TECHNICAL FIELD

The present invention relates to a folding and unfolding box, capable of minimizing their volumn during transportation and storage of empty boxes.

BACKGROUND ART

A conventional plastic box, which is used for containing and transporting materials, such as beverages, alcoholic liquors, and fruits etc., requires much costs and spaces due to maintaining the original volumn and shapes, in spite of containing nothing. Therefore, to solve such a drawback, there have been provided a variety of folding -unfolding or fabricating -type boxes. However, The conventional foldin -unfolding or fabricating-type boxes have typically had drawbacks which include inconvenient work in assembling or folding, weak stiffness in a fabricated state and not easy storage after disassembling.

DISCLOSURE OF INVENTION

Therefore, to solve the above problems in the conventional boxes, it is an object of the present invention to provide a folding and unfolding box, which includes an easy fabrication and folding, good stiffness, and improved stackability of fabricated and folded boxes.

To accomplish the above object of the present invetion, there is provided a folding and unfolding box in which four lateral walls are hinge-joined at each of corners and edges on a base, the box comprising : a base of a nearly rectangular form; protrusion steps,

which are protruded from the exterior of edge regions of two lateral walls opposite to each other among four lateral walls; and receiving ribs, which are protruded from the interior of edge regions of the other lateral walls opposite to each other, thereby fitting and receiving the protrusion steps of adjacent lateral walls which are inwardly moving in a single-acting state.

The protrusion steps and receiving ribs corresponding to each other are formed not to break away from other directions, exclusive of an interlocking direction. Accordingly, it is convenient to fabricate boxes and maintain securely their fabricated state. Fixing means can be further comprised so as to protect departing of the protrusion steps and receiving ribs in an interlocking shape. A fixing pin, which pierces through the edge regions of both ends of the protrusion steps and receiving ribs, is preferred as the fixing means. For a folding and unfolding method with easy and convenient treatment, it is desirable that each of lateral walls is all folded and stacked onto the base. Here, the underside of the base fits the top of the folded boxes so as to be stacked on top of the other folded boxes, thereby improved stackability being obtained.

BRIEF DESCRIPTION OF DRAWINGS

FIG.l is a perspective view of a folding and unfolding box according to the present invention. FIG. 2 is a perspective view partly taken away from FIG. 1.

FIG. 3 is an enlarged separate perspective view of A portion in FIG. 1.

FIGs. 4 to 6 are perspective views of other embodiments of protrusion steps and receiving ribs. FIG. 7 is a front view of a folding and unfolding box according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG.l is a perspective view of a folding and unfolding box according to the present invention, and FIG. 2 is a perspective view partly taken away from FIG. 1. As shown in FIGs. 1 and 2, the folding and unfolding box comprises a base 20 of a nearly rectangular form, on which four lateral walls 2, 2 3, 3' are hinge- joined at each of corners and edges. The four lateral walls 2, 2', 3, 3' are composed of two short walls 2, 2' opposite to each other and two long walls 3, 3' contrary to each other. Each of lateral walls is built up so that it can be moved by hinge portions 4, 5 at respective edges of the base 20. Preferably, by the lateral walls to move only inwardly, the stiffness of the boxes in folding and assembling states can be further maintained. Each of lateral walls 2, 3 and the base 20 are preferred to form a plurality of air vents 13 of lattice shapes for rigidity improvement and the reduction of raw materials. The lateral bottom of the base 20 is composed of step shapes that hinge- joined stage levels of second lateral walls 2, 2' are higher than those of first lateral walls 3, 3', according to the folding order of each of lateral walls 2, 2', 3, 3 ¹ . That is, as shown in FIGs. 1 and 2, a first stage 21 of the base 20, which is first folded in a pair of long lateral walls 3, 3', is lowest. A second stage 22 of the base 20, the second long lateral wall 3' to be folded, is formed higher than the stage of the first long lateral wall 3. Besides, in folding the boxes, since a pair of short lateral walls 2, 2' lie onto a pair of folded long lateral walls 3, 3', stages 23 and 24 of the short lateral walls 2, 2', which are connected to the base 20, are higher than the folded long lateral walls 3 and 3'.

Each of long lateral walls 3, 3' includes a number of protrusion steps 6 with flat surfaces of trapezoids at the exterior of both edge regions. Each of short lateral walls 2 and 2* includes a plurality receiving ribs 7, being in protruded forms, for fitting and containing - the protrusion steps 6.

FIG. 3 is an enlarged separate perspective view of the protrusion steps 6 and receiving ribs 7 in FIG. 1. A plurality of protrusion steps 6 of the long lateral wall 3, being in the form of trapezoids, are formed to be protruded outwardly from the both edge regions. The receiving ribs 7, being protruded inwardly from the both edges of the short lateral wall 2, are inverse-trapezoid types and include open spaces for fitting and receiving the protrusion steps 6. By the construction of the protrusion steps 6 and receiving ribs 7, when the long lateral wall 3 are moved by its hinge portion 5 in a standing state of the short lateral wall 2, the protrusion steps 6 are fitted between the receiving ribs 7. Accordingly, the short lateral wall 2 and long lateral wall 3 are in an interlocking fashion of their both edges.

