Patent Publication Number: US-2003230573-A1

Title: Air freight container

Description:
[0001] The present invention relates to a cargo container for the transportation of goods, in particular an air freight container being adapted for use on air crafts, including a top, bottom and sides with one or more openings for loading and unloading, each opening being provided with a closing and load supporting closure in the form of pivot gate door, or a fabric material preferably with cables or reinforcing members, the closure in turn, at its outer (lower) end being provided with a device for tensioning and locking the closure.  
       [0002] Cargo containers of the above kind are previously known and used in large numbers in connection with the transportation of goods on air crafts world wide. U.S. Pat. No. 4,538,663 shows a cargo container where the closure is provided with a locking and tensioning means in the form of an elongate bar attached to the lower end of the fabric material, and where the elongate bar at either end is supplied with a pin for engaging complimentary hook means attached to the cargo container on either side of the opening. Briefly explained the closing and tensioning of the material by an operator is accomplished by firstly moving the elongate bar with its pins in engagement with the hook means and thereafter rotating the bar around the pin ends in the hook means such that the material is pulled taut. Under rotation the elongate bar passes a point of balance and is held in place in an over balance point position. However, to retain the elongate bar in a secure, locked state, extra safety locks are required.  
       [0003] One disadvantage with this known solution is that an operator, when closing (and vice versa opening) the closure, in most cases would need to use both hands to pull down the closure, rotating the elongate bar and securing it with the locking means.  
       [0004] Another disadvantage is that the known solution only can be used on flexible, material type of closures, since the elongate bar needs to be rotated (pivot type closures cannot be rotated).  
       [0005] A third and cumbersome disadvantage is that the known solution only can be used on small (narrow)  
       [0006] closures since the elongate bar is attached to hooks on the container at its ends. There is no support  
       [0007] in between.  
       [0008] With the present invention is provided an improved and simple tensioning and locking means for container closures and doors which is not encumbered with the above disadvantages, but which is cheap to produce and which can be operated by an operator by one hand and which in one step is tensioning and locking the closure in a safe position.  
       [0009] The invention is characterised in that the tensioning and locking device includes a drive mechanism for linear movement of at least two tensioning and locking studs provided at each end of the elongate member, each stud having an inclined party and fitting into counter tensioning and locking elements provided on the corner post of the container opening, and that the drive mechanism is operated by a handle whereby the studs are moved in the axial, outward direction of the elongate member such that by interaction of the inclined parties of the studs against the counter tensioning and locking elements the elongate member is moved downwards and the closure is pulled tout and locked, as defined in the attached claim 1.  
       [0010] The subordinate claims 2-7 define preferred embodiments of the invention. 
     
    
    
     [0011] The invention will be further described in the following by means of examples and with reference to the drawings in which:  
     [0012]FIG. 1 a ) is a side view and  b ) is an end view of an aircraft container with a flexible, material type closure being provided with a tensioning and locking device according to the invention,  
     [0013]FIG. 2 a ) shows in larger scale, partly in longitudinal cross section, the tensioning and locking device according to the invention in an open position, FIG. 2 b ) shows the same device in a closed position FIG. 2 c ) shows a top a sectional view of the device in position  2   a ),  2   e ) shows a sectional view along line A-A in  2   b ) and  2   f ) shows a cross section of the device along line B-B in FIG. 2 b ).  
     [0014]FIG. 3 shows in still larger scale a side view a) top view b) and c) cross section along line A-A of an elongate locking member shown in FIG. 2. 
    
