Abstract:
The invention relates to a transport container having a low weight. The transport container comprises a self-supporting first element ( 10 ), which is designed as an injection-molded plastic part and which has an inside ( 10   b ) and an outside ( 10   a ) and which encloses a first interior space (I 1 ), and a second element ( 30 ), which lies against the first element ( 10 ) at least in some sections and which encloses a second interior space (l 2 ). The second element ( 30 ) is arranged on the inside of the first element ( 10 ) so that the second interior space (l 2 ) lies completely within the first interior space (I 1 ).

Description:
TECHNICAL FIELD OF INVENTION 
       [0001]    The invention relates to a transport container as is disclosed in the preamble to claim  1 . 
         [0002]    In modern economic systems, the transporting of goods and especially of semi-finished products plays a central role. In particular if the goods to be transported are relatively light-weight but sensitive components, the problem frequently arises that comparatively few components to be transported must be packed into in a transport container. As a result, the weight of the transport container, meaning the tare weight, accounts for a considerable share of the total weight of the load to be transported. An increase in the transport weight leads to an increase in the energy consumption during the transport which is undesirable for reasons of economy and ecology. A high tare weight, in particular, worsens the total energy balance for each component to be transported. 
       PRIOR ART 
       [0003]    Transport containers used so far, especially for transporting sensitive goods, are for the most part designed as follows: The actual transport container is a first element that is produced as one piece with the aid of an injection-molding technique and generally also with standard dimensions, so as to be stackable. A lid is fitted onto this first element, thereby ensuring that the transport container is closed tightly, in particular sealed against dust, with the aid of the first element and the lid. A specially formed insert can be inserted into this first element, which is shaped such that the components to be transported are held securely in place and do not rub against each other or against the inside wall of the first element during the transport. 
         [0004]    A transport container is disclosed in the prior art document EP 0000824 A1 which consists of a type of grid basket with foil wrapped tightly around. A transport container of this type is intended for and is suitable for the transport of fruit. However, this transport container is not suitable for transporting technical components or sensitive technical semi-finished products. 
       SUBJECT MATTER OF THE INVENTION 
       [0005]    Starting with this premise, it is the object of the present invention to create a transport container having a low weight, in particular for technical products, components or semi-finished products. 
         [0006]    This object is solved with a transport container having the features as disclosed in claim  1 . 
         [0007]    The transport container according to the invention comprises a self-supporting first element, embodied as a plastic injection-molded part, and a second element which fits tightly against the first element, at least in some sections. For this, the second element is preferably arranged on the inside of the first element in such a way that it completely lines the inside, is thus supported by the first element, and prevents the components inside the the transport container from coming in contact with the first element. The first element consequently takes over exclusively the mechanical supporting function and can advantageously be embodied so as to be stackable. As a rule, the second element together with a lid that rests directly on the second element when it is closed, ensures that the parts to be transported are sealed in and, in particular, are protected against dust and spraying water. 
         [0008]    A separation therefore occurs between the tasks of sealing in, meaning the protection against environmental influences, and the mechanical stability. The weight of the individual components, that is to say of the first element and the second element, can thus be optimized with respect to the respective task to be met. 
         [0009]    The first element in particular can thus be embodied as a plastic injection-molded part with openings, so that the first element has a grid-type structure. Owing to the aforementioned openings, meaning the missing material, no mechanical stability is lost if the geometry is selected carefully, but a considerably savings in weight can be achieved. 
         [0010]    The second element only needs to have a very low mechanical stability so that it can be embodied with extremely thin walls, in particular in the form of a deep drawn or thermoformed plastic part. The weight of the second element can be very low, as compared to the first element, so that the savings in weight which can be achieved for the first element is not compensated for by the existence of the second element. 
         [0011]    In addition to the pure savings in weight, the design of the transport container in the form of two shells with an outside part and an inside part has another considerably advantage, especially if the second element is a deep drawn plastic part. As compared to the production of an injection-molded part, producing a deep drawn part is considerably simpler and noticeably cheaper. The actual production process for a deep drawn part is furthermore considerably easier as compared to the production of an injection-molded part. Thus, it makes economic sense to produce relatively small numbers of the second elements, so as to adapt these to the goods to be transported. The first elements, on the other hand, are advantageously produced in identical large piece numbers, so that they can be used for a plurality of different goods to be transported with respectively a different second element inserted therein. 