In order to easy to interlock the short lateral wall 2 and long lateral wall 3, as shown in FIG. 3, mutual friction surfaces of the protrusion steps 6 and receiving ribs 7 are composed of oblique planes. Therefore, since the protrusion steps 6 do not pass through the receiving ribs 7 due to the oblique planes, easy assembling can be performed. Owing to the trapezoid shape of the protrusion steps 6, the interlocking arrangement of the protrusion steps 6 and receiving ribs 7 surely prevents their departing toward right angle directions.

When the protrusion steps 6 and receiving ribs 7 are interlocked at four edges, all lateral walls 2 and 3 rise from the base 20, thereby boxes for receiving materials inside being obtained. The friction surfaces of the protrusion steps 6 and receiving ribs 7 are obliquely formed in an interlocking direction. Therefore, in case interior

materials or compartment dividers for separately housing the materials are present therein, the long lateral wall 3 can maintain the interlocking state with the short lateral wall 2 by their supporting. If not, the long lateral wall 3 is susceptible to break away from the short lateral wall 2. In order to keep firmly their interlocking arrangement, a fixing pin 11 is inserted accross the protrusion steps 6 and receiving ribs 7. As shown in FIG. 3, hollows 8 and 9 for inserting the fixing pin 11 are pierced through the protrusion steps 6 and receiving ribs 7. In assembling the boxes, the fixing pin 11 fixes all the protrusion steps 6 and receiving ribs 7. In folding them, the fixing pin 11 is placed in one of hollows 8, 9 of the protrusion steps 6 or receiving ribs 7. One of lateral wall 2 or 3 can form a hole suitable for leaving the fixing pin 11.

As shown in a reference numeral 12 of FIG. 3 in place of the fixing pin 11, a fixing step is formed on the interior top of the short lateral wall 2, thereby a fixing state between the protrusion steps 6 and receiving ribs 7 being easily obtained. A fixing step 12 is composed of an oblique surface from the rising direction of the long lateral wall 3 and protruded to prevent departing of the long lateral wall in the opposite direction. The fixing step 12 is no more than protruded from the interiors of the short lateral wall 2, or can be installed by inserting an elastic spring into the interiors. When the long lateral wall 3 rises, the fixing step 12, being changed by the elasticity of the short lateral wall 2 or that of an inserted spring, fixes the long lateral wall 3 not to be moved away by interlocking arrangement of the protrusion steps 6 and receiving ribs 7. In the case of breaking away the long lateral wall 3 from the short lateral wall 2, the interlocking state of the protrusion steps 6 and receiving ribs 7 is disassembled by an elastically change or pressing the fixing step 12 with the inserted spring.

FIGs. 4 to 6 are perspective views of other preferred

embodiments of the protrusion steps and receiving ribs. The protrusion steps 6 of FIG. 3 show the flat surfaces of a trapezoid shape, but FIGs. 4 to 6 show rectangular, "T" or similar "T" shapes, respectively. Unlike the embodiment of FIG. 3, portions for receiving each of the protrusion steps in the embodiments are connected to each other with no open states, thereby the stiffness of the receiving ribs being further improved. The incline of contact surfaces and the fixing pin used for the easiness of assembling can be applied like the embodiment of FIG. 3. In order to achieve the objcet of the present invention, the protrusion step and receiving rib shapes can be variouly modified, not limited only to the embodiments of FIGs. 3 to 6.

FIG. 7 is a front view of a folding and unfolding box according to the present invention. Rising on the base 20, each of lateral walls 2, 2', 3, 3' is all folded inwardly and stacked thereon. First, one of the long lateral walls 3 and 3' is folded on the base 20 and the other is lay on the folded wall, and then the short lateral walls 2, 2 ¹ are in order folded and stacked thereon. The hinge portions 4 and 5 of each of the lateral walls are in the step shape corresponding to the folding state. The folded boxes will be fitted and stacked on top of the other boxes, as shown in dotted line of FIG. 7. The underside of the base 20 is formed to be suitable for the top shape of the folded boxes. That is, the underside of the base 20 is recessed for receiving protrusions on the top of the folded boxes. Since the method makes a plurality of the folded boxes to be securely stacked, transported or housed, it provides an effitiently use of spaces as well as an easy treatment in compact volumn. In FIG. 7, the exterior of the folded boxes is in a recessed or protruded form, and the folded boxes are arranged in an interlocking fashion along only the long axis. However, they can be firmly interlocked in a cross format by suitably forming the exteriors of the lateral walls and the underside of the base 20. Accordinly, the stacked boxes can be maintained with an

interlocked state in all directions.

Even if fabricated boxes contain materials inside, they can be suitably stacked up so that the top ends of the lateral walls may match with the bottom ends of the base 20. The present invention can include lattice members apart so as to separate and store interior materials or a lid to protect them.

INDUSTRIAL APPLICABILITY

As described above, a folding and unfolding box in accordance with the present invention provides advantages which include easy fabrication and folding, minor volumn of folded empty boxes, and cost reduction of storage and transportation.