Abstract:
A freight container has doors at one end of different widths but the same height. The larger door has a lock by which that door can be opened through one lock operation. The smaller door has no external lock but is locked internally.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This invention relates to a freight container. Such containers are conventionally of generally cuboidal shape and have standard external dimensions so that they can fit in standard spaces on road, rail or sea transport vessels.  
           [0002]    Such freight containers are delivered full of goods to the recipient of those goods. In a number of situations, those goods are not all unloaded at once, and the container remains on site and is used as a temporary static storage location.  
           [0003]    Some such containers are refrigerated and contain goods which have to be held below a certain temperature. In this case, the container itself includes a refrigeration plant which will require connection to an external power supply.  
         SUMMARY OF THE INVENTION  
         [0004]    According to the present invention, there is provided a rectangular freight container having length width and height dimensions of a standard size, and two doors at one end, the doors being of the same height but with different width dimensions and extending to the floor of the container.  
           [0005]    Making the doors of different sizes means that one door can be large enough to allow access into the container with trolleys or vehicles larger than would be possible with a single door.  
           [0006]    The larger door preferably has a lock which can be unlocked by operating a single lock handle. This makes it easy for the door to be opened and closed which is a particular requirement where a container is being used as a temporary storage facility from which goods will be unloaded from time to time and where the access door has to be repeatedly opened and closed. This is especially the case with refrigerated containers which may be used for example by supermarkets to hold stock until it is needed to replenish store shelves.  
           [0007]    In a suitable embodiment, the lock can be a vertical locking bar mounted for rotation about its own axis adjacent the opening edge of the door, with keepers at the top and bottom of the door frame to receive locking tongues on the bar, and a lock handle between the ends of the bar which can be turned to rotate the bar to free the tongues from the keepers.  
           [0008]    Preferably the smaller door has locks which can only be operated from inside the container. The smaller door will generally only need to be opened when all the contents of the container are being loaded or unloaded at once, and can be left closed and locked when the larger door is opened and close for routine visits to and from the container. The locks a for the smaller door can be shoot bolts at the top and bottom corners of the inside face of the door.  
           [0009]    The larger door preferably has an internal door release mechanism, so that if the door is shut with somebody inside the container, they will be able to open the door to release themselves. The internal door release mechanism can act from inside the container on an external door release mechanism which will normally be the same lock mechanism which opens the door from outside.  
           [0010]    A security bar can be locked between the two doors to prevent operation of the single lock handle. There is a requirement for a secure lock (and a customs seal) to be available to prevent unauthorised tampering with the container contents. The security bar can be locked across the single lock handle, so that the lock handle cannot be operated until the security bar is removed.  
           [0011]    When the container is used for storage purposes, and the main door has to be regularly opened and closed, it is important that the door fits properly into its frame, especially where the container is a refrigerated container. To ensure that the frame is not distorted if the container is resting on uneven ground, the door frame is preferably reinforce to prevent any skewing.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    The invention will now be further described, by way of example, with reference to the accompanying drawings, in which:  
         [0013]    [0013]FIG. 1 is a partial perspective view of a freight container in accordance with the prior art;  
         [0014]    [0014]FIG. 2 is a rear view of a freight container in accordance with the invention;  
         [0015]    [0015]FIG. 3 is a section through the container of FIG. 2 on the lines A-A;  
         [0016]    [0016]FIG. 4 is a view, on a larger scale, of part of the section from FIG. 3, showing a door open;  
         [0017]    [0017]FIG. 5 is a detail of the door locking mechanism, shown in section;  
         [0018]    [0018]FIG. 6 shows another view of another part of the locking mechanism; and  
         [0019]    [0019]FIG. 7 shows a detail of the door seals, 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    [0020]FIG. 1 shows a conventional storage container  10  which, as is known, has standard rectangular dimensions, closed sides  16 , a closed roof  14  and a floor, and two ends. At one end there are two doors  18 ,  20 . The doors are hinged to the container frame at  22  and each door has two locking bolts  24  which can be released using operating bars  26  to allow the doors to be opened and closed.  
