WO1993012945A1

WO1993012945A1 - An electric battery powered heavy vehicle

Info

Publication number: WO1993012945A1
Application number: PCT/GB1992/002373
Authority: WO
Inventors: Terence Raymond Penfold
Original assignee: Iad Design Limited
Priority date: 1991-12-20
Filing date: 1992-12-21
Publication date: 1993-07-08
Also published as: GB9127081D0

Abstract

An electric battery powered bus (10) having a massive replaceable battery (14) as its power plant. The battery (14) is mounted on chassis structure at the rear of the bus (10) which is provided with an opening at the rear through which the battery (14) can be withdrawn for recharging and replaced by a recharged battery (14). A major part of the battery (14) is above the chassis structure on which it is supported and extends laterally to either side so that it occupies a major part of the width of the bus (10). The suspension of the bus (10) is adjustable whereby the chassis structure is lowered on the wheels (12) to lower the battery (14) onto a trolley for withdrawal and a replacement battery installed in its place is raised by raising the chassis structure relative to the wheels (12).

Description

AN ELECTRIC BATTERY POWERED HEAVY VEHICLE

DESCRIPTION

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This invention relates to electric battery powered heavy vehicles, especially buses.

The most common form of electric battery powered

10 vehicle currently in use is a milk float. These have electric batteries installed under the load bearing platform of the vehicle, substantially in the middle of the vehicle between the front and back wheels. The vehicle is designed so that, when charged, the

15 batteries provide sufficient electrical power for the vehicle for a normal days running. At the end of each day, the vehicle is returned to its garage where it is connected to a battery recharging system whereby its batteries are recharged overnight in situ within the

20 vehicle.

An object of this invention is to provide an electric battery powered bus. Although the bus can be provided with a massive battery arrangement which generates

25 sufficient power to drive it, it will be necessary for that battery arrangement to be recharged periodically during any one day for economic utilisation of the bus. It is impractical to consider recharging the batteries in situ within the bus

30 because of the length of time for which the bus would have to be out of service.

By this invention we provide an electric battery powered heavy vehicle, such as a bus, wherein the

35 battery arrangement is replaceable by another freshly charged battery arrangement when it needs recharging. That enables the batteries to be recharged whilst service operation of the bus continues.

FR-A-2208366 discloses the idea of removing a centrally mounted battery from the side of a vehicle for charging and installing a recharged battery through the side of the vehicle, using trolleys to transport the battery between the vehicle and a charging station. The battery is removed by positioning a trolley under the vehicle, lowering the vehicle body on its suspension at the front and rear to lower the battery installed in the vehicle onto the trolley until the weight of the battery has been transferred from the vehicle to the trolley, whereupon the trolley, with the battery loaded on it, is pulled away from the vehicle. The procedure is reversed for installing a recharged battery.

Housing a battery under the floor of a bus substantially in the middle of the bus between the front and back wheels limits the mass of battery that can be installed in the bus, particularly in the context that it is desirable for the floor of a bus to be low to facilitate access for passengers. Also removal of a battery for charging through the side of the bus and reinstallation after charging is time consuming and requires a considerable dedicated area at the battery changing location. In order to optimise utilisation of the bus it is desirable for the time required to remove a battery arrangement that is to be recharged and to replace it with freshly charged battery arrangement should be kept to a minimum. For that it is preferable for the battery means that are going to be recharged to be withdrawn from the vehicle through an opening at the rear of the vehicle and to be inserted into the vehicle after having been recharged through that opening at the rear of the vehicle.

FR-A-798464 discloses an electric battery powered bus having replaceable battery means operable as the power plant of the vehicle, at the rear of the vehicle and provided with an opening at the rear of the vehicle through which the battery means can be passed so that the battery means can be withdrawn for recharging and replaced by recharged battery means. The battery is mounted on its own wheels and axle by its own suspension so that it is a separable carriage. The bus chassis is provided with an opposed pair of guide rails below the floor at the rear of the vehicle. Those guide rails receive rollers mounted on the battery when the latter is installed. By that arrangement the weight of the battery and part of the weight of the vehicle are shared between the wheels of the separable battery carriage and the adjacent rear wheels of the bus. Again the mass of the battery is limited by the confined space behind the rear wheels and under the rear seats of the bus with the result that there is not enough battery available for effective commercial operation of the bus.

