Abstract:
The cushioning material is assembled by: bending a single sheet, which comprises a bottom sheet, a first side sheet, a second side sheet, and an upper sheet, into a rectangular cylinder shape and inserting second flaps and an interlocking sheet in an insertion hole of a middle sheet; bending each first flap away from the first side sheet and bending the middle sheet towards the first side sheet to fit together second interlocking grooves with first interlocking grooves; bending the interlocking sheet to be roughly perpendicular to the upper sheet and bending the second flaps to be roughly perpendicular to the interlocking sheet to engage interlocking sections with the first flaps.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a national stage of International Application No. PCT/JP2014/076655, filed Oct. 6, 2014, which claims the benefit of Japanese Application No. 2013-222095, filed Oct. 25, 2013, in the Japanese Patent Office, the disclosures of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention relates to a cushioning material constructed by folding a single sheet, and to a package using such a cushioning material. 
     BACKGROUND ART 
     Conventionally, when an electronic appliance or the like is packed, it is common to place, in a cardboard case, a cushioning material for absorbing impact and vibration from outside during transport and place a product (article to be packed) on the cushioning material such that the to-be-cushioned surface of the product rests on the product placement surface of the cushioning material. As one type of such cushioning materials, there are known those which are constructed by folding a single cardboard sheet into a predetermined shape. 
     For example, Patent Document 1 identified below discloses, as a cushioning material that is constructed by folding a single cardboard sheet, a cardboard cushioning material in which cuts are formed in part of a cardboard sheet according to the exterior shape of an article to be packed so that, when the sheet is folded such that the cuts fit the exterior shape of the article, an article insertion space is left into which at least part of the article can be inserted. Here, with a remaining part of the cardboard sheet, a hollow cushioning portion is formed so as to adjoin the surface of a cardboard stack opposite the article insertion surface. 
     LIST OF CITATIONS 
     Patent Literature 
     Patent Document 1: Japanese Patent Application Publication No. 2007-22566 
     SUMMARY OF THE INVENTION 
     Technical Problem 
     Inconveniently, however, the cushioning material disclosed in Patent Document 1 is configured such that the entire exterior of the packed article is covered by the cardboard sheet. This requires a large amount of cardboard sheet, and requires an increasingly large amount of cardboard sheet as the number of faces, or the area of the surface, on which to rest the article increases. 
     Against the background discussed above, an object of the present invention is to provide a cushioning material that can be constructed by folding a single sheet and that can absorb external forces from five directions with no increase in the amount of sheet used. 
     Means for Solving the Problem 
     To achieve the above object, a first configuration of the present invention is a cushioning material that is constructed from a single sheet material. The cushioning material has a rectangular bottom segment, a first and a second side segment, a top segment, an engagement segment, a pair of first flaps, a penetrated hole, a pair of second flaps, a pair of first engagement grooves, and a pair of second engagement grooves. The first and second side segments are arranged at two opposite sides of the bottom segment, so as to be contiguous with the bottom segment across folding lines respectively. The top segment is arranged at the side of the first side segment opposite from the bottom segment, so as to be contiguous with the first side segment across a folding line. The middle segment is arranged at the side of the second side segment opposite from the bottom segment, so as to be contiguous with the second side segment across a folding line. The engagement segment is arranged at the side of the top segment opposite from the first side segment, so as to be contiguous with the top segment opposite across a folding line. The first flaps are arranged at two sides of the middle segment perpendicular to its side at which the second side segment is contiguously arranged, so as to be contiguous with the middle segment across folding lines respectively. The penetrated hole is formed to extend from the middle segment beyond folding lines into parts of the first flaps respectively, so as to be penetrated by the engagement segment. The second flaps are arranged at two sides of the engagement segment perpendicular to its side at which the top segment is contiguously arranged, so as to be contiguous with the engagement segment across folding lines respectively. The second flaps have engagement portions formed at their respective tip ends. The first engagement grooves are formed at the gaps between the first side segment and the top segment by extending the first side segment such that the first side segment embraces the top segment from opposite sides. The second engagement grooves are formed by extending the penetrated hole at its opposite ends. The bottom segment, the first side segment, the second side segment, and the top segment are folded into a rectangular column such that the second flaps and the engagement segment are inserted into the penetrated hole. The first flaps are folded away from the first side segment and the middle segment is folded toward the first side segment such that the second engagement grooves are fitted in the first engagement grooves. The engagement segment is folded to be substantially perpendicular to the top segment and the second flaps are folded to be substantially perpendicular to the engagement segment such that the engagement portions are engaged with the first flaps. Now, the middle segment and the top segment are held substantially parallel to the bottom segment. 
