BATTERY HANDLING EQUIPMENT

The present invention relates to equipment to facilitate the exchange of battery units from electrically-powered vehicles. More particularly, but not exclusively, it relates to equipment for handling battery power packs from electrically-propelled fork-lift trucks and the like.

Modern warehouses and other distribution facilities rely on fork-lift trucks, powered pallet trucks, pallet loaders and the like to move goods on and off transport vehicles and from place to place within the warehouse. Such trucks are very often electrically powered, using a massive battery as a power source. In a facility that operates only daytime shifts, for example, fork-lift trucks may be left on charge between shifts, to re-charge their batteries. However, warehouses are frequently operated on a continuous basis, without any down-time during which fork-lifts might be re-charged. As a result, it has become customary to provide facilities in which spare batteries may be kept on charge. When the battery of a fork-lift, pallet loader or other such vehicle reaches a predetermined low charge level, the vehicle is taken to the facility, its battery is removed, and a fully-charged battery is inserted in its place. The removed battery is then left in the facility to re-charge. Thus, the vehicle can be available for use almost continually.

Such arrangements have associated problems, however. The battery of a fork-lift truck typically weighs 1 tonne, while a pallet loader normally has a battery weighing around 400kg. Handling such loads is not straightforward.

The charging facilities usually comprise long runs of racking, similar to that used for warehouse storage, on which the batteries are stored while charging. Each module in the facility has a charger unit, to which a battery inserted into the module is connected. Sufficient aisle space must be left to allow the batteries to be inserted and removed conveniently and safely. However, space in a warehouse is usually at a premium, which conflicts with the space required for a conventional charging facility.

The standard batteries for such vehicles are rectangular in plan form, disposed with their longer axis extending from side to side of the vehicle. They are so mounted as to be removable from the vehicle along this axis. For compactness, the racking of the charging facility is so arranged that the batteries are insertable and removable along this longer axis, transversely to the racking and the adjacent aisle.

In current practice, a fork-lift truck or pallet loader with a low battery is driven to a location adjacent the charging facility; a casing enclosing its battery is opened or removed; the battery is extracted on to a suitable carrying vehicle; the battery is transported to a vacant module in the charging facility, inserted and connected to a respective charger; a charged battery is removed from another module of the facility and transported back to the fork-lift truck/pallet loader; the charged battery is inserted into the truck/loader; the casing is replaced; and the truck/loader is driven away to resume work.

This involves a great deal of manoeuvring by the carrying vehicle. Transportation of such massive batteries requires considerable care; so tends to be slow, particularly when turning with such a cumbersome load on board. Securing the batteries to ensure that they do not move around in transit is another inconvenience.

Custom-built carrying vehicles are known, but they are extremely expensive, even compared to top-of-the-line fork-lift trucks. Another issue with custom-built vehicles is what one does when these vehicles are themselves on low battery charge, or if they break down. Such vehicles thus afford little flexibility of operation. Using existing vehicles might therefore be preferable, and a conventional fork-lift truck easily has the necessary load-carrying capacity, but it is not well-adapted actually to handle the batteries.

Another important consideration is that a distribution warehouse for a supermarket chain, to take a common example, may easily be equipped with at least three hundred low pallet loaders and at least sixty fork-lift trucks. All of these will be required to operate as close to continually as can be achieved. The time required for a "pit stop" to exchange batteries must therefore be kept to a minimum, and even small improvements in turn-around time could be valuable.

It is hence an object of the present invention to provide apparatus for handling batteries from fork-lift trucks and other such electrically-powered vehicles that obviates the above disadvantages and allows rapid, convenient and safe exchange of fully-charged and low- charged batteries without involving excessive cost.

According to a first aspect of the present invention, there is provided handling apparatus for battery means of electrically-propelled vehicles, comprising platform means mountable to fork-lift truck means and provided with attachment means selectably engageable with said battery means, said attachment means being so controllably movable along a first axis of motion as to draw said battery means on to, or displace said battery means from the platform means.

Preferably, said platform means is provided with side wall means extending along at least one side thereof, optionally along at least two opposite sides thereof.

Advantageously, said side wall means extend substantially parallelly, each to the other.

Said side wall means may extend substantially parallelly to said first motion axis.

The platform means may be generally rectangular.

Said first motion axis may be parallel to an axis of symmetry of the rectangular platform, optionally parallel to the longer axis thereof.

The handling apparatus may be detachably mountable to said fork-lift truck means.

Alternatively, the handling apparatus may be permanently mountable thereto.

Preferably, the handling apparatus is mountable to load lifting means of said fork-lift truck means, optionally to lifting fork means thereof.

The handling apparatus is preferably so mountable that said first motion axis is transverse to lifting fork means of the fork-lift truck means, advantageously orthogonal thereto.