An object of this invention is to provide a bus with a sufficiently massive battery arrangement which generates sufficient power to drive it on a commercial scale.

According to this invention there is provided an electric battery powered heavy vehicle, such as a bus, having replaceable battery means operable as the power plant of the vehicle, at the rear of the vehicle and provided with an opening at the rear of the vehicle through which the battery means can be passed so that the battery means can be withdrawn for recharging and replaced by recharged battery means, including spaced support surfaces formed by chassis structure in the region of the rear of the vehicle and extending generally towards the front of the vehicle, said support surfaces supporting said replaceable battery means which are sufficiently massive as to be operable as the power plant of the vehicle, said replaceable battery means having spaced surface portions which are seated on said support surfaces when said battery means are installed in the vehicle such that the whole of the weight of said replaceable battery means is borne by said chassis structure, a major part of said replaceable battery means being above said support surfaces when so installed.

Preferably said major part of said replaceable battery means extends laterally to either side of said support surfaces so that said battery means occupies a major part of the width of the vehicle at the rear of the vehicle when so installed.

Preferably said vehicle includes an adjustable suspension system which is operable to lower or raise the chassis structure relative to wheels of the vehicle whereby electric battery means of the vehicle to be removed for recharging are lowered by lowering the chassis structure and charged battery means installed in their place are raised by raising the chassis structure. In such an arrangement it may be that it is only the rear suspension system of the vehicle that is adjustable. If the replaceable battery means were to comprise a modular assembly having its own wheels upon which the battery assembly would be supported outside the vehicle and on which it would run to and from the charging location, there would be a risk of suspension problems if the station at which a bus is located for replacement of its battery arrangement is not flat and the battery arrangement is to be put down upon and picked up from a ramp. Therefore, it is preferred for the battery means to be lowered on to a trolley when being^" removed from the vehicle for recharging and to be lifted from such a trolley when being installed in the vehicle structure as the power plant after recharging.

Accordingly, in a preferred embodiment of this invention, the chassis structure and the trolley are arranged so that, during initial lowering of the chassis structure by operation of the adjustable suspension system, the battery means that are to be recharged are supported by the vehicle structure until lowered onto a trolley whereafter said battery means will be supported by the trolley during the later stages of lowering of the chassis structure when that structure will separate from the battery means to allow the battery means to be removed through the opening at the rear of the vehicle by moving the trolley away from the rear of the vehicle. Likewise a recharged battery arrangement will be supported by the trolley during the initial stages of presentation to the rear of the vehicle, the trolley being located relative to the chassis structure. Other features of a preferred embodiment of the invention are defined in the sub claims.

One embodiment of this invention is described now by way of example with reference to the accompanying drawings, of which:-

Figure 1 is a schematic side view of a bus showing a power plant comprising a rear mounted battery assembly;

Figure 2 is a schematic plan of the bus shown in Figure 1;

Figure 3 is a view of the installation of the battery assembly of the bus as seen from the rear of the bus;

Figure 4 shows the installation of the battery assembly of the bus shown in Figures 1 and 2 in more detail and to a larger scale, with a trolley in position to receive and remove the battery assembly for recharging;

Figure 5 shows the battery assembly on the trolley shown in Figure 4, outside the bus;

Figure 6 is a view similar to Figure 4 with the battery assembly removed;

Figure 7 is a plan view illustrating insertion of a charged replacement battery assembly into the bus shown in Figures 1 and 2; Figure 8 is a side elevation of a battery assembly as shown in Figures 1 to 5 and 7;

Figure 9 is an end elevation of the battery assembly shown in Figure 8; and

Figure 10 is a plan of the battery assembly shown in Figure 8 and 9.

Figures 1 and 2 show a single decker bus 10 comprising a body 11 supported on wheels 12 by an air suspension system 13. A large opening (not shown) is formed in the rear of the vehicle body and a door arrangement (not shown) is provided for closing that opening. The opening is large enough, when the door arrangement is open, to allow a massive modular assembly 14 of electric batteries to be inserted and withdrawn through it to or from a suitable compartment within the rear of the vehicle body 11. Our co-pending British Patent Application no. 9225010.9 discloses a suitable door arrangement for this purpose.

