Abstract:
A fully electric straddle carrier device for ISO containers, comprising electric drives which are powered by a battery and comprising liftable and lowerable load-receiving means for the ISO containers, where the battery is arranged above the load receiving means.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims the priority benefits of International Patent Application No. PCT/EP2012/056090, filed on Apr. 3, 2012, and also of German Patent Application No. DE 10 2011 001 847.6, filed on Apr. 6, 2011, which are hereby incorporated herein by reference in their entireties. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The invention relates to a straddle carrier device for ISO-containers with electric drives which are powered via a battery, with a front gantry frame and a rear gantry frame which are connected to each other in the region of their upper ends via an upper frame, and with a load picking-up means, which is suspended on the upper frame and which can be raised and lowered, for ISO-containers suspended thereon. 
         [0003]    Straddle carrier devices of this type—also known as straddle carrier stacking trolleys, straddle stacking trolleys, straddle carriers, van carriers, shuttle carriers or runners—are generally known. They are specific handling devices for ISO-containers in terminals, in particular port terminals or terminals for combined transport between road and rail. With the aid of a lifting device and a load picking-up means, designated as a spreader, straddle carrier devices can lift containers and—after transportation—set them down at a target location. Since the straddle carrier devices have a spider-leg structure, they can travel over a container resting on the floor or on another container and in so doing also—depending on construction—additionally transport a lifted container. Depending on the construction height, the straddle carrier devices are designated, for example, as 1 over 3 devices, 1 over 2 devices etc. A 1 over 3 device can set down a container on 3 stacked containers, pick up one of 3 stacked containers or travel over 3 stacked containers with a picked-up container. In this context, standardised large-size or sea freight containers which are used in the international transportation of goods are understood to be ISO-containers. The most widely used are ISO-containers with a width of 8 feet and a length of 20, 40 or 45 feet. 
         [0004]    From international patent application WO 2009/150303 A1, a straddle carrier device for ISO-containers is already known. In the conventional manner the straddle carrier device—as seen in its direction of travel—has a right-hand travelling mechanism girder and a left-hand travelling mechanism girder. At least two rubber-tyred and steerable tyre-mounted travelling mechanisms disposed one behind the other in the direction of travel are attached to each travelling mechanism girder. The right-hand and the left-hand travelling mechanism girders are connected to each other via a front and a rear gantry frame. In the region of their upper ends, the two gantry frames are connected to each other via an upper frame. A lifting device is suspended on the upper frame and from it a load picking-up means for the ISO-containers can be raised and lowered. The straddle carrier device is fully electric and therefore has electric travel drives, electric steering drives and electric lifting drives. These drives are powered via an on-board rechargeable battery. The charging process for the battery is effected at a charging station which is disposed in the region of a stacking area for containers. 
         [0005]    Furthermore, from German utility model document DE 20 2004 018 066 U1, a further straddle carrier device is known which is driven by a diesel-electric drive. In the conventional manner, this straddle carrier device also has a front and rear gantry frame which are connected to each other via an upper frame. The diesel-electric drive is disposed in the region of the upper frame and above a load picking-up means for containers. 
         [0006]    The U.S. Pat. No. 6,155,770 A discloses a support structure with a lifting frame. By means of the support structure a container picked up by the lifting frame can be raised and can be set down on a loading surface of a heavy goods lorry. The container is thus supported underneath by the lifting frame and the lifting frame is raised and lowered via lifting cylinders. Furthermore, a winch driven by an electric motor is disposed on the lifting frame, wherein the electric motor is powered via a battery also disposed on the lifting frame. The winch serves to move and position the lifting frame relative to the container or together with the container relative to the heavy goods lorry on the ground. To this end, the support structure is supported on the ground by non-driven wheels. 
         [0007]    The international patent application WO 2007/143841 A1 describes straddle carrier devices which can be operated via hybrid drives of different designs. Various arrangements in the area of travelling mechanism girders are disclosed for batteries for the hybrid drives. 
         [0008]    The European patent application EP 2 281 769 A2 discloses a straddle carrier device having a driver&#39;s cabin and the German patent document DE 10 2008 011539 B3 discloses a fully automatic straddle carrier device. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention provides an improved, fully electric straddle carrier device. 