         [0012]    A further advantage is that the raw material expenditure and the energy expenditure for producing the second element is noticeably lower than the raw material and energy expenditure for producing the first element, so that even if a second element has only a relatively short service life, whether that is due to wear and tear or because the dimensions change for the parts to be transported, the energy balance for the complete transport container remains very favorable because of the long service life of the first element. 
         [0013]    The total energy balance of the transport container according to the invention is therefore advantageous with respect to its production as well as its operation which, of course, also has a positive effect on the total energy balance of the transported components. 
         [0014]    The container is particularly suitable for transporting enclosed volumes ranging from 20 to 100 liters. 
         [0015]    The invention will now be explained in further detail with the aid of an exemplary embodiment and with reference to the Figures, wherein these show in: 
     
    
     
       SHORT DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  A perspective representation the three components of a transport container, namely a first element, a second element, and a lid; 
           [0017]      FIG. 2  A first element and a second element according to  FIG. 1 , in the assembled state; 
           [0018]      FIG. 3  The same elements as shown in  FIG. 2 , but with the lid fitted on; 
           [0019]      FIG. 4  The lid according to  FIG. 1  as seen from a different viewing direction; 
           [0020]      FIG. 5  Two transport containers, one stacked above the other; 
           [0021]      FIG. 6  A cross-sectional view of the elements shown in  FIG. 1 ; 
           [0022]      FIG. 7  A cross-sectional view of the elements shown in  FIG. 3 , corresponding to  FIG. 6 ; 
           [0023]      FIG. 8  The elements from  FIG. 1  in a cross-sectional, perspective view 
           [0024]      FIG. 9  A three-dimensional view of a detail of the transport container from  FIG. 3 ; and 
           [0025]      FIG. 10  Another three-dimensional view of a detail of the transport container shown in  FIG. 3 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]    The Figure shows the three elements of a transport container. These three elements are the first element  10 , the second element  30  and the lid  50 . The first element  10  is a plastic injection-molded part with four side walls  12   a,    12   b,    12   c,    12   d  and a bottom  14 . The side walls  12   a  to  12   d  and the bottom  14  enclose an inside space l 1  which typically encloses a volume between 20 and 100 liters. The side walls  12   a  to  12   d  as well as the bottom  14  are configured in the manner of a lattice or grid, with ribs  16  and openings  18  in-between. The wall strength of the ribs typically ranges from 1.5 to 2.5 mm. To increase the stability, some of the ribs, in particular the ribs for the side walls  12   a  to  12   d,  can have a U-shaped cross section. The side walls  12   a  to  12   d  end in a circumferential top edge  20  which, as will be obvious later on, comprises a horizontal section and a downward pointing section. 
         [0027]    The second element  30  is a deep drawn plastic part which also comprises four side walls  32   a  to  32   d  and a bottom  34 . The wall thickness of this deep drawn plastic part typically ranges from 0.2 to 0.8 mm. The outside dimensions of the side walls  32   a  to  32   d  essentially correspond to the inside dimensions of the side walls  12   a  of the first element, so that the second element  30  can be inserted into the inside space l 1  of the first element and completely lines the inside, as will be seen in more detail later on. The volume of the second inside space l 2  which is enclosed by the second element is slightly smaller than the volume of the first inside space l 1 , wherein the volume of the second inside space preferably amounts to at least 95% of the volume of the first inside space. The second inside element  30  also comprises an edge  40  around the top, with a horizontal section and a downward-pointing section (see also in particular  FIG. 9 ). Holding structures  36  are formed onto the bottom  34  of the second element  30 . 
         [0028]    The lid  50  is preferably also a deep drawn plastic part and, in the same way as the bottom  34  of the second element  30 , is provided with holding structures  52 , as can be seen in particular in  FIG. 4 . The lid  50  has a circumferential edge  54 . 
