Abstract:
The invention provides a packing method using pulp mold which can be easily disposed of and recycled, and which has high mechanical strength. A packing method, wherein a top pad  1,  with a recess and a protrusion, and a bottom pad, with a recess and a protrusion, are positioned so as to oppose each other in order to accommodate a delicate item to be protected therebetween. A reinforcing pad, with a protrusion which is brought into contact with the bottom pad, is also used.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of Invention  
           [0002]    The present invention relates to a packing method, and package within which an item is packed.  
           [0003]    2. Description of Related Art  
           [0004]    A packing method using two pads is disclosed in, for example, Japanese Unexamined Utility Model Publication No. 5-7662. As illustrated in FIG. 2 of this document, the protrusion  6   a  is formed so that it can come into contact with a packaging box  10  such as a corrugated cardboard box. In this case, it is true that packing strength is ensured, but shock tends to be transmitted to the packed item, which is particularly not desirable when packing electronic devices such as optical devices or precision instruments.  
         SUMMARY OF THE INVENTION  
         [0005]    Accordingly, the present invention provides a packing method which can overcome the above-described problem present in conventional packing methods, and which allows the use of materials which can be recycled.  
           [0006]    There is provided a method of packing an item such that the item is accommodated between a first pad, with a plurality of protrusions and a plurality of recesses, and a second pad, with a plurality of protrusions and a plurality of recesses, wherein a third pad, with a protrusion which can come into contact with at least one of the plurality of recesses of the second pad, is disposed opposite to the first pad with reference to the second pad.  
           [0007]    When the protrusion of the third pad is disposed so that it comes into contact with the recess or recesses of the second pad, at least one of the recesses of the second pad does not come into direct contact with the packaging box in which the item is accommodated, and the protrusion of the third pad and the recesses of the second pad can absorb shock to reduce the amount of shock exerted on the packed item compared to that exerted on items packed in conventional packaging boxes.  
           [0008]    The protrusion of the third pad may be disposed such that the longitudinal direction thereof is substantially perpendicular to the longitudinal direction of the recesses of the second pad.  
           [0009]    When the protrusion is positioned substantially perpendicular to the recesses, instead of in the same direction as the recesses, the area of the protrusion of the third pad which receives the load of the recess or recesses of the second pad becomes narrower, making it possible to ensure deformation of the pads by the required amount. Making the protrusion of the third pad long in the longitudinal direction is more effective in ensuring the required deformation.  
           [0010]    The recesses of the second pad may be tapered, and the protrusion of the third pad may be tapered. Tapers make it harder for shock to reach the packed item. The depth of the recesses of the second pad may be substantially equal in value to the height of the protrusion of the third pad. When the depth is made substantially equal in value to the height, it is possible to ensure deformation of the pads by the required amount, thereby increasing the shock absorbing capability of the pads. The pads may be formed of pulp mold or recycled pulp mold. Paper pulp, instead of the conventionally and generally used petroleum chemicals, may be used, thereby facilitating recycling. The use of very firm, recycled pulp, instead of virgin pulp, results in increased pad strength. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a perspective view of the pads and the packaging box (corrugated cardboard box), used to illustrate the present invention;  
         [0012]    [0012]FIG. 2 is a perspective view of the pads and the electronic device, used to illustrate the present invention;  
         [0013]    [0013]FIG. 3 is a sectional view of the pads within which an item is packed;  
         [0014]    [0014]FIG. 4 is a perspective view of the top pad;  
         [0015]    [0015]FIG. 5 is a perspective view of the bottom pad;  
         [0016]    [0016]FIG. 6 is a perspective view of the reinforcing pad;  
         [0017]    [0017]FIG. 7 is a plan view of the bottom pad;  
         [0018]    [0018]FIG. 8 is a plan view of the reinforcing pad;  
         [0019]    FIGS.  9 ( a ) and  9 ( b ) are horizontal sectional views of the protrusions provided at the corners of the top and bottom pads;  
         [0020]    [0020]FIG. 10 is a sectional view of pads, whose forms are different from those of the pads of FIG. 3, within which an item is packed;  
         [0021]    [0021]FIG. 11 illustrates an integral structure of the bottom pad  20  and the reinforcing pad  30 ;  
         [0022]    [0022]FIG. 12 is a sectional view of the integral structure of the bottom pad and the reinforcing pad; and  
         [0023]    [0023]FIG. 13 illustrates another integral structure of the bottom pad  20  and the reinforcing pad  30 . 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0024]    A description will now be given of the invention applied to the packing of an electronic device, with reference to the drawings.  