     Advantageous Effects of the Invention 
     With the first configuration according to the present invention, a cushioning material is constructed integrally from a single sheet material. This helps reduce the number of components of a cushioning material and facilitate its construction. It is also possible to reduce the space for storage of cushioning materials before being constructed. Moreover, since external forces from five directions can be absorbed reliably, it is possible to reduce the number of cushioning materials needed and the amount of sheet material used to form the cushioning material, and to effectively prevent jolting and rattling of the packed article during transport. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a developed view of a cushioning material  100  according to the present invention; 
         FIG. 2  is a perspective view showing a procedure of constructing the cushioning material  100 , at a stage where the bottom segment  1 , the first side segment  2 , the second side segment  3 , and the top segment  5  are folded into a rectangular column and the engagement segment  6  having the second flaps  11   a  and  11   b  folded to overlap it is inserted into the penetrated hole  15  in the middle segment  4 ; 
         FIG. 3  is a perspective view showing a procedure of constructing the cushioning material  100 , at a stage where, as compared with the stage shown in  FIG. 2 , the first flaps  7   a  and  7   b  are folded away from the first side segment  2 ; 
         FIG. 4  is a perspective view showing a procedure of constructing the cushioning material  100 , at a stage where, as compared with the stage shown in  FIG. 3 , the middle segment  4  is folded toward the first side segment  2  so that the second engagement grooves  17   a  and  17   b  are fitted into the first engagement grooves  8   a  and  8   b , the engagement segment  6  is folded to be substantially perpendicular to the top segment  5 , and the second flaps  11   a  and  11   b  are folded to be substantially perpendicular to the engagement segment  6 ; 
         FIG. 5  is a perspective view showing a procedure of constructing the cushioning material  100 , at a stage where, as compared with the stage shown in  FIG. 4 , the engagement portions  20  are engaged with the engagement claws  9  to complete construction; 
         FIG. 6  is a perspective view of the cushioning material  100  shown in  FIG. 5  as seen from the first side segment  2  side; 
         FIG. 7  is an enlarged perspective view showing an engagement claw  9  engaged with a side edge  7   ba  of the first flap  7   b;    
         FIG. 8  is a perspective view showing a to-be-packed article  30  having the cushioning material  100  attached to it at each end; and 
         FIG. 9  is a perspective view showing the to-be-packed article  30  having the cushioning material  100  attached to it placed in a package box  101 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.  FIG. 1  is a developed view of a cushioning material  100  according to the present invention. In  FIG. 1 , cuts are indicated by solid lines, and folding lines (creases) are indicated by broken lines. The cushioning material  100  is formed by being constructed from a single sheet material punched out into a predetermined shape as shown in  FIG. 1 . The cushioning material  100  is roughly composed of a bottom segment  1 , a first side segment  2 , a second side segment  3 , a middle segment  4 , a top segment  5 , and an engagement segment  6 , all these segments being contiguous with each other across folding lines. 
     At two opposite sides of the bottom segment  1 , the first and second side segments  2  and  3  are arranged contiguously across folding lines L 1  and L 2  respectively. At the other two sides of the bottom segment  1 , third flaps  19   a  and  19   b  are arranged contiguously across folding lines L 3  and L 4  respectively. 
