Abstract:
A device for holding freight is composed of two containers, which are connected to each other by at least two connecting elements. The area where the containers are connected to each other is sealed off from the environment by at least one sealing element. Each container has a closable access opening at the end which faces the other container. The sealing element extends around the area of the outside edges of the two facing ends of the containers. The connecting element is installed on the containers in such a way that, when the containers are not connected to each other, an external contour of the connecting element is essentially in an interior position with respect to the external contour of the container.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The invention relates to a device consisting of two containers for holding freight, the containers being connected to each other by at least two connecting elements and sealed off against the environment in the area where they are connected by at least one sealing element, wherein each container has a closable access opening at the end which faces the other container.  
         [0003]     2. Description of the Related Art  
         [0004]     So-called 20-foot containers and 40-foot containers are often used for the transport of freight. The containers are transported on land, on the sea, and in the air. The requirements on container size applicable in a specific case differ considerably from one transfer point to another. It happens frequently that small containers are required in one transport direction and large containers in the opposite transport direction. As a result, it is often necessary to transport empty containers back in the opposite direction to their point of origin.  
         [0005]     To avoid the need to transport empty containers back to where they came from, it has already been proposed in DE 43 29 355 that smaller containers be designed so that they can be connected to each other. This means that the smaller containers can either be used individually or combined with each other to form larger containers.  
         [0006]     The principle of connecting containers together, according to which two 20-foot containers can be connected to form a 40-foot container, has thus already been described in DE 43 29 355. These previously described basic possibilities of connecting containers together, however, are not yet able to provide a sufficiently low-cost, easy-to-handle, and yet sturdy design which can withstand the transport loads to which containers are subject.  
       SUMMARY OF THE INVENTION  
       [0007]     The object of the present invention is therefore to make available a device of the type described above in such a way that both ease of handling and high reliability are provided while manufacturing costs are kept low at the same time.  
         [0008]     This object is met according to the invention in that the sealing element extends around the area of the outside edges where the two ends of the containers face each other, and in that the connecting element is installed on the container in such a way that, when the containers are not attached to each other, the external contour of the connecting element is located in an essentially interior position with respect to the external contour of the container.  
         [0009]     Because the sealing element is installed around the edges, a functional seal is ensured. Because only one component must be handled and fitted into position, furthermore, the seal can be handled much more easily during the connecting and disconnecting operations. The connecting elements are arranged in such a way that, when not in use, they are essentially recessed below the external contour of the containers. This also contributes to the ease of handling, because there are no components present which project out from the container. There is therefore no danger that an unused connecting element could be broken off or that a projecting connecting element could cause damage to other containers. Thus it is also guaranteed that the inventive device can meet the requirements of the ISO standards for containers. When the containers are disconnected from each other, therefore, the sealing element is removed from the containers and stowed out of harm&#39;s way, and the connecting elements are recessed into openings provided for the purpose.  
         [0010]     An especially good sealing action can be achieved by designing the sealing element as a closed ring, which extends peripherally around the containers.  
         [0011]     An adaptation to conventional container contours is supported by the fact that the sealing element frames an essentially rectangular interior surface.  
         [0012]     An especially high degree of mechanical strength in the sealing area is achieved by making the sealing element out of an elastomeric base material and by embedding stiffening plates into it.  
         [0013]     So that the sealing element will be both mechanically strong and highly flexible and foldable, it is proposed that the stiffening plates be spaced a certain distance apart.  
         [0014]     The sealing element can be held reliably in place with good mechanical strength by installing it in recesses formed in the two connected containers.  
         [0015]     An even better sealing action can be obtained by providing a base seal in at least one of the recesses to cooperate with the sealing element.  
         [0016]     It is possible to open and to close the container at the end surface to be connected to the other container by providing a swinging communicating door at this end of the container.  
         [0017]     The extent to which the usable storage space available is reduced by the communicating door when it is in the open position can be minimized by installing the communicating door so that it pivots vertically upward.  
         [0018]     The container can be handled more easily if the communicating door is designed to pivot inward around an axis of rotation into the interior space of the container.  
         [0019]     The communicating doors can be operated in a mechanically simple yet reliable manner by providing a cable pull to move them from one position to another.  
         [0020]     The communicating doors can be opened and closed more easily without additional help by providing a crank so that the cable pull can be actuated manually.  
         [0021]     Especially good security against unauthorized access can be provided by designing the communicating door so that it can be locked from the inside of the container.  