Preferably, said attachment means is controllably displaceable along a second motion axis transverse to the first, advantageously orthogonal thereto.

The attachment means may thus conveniently be aligned with a selected battery means to be drawn on to or displaced from the platform means.

Preferably, the platform means is so adapted that battery means may be drawn thereon to or displaced therefrom at two opposite ends thereof.

Said opposite ends may be defined by said side wall means.

The attachment means is advantageously engageable with battery means adjacent either said end of the platform means.

Preferably, the platform means is provided with a low-friction support surface for the battery means.

Said support surface may comprise a plurality of roller means.

Each said roller means may then have a horizontal axis of rotation extending orthogonally to said first motion axis.

Alternatively or additionally, said support surface may comprise a low-friction material, such as a fiuoropolymer composition.

The attachment means may comprise sucker means, optionally provided with selectably operable suction means.

The attachment means may comprise magnet means, optionally selectably energisable electromagnet means.

Preferably, the attachment means is mounted to beam means extending transversely between said side wall means, advantageously beam means extending substantially horizontally.

Advantageously, said beam means extends above any battery means located on the platform means and the attachment means is disposed below the beam means.

The beam means is preferably controllably displaceable along said side wall means.

The attachment means is advantageously controllably displaceable along the beam means.

Preferably, the attachment means is adapted to engage with battery means located on either of two opposite sides thereof.

According to a second aspect of the present invention, there is provided a vehicle comprising load-handling means and provided with battery handling apparatus as described in the first aspect above mounted to said load-handling means.

Preferably, said load-handling means comprises load lifting means.

Advantageously, said vehicle comprises a fork-lift truck or the like, and said load-lifting means comprises lifting fork means thereof.

Preferably, the battery handling apparatus is fixedly mounted to said load handling means.

Alternatively, the battery handling apparatus is detachably mounted thereto.

Said vehicle may be automatically guided or remotely controllable.

According to a third aspect of the present invention, there is provided a method for exchanging battery means of an electrically-powered vehicle, comprising the steps of providing a vehicle as described on the second aspect above, operating the battery handling apparatus thereof to extract a first battery means from said electrically-powered vehicle, transporting the first battery means to first charging means, operating the battery handling apparatus to deposit the first battery means, optionally for recharging by the first charging means, operating the battery handing apparatus to extract a second battery means from second charging means, transporting the second battery means to the electrically propelled vehicle, and operating the battery handling apparatus to insert the second battery means into the electrically-powered vehicle.

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

Figures IA to IF are perspective views of battery handling apparatus embodying the present invention, in alternative operating configurations;

Figures 2A to 2C are perspective view of the battery handling apparatus shown in

Figures IA to IF, in use handling batteries;

Figures 3 A to 3H are plan views from above of the battery handling apparatus shown in Figures IA to IF, in use handling batteries; and

Figures 4 and 5 are plan views from above of the battery handling apparatus shown in Figures IA to IF, mounted to a fork-lift truck and in use in a battery recharging facility.

Referring now to the Figures, and to Figures IA to IF in particular, a battery handling device 1 embodying the present invention comprises a rectangular base 2, having a longer and a shorter axis of symmetry, orthogonal each to the other. A side frame 3 extends along each of two opposite sides of the base 2, parallelly to said longer axis. A travelling bridge member 4 extends between a respective upper rim of each side frame 3, above the base 2, parallelly to its shorter axis. A battery-holding unit 5 is mounted to a strut 6 extending downwardly from the bridge member 4. In this particular embodiment, the battery-holding unit 5 comprises two electromagnet pads 7, facing in opposite directions (Other arrangements are possible; see below).

The travelling bridge member 4 is controllably displaceable along the upper rims of the side frames 2, in this particular embodiment by means of a rack-and-pinion arrangement with the rack thereof extending along one or both said upper rims. (Compare the position of the bridge member 4 in Figures IA, IB, 1C with its position in Figures ID, IE, IF). A motor and control unit (not shown for simplicity) are provided to drive the bridge member 4 to the required position.

The battery-holding unit 5 is itself controllably displaceable laterally along the bridge member 4. (Compare its positions in Figures IA and ID, over a midline of the base; in Figures IB and IE, displaced to a first side of said midline; and in Figures 1C and IF, displaced to a second side remote from the first). Again, the motion of the battery-holding unit 5 is motor-driven and fully controllable.

In this embodiment, the base 2 is provided with a plurality of horizontal gravity rollers 8, each with its rotational axis extending orthogonally to the longer axis of the base 2. In alternative embodiments, low-friction slides coated with PTFE (polytetrafluoroethane) may be used instead.

In place of the electromagnet pads 7 shown, suction pads may instead be used. The electromagnet pads 7 grip a steel casing of a battery pack when energised. Similarly, the suction pads grip the casing when a vacuum is applied.