         [0025]    As shown in FIGS.  1  to  3 , an electronic device (projector), being an item  40  to be packed, is packed by placing a top pad  10  and a bottom pad  20  upon each other so that the protrusions  11  of the top pad  10  and the protrusions  21  of the bottom pad  20  come into contact. As shown in FIGS. 2 and 3, the item  40  is accommodated in the space between the protrusions  11  of the top pad  10  and the protrusions  21  of the bottom pad  20 . FIG. 3 is a horizontal sectional view of the center portion where the top pad  10  and the bottom pad  20  are placed upon each other.  
         [0026]    The portions of the top pad  10  which come into contact with the top planar surface of the item  40  are called flat portions  14 , while the portions of the bottom pad  20  which come into contact with the bottom planar surface of the item  40  are called flat portions  24 ; and the portions of the top pad  10  which extend from their respective flat portions  14  and which are spaced from the item  40  are called recesses  12 , while the portions of the bottom pad  20  which extend from their respective flat portions  24  and which are spaced from the item  40  are called recesses  22 . Skirts  13  and  23 , provided at the lower portions of their respective protrusions  11  and  21 , are formed continuously along the outer periphery of the pads  10  and  20 , resulting in increased strength of the respective pads  10  and  20 . Ordinarily, the item  40 , which has been packed using the top and bottom pads  10  and  20 , are accommodated in a packaging box  60 , such as a corrugated cardboard box, along with an additional box  70 , and then shipped or stored. In FIG. 1, reference numerals  8  and  9  denote corrugated cardboard holding plates.  
         [0027]    When the item  40 , accommodated in the packaging box  60 , is dropped with the bottom surface (the bottom pad  20  side) of the packing item  40  faced downward, and is subjected to external shock, the weight of the item  40  is transmitted to the bottom pad  20  primarily through the flat portions  24 . In this case, the recesses  22  of the bottom pad  20 , and the skirt  23  below the protrusions  21  get deformed in order to prevent transmission of shock, produced when the packaging box  60  is dropped, to the item  40 . Accordingly, they act as shock absorbers. When the pads are formed of pulp mold, or when the item  40  is relatively heavy, the respective pads may break. A possible solution to this problem is to strengthen the pads by forming the protrusions  21  and the recesses  22  without tapers so that their wall surfaces are perpendicular to their respective flat portions  24 . However, when the protrusions  21  and the recesses  22  are formed in this manner, the pads tend to resist getting deformed, causing transmission of shock to the item  40 , and in worst cases breakage of the item  40 .  
         [0028]    Therefore, the protrusions  21  and the recesses  22  are formed with tapers so that they are deformed easily, thereby making it difficult for shock to reach the item  40 . In addition, a reinforcing pad  30 , with protrusions  31  formed at locations which allow them to come into contact with the recesses  22  of the bottom pad  20 , is placed between the packaging box  60  and the bottom pad  20  so that shock, produced when the packaging box  60  is dropped, is absorbed by the protrusions  31 .  
         [0029]    The number and size of the protrusions  31  of the reinforcing pad  30  are determined based on the material of the pads  10 ,  20 , and  30 , and the weight of the packing item  40 . When the recesses  22  have substantially a rectangular shape when viewed in a plane, it is preferable that the protrusions  31  be positioned at substantially right angles to the recesses  22 , as shown in FIGS.  1  to  3  and  8 , rather than being formed into the same shape as the recesses  22  and being positioned so as to overlap the recesses  22 . In the latter case, the protrusions  31  and the recesses  22  become more rigid, so that shock tends to be transmitted to the item  40 . In the former case, as shown in FIGS. 3 and 8, the load of each recess  22  is received by a narrow portion of its associated protrusion  31 , so that compared to the latter case the protrusions  31  and the recesses  22  become less rigid, thereby reducing the amount of shock. Here, when the depth of each recess  22  (as measured from its associated flat portion  24 ) and the height of each protrusion  31  (as measured from its associated flat portion  24 ) are made substantially the same in value, they can be deformed by the greatest amount possible, thereby increasing their capability to function as shock-absorbers.  