     At the side of the first side segment  2  opposite from the bottom segment  1 , the top segment  5  is arranged contiguously across a folding line L 5 . The first side segment  2  is extended so as to embrace the top segment  5  from opposite sides, and the gaps between the first side segment  2  and the top segment  5  form first engagement grooves  8   a  and  8   b . Near the open ends of the first engagement grooves  8   a  and  8   b  respectively, engagement claws  9  are formed that protrude inward from the first side segment  2 , and in the first side segment  2 , oblong cut holes  10  are formed at four places. 
     At the side of the second side segment  3  opposite from the bottom segment  1 , the middle segment  4  is arranged contiguously across a folding line L 6 . At the two sides of the middle segment  4  adjoining the folding line L 6 , first flaps  7   a  and  7   b  are arranged contiguously across folding lines L 7  and L 8 . At side edges of the first flaps  7   a  and  7   b  respectively, engagement tabs  13  are formed. A penetrated hole  15  is formed so as to extend from the middle segment  4  across the folding lines L 7  and L 8  into the first flaps  7   a  and  7   b , and at opposite ends of the penetrated hole  15 , second engagement grooves  17   a  and  17   b  are formed. 
     Here, in a base-end part of the middle segment  4  relative to the penetrated hole  15  (in  FIG. 1 , the part upward of the penetrated hole  15 ), the interval between the folding lines L 7  and L 8  is substantially equal to the interval between the first engagement grooves  8   a  and  8   b . On the other hand, in a tip-end part of the middle segment  4  relative to the penetrated hole  15  (in  FIG. 1 , the part downward of the penetrated hole  15 ), the interval between the folding lines L 7  and L 8  is wider than the interval between the first engagement grooves  8   a  and  8   b . In this tip-end part of the middle segment  4  relative to the penetrated hole  15 , a folding line L 9  is formed between the folding lines L 7  and L 8 . 
     At the side of the top segment  5  opposite from the first side segment  2 , the engagement segment  6  is arranged contiguously across a folding line L 10 . At the two sides of the engagement segment  6  adjoining the folding line L 10 , second flaps  11   a  and  11   b  are arranged contiguously across folding lines L 11  and L 12  respectively. At tip ends of the second flaps  11   a  and  11   b  respectively, engagement portions  20  are formed. 
     Here, the width-direction dimension w 1  of the engagement segment  6 , the opening width w 2  of the penetrated hole  15  plus the second engagement grooves  17   a  and  17   b  in their length direction, and the width-direction dimension w 3  of the engagement segment  6  plus the second flaps  11   a  and  11   b  fulfill the relationship w 1 &lt;w 2 &lt;w 3 . 
     Next, with reference to  FIGS. 1 to 6 , a procedure of constructing the cushioning material  100  according to the present invention will be described. First, as shown in  FIG. 2 , starting with the state shown in  FIG. 1 , the bottom segment  1 , the first side segment  2 , the second side segment  3 , and the top segment  5  are folded along the folding lines L 1 , L 2 , and L 5  into a rectangular column. Next, the second flaps  11   a  and  11   b  on the engagement segment  6  arranged contiguously with the top segment  5  are folded along the folding lines L 11  and  12  so as to overlap the engagement segment  6 . 
     Then, as shown in  FIG. 3 , the engagement segment  6  having the second flaps  11   a  and  11   b  folded to overlap it is inserted into the penetrated hole  15  in the middle segment  4 . Moreover, the first flaps  7   a  and  7   b  arranged contiguously at opposite sides of the middle segment  4  are folded along folding lines L 7  and L 8  away from the first side segment  2 . 