         [0029]      FIG. 2  shows the first element  10  and the second element  30  from  FIG. 1 , wherein the second element  30  is inserted into the first element  10 . Owing to the thin-wall design for the second element  30 , it is possible to see the ribs  16  of the bottom  14  of the first element  10 , as indicated. It follows from  FIG. 2  that the usable inside space is barely reduced since the second inside space l 2  which is enclosed by the second element  30  essentially encloses the same volume as the inside space l 1  of the first element  10 . 
         [0030]      FIG. 3  shows the elements according to  FIG. 2 , but with the lid  50  fitted on. 
         [0031]    As previously mentioned,  FIG. 4  shows a view of the lid  50  in which the holding structures  52  of the lid  50  are visible. 
         [0032]      FIG. 5  shows two transport containers  5 , one stacked on top of the other. 
         [0033]      FIGS. 6 to 8  again show the elements from  FIGS. 1 and 3 , but in a cross-sectional view. It follows in particular from  FIGS. 7 and 8  that the second element completely lines the inside of the first element and that the second element fits tightly or at least nearly tightly against the first element. A certain spacing in the region of the side walls is generally possible. The bottom of the second element as a rule rests on the bottom of the first element, so that forces which are exerted onto the second element are introduced directly into the bottom of the first element. This is necessary since the second element has only a slight mechanical stability. 
         [0034]    The design of the top edge  20  on the first element, the design of the top edge  40  on the second element  30  and the design of the edge  54  on the lid  50 , as well as the positions relative to each other are explained in the following with reference to  FIG. 9 . It is obvious that the top edge  20  on the first element  10  comprises a horizontal section  20  [sic] and a downward pointing section  24 . The top edge  40  of the second element  30  is designed in the same way, namely with a horizontal section  42  and a downward pointing section  44 . For this, the top edge  40  of the second element  30  encompasses the top edge  20  of the first element  10  and fits tightly against it, at least in some sections. The position of the second element  30  relative to the first element  10  is thus completely determined. 
         [0035]    In the closed state, the edge  54  on the lid  50  rests exclusively on the top edge  40 , in this case on the horizontal section  42  of the second element  30 . That is to say, the parts are enclosed exclusively by the second element  30  and the lid  50 . The first element does not contribute to enclosing the transported parts. 
         [0036]    It follows from  FIG. 10  that the bottom  34  of the second element  30  rests in some sections on the bottom  14  of the first element  10 . From  FIGS. 9 and 10  we can easily see the different wall thicknesses of the first element  10  and the second element  30 . 
         [0037]    A further advantage of the above-described exemplary embodiment is that the second element  30  is composed of a translucent plastic. Owing to the openings  18  in the side walls of the first element  10 , it is possible to look into each transport container to check the content if the second element is also made of a translucent plastic, even if the containers are stacked and closed. As a result, many faulty shipments an thus be prevented (for example transport containers that are not emptied or not completely emptied). It also makes sense in that case if the lid  50  is produced of a translucent plastic, so that the content of a transport container can be checked from every viewing angle. Suitable materials for producing a translucent second element/a translucent lid can include PVC, PPT, PC (polycarbonate), PE (polyethylene) and PS. 
         [0038]    In particular if the second element is produced from a translucent material, a transport box of this type is not only suitable for transporting but also for storing objects, in particular also in the household area. 
         [0039]    It is understood that the first element  10 , the second element  20  [sic] and the lid  50  for the preferred embodiment shown herein are produced as one-piece elements. 
       REFERENCE NUMBER LIST 
       [0000]    
       
           10  first element 
           10   a  outside 
           10   b  inside 
           12   a - d  side walls 
           14  bottom 
           16  rib 
           18  opening 
           20  top edge 
           22  horizontal section 
           24  downward pointing section 
           30  second element 
           32   a - d  side wall 
           34  bottom 
           36  holding structure 
           40  top edge 
           42  horizontal section 
           44  downward pointing section 
           50  lid 
           52  holding structure 
           54  edge 
           56  horizontal section 
           58  downward pointing section 
         l 1  first inside space 
         l 2  second inside space