         [0030]    A description will now be given in more detail of the protrusions, the flat portions, and the recesses of the top and bottom pads  10  and  20 , and the protrusions of the reinforcing pad  30 , with reference to FIGS.  4  to  8 .  
         [0031]    The top and bottom pads  10  and  20  are rectangular in shape when viewed in a plane, with protrusions  11  and  21  being formed so as to be disposed at predetermined intervals along the side edges of their respective top and bottom pads  10  and  20 .  
         [0032]    As shown in FIGS. 5 and 7, flat portions  24  ( 24   a  to  24   i ) are formed inwardly of the protrusions  21  of the bottom pad  20 , substantially in correspondence with their respective protrusions  21  and so as to be surrounded by the protrusions  21 ; and as shown in FIG. 4, flat portions  14  ( 14   c,    14   d,    14   e,    14   f,    14   h,  and  14   i ) are formed inwardly of the protrusions  11  of the top pad  10 , substantially in correspondence with their respective protrusions  11  and so as to be surrounded by the protrusions  11 .  
         [0033]    In the bottom pad  20 , recesses  22  ( 22   a  to  22   i ) are formed between their respective flat portions  24  and their respective protrusions  21 , with a shallow recess  22   j,  being rectangular when viewed in a plane, being formed at the center of the bottom pad  20 .  
         [0034]    The recesses  22  ( 22   a  to  22   i ), which are formed between their respective flat portions  24  ( 24   a  to  24   i ) and their respective protrusions  21  so as to protrude downward, form ribs which extend along the side edges of the pad  20 . The ribs make the entire bottom pad  20  more rigid and thus more resistant to deformation.  
         [0035]    Reference numeral  26  (or reference numerals  26   a  and  26   b ) denote deep recesses, or legs, disposed along the locations where the recesses  22 , or ribs  22 , are formed, with the amount by which they protrude downward being substantially the same in value as the height of the skirt  23 .  
         [0036]    More specifically, the amount by which the respective recesses  26   a,  disposed near the corners of the bottom pad  20 , protrude downward is equal in value to the height of the skirt  23 , so that when the bottom pad  20  is placed upon the reinforcing pad  30 , the recesses  26   a  come into contact with the flat portion  34  of the reinforcing pad  30 , and cooperate with the skirt  23  to support the weight of the item  40 .  
         [0037]    The amount by which the pair of recesses  26   b,  disposed at substantially the center of the long side of the bottom pad  20 , is slightly less in value than the height of the skirt  23  (or the amount by which the recesses  26   a  protrude downward), so that when the bottom pad  20  is placed upon the reinforcing pad  30 , the recesses  26   b  are located slightly above the flat portion  34  of the reinforcing pad  30 . Therefore, although, unlike the recesses  26   a,  the recesses  26   b  do not directly support the weight of the item  40 , they cooperate with the skirt  23  and the recesses  26   a  to absorb the shock produced when the packaging box  60 , in which the item  40  is accommodated, is dropped with the bottom pad  20  facing downward.  
         [0038]    Similarly with the bottom pad  20 , in the top pad  10  shown in FIG. 4, protrusions  12  are formed between the protrusions  11  and the corresponding flat portions  14 , and form ribs which make the entire top pad  10  more rigid. Deep recesses  16  ( 16   a  and  16   b ), or legs, having a depth substantially equal in value to the height of the skirt  13 , are formed in correspondence with the deep recesses  26  of the bottom pad  20  in the vertical direction.  