         [0022]     It is easier to ensure that the access door will lock automatically if the connecting door can be locked by at least one drop latch.  
         [0023]     By locating the connecting element in a connecting box, in which the element is free to slide back and forth, the connecting element becomes easy to actuate, and there are no projecting parts when the connecting elements are not in use.  
         [0024]     To ensure that all of the inventive devices are of similar design, all of the containers are provided with the same number of connecting elements and the same number of sockets, these being distributed on the end surfaces to be connected in such a way that the connecting elements are always on one side of the end surface and the connecting sockets are always on the other side or in such a way that they are always distributed diagonally on the end surface in the same way, so that any of the inventive containers can be connected to any of the other inventive containers without restriction.  
         [0025]     The connecting and disconnecting operations can be made easier by designing the connecting element in the form of a connecting shaft with a spacer.  
         [0026]     By providing the connecting shaft with an external thread to guide an impact nut, the containers can be clamped together in a minimal amount of time.  
         [0027]     By providing the connecting element with an operating lever, the locking operation can be carried out with minimal expenditure of force.  
         [0028]     High mechanical strength with simultaneous protection of the connecting elements from possibly harmful external loads is achieved by locating the connecting elements adjacent to the corner fittings of the container.  
         [0029]     While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.  
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0030]     In the drawings:  
         [0031]      FIG. 1  shows a schematic side view of two containers, connected to each other;  
         [0032]      FIG. 2  shows a partial, enlarged cross section through the side posts and a sealing element;  
         [0033]      FIG. 3  shows a longitudinal cross section through the sealing element;  
         [0034]      FIG. 4  shows the end surface of a container which can be connected to another container, where an adjustable door is provided in this end area;  
         [0035]      FIG. 5  shows a partial schematic cross section through two containers connected together, where one communicating door is closed and the other is swung open;  
         [0036]      FIG. 6  shows an enlarged cross section through the area of a hinge joint of the communicating door;  
         [0037]      FIG. 7  shows a partial cross section through the communicating door in the area of a lower lock;  
         [0038]      FIG. 8  shows a partial schematic longitudinal cross section through a container to illustrate an actuating device for the communicating door;  
         [0039]      FIG. 9  shows a partial schematic plan view to illustrate the mechanism for actuating the communicating door;  
         [0040]      FIG. 10  shows a partial longitudinal cross section from above through a connecting element in the upper connecting area between two containers;  
         [0041]      FIG. 11  shows another longitudinal cross section from the side through a connecting element in the upper connecting area between two containers;  
         [0042]      FIG. 12  shows a side view of a socket for a connecting element, the socket being located next to a conventional corner fitting;  
         [0043]      FIG. 13  shows the design of the individual components of the connecting element from each of two different perspectives;  
         [0044]      FIG. 14  shows another longitudinal cross section from the side through a connecting element in the lower connecting area between two containers;  
         [0045]      FIG. 15  shows another longitudinal cross section from above through a connecting element in the lower connecting area between two containers;  
         [0046]      FIG. 16  shows another longitudinal cross section from the side through a connecting element in the lower connecting area in the unlocked state shortly before the connecting operation; and  
         [0047]      FIG. 17  shows a cross section in the area of an upper connecting element with a sealing element next to a corner fitting.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0048]      FIG. 1  shows a side view of two containers  1 , each of which is provided with corner fittings  2 . The containers  1  are provided with a sealing element  3  which extends around the edges in the area of their facing end surfaces.  
         [0049]      FIG. 2  shows a partial cross section through the sealing element  3  held by the containers  1 . The containers  1  are provided with groove-like recesses  4 , into which the loose sealing element  3  is inserted. To increase the mechanical stability, recesses  4  are made in the corner posts  5 . Base seals  6  are provided in the recesses  4 . The lateral edges of the sealing element  3  are held against these base seals. Through the combination of the sealing elements  3  and the base seals  6 , a reliable sealing action against the intrusion of moisture is provided, and in addition unauthorized external access to the interior spaces of the containers is prevented.  
         [0050]      FIG. 3  shows a longitudinal cross section through the sealing element  3 . The sealing element  3  consists of an elastomeric base material  7 , in which stiffening plates  8  are embedded. The stiffening plates  8  can be made of steel, for example. To ensure a satisfactory sealing effect, the stiffening plates  8  are a certain distance  9  away from the edge  10  of the sealing element  3 . In addition, the stiffening plates  8  are spaced a certain distance apart, so that the sealing element  3  is sufficiently flexible and foldable despite its considerable mechanical strength.  
