Abstract:
Battery exchange system for a battery-driven industrial truck, in which the chassis of the industrial truck comprises a battery compartment open to the side of the industrial truck for side installation and removal of a battery container, on the battery container on at least two opposing sides at least one respective laterally projecting support element being attached with a downwardly facing bearing surface and the battery compartment on opposing sides comprising horizontal support surfaces spaced apart from one another in parallel on which the support elements are supported with their bearing surfaces, when the battery container is inserted into the battery compartment.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     A battery exchange system for industrial trucks has become known from DE 103 33 594, the entire contents of which is incorporated herein by reference, in which the vehicle chassis comprises a side opening for receiving a battery. The battery is generally located in a so-called battery container. A profile strip is attached to the battery container, and which comprises an undercut on the underside. Spacers are attached to the lifting carriage of a forklift, on which generally fork aims are suspended, which engage under the profile strip. It is, therefore, possible to receive and to transport a battery by means of the lifting carriage. So that this process may be carried out, firstly the fork arms have to be removed from the load carriage and then the spacers positioned. Subsequently, the forklift is driven towards the other vehicle so that by means of the spacers the battery may be received. This requires, however, that the profile strip is never located more deeply than the level of the spacer. 
     Generally, a battery space accessible from the side in counterbalance forklift trucks brings advantages relative to the aforementioned solutions. When removing the battery, no components inside the operating space have to be awkwardly folded away or removed. The battery does not have to be moved in the region of the operating space, which prevents damage of delicate components in this region. Unnecessary lifting of the battery which poses a risk to the immediate vicinity of personnel is not required. However, the use of a forklift with removable fork arms is necessary. By the complete separation of the battery compartment and operating space a good seal of the passenger compartment is possible relative to sound, rain and battery gases. The disclosed known solution may not be applied to all variants of battery maintenance and battery removal and exchange associated with side battery removal. 
     The object of the invention, therefore, is to provide a battery exchange system for battery-driven industrial trucks, which makes it possible for the total height of the forklift to be as low as possible in spite of the side installation of the battery and the use of different variants of battery removal without alterations to the vehicle being required. 
     BRIEF SUMMARY OF THE INVENTION 
     The support elements may be formed from support strips which, for example, surround the battery container as a frame. Alternatively, U-shaped support elements may also be provided which are attached to opposing ends, encompassing the box with the arms. The support elements have downwardly facing bearing surfaces which project laterally over the contour of the battery container. In the battery compartment, complementary support surfaces are provided on which the bearing surfaces are supported when the battery is inserted into the battery compartment. 
     The attachment of support elements in terms of height may be relatively freely selected, an attachment in the upper region of the container being preferred and namely such that the support elements do not project upwards over the upper edge of the battery container. The battery compartment is thus designed to be only slightly wider than the battery container, the support surfaces being located laterally set back. 
     Generally, the battery containers have very large batteries, as they are used in industrial trucks, and in the upper region so-called crane eyes in order to move said batteries by means of a crane and to install into and remove from a vehicle. According to the invention, such eyes may be used in order to attach the support elements externally to the battery container. To this end, one embodiment of the invention provides that the support elements comprise a pin-shaped lateral projection which is passed through an eye. In the eye, the projection may be secured against withdrawal, for example by a split pin. An alternative embodiment of the invention provides that the pin-shaped projection comprises a spring-biased detent catch, which lockingly engages behind the rear edge of the eye when the pin-shaped projection is inserted into the eye. 
     The solution according to the invention comprises a series of advantages. The total height of the forklift may be low in order to allow driving into and driving through low spaces, storage areas, containers, doors and thoroughfares. As the support elements are attached to lateral faces of the battery container, the structural height of the battery container alone determines the total height of the forklift in addition to the predetermined height of the operating space located thereover and the predetermined ground clearance. No holders or other components project below or above the battery container. 
     In the system according to the invention, the battery may be secured against falling out of the vehicle by an integrated battery securing device. To this end, the support elements may comprise locking elements which cooperate with locking elements on the vehicle chassis. 
     By the use of different support elements, different types of solutions for overcoming the problems with so-called battery handling may be implemented without the vehicle chassis having to be altered. Thus, on the one hand, a particularly inexpensive solution is created, and on the other hand a particularly comfortable handling is made possible. 