Figure 2A shows the battery handling device 1 with a large battery pack 9 from a fork-lift truck on board. (These large battery packs 9. are usually conventional accumulators weighing around one tonne). This has been achieved by positioning the bridge member 4 and battery-

holding unit 5 as shown in Figure IA. The adjacent electromagnet pad 7 of the battery- holding unit 5 is brought into contact with an end wall of the battery pack 9, and is then energised, clamping the battery pack 9 thereto. The bridge member 4 is then moved to the position shown in Figure ID, drawing the battery pack 9 on to the base 2, the rollers 8 allowing it to move on to and across the base 2 smoothly. The electromagnet pad 7 is left energised when the battery handling device 1 and the battery pack 9 are moved, to hold the battery pack 9 securely in position. To push the battery pack 9 back off the base 2, the bridge member 4 is simply driven back towards the position shown in Figure IA.

Figures 2A and 2C show the battery handling device 1 with smaller battery packs 10, such as are used in pallet loaders, on board. (These smaller battery packs 10 are conventional accumulators typically weighing around four hundred kilograms). The procedure for drawing the smaller battery packs 10 on to the base 2, and for pushing them back off again, is largely identical to that for the larger battery packs 9, above. However, the smaller battery packs 10 are also narrower. The battery-holding unit 5 is therefore displaced along the bridge member 4 to one side or the other of the midline of the base 2, as shown in Figure IB or Figure 1C, before engaging with the casing of the battery pack 10 and drawing it into the base 2. (NB: in Figures 2B and 2C, the bridge member 4 is shown as having been moved just far enough to bring the battery pack 10 stably on to the base 2. It is not necessary to move it all the way to the position shown in Figures IE or IF respectively).

To facilitate the handling of smaller battery packs 10, this particular embodiment of the battery handing device 1 shown has a base 2 with two side-by-side runs of rollers 8. The smaller battery packs 10 may thus be drawn on to one or the other of these runs.

As shown by Figures 3A and 3B, the larger battery packs 9 may be drawn on to the symmetrical base 2 through either of two opposite ends; this is why this embodiment uses a battery-holding unit 5 having two electromagnet pads 7 aligned in opposite directions. It is also possible to produce a "one-ended" version of the battery handling device 1, but this would usually be less versatile (see below).

Figures 3C to 3F show the four positions possible when a smaller battery pack 10 is drawn on to the base 2 through either end. This also allows two smaller battery packs 1OA, 1OB to be carried at once, as shown in Figures 3G and 3H. For example, 1OA could be a fully-charged pack, and 1OB a low-charged pack, as described in more detail below.

Figures 4 and 5 show the battery handling device 1 in action. A known form of charging facility 11 has been installed in a convenient location within a warehouse. The facility 11 here comprises two arrays of racking 12, 13, arranged on opposite sides of an aisle 14. The first array 12 comprises a series of large modules 15, each of which can hold a larger battery pack 9, and each of which is provided with a recharging unit 16, connectable to the battery pack 9 so as to recharge it. The second array 13 comprises a series of small modules 17, each of which can hold a smaller battery pack 10 and is provided with a respective recharging unit 16.

The facility 11 is also provided with a battery truck 18. This is a conventional fork-lift truck with a battery-handling device 1 mounted to or in place of its lifting forks. This fork-lift truck may be any one of the existing fork-lift trucks with which the warehouse is equipped, or may be dedicated for use in the facility. When a truck is dedicated for use in the charging facility 11, the battery-handling device 1 is preferably permanently mounted to the lifting

gear of the truck, either in place of the lifting forks or by welding it to the forks. This is likely to provide increased safety, stability and reliability. Also, where a dedicated truck is used, one may use an automated/robotised or remote-controlled fork-lift truck, rather than one with a human driver, since it will only need to operate within the predictable and isolated confines of the facility 11. It may also be convenient to use a truck powered by alternating current, for example powered through a mast contacting an overhead power grid. Only a relatively limited overhead grid would be required, and this would obviate the problem of dealing with a battery truck 18 when its own on-board battery pack is run down. On the other hand, using a detachably mounted battery handling device makes it possible to swap the device 1 between existing trucks, or (in smaller facilities) to use the battery truck 18 as such some of the time, and (with the device 1 dismounted) as a general purpose truck at other times. The choice between a detachable device 1 and one fixed permanently to the battery truck 18 will probably depend on the size and needs of each warehouse.

The facility 11 is operated as follows. A general-purpose fork-lift truck 19 with a battery pack 9 on a low charge is driven up to the facility 11 and parked, conveniently adjacent an end of the first array 12. Its driver then removes or opens a body shell of the fork-lift truck 19 to reveal its battery pack 9, and unplugs it from the truck 19. It is a standard feature of fork-lift trucks 19 that the battery pack 9 is mounted transversely across a body of the truck 19.