Figures 2 and 3, as well as Figures 7, 9 and 10, show that the modular battery assembly 14 is symmetrical about an upright plane which includes its longitudinal axis and that when that battery assembly 14 is installed in the vehicle body 11, that upright plane is coincident with the upright plane that includes the longitudinal axis of the vehicle body 11. Also the modular battery assembly 14 is T shaped both in plan and in end elevation. Figure 6 shows the stem portion 14A of the T shaped section in plan projects forwardly whilst the stem portion 14B of the T shaped section in end elevation depends from the remainder of the modular assembly 14 as can be seen from Figure 8. For convenience, that part of the battery assembly to one side of the plane of symmetry is described in detail as a typical example of the two halves of the modular battery assembly 14 either side of that plane of symmetry.

Figures 3 and 4 show that the modular assembly battery 14 is supported by a number of support surfaces formed by the chassis structure of the vehicle body 11, a major part of the battery assembly 14 being above those^" support surfaces, extending upwards to a level well above the floor of the passenger compartment. The forwardly projecting portion 14A of the modular battery assembly 14 rests upon a support surface 15. The bottom 14C of the limbs 14D of the T shaped section, as seen in end elevation, are each supported by a respective support surface 17, the support surfaces 17 extending generally parallel to the longitudinal axis of the vehicle body 11. The bottom 16 of the stem portion 14B of the battery assembly 14, which is the lowermost part of that battery assembly, is spaced from the chassis structure of the vehicle body 11. In addition to extending upwards, the limbs 14D extend laterally beyond the support surfaces 17 so that the battery assembly 14 occupies a major part of the width of the bus.

The forward lower edge of the forwardly projecting portion of the modular battery assembly 14A forms a right angle which rests upon a correspondingly shaped portion 18 of the vehicle structure. A locator projection 19 which projects forwardly from the forward face of each limb 14D, either side of the forwardly projecting portion 14A, projects between a spaced pair of locating abutments 21 to provide a lateral location of the modular battery assembly 14 relative to the structure of the vehicle body 11. A latching pin 22 mounted on the same forward face of each limb 14D of the modular battery assembly 14 is latched into a respective hook support 23 by an automatically operable latch 24, the hook support 23 and the latch 24 being mounted on the structure of the vehicle body 11. An L shaped member 25 which is mounted on the same face of each limb 14D of the modular battery assembly 14, substantially above the edges of the forwardly projecting portion 14A of that assembly 14, projects outwardly and downwardly from that forward face of the modular battery assembly 14 so that its downwardly projecting portion 26 projects into a vertical aperture 27 formed in a member 27A mounted on the structure of the vehicle body.

The rear face of the modular battery assembly 14 carries a spaced pair of angle members 28, symmetrically disposed either side of the plane of symmetry, each at the bottom of a respective one of the two limb portions 14D. The projecting portion of each angle member 28 rests upon a pad of elastomeric material 29 mounted on the structure of the vehicle body 11 and is latched in that position by a respective locking lever 31. The forward face of each limb 14D of the battery assembly 14 abuts against a pad 32 of elastomeric material which is mounted on the rear face of the two locating abutments 21 which receive the respective locator projection 19 between them. The modular battery assembly 14 also has a U shaped member 33 projecting rearwardly from its rear face at substantially the same horizontal level as the latching pins 22. Figure 4 also shows a trolley 34 having a load bearing platform 35 which has been positioned below the bottom face 16 of the modular battery assembly 14 and an upstanding pillar 36 which is mounted on the platform 35 and which has been positioned adjacent the rear face of the modular battery assembly 14 so that its top is just below the rearwardly projecting member 33, the pillar 36 extending between the spaced pair of angles 28. The member 33 is adapted to receive a latching member 37 which is pivotally mounted on the pillar 36.

