Corrugated cardboard pallet

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TRANSLATION

SPECIFICATION

CORRUGATED CARDBOARD PALLET

TECHNICAL FIELD

The present invention relates to a corrugated cardboard pallet wherein beam members and pallet deck plates of the corrugated cardboard pallet are made of corrugated cardboard.

RELATED ART

A variety of corrugated cardboard pallets constructed with beam members and pallet deck plates of conventional technology have been proposed to replace metallic or wooden pallets that have conventionally been used in the transportation industry.

Corrugated cardboard pallets can roughly be classified into two types: (1) a core type, having beam members bonded to the bottom surface of a beam member made of a flat corrugated cardboard, which is further wrapped up like a roll or having a multiple flat corrugated cardboards stacked atop each other; and (2) a hollow type, having hollow beam members.

The applicant has proposed a hollow type corrugated cardboard pallet as disclosed in Japanese Unexamined Patent Application No. 2002-370738. The corrugated cardboard pallets of this type have load-bearing portions, which provide far better pressure resistance than the hollow type corrugated cardboard pallets of conventional technology.

Nonetheless, a beam member of the above corrugated cardboard pallet has edges where the corrugated cardboard pallet is cut across and exposed such that, when rain falls into the open surface of the edges, the corrugated cardboard pallet absorbs water therefrom, thereby deteriorating pressure resistance thereof.

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Understanding the above technical backgrounds, the objective of the present invention is to improve pressure resistance of corrugated cardboard pallets and to provide water proofing without using a water proof coating or water repelling technique without deteriorating its pressure resistance.

The present invention will prove other objective through Embodiments described herein.

DETAILED DESCRIPTION OF THE INVENTION

To overcome the above problem, the present invention provides a corrugated cardboard pallet whose edges are folded inside such that the edges cut open cannot be exposed, thereby making little water absorption possible therethrough and making the edges folded inside pressure resistant.

More specifically, the present invention relates to a corrugated cardboard pallet characterized by an upper pallet deck plate fixed onto an upper surface of multiple beam members made of corrugated cardboard wherein said beam member comprises a body having a 1^st square prism and a 2^nd square prism, said body made by overlaying inner plates on a common base platform and struts having side edges, said struts providing a square prism shape for said body by coupling said square prisms wherein the size of each of said struts is set such that said side edges of said struts contact an inner surface of said outer plates of corresponding square prisms, and load-bearing portions are provided on both side edges wherein a pair of struts to be folded inward is foldably connected to the ends of the inner and outer plates of both square prisms in such a manner that top and bottom ends of each of the struts touch the corresponding top platform and the bottom platform of square prisms in a folded position, thereby interfering with the other set of struts to be kept therein.

According to the present invention, firstly, when heavily loaded corrugated cardboard pallets are exposed to transverse vibrations that are generated during transportation by a vehicle such as a truck, and a force that crushes the outer plates of beam members is applied to the side edges of struts, the force spreads out from the outer plates through the struts’ side edges to

CA 02484040 2004-09-17 load-bearing portions because the bottom edge of load-bearing portions directly or indirectly touch the base platform of the beam member. Crushing of the edges of the struts and destruction of beam members is thus prevented.

Secondly, a pair of struts to be folded inward are foldably connected to the square prisms’ ends such that each of these struts to be folded inward touch corresponding top and bottom platforms therein while interfering with each other being held internally locked therein. As a result, the beam obtains enhanced pressure resistance and square prisms hold the struts therein by resisting unfolding force generated thereof. Bonding of a pallet deck plate onto a beam member thus becomes easy. In addition, in this configuration, the cut-open edge of the corrugated cardboard pallet does not expose itself. The corrugated cardboard pallet is thus protected from diminishing its pressure resistance. Consequently, the pallet is resistant to strong impact from a fork of a fork lift.

Thirdly, both the struts to be folded inward interfere with each other as being held internally. As a result, these struts once held internally will not inadvertently pop out. The pallet structure is thus enhanced by consistent pressure resistance where no pop out interruption occurs.

It is desirable that a pair of struts folded inward has engagement portions for maintaining the mutual pushing state thereof.

It is not always required that a pair of struts be connected to each other. It is desirable, however, that they are coupled with each other because coupled struts are more manageable and convenient for assembly.

In light of the coupling mode, either bottom edge to bottom edge coupling via a linking plate or side edge to side edge coupling via a linking plate may be desirable wherein the side edges contact the outer plates of each of the square prisms. This technique ensures spreading of the force applied from the outer plate to one end of a strut.