         [0051]     The combination of the stiffening plates  8  and the base material  7 , as shown in  FIG. 3 , thus provides a highly effective sealing action, high mechanical strength, high penetration resistance, and satisfactory flexibility and foldability all at once. In particular, the stiffening plates  8  can be vulcanized into an elastomeric base material  7 .  
         [0052]      FIG. 4  shows a side view of the container  1 , which is provided with a communicating door  12  in the area of its connecting end  1 . The figure also shows connecting elements  13  and connecting sockets  14  next to the corner fittings  2 . In the exemplary embodiment shown here, two connecting elements  13  are provided on one side of the container and two connecting sockets  14  are provided on the other side of the container. This guarantees that, when it is desired to connect two inventive containers  1  together, it will always be possible—provided that all the containers  1  are of the same design—to introduce a connecting element  13  into an assigned connecting socket  14 . As a result, any containers  1  of similar design can always be connected without additional modifications.  
         [0053]     According to another embodiment, it would also be possible to arrange the connecting elements  13  on one diagonal on the end surface of the container and to locate the connecting sockets  14  on the other diagonal. It would be possible to design all of the containers  1  in this way, and it would thus always be possible to connect two containers  1  together easily.  
         [0054]      FIG. 5  shows a schematic side view of two associated containers  1 , the communicating doors  12  of which are both closed. In one of the containers, broken lines show the communicating door  12  in an upward-pivoted position. The pivoting movement takes place around an axis of rotation  15  of the communicating door  12 .  
         [0055]     According to another embodiment, it would also be possible to pivot two-leaf communicating doors around a vertical axis of rotation toward the inside walls.  
         [0056]      FIG. 6  shows how the communicating door  12  is supported in the area of the axis of rotation  15  and where the door seal  16  is located. The communicating door  12  is supported with freedom to swing up and down by way of a connecting lever  17  in the area of the axis of rotation  15 . The design of the connecting lever  17  ensures that the communicating door  12  will assume a vertical position when the container  1  is closed, and that a slight gap will remain between the communicating door  12  and the roof of the container  1  after the door has been pivoted upward. As a result, the available storage height is reduced only slightly when the communicating door  12  is swung up into its open position.  
         [0057]     In the closed state, the communicating door  12  is held against the door seal  16 . The door seal  16  is thus clamped between the downward-pivoted communicating door  12  and an outer retaining sidepiece  18 . The door seal  16  is deformed elastically and thus offers a highly effective sealing action.  
         [0058]      FIG. 7  shows a locking device  19  for the communicating door  12 . The locking device  19  is designed as a drop latch  20 , which is supported in a guide  21  in the communicating door  12 . The container  1  has a locking socket  22 , into which the drop latch  20  can be introduced. To unlock the door, the drop latch is manually pulled up out of the locking socket  22 , and the communicating door  12  can then be swung upward. In the locking position, the drop latch  20  is held in the locking position by the force gravity alone.  
         [0059]      FIG. 8  illustrates schematically a mechanical actuating system for the communicating door  12 . This system makes it possible to open and to close the communicating door  12  manually, without additional means. The communicating door  12  is for this purpose provided with a cable pull  23 , which is guided over cable pulleys  24 . A crank  15  is used to actuate a winding device  26  for the cable pull  23 . When the cable pull  23  is completely wound up, the communicating door  12  is in the fully open position. By unwinding the cable pull  23 , the communicating door  12  can be returned to the fully closed position.  
         [0060]      FIG. 9  shows another view of the course of the cable pull  23  and the arrangement of the cable pulleys  24 . It can be seen that two cable pulls  23  are attached to the communicating door  12  to ensure the uniform introduction of the pulling forces and to avoid forces which would tend to twist the door. The cable pulls  23  proceed first along the side walls of the container  1 ; one of the cable pulls  23  is then diverted to the opposite side of the container  1  so that both cable pulls  23  can be extended jointly to the winding device  26 . The mechanical construction work is simplified by this design.  
         [0061]     If the cable pulls  23  are joined together to form a single cable pull behind the common deflecting pulley, the winding device  26  must be located at the end of the side opposite the common deflecting pulley  24 , so that the overall length of the cable pull from the common deflecting pulley to the winding device  26  will be longer than that from the common deflecting pulley to the attachment point on the door.  