         [0039]    A plurality of protrusions  31  ( 31   a  to  31   e,    31   h,  and  31   i ) are formed on the flat portion  34  of the bottom surface of the reinforcing pad  30 , being rectangular in shape when viewed in a plane like the top and bottom pads  10  and  20 , so as to protrude from the flat portion  34 . The protrusions  31   a,    31   b,    31   c,    31   d,    31   e,    31   h,  and  31   i  are formed in correspondence with the recesses, or ribs,  22   a,    22   b,    22   c,    22   d,    22   e,    22   h,  and  22   i  of the bottom pad  20 , while the pair of protrusions  31   j  and  31   j  at the center of the flat portion  34  are formed in correspondence with the shallow, center recess  22   j  of the bottom pad  20 . When the bottom pad  20  is placed upon the reinforcing pad  30 , the recesses  22   a ,  22   b,    22   c,    22   d,    22   e,    22   h,    22   i,  and  22   j  of the bottom pad  20  are, as indicated by phantom lines in FIG. 8, positioned so as to be in contact with their respective protrusions  31   a ,  31   b,    31   c,    31   d,    31   e,    31   h,    31   i,  and  31   j  of the reinforcing pad  30 .  
         [0040]    The respective recesses  22  of the bottom pad  20  and the respective protrusions  31  of the reinforcing pad  30  are brought into contact with each other such that the longitudinal direction of the recesses is substantially perpendicular to that of their respective protrusions. The recesses  22  of the bottom pad  20  and the protrusions  31  of the reinforcing pad  30  cooperate with the skirt  23  and the deep recesses  26  of the bottom pad  20  to support the weight of the item  40  and to act as shock absorbers for absorbing the shock produced by the item  40  which has been dropped.  
         [0041]    Reference numeral  36  denotes a rib extending primarily along the side edges of the reinforcing pad  30 , and acts to increase the rigidity, and thus, to reduce warpage of the entire reinforcing pad  30 . Reference numeral  38  denotes an arrow formed between the protrusion  31   a  and the protrusion  31   b,  and is provided on the reinforcing pad  30  to indicate the positioning of the projecting lens of a projector  40 .  
         [0042]    Reference numeral  21   c   1  in FIGS. 5 and 7 denotes curved accommodating faces for accommodating the projecting lens of a projector  40 . The accommodating faces correspond to the opposing side faces of the protrusions  21  c provided at substantially the center of a short side of the bottom pad  20 . As shown in FIGS. 1, 2, and  7 , the projector  40  is accommodated in the packaging box  60  by, in general, packing it within the top and bottom pads  10  and  20  such that the projecting lens  42  faces the additional box  70 . Prior to accommodating the projector  40 , it is necessary to accommodate the reinforcing pad  30  in the packaging box  60 . One cannot tell which of the short sides is the projecting lens positioning side (or additional box  70  accommodating side) by just looking at the reinforcing pad  30 . To overcome this problem, the arrow mark  38  is provided on the reinforcing pad  30  to indicate which of the short sides is the projecting lens positioning side, making it possible to prevent the reinforcing pad  30  from being accidentally placed in the packaging box  60  when its projecting lens positioning side is not facing the additional box  70 .  
         [0043]    As shown in FIG. 9( a ), the protrusions  11   a,  provided at the corners of one of the short sides of the top pad  10 , and the protrusions  21   a,  provided at the corners of one of the short sides of the bottom pad  20 , are formed into a simple, substantially L shape when viewed in a plane; and as shown in FIG. 9( b ) the protrusions  11   b,  provided at the corners of the other short side of the top pad  10 , each have vertical grooves  19  at side surfaces thereof, and the protrusions  21   b,  provided at the corners of the other short side of the bottom pad  20 , each have vertical grooves  29  at side surfaces thereof, so that the protrusions  11   b  and  21   b  have a complicated, odd shape when viewed in a plane.  
         [0044]    Since the additional box  70  is accommodated adjacent to the protrusions  1  la of the pad  10  and the protrusions  21   a  of the pad  20 , the impact force, which acts, as indicated by arrows P 1  in FIG. 7, on the corners where the protrusions  11   a  and  21   a  adjacent to the packaging box  60  are formed, is absorbed by the additional box  70 , thereby reducing the amount of impact force acting on the protrusions  11   a  and  21   a.    
         [0045]    Accordingly, the protrusions  11   a  and  21   a  are formed into a simple, substantially L shape, so that they are not very rigid, and thus can absorb as much small impact forces as possible, thereby not allowing the impact forces to reach the item  40 .  