    
     [0015]FIG. 1 shows as stated above a side view a) and end view b) (seen from the left hand side in FIG. 1 a )) of a cargo container  1  for transporting cargo on air crafts. The container may preferably be constructed of aluminium, including a frame construction of extruded aluminium members being claded with aluminium plates (not further shown) to obtain low weight. The end of the container as shown in FIG. 1 b ) is provided with an opening which may be closed with a closure  2 , e.g. of fabric material. It is required that the closure  2  should have sufficient strength and sideways rigidity to withstand sideways and vertical forces acting on the container in connection with lifting and transportation. It is further required that the closure, in its closed position, does not enable unauthorised persons to get access to the container through the closure or between the sides of the closures and the side posts (structural side members) of the opening. The fabric material is therefore provided with vertical cables  3  and preferably diagonally (in criss-cross fashion) embedded enforcement (not further shown). The upper end of the fabric material  2  is attached to an upper horizontal post (structural member of extruded aluminium) or preferably spring loaded roller mechanism (not further shown) on which it may be wound up in its open position, whereas the lower end of the fabric material is attached to an elongate bar  4  which is further shown in FIG. 2 e ). More precisely, the lower end of the fabric material, as seen in FIG. 2 e ), is through an elongate expansion  5  retained in a complimentary recess  6  of an elongate upwardly protruding plate member  10  attached to the elongate bar  4  which is hollow and may have a square cross section. Attached to the elongate plate  10  are further two cable adjusting devices  7  for adjusting the cables  3  on the side ends of the fabric material.  
     [0016] The tensioning and locking device according to the invention will now be further described with reference to FIGS. 2 and 3.  
     [0017] It forms partly an integral part of the elongate bar  4  by being provided in the hollow space of the bar, including two elongate tensioning and locking rods  8  extending in opposite direction from a manually operable drive mechanism  9  towards the ends of the elongate bar  4 , and partly, in operational relationship, counter tensioning and locking elements  11  provided on the corner posts  12  (see FIG. 1 b ), FIGS. 2 a ),  b ),  c ) and  d ) of the container. Tensioning studs  13  are attached to the respective ends of the elongate rods  8  protruding partly outside the ends of the elongate bar  4 . The studs  13  are designed with a narrow outer end  14  passing on to an inclining, rounded party  15  and further to an elevated party  16 .  
     [0018] The elongate rods  8  are axially movable in opposite direction by means of the manually operable handle  17  via the drive mechanism  9 , which may be any kind of double sided mechanism transferring rotational movement to linear movement, such as a double sided pivot arm or gear rod mechanism.  
     [0019] The counter tensioning and locking elements  11  are formed of a hollow box profiles  18  attached to said corner posts  12  and are provided with an opening or recess  19  outwards and towards the studs  13 . The recesses  19  have a width and height being sufficient to receive the studs  13 . Inside each box profile  18 , above the recess  19  is provided a roller  20 .  
     [0020] In operation the mechanism, when closing the closure, function as follows: An operator places, by holding the handle  17  with one hand, the elongate member  4  with the tensioning and locking mechanism into its closing position as shown in FIG. 2 a ) where the studs  13  on each side fits into the recesses  19  and rest against the rollers  20 . The fabric material is now held in a stretched state covering the end opening of the container. By now turning the handle in the direction of the arrow  21  the rods  8  with the studs  13  move axially outwards, whereby the elongate member will be forced downwards as the inclined party  15  of the studs  13  by the travelling along the rollers  20  will cause such movement  
     [0021] The radius of the inclined party  15  is selected such that the force required to turn the handle  17  is optimally low over the total travelling of the studs  13 .  
     [0022] The tensioning and locking device is now in a locked position as shown in FIG. 2 b ) and the fabric material is held tout. Further the studs in the locked position have passed beyond (outwards) the edge of the recess  19 , whereby in addition the studs  13  and thereby the elongate member  4  is held securely in place, being prevented from falling out of or pulled out by accident.  
     [0023] To detention and unlock the elongate member  4 , it will be apparent from the above explanation that the handle needs to be turned in the opposite direction as indicated by the arrow  22  in FIG. 2 b ).  
     [0024] With the present invention is provided a tensioning and locking device that may be operated by an operator with one hand and in one sequence.  
     [0025] The invention as defined in the claims may further, beyond the example as shown in the drawings and described above where fabric material is applied, be used for other types of closures or doors that requires tensioning, such as articulated doors etc.  
     [0026] In a preferred embodiment the invention may also be used on larger closures as additional studs  13  may be provided on the bottom side of the rod  8  and through a structural arrangement being designed to fit in to openings with corresponding roller  20  attached to the bottom end post of the container.