     The battery compartment is preferably externally closed. To this end, a casing for the battery compartment may be attached to the support elements. Alternatively, the battery compartment may be sealed by an external flap which is either suspended pivotably as a door or is fixedly attached by screwing to the chassis of the industrial truck. 
     So that the battery is securely received in the compartment, a further embodiment of the invention provides at least one clamping element in the battery compartment, which laterally engages the received battery container. To this end, a rubber wedge or a spring-loaded catch may be provided. An electromechanically or hydraulically actuatable clamping element is also conceivable for selective engagement with the battery container. 
     When the battery compartment is fully or substantially open at the bottom, the fork arms of a forklift may grip the battery container from below and move said battery container outwards. This is irrespective of the distance of the fork arms from one another, as long as the width of the battery container and/or the battery compartment is not exceeded. 
     Alternatively it is conceivable to provide a cooperating telescopic guide between the support element and the battery compartment, for removing the battery container in the manner of a drawer from the battery compartment. Such telescopic guides are known per se for furniture drawers, grill racks in cookers, etc. 
     When a battery container is moved laterally out of the battery compartment by means of such a guide, a not inconsiderable tilting moment results on the forklift. So that it is secured against tilting, one embodiment of the invention may provide that the vehicle comprises a supporting device, which laterally supports the industrial truck when the battery container is moved out from the side. 
     According to a further embodiment of the invention, the supporting device may be automatically moved into the supporting position, when the battery container is removed. 
     To remove a battery container from the battery compartment it is also conceivable to insert movable roller tracks which are pushed under the battery compartment. In order to be able to position the battery container on the roller track, in a further embodiment of the invention it is provided that a lifting device is arranged between the support elements and the battery container. Alternatively, a lifting device may also be provided between the support surfaces and the vehicle chassis. For actuating the lifting device, a rotating spindle may be provided in the manner of a jack mechanism. Alternatively, an external drive may also be provided with a cordless screwdriver or a compressed air screwdriver. For receiving by means of the roller track the entire underside of the battery container is open. Between the battery container and the walls of the battery compartment, a gap may be provided through which lateral guide surfaces of roller tracks or exchange devices facilitate the installation and removal. By means of a roller track, the battery may be directly transferred to a horizontal roller track installation at the same level. 
     An alternative arrangement for battery exchange consists according to the invention in that the support elements comprise two insertion pockets spaced apart from one another in parallel with openings which face the opening of the battery compartment. A C-shaped hook is further provided with two aims spaced apart from one another in parallel in the lower region which move into the insertion pockets. An upwardly facing arm of the hook may be suspended on a lifting device extending above. 
     After the installation of the battery container, the connection of the onboard power supply to the battery has to be made. In this connection a further embodiment of the invention provides that in one support element a first contact arrangement is integrated which cooperates with a contact arrangement on the vehicle side when the battery container is inserted into the battery compartment. Preferably the contact arrangements form a rapid coupling system which carries out an automatic contact. In this connection, rapid exchange of the battery is possible without having to disconnect a battery connector. In this case, the charging station may expediently be provided with a contact arrangement which corresponds to the second contact arrangement in order to allow the rapid connection of the battery to the charging unit. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Embodiments of the invention are described in more detail hereinafter with reference to drawings, in which: 
         FIG. 1  shows in perspective an industrial truck with a side battery compartment and received battery container, 
         FIG. 2  shows in enlarged perspective a side view of the industrial truck according to  FIG. 1  with an empty battery compartment, 
         FIG. 3  shows the industrial truck according to  FIG. 1  with the battery container withdrawn in a modified embodiment, 
         FIG. 4  shows a similar view to  FIG. 3  with a possibility for removing the battery container from a telescopic guide, 
         FIG. 5  shows a section through a support element of a battery container in the region of a fixing on the edge of the battery container. 
         FIG. 6  shows a similar view to  FIG. 3  with a further embodiment of support elements, 
         FIG. 7  shows a horizontal section through an industrial truck with the received battery container and an electrical connection to the onboard power supply, 
         FIG. 8  shows in perspective a further embodiment of a battery space for an industrial truck, 
         FIG. 9  shows in perspective a lifting device for lifting a battery container, 
         FIG. 10  shows in perspective the side view of an industrial truck with the received battery container and closure flap. 