         [0010]    In accordance with the invention an improved straddle carrier device for ISO-containers with electric drives, which are powered via a battery, with a front gantry frame and a rear gantry frame which are connected to each other in the region of their upper ends via an upper frame and with a load picking-up means, which is suspended on the upper frame and which can be raised and lowered, for the ISO-containers suspended thereon is achieved by arranging the battery above the load picking-up means in the region of the upper frame. Above the load picking-up means there is sufficient space to house a high-capacity battery of appropriate size. The electric drives in the form of electric motors act in a conventional manner via gearing on the components to be driven in order to fulfil the drive functions provided in the straddle carrier device such as, for example, travel drive, braking drive, steering drive and lifting drive. For specific drive functions such as, for example, the steering drive or the lifting drive it may be necessary to drive a hydraulic pump via the electric drive in order to design the steering drive or the lifting drive in an electro-hydraulic manner. The selected battery-electric drive has the advantage that a degree of effectiveness is achieved which is approximately more than double that of a diesel engine. This leads to a lower level of power consumption, increased efficiency, lower maintenance and a high level of environmental compatibility especially in relation to noise and emissions. 
         [0011]    Provision is made that only purely electric drives, i.e. no electro-hydraulic drives, are provided, which means that the straddle carrier device does not need hydraulic components. 
         [0012]    For the purpose of a charging process for the battery outside the straddle carrier device, this battery is connected to the straddle carrier device in a replaceable manner. It is therefore particularly easy to replace a battery which needs to be charged with a charged battery, without the availability of the straddle carrier device being limited for a charging process as in the case of a non-replaceable battery. The replacement process can be carried out manually, semi-automatically or fully automatically. 
         [0013]    A high level of reliability for the straddle carrier device is achieved in that the battery is a lead-acid battery. Lead-acid batteries have been used in vehicles for many years. The battery required has a weight of about 6 to 10 metric tons (“t”). 
         [0014]    In a particular embodiment, provision is made that the battery has a supporting function within the straddle carrier device. This embodiment is particularly space-saving since the supporting construction in the region of the upper frame and the battery merge with each other in terms of their function. 
         [0015]    The straddle carrier device is designed as a 1 over 1 construction and preferably as a 1 over 0 construction. By means of the 1 over 0 construction only low lifting efforts are required because of the low lifting height. The 1 over 0 construction also leads to a low centre of gravity which permits a compact and also simple construction for the straddle carrier device. Since the straddle carrier device has a low centre of gravity and therefore has a high level of stability and resistance to tipping, it is able to travel on only four tyre-mounted travelling mechanisms with rubber tyres. The limitation to four tyre-mounted travelling mechanisms also makes it possible to reduce the complexity of the straddle carrier device as a whole. Driving and steering can be rendered simpler. In the case of an automatically guided straddle carrier device, navigation also becomes simpler. 
         [0016]    In a preferred embodiment the straddle carrier device is automatically guided. 
         [0017]    Alternatively, provision is made that a driver&#39;s cabin is disposed on the straddle carrier device and the straddle carrier device can be driven manually. 
         [0018]    The invention will be explained in more detail hereinafter with the aid of an exemplified embodiment illustrated in the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  shows a schematic side view of a first embodiment of a straddle carrier device, 
           [0020]      FIG. 2  shows a schematic side view of a second embodiment of a straddle carrier device and 
           [0021]      FIG. 3  shows a plan view of a port layout with the straddle carrier devices in accordance with  FIG. 1  or  2 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0022]      FIG. 1  shows a schematic side view of a straddle carrier device  1  which can travel via a total of four rubber-tyred wheels  2  on a ground surface  3 . The wheels  2  are disposed in the conventional manner in the corners of an imaginary rectangle. It is also fundamentally possible to provide more than four rubber-tyred wheels  2  if this is required for technical reasons. However, this is then associated with an increase in the complexity of the straddle carrier device  1  as a whole and therefore more complex technology must be used in the area of driving and steering. In the case of automatically guided straddle carrier devices  1 , navigation also becomes more complex owing to the increase in wheels  2  to be steered. 