         [0062]      FIG. 10  shows two containers  1  connected to each other by the connecting element  13 , the perspective being from the interior of the container toward the roof. The connecting element  13  is supported in a connecting box  27 , in which the element is free to slide back and forth. In the unused state, the unused connecting element  13  is recessed within the connecting box  27 . When in the locking position shown in  FIG. 10 , the connecting element  13  projects out from the connecting box  27 , and its locking end  28  fits into the connecting socket  14 . An operating lever  29  can be used to rotate the connecting element  13 .  
         [0063]     A typical locking procedure is carried out by first introducing the locking end  28  of the connecting element  13  into the connecting socket  14  and then by using the operating lever  29  to rotate the connecting element by about 90°. After this rotation, the locking end  28  is held positively in the connecting socket  14 . By the use of an impact nut  30 , the containers can then also be firmly fastened together.  
         [0064]     It can be seen from the diagram of  FIG. 11  that the connecting element  13  consists essentially of two parts. The locking end  28  is held by a connecting shaft  31 , which extends through an essentially sleeve-shaped spacer  32 . The spacer  33  is provided with an external profile  33 , which determines the distance between the two containers  1  in the locked position. The connecting element  13  is guided in the area of the connecting box  27  by an element holder  34 . The element holder  34  is rigidly connected to the connecting box  27 . A lock nut  39  is located behind the impact nut  30 .  
         [0065]      FIG. 12  shows a side view of the connecting socket  14  located next to the corner fitting  2 . It can be seen that the connecting socket  14  has an insertion opening  35 , which is designed in such a way that the locking end  28  can be pushed into the insertion opening when it is in a first position but cannot be pulled back out of the insertion opening  35  after it has been rotated by approximately 90° into a second position. By means of a design of this type, the locking and unlocking operations can be carried out very quickly, whereas a high mechanical load-bearing capacity is obtained at the same time.  
         [0066]      FIG. 13  shows the design of the connecting element  13  after the connecting shaft  31  has been separated from the spacer  32 . To be seen in particular is the design of the locking end  28 , which, in one of the positions shown, can be introduced into the insertion opening  35 , whereas, when in the other position, it cannot be pulled out of the opening  35 . It can also be seen that the spacer  32  is essentially in the form of a sleeve and has a rotationally symmetric external profile  33 . It can also be seen that the connecting shaft  31  has an external thread  36 , which is designed to cooperate with a corresponding internal thread of the impact nut  30 . In the area of the external thread  36 , the connecting shaft  31  is provided with a bore  37 , which accepts the operating lever  29 .  
         [0067]      FIG. 14  shows the arrangement of the connecting element  13  in a lower bottom area of the container  1 . An additional cover plate  38  is mounted over the recesses  4  for the sealing element to protect against external mechanical damage.  
         [0068]      FIG. 15  shows again the arrangement of the connecting box  27  and of the connecting socket  14  next to the associated corner fittings  2  in the lower part of the container. Positioning the components in the interior next to the corner fittings  2  provides a considerable degree of mechanical strength.  
         [0069]      FIG. 16  shows a partial cross section of a container  1 , where the connecting element  13  has been pushed out of the connecting box  27 .  
         [0070]     Two containers  1  can be connected to each other in the following manner. First, the containers  1  are arranged with their communicating doors  12  facing each other. The distance between them is selected typically so that, in a first step, the edge sealing element  3  can be inserted into the associated recess  4  in one of the containers  1 . Then the containers  1  are pushed together in such a way that the connecting elements  13  can be pushed into their assigned connecting sockets  14 . During this step, it is preferable for at least one of the communicating doors  12  to be open, so that the sealing element  3  can be supported or guided from the inside as it is being introduced into the second recess  4 .  
         [0071]     After the containers  1  have been brought together in the proper position, the connecting elements  13  are rotated into their locking positions, and then, with the use of the impact nuts  30 , the containers are then also clamped firmly together. The containers  1  are disconnected from each other by performing these same steps in reverse order.  
         [0072]     The locking device  19  is preferably designed in such a way that it can be actuated only from the interior of the container  1 . A design of this type offers the advantage that it is impossible to open the communicating door from the outside.  
         [0073]      FIG. 17  shows the use of a sealing element  40  in the area of an upper connecting socket  14 . This element is designed as a rubber flap, which prevents the intrusion of water or moisture into the interior of the container  1  through the parts of the connecting socket  14  next to the circular part.  
         [0074]     While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.