         [0021]    [0021]FIG. 2 shows a corresponding view of one end of a container in accordance with the invention. This container has a primary door  124  and a secondary door  125  of smaller dimensions. Both doors have hinges  122  by which they are hinged to a frame  101 . The secondary door  125  is closed by internal shoot bolts  128  which are operated from inside the container, such that when both doors are closed there is no accessible mechanism for opening the secondary door  125 .  
         [0022]    The primary door  124  has a single latch mechanism at  130 . This latch mechanism operates a vertical bar  132 . The ends of the bar are held in keepers  134  on the frame  101  when the door is closed and latched. When the latch  130  is released (by operating a handle  142 ), the bar  132  can be rotated about its own axis to release its end portions from the keepers  134 , so that the door can be opened.  
         [0023]    This latch mechanism may require a key to unlock it before the handle can be moved. A keyhole  162  can be seen in FIG. 6. The latch can however be closed without being locked, so that access by authorised personnel is not inhibited. It may also be possible to apply a separate padlock to the latch mechanism.  
         [0024]    [0024]FIG. 3, which is a section on the lines A-A from FIG. 2 also shows flexible seals  136  between the outer edges of the doors  124 ,  125  and the frame  110 , and further seals  138  where the doors  124 ,  125  meet one another. It can also be seen from FIGS. 3 and 4 that the latch  130  has a part which extends through the thickness of the door to an unlatching member  140  on the inside surface of the primary door  124 . This mechanism is shown in more detail in FIG. 5, where the main door handle accessible from outside the container is shown at  142 , shielded within a housing  144 .  
         [0025]    The internal release knob  140  is mounted at the top of a stem  146  which projects through a recess in the door and has an opposite end which abuts against the main door unlatching handle  142 . The shaft  146  projects through a saucer recess  148  on the inside of the door, and when the knob  140  is pushed fully home to the floor of the recess  148 , the pressure of the stem acting on the handle  142  will rotate the handle far enough to release the upper and lower ends of the bar  132  from their keepers  134 , so that the door can be opened from inside.  
         [0026]    [0026]FIG. 5 shows a security bar  150  which is hinged to the primary door  124  at  152 , extends across the housing  144 , and is then retained in a socket  154  on the secondary door  125 . A padlock and/or customs seal can be applied to the socket  154  to prevent the security bar  150  from being removed. Whilst in place, the security bar  150  prevents the main door handle  142  from being moved to an unlocking position.  
         [0027]    The primary door  124  also has a keeper  156  (see FIG. 2) into which the security bar  150  can be located once it is safe for the container door to be held closed just by the lock  130 .  
         [0028]    [0028]FIG. 7 shows a detail of the way in which the doors seal against one another. At the outer edges of the doors, extrusions  168   a  and  168   b  are mounted, and the extrusion  168   b  on the primary door carries an outer gasket  166  made of EPDM. The form of the extrusions  168  are such that the edge of the primary door  124  is staggered relative to the secondary door  125  which allows the primary door to be easily opened and closed. Secondary lip seals  164   a  and  164   b  are mounted in identical extrusions  170   a  and  170   b  on the container interior side of the seal  166 .  
         [0029]    The use of a single latch  130  makes it much easier for the primary door  124  to be opened and closed than is the case with a conventional container door locking arrangement. This allows the container to be used at its destination as a storage location, where personnel need and can obtain frequent access to the contents of the container. The door can easily be opened and closed without complication and without requiring undue strength. To ensure that the door can always be opened, and to ensure that the seals  136 ,  138  make effective sealing contact between the door and the frame, the frame is reinforced compared to standard freight containers. Additional strengthening will be built in on all four sides of the frame, so that the frame resists skewing which might otherwise arise should the container be set down on uneven ground, and which might hamper opening and closing of the doors.  
         [0030]    Furthermore, because the primary door  124  is wide, trolleys or barrows can be brought into the container to unload its contents.  
         [0031]    The invention is especially useful on refrigerated containers, where it is important to ensure that the door is not left open.