In operation of the invention, when it is time to replace the modular battery assembly 14 by another which, has been recharged, the bus is parked at a loading station, there being a clear space behind it. The door arrangement is opened. An unladen trolley 34 is wheeled into the position as shown in Figure 4 so that the load bearing platform 35 extends below the lower surface 16 of the modular battery pack 14 that is mounted in the structure of the vehicle body 11 and so that its post 36 is located against the rear face of the modular battery assembly 14 between the spaced pair of angled members 28 with its top below the rearwardly projecting U shaped member 33. Thus the trolley 34 is located relative to the battery assembly 14. The vehicle suspension is operated by means of an actuating valve at the rear of the vehicle so that the vehicle body 11 is lowered relative to the wheels 12 until the bottom surface 16 of the battery assembly 14 seats upon the upper surface of the loading platform 35 of the trolley 34 such that the trolley supports the battery assembly 14. The vehicle body 11 is lowered further so that the support surfaces 15 and 17 formed by the vehicle structure are separated from the cooperating surfaces of the modular battery assembly 14 that was seated upon them.

As the structure of the vehicle body 11 is lowered, the members 27A which form the apertures 27, are lowered to clear the depending projections 26, and the latches 24 are pivoted to their open positions by the movement, relative to the locating pins 22, of the structure of the vehicle body 11 on which they are pivotally mounted, as shown in Figure 6. Also the locking levers 31 are released automatically, conveniently by robotic means, to the position shown in Figure 6. At the same time, by other robotic means, the electical connection of the battery assembly 14 to the electrically operable services of the vehicle are disconnected.

As soon as the battery assembly 14 is mechanically and electrically disconnected from the vehicle, and the latch member 37 is engaged with the U shaped member 33, as shown in Figure 5, the trolley 34 is withdrawn from the vehicle carrying the modular battery assembly 14 with it so that the battery assembly 14 can be conveyed to a battery charging station.

Another trolley 34 carrying a charged replacement modular battery assembly 14 is wheeled into place, again as shown in Figure 4, so that the support surfaces 15 and 17 extend below the cooperating surfaces of the modular battery assembly 14 that are to seat upon them. Figure 7 illustrates this manoeuvre and together with Figure 10, shows that the leading lateral edges of the forwardly projecting portion 14A of the modular battery assembly 14 are chamfered at 38 to serve as alignment guides which cooperate with corresponding parts of the vehicle body 11 (see Figure 7) so as to align the modular battery assembly 14 with the structure of the vehicle body 11. Once the modular battery assembly 14 is positioned by its trolley 34 with its plane of symmetry substantially coincident with the corresponding plane of symmetry of the vehicle, the suspension system of the vehicle is operated to raise the structure of the vehicle body 11 relative to the wheels 12 thus raising the support surfaces 15 and 17 into contact with the cooperating surfaces of the modular battery assembly 14 and then raising the modular battery assembly 14 off the trolley 34, the latch 37 having first been released. As the structure of the vehicle body 11 is raised, the latching pins 22 are lowered into the recesses of the corresponding hook members 23, pivoting the latching members 24 automatically into the position in which they latch the pins 22 within the recesses 23 as shown in Figure 4. At the same time the hole 27 formed in the member 27A carried by the structure of the vehicle body 11, receives the downwardly projecting portion 26, and the locking lever 31 is moved automatically into the locking position shown in Figure 4 by the respective robotic means. Also the electrical connections are made automatically by appropriate robotic means. Thus it will be understood that the battery assembly 14 is latched and located automatically in situation within the structure of the vehicle body 11 and electrically connected automatically at the same time.

Once installation of the battery assembly 14 is completed, the empty trolley 34 is removed and the rear door arrangement closed. The bus can now be driven away.

Claims

1. An electric battery powered heavy vehicle having replaceable battery means operable as the power plant of the vehicle, at the rear of the vehicle and provided with an opening at the rear of the vehicle through which the battery means can be passed so that the battery means can be withdrawn for recharging and replaced by recharged battery means, characterised by spaced support surfaces formed by chassis structure in the region of the rear of the vehicle and extending generally towards the front of the vehicle, said support surfaces supporting said replaceable battery means which are sufficiently massive as to be operable as the power plant of the vehicle, said replaceable battery means having spaced surface portions which are seated on said support surfaces when said battery means are installed in the vehicle such that the whole of the weight of said replaceable battery means is borne by said chassis structure, a major part of said replaceable battery means being above said support surfaces when so installed.

