangement 70 of the right arm 60 that acts to draw the two arms 40, 60 together. Acting against this force is the tension in the springs 92. Once the tension in the springs is exceeded, the arms 40, 60 move together. As the arms 40, 60 move together, the distance therebetween decreases such that the and spaced-apart and overlapping lengths of cable 80 that extend between the pulleys 52 of the left arm 40 and the pulleys 72 of the right arm 40 are each shortened, thereby allowing equivalent lengths of cable 80 to be withdrawn via the mouth 108 in the arrestor unit 100.

Once a length of cable 80 has been withdrawn that is sufficient to connect the cable 80 to an extemal supply of electrical power, the free end of the cable 80 is released. Upon this release, the tension in the springs 92 of the tensioning arrangement 90 tries to pull the arms 40, 60 apart and so tends to withdraw the cable 80 back through the mouth 108 of the arrestor unit 100. In response to this, the arrestor unit 100 operates to clamp the cable 80 and prevent retraction of the cable 80 back therethrough. Figure 4 is a simplified view showing the arms 40, 60 in a position in which the cable 80 is withdrawn and deployed

The cable 80 is then connected to the external electrical supply and a current allowed to flow therein in order to recharge energy storage means, such as batteries, of the car. The current would typically be a high current, for example about 13 A. By arranging the cable in, in this embodiment, generally co-planar spaced-apart overlapping lengths, coils of cable 80 are avoided. By avoiding such coils, the strong magnetic fields which would otherwise be set up thereby are also avoided, as are the undesirable effects of these magnetic fields, such as currents in the cable 80 induced thereby and the resulting high temperatures. As a result, the cable operates at a lower temperature, reducing appreciably the risk of the cable 80 melting and failing. Safety is therefore greatly improved. When recharging is complete, the arrestor unit 100 is manually operated, in this embodiment by moving the position of the head 106, such that the arrestor unit 100 disengages the cable 80. Once the cable 80 is disengaged, the outward force exerted on the arms 40, 60 by the springs 92, causes the arms 40, 60 to move apart. Thus, the generally parallel lengths of cable 80 between the arms 40, 60 are lengthened and the cable 80 is retracted. In this way, the apparatus 10 moves back into the retracted position in which the cable 80 is stored within the apparatus 10.