     Next, as shown in  FIG. 4 , the middle segment  4  is folded along the folding line L 6  so as to lean toward the first side segment  2 , and the second engagement grooves  17   a  and  17   b  in the first flaps  7   a  and  7   b  are fitted into the first engagement grooves  8   a  and  8   b  in the first side segment  2 . Then, the engagement segment  6  is folded along the folding line L 10  so as to be substantially perpendicularly upright relative to the top segment  5 , and the second flaps  11   a  and  11   b  arranged contiguously at opposite sides of the engagement segment  6  are folded so as to be substantially perpendicularly upright relative to the engagement segment  6 . 
     Next, as shown in  FIG. 5 , the second engagement grooves  17   a  and  17   b  and the first engagement grooves  8   a  and  8   b  are engaged together completely. Then, the engagement tabs  13  formed at side edges of the first flaps  7   a  and  7   b  are folded inward so as to be engaged with the engagement portions  20  formed at the tip ends of the second flaps  11   a  and  11   b , so that the middle segment  4  and the top segment  5  are held substantially parallel to the bottom segment  1 . Lastly, the third flaps  19   a  and  19   b  are folded along the folding lines L 3  and L 4  so as to be put under the middle segment  4 . In this way, the cushioning material  100  is constructed. 
     As described previously, in a tip-end part of the middle segment  4  relative to the penetrated hole  15 , the interval between the folding lines L 7  and L 8  is wider than the interval between the first engagement grooves  8   a  and  8   b . Accordingly, as shown in  FIG. 6 , when the constructed cushioning material  100  is seen from the first side segment  2  side, the tip-end part of the middle segment  4  relative to the penetrated hole  15  (the part protruding outward from the first side segment  2 ) is folded substantially into a V shape along the folding line L 9 . Thus, owing to the resilient force of the folded sheet, the first flaps  7   a  and  7   b  are acted on by a force that tends to unfold them, and this makes it difficult for the first engagement grooves  8   a  and  8   b  and the second engagement grooves  17   a  and  17   b  to disengage from each other. 
     Moreover, owing to the resilient force of the middle segment  4  folded toward the first side segment  2 , even if the first flaps  7   a  and  7   b  swing upward (in such a direction as to disengage the first engagement grooves  8   a  and  8   b  and the second engagement grooves  17   a  and  17   b  from each other), as shown in  FIG. 7 , side edges  7   aa  and  7   ba  (of which the former is not illustrated) of the first flaps  7   a  and  7   b  that have been overlapping the engagement tabs  13  engage with the engagement claws  9  on the first side segment  2 . This prevents the first flaps  7   a  and  7   b  from swinging farther, and thereby prevents the first engagement grooves  8   a  and  8   b  and the second engagement grooves  17   a  and  17   b  from disengaging from each other. 
     Moreover, the resilient force of the sheet resulting from the top segment  5  and the engagement segment  6  being folded relative to each other makes it difficult for the engagement tabs  13  on the first flaps  7   a  and  7   b  and the engagement portions  20  on the second flaps  11   a  and  11   b  to disengage from each other. 
     When an article to be packed is packed using the cushioning material  100  according to the present invention, as shown in  FIG. 8 , each end part of the article  30  is inserted into the space S (see  FIG. 5 ) between the middle segment  4  and the top segment  5  of the cushioning material  100 . Now, the article  30  is supported at each end on the cushioning material  100 . Then, as shown in  FIG. 9 , the article  30  having the cushioning materials  100  attached to it is placed and enclosed in a package box  101 . In this way, the article  30  is packed. 
     In  FIGS. 8 and 9 , the to-be-packed article  30  having the cushioning materials  100  attached to it is placed in the package box  101 . Instead, the cushioning materials  100  can be placed in the package box  101  first, and the article  30  can be placed on them later. Specifically, first, two cushioning materials  100  with the engagement portions  20  on the second flaps  11   a  and  11   b  disengaged from the engagement tabs  13  are placed in the package box  101 . In this state, the top segment  5  and the engagement segment  6  are freely swingable relative to the first side segment  2 . Thus, the top segment  5  and the engagement segment  6  can be swung toward the first side segment  2  to secure a wide passage over the space S, and each end part of the article  30  can be inserted into the space S. Then, as shown in  FIG. 5 , the engagement portions  20  can be engaged with the engagement tabs  13  to complete the construction of the cushioning material  100 . 