The battery truck 18 is then moved alongside the truck 19. The battery handling device 1 is itself mounted transversely to the battery truck 18, so that the battery-holding unit 5 may be operated as described above to draw the battery pack 9 on to the battery-handling device 1 when the trucks 18, 19 are compactly arranged side by side.

The battery truck 18 is then driven off, straight down the aisle 14, until it reaches a vacant first large module 15 of the first array 12. The battery pack 9 is then pushed off the battery handling unit 1 into the vacant first large module 15 and connected to the respective recharging unit 16. The battery truck 18 then proceeds further or back along the aisle 14 until it is aligned with a fully-charged battery pack 9 in a second large module 15 (not shown).

This battery pack 9 is disconnected from the respective recharging unit 16 and drawn from its module 15 on to the battery-handling device 1. The battery truck 18 is then backed up until it is parked alongside the truck 19, once more, and the fully-charged battery pack 9 is pushed off the battery-handling device 1 into place in the body of the truck 19. The driver then plugs it in, reassembles the body shell of the truck 19 and drives it off to resume work.

Figure 5 represents the same process for exchanging a battery pack 10 of a pallet loader 20. Since the battery handling device 1 is adapted to operate to either side of the battery truck 18, all that is required is that the vehicle 19, 20 having a low battery should be parked to the same side of the aisle 14 as the respective modules 15, 17 for the appropriate battery pack 9,10.

For the smaller battery packs 10 of the pallet loaders 20, one may vary the procedure described for even faster turn-around. Since two smaller battery packs 10 may be carried at once, it is possible for the battery truck 18 coming alongside the pallet loader 20 to have a fully-charged battery pack 1OA already on board. Thus, the low-charged battery pack 1OB may be withdrawn as described above (to give the situation as shown in Figures 3G and 3H), and the fully-charged battery pack 1OA immediately inserted in its place. The pallet loader

20 may then be driven off to resume work almost at once, without having to wait for the battery truck 18 to trundle down the aisle 1.4, drop off the low-charged battery pack 10 for recharging and pick up a fully-charged one.

In either case, this arrangement greatly simplifies and speeds the procedure of exchanging battery packs 9, 10. The battery truck 18 only has to move up and down the aisle 14, which can thus be much narrower than if a conventional "end-on" loading and unloading approach were used. This is important, as it frees up warehouse space. The battery truck 18 never has to turn, so the risks of manoeuvring with a heavy load are greatly reduced. This also makes automation of the operation of the battery truck 18 much easier.

Using a conventional fork-lift truck as the battery truck 18 would also allow one to operate with arrays 12, 13 having recharging modules 15, 17 on multiple levels. Once the battery truck 18 is level with the appropriate module 15, 17, it need only operate its lifting forks to bring the battery-handling device 1 level with the module 15, 17, then operate the device 1 as described. Since one can bring the battery truck 18 close alongside the arrays 12, 13 of modules 15, 17, this should not lead to stability problems, even with the lifting forks raised to reach modules on upper levels. Even using single-level arrays 12, 13, it is not necessary to build the modules 15, 17 at exactly the same height as the battery packs 9, 10 are located in their respective vehicles; the battery truck 18 need only adjust the height of the device 1 once it reaches the respective module 15, 17.

A further unanticipated practical benefit of the arrangement shown is that it is common practice, in warehouses having perhaps a hundred or more fork-lift trucks and loaders, to have full-time service personnel from the truck manufacturer on the premises. Thus, if there

is any problem requiring service work on the battery truck 18, one may simply transfer a detachable battery-handling device 1 to another fork-lift truck 19 while the on-site servicing personnel deal with the problem. Where the battery truck 18 has its battery-handling device 1 permanently mounted, it will still be as straightforward to trouble-shoot and repair as any other fork-lift truck 19 on the premises. Conventional custom-built battery handling vehicles have to be taken off-site for repairs, or have to wait for their specialist manufacturer's service personnel to be called out. Even if they could be dealt with by on-site personnel, the downtime is still highly inconvenient.

Such battery-handling devices could even be mounted, detachably or permanently, to a fork- lift truck of the type having a rotatable mast to which its lifting fork system is mounted. Such fork-lift trucks can direct their forks to their left, to their right or through an entire forward arc therebetween. For such fork-lift trucks, one could use a single-ended device aligned parallelly with the forks, since the forks could be turned to align the device transversely to the battery truck 18, when alongside the modules 15, 17, or alongside the truck 19 having its battery pack changed. The single-ended device would be cheaper than the double-ended battery-handling device 1 shown, but fork-lift trucks with such a fork arrangement are significantly more expensive than conventional fork-lift trucks. The choice may then depend on the type of fork-lift truck with which the user is already equipped.

In either case, the devices of the present invention provide significant benefits in speed, compactness, convenience, economy and safety compared to existing systems.