         [0023]    The wheels  2  of the straddle carrier device  1  are component parts of wheel-mounted travelling mechanisms  5  which have electric travel drives and electric steering motors, not shown. The individual wheel steering provided means it is possible, with appropriate control, to carry out different steering programmes, such as for example optimised Ackermann steering or backwards movement. Out of the total of four wheel-mounted travelling mechanisms  5 , in each case two—in a spaced relationship and one behind the other as seen in the direction of travel F of the straddle carrier device  1 —are attached to a right-hand travelling mechanism girder  6   a  and to a left-hand travelling mechanism girder which is concealed by the right-hand one, which are each oriented with their longitudinal extension in the direction of travel F of the straddle carrier device  1 . The two travelling mechanism girders  6   a  which are disposed in parallel next to each other and in a mutually spaced manner are connected to each other at the front via a front gantry frame  7   a  and at the rear via a rear gantry frame  7   b.  Each of the two u-shaped gantry frames  7   a  and  7   b  consists of a horizontal upper gantry girder  7   c  oriented transverse to the direction of travel F, the lateral ends of which are each adjoined by a vertical gantry support  7   d.  The front and rear gantry frames  7   a,    7   b  are connected to each other via longitudinal girders  8  oriented in the direction of travel F. 
         [0024]    The two gantry girders  7   c  and the longitudinal girders  8  form an upper frame  9  on which a lifting apparatus  10  is suspended in order to be able to pick up the ISO-containers  4  from the ground  3  and to set them down on the ground  3 . The lifting height h required for this purpose is about 150 to 300 mm. The lifting apparatus  10  includes one or a plurality of electric lifting drives, not shown, which are connected to a load picking-up means  11  via cables or a lifting mechanism  10   a.  The load picking-up means  11  is designed as a so-called spreader frame in order to be able to handle ISO-containers  4 . The spreader frames are designed as so-called single-lift or twin-lift spreaders, i.e. in the twin-lift version, two 20 foot ISO-containers  4  can be picked up one after the other as seen in the direction of travel F of the straddle carrier device  1 . 
         [0025]    In a conventional manner the load picking-up means  11  is able to move up and down below the upper frame  9  and between the gantry supports  7   d  of the front gantry frame  7   a  and the gantry supports  7   d  of the rear gantry frame  7   b  in an essentially vertical lifting direction H. 
         [0026]    Furthermore, in the region of the upper frame  9  sufficient space is available to house switch cabinets  12  and one or a plurality of batteries  13 . A high level of reliability in the heavy goods transport vehicle is achieved by the battery  13  being a lead-acid battery. Lead-acid batteries have been used in vehicles for many years. The weight of the battery is in the range of about 6 to 10 t, preferably 8 t to 9 t. Furthermore, provision is made so that a flat battery  13  can be replaced by a charged battery  13  and can be moved by an appropriate apparatus, transverse to the direction of travel F, horizontally out of the upper frame  9  or into this upper frame. The charging process for the battery  13  therefore takes place outside the straddle carrier device  1  and the straddle carrier device  1  is available immediately after the battery has been replaced. 
         [0027]    The replacement process can be carried out manually, semi-automatically or fully automatically. 
         [0028]    If, in the next few years, other types of battery, such as, for example, lithium-ion batteries, achieve an equivalent level of reliability to lead-acid batteries, it will also be possible to use them. 
         [0029]    As a whole, the straddle carrier device  1 , in particular the lifting height of the lifting apparatus  10 , is designed as a so-called 1 over 0 device, i.e. by means of the straddle carrier device  1  a single ISO-container  4  can be picked up from the ground  3  and set down. Stacking of ISO-containers  4  is not possible. With an appropriately designed load picking-up means  11  (twin-lift) it is naturally possible to pick up together two ISO-containers  4  which are disposed one behind the other as seen in the direction of travel F and have a length of 20 feet each. By means of this embodiment as a 1 over 0 device, the straddle carrier device  1  has a low centre of gravity, a good level of stability and the construction can be extremely compact. The demands placed on the performance of the electric lifting drives are also not so great. Furthermore, the construction height is low and consequently the weight is light, which means that four wheels suffice to receive the load. 