     Once the article  30  with the cushioning materials  100  attached to it is packed in the package box  101 , the space between the middle segment  4 , on which the article  30  is placed, and the bottom segment  1  absorbs (cushions) an external force from the direction of the bottom face of the package box  101  (i.e., from the direction indicated by arrow A in  FIGS. 5 and 6 ). Moreover, owing to the third flaps  19   a  and  19   b  arranged contiguously with the bottom segment  1  being put under the middle segment  4 , the resilient force of the third flaps  19   a  and  19   b  augments the cushioning effect. 
     In the cushioning material  100 , opposite side edges of the first side segment  2  abut on the inner side faces of the package box  101  in its length direction, and top edges of the first side segment  2 , the first flaps  7   a  and  7   b , and the second flaps  11   a  and  11   b  abut on the inner side of the ceiling face of the package box  101 . Thus, external forces from the directions of the side faces of the package box  101  in its length direction (e.g., from the directions indicated by arrows B and C in  FIGS. 5 and 6 ) and from the direction of the ceiling face of the package box  101  (in  FIGS. 5 and 6 , the direction indicated by arrow D) can be absorbed. 
     Moreover, in the cushioning material  100 , those edges (see  FIG. 6 ) of the middle segment  4  and the first flaps  7   a  and  7   b  which protrude toward the first side segment  2  abut on an inner side face of the package box  101  in the direction perpendicular to its length direction. Thus, an external force from the direction of the side face of the cushioning material  100  in the direction perpendicular to its length direction (i.e., from the direction indicated by arrow E in  FIGS. 5 and 6 ) can be absorbed. 
     Thus, using the cushioning material  100  according to the present invention, it is possible to securely absorb external forces from five directions with a single cushioning material  100 . This helps reduce the number of cushioning materials  100  needed and the amount of cardboard sheet used to form the cushioning material  100 , and to effectively prevent jolting and rattling of the packed article  30  during transport. 
     Moreover, by adjusting the number and size of the cut holes  10  formed in the first side segment  2 , it is possible to adjust the cushioning performance of the cushioning material  100 . The cut holes  10  do not necessarily have to be formed in the first side segment  2 ; they may instead be formed in the second side segment  3 , the middle segment  4 , the top segment  5 , or elsewhere depending on the place where the cushioning performance needs to be adjusted. 
     Before being constructed, the cushioning material  100  is in the form of a single sheet as shown in  FIG. 1 . This permits a number of cushioning materials  100  to be stacked together. Out of the stacked cushioning materials  100 , one after another can be taken and constructed to improve the efficiency of packing. Moreover, cushioning materials  100  before being constructed can be stored in a small space. 
     The present invention can be implemented in any manners other than specifically described above, and allows for many modifications and variations without departing from the spirit of the invention. For example, in the embodiment described above, the cut holes  10  are formed to lessen the cushioning performance. Instead, in a case where higher cushioning performance is required, the first flaps  7   a  and  7   b , the third flaps  19   a  and  19   b , or the like can be configured to have the sheet folded up into two stacked layers. 
     The cushioning material  100  according to the embodiment described above is merely a preferred example: the cut holes  10  and the third flaps  19   a  and  19   b  are not essential. That is, the configuration of the cushioning material  100  in its details can be modified as necessary to suit the shape of the article to be packed. 
     INDUSTRIAL APPLICABILITY 
     The present invention finds applications in cushioning materials constructed by folding a single sheet. The present invention provides a cushioning material that can be constructed easily by folding a single sheet and that can absorb external forces from five directions with no increase in the amount of sheet used.