         FIG. 11  shows a flap for a battery compartment and 
         FIG. 12  shows the opened flap of  FIG. 11  and lifting means for a battery. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     While this invention may be embodied in many different forms, there are described in detail herein a specific preferred embodiment of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiment illustrated 
     An industrial truck  10  is indicated in  FIGS. 1 to 4  which is of conventional construction. In the case shown the industrial truck is a counterbalanced forklift truck. Details thereof are not explained. 
     As emerges from  FIGS. 1 to 4 , the industrial truck comprises a battery compartment  14  which is open to the side for receiving a battery container  16 . As emerges from  FIGS. 3 and 4 , the battery container which projects over the battery  18  with its edge  8  ( FIG. 5 ), is provided with frame-like support elements. In  FIGS. 3 and 4 , a U-shaped frame part  20  may be seen which surrounds the battery container from the rear and to the side. Heightwise, the frame part  20  does not extend higher than the edge  8  of the battery container. At the free ends, the arms of the U-shaped frame part  20  strike a strip-like support element  22  which—as may be seen in  FIG. 4  at  24 —may be pivoted upwardly about a horizontal axis which extends through the arm to the right in  FIGS. 3 and 4 . The frame part  20  and the strip-like support element  22  comprise downwardly facing horizontal bearing surfaces (not visible) which are located approximately in one plane. 
     As may be seen in particular in  FIG. 2 , the battery compartment  14  in the upper region is provided with widened portions  6  extending on both sides, which form upwardly facing horizontal support surfaces  26 . A battery container as is shown in  FIGS. 3 and 4  and denoted by  28 , may be inserted approximately positively into the battery compartment, the front face of the battery container  28  being slightly retracted relative to the skin of the vehicle  10 , so that the battery compartment  14  may be sealed by a cover, casing or flap (not shown). The battery compartment  14  is fully open at the bottom, so that a forklift may move with its fork under the compartment  14  and insert a battery into or remove a battery from the compartment  14 . In  FIG. 1  it may be seen that a similar frame as is shown in  FIGS. 3 and 4 , is provided on the front face with insertion pockets  13  which extend a predetermined distance into the supporting frame. Parallel arms  30  of a C-shaped hook  14   a  are inserted into the pockets  13 , the arms being connected to a vertical supporting arm  32 —which is shown at  34 —which may be suspended on a hoist. Therefore, the received battery container may be installed and/or removed by means of the hook  14   a.    
     In  FIG. 2  it may be seen that in the battery compartment  14  catches  7  are arranged on opposing sides. The catches  7  are biased by a spring (not shown) and come into engagement with the facing sides of the inserted battery container, in order to define said battery container laterally and to prevent striking against the lateral walls of the battery compartment  14 . 
     It is further shown in  FIGS. 3 and 4  that on the arms of the U-shaped supporting part  20  a telescopic guide  1  is provided which cooperates with corresponding guide means in the widened portions  6  of the battery compartment  14 . In this manner, the battery container may be moved out of the battery compartment  14 , for example for maintenance and charging purposes. 
     Such telescopic guides  26  are, for example, known in drawers in furniture. 
     So that the vehicle  10  does not tilt, a radial arm  36  is provided which laterally supports the vehicle  10  when the battery container  28 , as shown in  FIG. 3 , is laterally moved in the vicinity of the vehicle  10 . The radial arm  36  may be actuated manually or even automatically extended when the battery container  28  is pushed outwardly. Conversely, the radial arm  36  may be automatically retracted when the battery is inserted into the battery compartment  14 . 
     When it is also necessary to release the battery container  28  from the vehicle  10 , the support element  22  is pivoted upwards as shown in  FIG. 4 . Before pivoting, the connection between the U-shaped support part and the battery container  28  is released, so that by means of a hand pallet truck  40  or the like the battery may be removed. 
     The fastening of the support part  20  or even the support element  22  is shown in  FIG. 5 . At least one pin-like projection  11  is provided, which extends through an opening  42  in the edge  8  of the battery container  14  and/or  28 . In the pin-like projection  11  a catch  9  is mounted in a spring-loaded manner, which normally adopts the position shown in  FIG. 5 , in which it engages behind the edge of the opening  12  remote from the support part  20 . The outer face of the catch  9  is provided with an oblique surface so that the pin-like projection  11  may be passed easily through the opening  12 . 