         [0030]    Furthermore, the straddle carrier device  1  can be controlled manually by a driver or be guided automatically. For the manual version, a driver&#39;s cabin  14  is attached in the region of the front gantry frame  7   a.  In the case of the automatically guided version, sufficient space for sensors  15  is provided in the region below the travelling mechanism girders  6   a  and between the front and rear wheel-mounted travelling mechanisms  5  respectively, the sensors being designed according to the navigation system used. If transponders let into the ground  3  are used then the sensors  15  are designed as antennas. 
         [0031]      FIG. 2  shows a schematic side view of a second embodiment of a straddle carrier device  1 . This straddle carrier device  1  corresponds essentially to the straddle carrier device  1  described above, which means that reference is made to the entire content of the preceding description. The same reference numbers as in  FIG. 1  have also been used. 
         [0032]    In this second embodiment, the battery  13  or the receiving frame  13   a  thereof is designed as a supporting component which provides the upper frame  9  with sufficient solidity during operation of the straddle carrier device  1 . For this purpose the battery  13  is additionally secured, for example by bolts, after its insertion into the straddle carrier device  1 . The battery  13  also has an appropriately arranged battery frame  13   a  in order to be able to absorb the forces resulting from the operation of the straddle carrier device  1  between the front and rear gantry frames  7   a,    7   b.  Although in conjunction with the replacement of the battery  13  the upper frame  9  is then weakened without the battery  13 , the upper frame  9  does have sufficient solidity during the time the straddle carrier device  1  is waiting for a new charged battery  13 . 
         [0033]    For the automatic guided version, in the region below the travelling mechanism girders  6   a  and between the front and rear wheel-mounted travelling mechanisms  5  respectively there is sufficient space for sensors  15  which are designed according to the type of navigation system used. If transponders let into the ground  3  are used, the sensors  15  are designed as antennas. In conjunction with the automated guided version, fully automatic object-recognition for the containers  4  to be picked up can also be provided. Since the positions of the containers  4  on the quay  16  are approximately known, the straddle carrier device  1  can navigate its way thereto independently. Prior to reaching the final position the containers  4  are passed over by an object-recognition sensor arrangement and the straddle carrier device  1  can be finely positioned from the position data thereby obtained. The containers  4  are then picked up. 
         [0034]      FIG. 3  shows a plan view of a port layout using the straddle carrier devices  1  described above as shown in  FIG. 1  or  2 . The ground surface  3  is a component part of a quay  16  over which—by means of a large number of straddle carrier devices  1 —the ISO-containers  4  are moved by container stacking cranes  19  between a plurality of container crane bridges  17  and a container stacking area  18  adjoining the quay  16 . Instead of the container-handling crane bridges it is naturally also possible to use other handling devices such as, for example, mobile port cranes, in particular in the case of smaller handling ports. 
         [0035]    Furthermore, provision can be made, or it may be technically necessary, to resort to electro-hydraulic drives instead of purely electric drives, which act on gears, for certain drive functions such as steering or lifting. It is also possible in the case of the straddle carrier devices  1  to provide for energy recovery when the ISO-containers  4  are being lowered or the straddle carrier device  1  is being braked. The recovered energy is then stored in short-term energy stores such as so-called ultracaps or supercaps. 
       Reference List 
       [0000]    
       
           1  Straddle carrier device 
           2  Wheel 
           3  Ground surface 
           4  ISO-container 
           5  Wheel-mounted travelling mechanism 
           6   a  Right-hand travelling mechanism girder 
           7   a  Front gantry frame 
           7   b  Rear gantry frame 
           7   c  Upper gantry girder 
           7   d  Gantry support 
           8  Longitudinal girder 
           9  Upper frame 
           10  Lifting apparatus 
           10   a  Lifting mechanism 
           11  Load picking-up means 
           12  Switch cabinet 
           13  Battery 
           14  Driver&#39;s cabin 
           15  Sensor 
           16  Quay 
           17  Container bride crane 
           18  Container stacking area 
           19  Container stacking crane 
         F Direction of travel 
         H Lifting direction 
         h Lifting height