         [0046]    Unlike the protrusions  11   a  and  21   a,  the protrusions  11   b  of the pad  10  and the protrusions  21   b  of the pad  20  are formed close to corners of the packaging box  60 . Therefore, the impact force, acting on the corners where the protrusions  11   b  and  21   b  in the packaging box  60  are formed, act directly on the protrusions  11   b  and  21   b,  as shown by arrows P 2  of FIG. 7.  
         [0047]    Therefore, the protrusions  11   b  and  21   b  are formed into a complicated, odd shape, with the transverse sectional area (horizontal sectional area) of the walls where the protrusions  11   b  and  21   b  are formed being large. Although this makes the protrusions  11   b  and  21   b  more rigid, making it easier for small impact forces to be transmitted thereto, this makes them harder to break, making it possible to protect the item  40  from large impact forces.  
         [0048]    Marks (not shown) are provided at the inside center portion of the top and bottom pads  10  and  20  in order to allow anyone to identify pads. The marks can eliminate the problem of a user placing the top pad  10  at the bottom and the bottom pad  20  at the top.  
         [0049]    [0049]FIG. 10 illustrates the pads used in another embodiment of the present invention, and corresponds to FIG. 3 illustrating the pads used in the first embodiment of the present invention. The difference between the pads of FIGS. 3 and 10 is that the pads of FIG. 10 do not have flat portions  14  between their respective protrusions  11  and their respective recesses  12  and between their respective protrusions  21  and their respective recesses  22 . In both cases, the longitudinal direction (or horizontal direction along the plane of FIG. 10) of the protrusions  31  is substantially perpendicular to the longitudinal direction (vertical direction along the plane of FIG. 10) of their respective recesses  22 .  
         [0050]    [0050]FIG. 11 illustrates the bottom pad  20  and the reinforcing pad  30  formed into an integral structure, in which the reinforcing pad  30  is formed by cutting out the center portion of the reinforcing pad  30  shown in FIG. 3, and the resulting portions of the reinforcing pad  30  are joined to the ends of the bottom pad  20  through hinges  50 . When this type of integral structure is used, it is possible to use fewer parts.  
         [0051]    More specifically, as shown in FIG. 12, the bottom pad and the reinforcing pad, which are formed continuously through the hinges  50  at the outer sides of the bottom pad  20 , are molded into an integral structure. When, as indicated by the phantom lines in FIG. 12, the portions, formed by cutting, of the reinforcing pad  30  are bent inwards at the locations where the hinges  50  are formed, the integral structure takes the form shown in FIG. 11.  
         [0052]    The hinges  50  may have a thin-walled structure, as shown in FIG. 12, or a structure containing perforations formed at a predetermined pitch.  
         [0053]    Like the structure illustrated in FIG. 11, the structure shown in FIG. 13 is an integral structure of the bottom pad  20  and the reinforcing pad  30 , wherein tongue-shaped areas  38 , surrounded by a slit  39  with a U shape when viewed in a plane, are formed in the bottom surface wall of the bottom pad  20 . When the tongue-shaped areas  38  are bent, as indicated by phantom lines in FIG. 13, at their respective hinges  50 , a structure is formed, which can support the recesses  22  of the bottom pad  20  by their respective protrusions  31  of the reinforcing pad  30  as the tongue-shaped areas  38 , from below the recesses  22 .  
         [0054]    Although engineering plastics such as polypropylene (PP) or polyethylene teraphtalate (PET), may be used as pad material in the above-described embodiments, it is preferable, from the point of view of environmental protection, to use pulp mold which can be easily recycled or disposed of. In order to increase pad strength, it is preferable to use pulp mold composed of recycled pulp rather than virgin pulp.  
         [0055]    In the above-described embodiments, a structure in which a reinforcing pad is placed between the bottom pad and the packaging box has been given as an example. However, when necessary, a structure may be used, in which a reinforcing pad is placed between the top pad and the packaging box such that the recesses of the top pad and the protrusions of the reinforcing pad similarly come into contact with each other. This structure is effective when the packaging box is placed with its top and bottom sides reversed, or when the top pad is dropped with the top pad facing downward.