     In  FIG. 6  it is shown how two U-shaped support elements  46 ,  48  are provided on opposing sides of the battery container  28 , encompassing said battery container with the arms. The upper face of the support elements  46 ,  48  is in turn flush with the upper edge of the battery container  28 . The fastening of the support elements  46 ,  48  may be carried out in a similar manner as is shown in connection with  FIG. 5 . 
     In  FIG. 6 , a locking part  3  in the region of a widened portion  6  of the battery compartment  14  is moreover visible. The locking arrangement cooperates with a locking part  4  in one arm of the U-shaped support element  48 , when the battery container  28  is fully inserted into the battery compartment  14 . In this manner the battery container  28  is prevented from slipping out or falling out of the battery compartment  14 . 
     In  FIG. 6  at  50  a battery cable is indicated which leads from the battery via a connector, not shown, to a terminal of the onboard power supply. In  FIG. 7  it is shown that such a cable is not required. 
     In  FIG. 7  a plan view of the battery container  28  is shown inside the battery compartment  14 , it being visible that the support elements are again formed by a peripheral frame  52 . It may further be seen in  FIG. 7  that in a longitudinal portion of the frame  52  a first contact arrangement  12  is integrated, which is connected to the battery terminals via a connecting cable  56 . In the region of the widened portion  6  a second contact arrangement  11   a  is installed—which is not shown—which is connected to the onboard power supply and comprises two movable contact pins, of which one is shown at  58 . If the battery container  28  is inserted into the compartment  14 , the contacts of the contact arrangements  12  and  11   a  are automatically in engagement so that as a result the connection to the onboard power supply is created without additional handles being required. 
     In  FIG. 8  the battery receiving space  14  is indicated in the industrial truck  10 , with lateral elongate recesses  6  as has already been mentioned in particular in connection with  FIG. 2 . Angle sections  60  are seen in the recesses which are supported by hydraulic rams  62 . By means of the hydraulic rams  62  the angle sections  60  may be lifted. If a battery container  28  is located with the lateral support elements, as has already been described further above, on the angle sections  60 , then said battery container may be lifted by a certain distance, so that a roller track may be pushed under and lowering onto the roller track is possible in order to remove the received battery. 
     In  FIG. 9  a U-shaped support element  64  is shown, which encompasses the battery container  9  on three sides and may be attached thereto via holes  66  coinciding with the holes  42  in the battery container by suitable fastening means. The arms of the support element  64  have, with regard to the retaining in the industrial truck, the same function as the aforementioned support elements. The arms of the support element  64  according to  FIG. 9  are divided into two portions. The upper portion  68  is formed integrally with the web of the U-shaped support element  64 . A lower portion  70  is a separate part. The surfaces of the portions  68 ,  70  facing one another, extend at the same angle to one another. A wedge  72  of complimentary configuration is arranged between these surfaces and may be moved by means of a threaded spindle  74 . The drive of the threaded spindle is carried out via an opening  75  in the fixed part of an arm. In this manner, the height of the U-shaped support element  64  may be altered and thus also the height of the battery container  28  above the base. It is understood that such a height adjustment may also be provided for the other arm, which however may not be seen in  FIG. 9 . In order to bring about a displacement from only one position, a chain wheel  77  is coupled to the spindle  74  at the other end, which is drive-connected to a further chain wheel via a chain, which also displaces the wedge for the other arm via a spindle. 
     In  FIG. 10  it is indicated how the battery space  14  may be externally covered by a flap  80 , which is hinged to the industrial truck at  82  via hinges. Locking openings  84 ,  86  on both sides of the battery space  14  serve to secure the flap  80  in a closed position. 
     In  FIG. 11  a battery compartment  14  is closed by a flap  81  which is shown in  FIG. 12  in opened state. Hinges for flap  81  are located laterally. 
     Lifting cylinders within the battery compartment are located on opposite sides one of which shown at  83 . The cylinder  83  is supported on a shoulder  13  in compartment  14 . The piston rod of the cylinder  83  supports at the free end thereof a roll  87  which engage a guide way  89  of lateral support members  20 . The lifting cylinders  83  are designed to lower the battery container  28  onto a roller way  91  or to lift the battery container from the roller way  91 . The guide way  89  is preferably open at the inner end to allow the removal or the insertion of a battery container  28  (not shown). 
     The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims. 
     This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.