2. An electric battery powered heavy vehicle according to claim 1, wherein said major part of said replaceable battery means extends laterally to either side of said support surfaces so that said battery means occupies a major part of the width of the vehicle at the rear of the vehicle when so installed.

3. An electric battery powered heavy vehicle according to claim 2, wherein said replaceable battery means is generally T-shaped in plan having a stem portion which projects forwardly relative to the remainder which occupies said major part of the width of the vehicle when said battery means are so installed, said forwardly projecting stem portion resting on a respective support surface formed by said chassis structure.

4. An electric battery powered heavy vehicle according to claim 2 or claim 3, wherein said replaceable battery means is generally T-shaped in end elevation, having a depending stem portion which depends from said major part between said support surfaces and which is spaced from structure of the vehicle.

5. An electric battery powered heavy vehicle according to any one of claims 1 to 4, comprising an adjustable suspension system of the vehicle which is operable to raise or lower said chassis structure relative to wheels of the vehicle whereby electric battery means of the vehicle seated on said support surfaces which are to be removed for recharging are lowered by lowering the chassis structure and charged battery means installed in their place are raised by raising the chassis structure.

6. An electric battery powered vehicle according to claim 5, wherein it is only the rear suspension system of the vehicle that is adjustable.

7. An electric battery powered vehicle according to any one of claims 1 to 6, wherein the battery means are arranged to be lowered on to a trolley when being removed from the vehicle for recharging and to be lifted from such a trolley when being installed in the vehicle structure as the power plant after recharging.

8. In combination, an electric battery powered vehicle according to claim 7 when appended to claim 5 and a trolley, wherein the chassis structure and the trolley are arranged so that, during initial lowering of the chassis structure by operation of the adjustable suspension system, the battery means that are to be recharged are supported by the chassis structure until lowered onto the trolley whereafter said battery means will be supported by the trolley during the later stages of lowering of the chassis structure when that structure will separate from the battery means to allow the battery means to be removed through the opening at the rear of the vehicle by moving the trolley away from the rear of the vehicle.

9. A combination according to claim 7, wherein recharged battery means are supported by the trolley during the initial stages of presentation to the rear of the vehicle, the trolley being located relative to the chassis structure.

10. A combination according to claim 7 or claim 8, wherein said support surfaces extend under said surface portions of the battery means that are to seat thereon when said battery means are supported by the chassis structure whilst the battery means are supported by the trolley, initial raising movement of the chassis structure by operation of the adjustable suspension system raising the support surfaces of the chassis structure in contact with the corresponding surface portions of the battery means and further raising of the chassis structure lifting the battery means from the trolley.

11. An electric battery powered heavy vehicle according to any one of claims 1 to 10, wherein automatically operable and automatically releaseable latching and coupling means are provided which, when operated to latch, positively locate the replaceable battery means in an installation location wherein they are supported by the chassis structure, and when operable to couple, electrically connect said battery means with the electrically operable driving means of the heavy vehicle.

12. An electric battery powered heavy vehicle according to claim 11, wherein the automatically operable latching means are adapted to be operated to latch the battery means in position within the vehicle automatically by the action of raising the chassis structure relative to the wheels.

13. An electric battery powered heavy vehicle according to any one of claims 1 to 12, wherein the battery means and the chassis structure are arranged so as to allow for and automatically correct some misalignment of the battery means with said installation location as the battery means are being presented to said installation location.

14. An electric battery powered heavy vehicle according to any one of claims 1 to 13, wherein a door arrangement is provided to close and-open the opening at the rear of the vehicle through which the battery means are inserted or withdrawn.

15. A system comprising a heavy vehicle according to any one of claims 1 to 14, and carrier devices operable to receive battery means to be withdrawn from the vehicle and to convey said battery means to a battery charging station for recharging, and to present recharged battery means for installation in place of the withdrawn battery means, wherein the carrier means are arranged so that the battery means are withdrawn from, and are inserted through the opening at the rear of the vehicle in a direction which^' is generally in line with the longitudinal axis of the vehicle.

16. An electric battery powered heavy bus according to any one of claims 1 to 15.