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As to the load-bearing portion, it is desirable that the bottom edges of struts directly or indirectly touch the base platform of the beam member. This further enhances dispersion of the force applied from the outer plate toward the side edges of the strut.

When the bottom edge of one strut is coupled to the bottom edge of another strut via a linking plate to construct a load-bearing portion, the load-bearing portion is foldably connected via folding lines along the side edges of each strut; the load-bearing portion is made up with flaps that extend toward inner plate in an inclined manner such that the flaps contact the inner plates. It is desirable that the bottom edge of each flap directly or indirectly contact the base platform, and that the size of the flaps housed in the same square prism be set such that tips of the flaps interfere with each other. The function of the load-bearing portions can thus be enhanced.

In struts, when the side edges contacting the outer plate of one of the square prisms are coupled via a linking plate, the linking plate works as a load-bearing portion. In this case, the linking plate comprises: a 1^st linking plate that is foldably connected to one strut and a 2^nd linking plate that is foldably connected to another strut. A slit is provided at the end of one of the linking plates; a latch portion is formed at the end of another linking plate in such a manner that the latch portion extends outward at a point which corresponds to the edge of 2^nd linking plate. The desirable arrangement at the time when a slit for latching and the latch portion are engaged is that a pair of struts is assembled with linking plates to provide a square shape in a plan view. Handling of a set of square prisms and linking plates of the beam member is thus made easier.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a perspective view of an embodiment of the corrugated cardboard pallet of the present invention.

Figure 2 is a perspective view of the beam member of the corrugated cardboard pallet of Figure 1.

Figure 3 is an enlarged cross section along ΙΠ-ΙΙΙ of the beam member of Figure 2.

Figure 4 is a cross section along 1V-IV of the beam member of Figure 2.

Figure 5 is a perspective view of struts.

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Figure 6 is an exploded plan view of the body of a beam member.

Figure 7 is an exploded plan view of struts and load-bearing portions of beam members.

Figure 8 is a perspective view of the beam member on its way to being assembled in the first phase.

Figure 9 is a perspective view of the beam member on its way to being assembled in the second phase.

DETAILED DESCRIPTION OF THE INVENTION

EMBODIMENTS

The present invention is described herein with reference to embodiments illustrated in the drawings.

Figure 1 illustrates an embodiment of the corrugated cardboard of the present invention. Corrugated cardboard pallet deck plates (18) (19) are bonded to both upper and lower surfaces of multiple corrugated cardboard beam members (1) (1)..... spaced from each other in such a manner that a forklift can insert its fork from all sides.

As illustrated in Figure 2, a beam member (1) is constructed with a body (2) and struts (11) (11). Overlaying inner plates (8) of 1^st square prism (3) and that of 2^nd square prism (4) on a common base platform (5) provides body (2), Struts (21) (21), which are assembled in the manner that two assembly phases as illustrated in Figures 8 and 9 are combined, help coupling the two square prisms (3) (4) to maintain the square prism shape of beam member (1). Beam member (1) and struts (21) (21) are made of a 7 mm thick three layered corrugated cardboard; pallet deck plates (18) (19) are made of a 10mm thick three layered corrugated cardboard. However, the type and thickness of a corrugated cardboard is not limited to this.

Figure 6 is an exploded plan view of beam member body (2): outer plate (6), top platform (7) and inner plate (8) that constitute 1^st square prism (3) are foldably connected to one end of base platform (5) via folding lines (a) (b) (c), respectively; outer plate (6), top platform (7) and

CA 02484040 2004-09-17 inner plate (8) that constitute 2^nd square prism (4) are foldably connected to the other end of base platform (5) via folding lines (a) (b) (c), respectively.

1^st struts (11)(11) to be folded inward are foldably connected to both ends of each of the inner plate (8) in both square prisms (3) (4) via folding lines (d) (d). The upper half of the free end of 1st strut (11) to be folded inward is provided with slit (1 la), thereby providing engagement portion (1 lb) at the lower half of the free end of 1st strut (11).

In contrast, 2^nd struts (12) (12) to be folded inward are foldably connected to both ends of each of the inner plate (8) in both square prisms (3) (4) via folding lines (e) (e). The upper half of the free end of 1^st strut (12) to be folded inward is provided with engagement portion (12b), thereby providing slit (12a) at the lower half of the free end of 1st strut (12), which is in contrast to the way the slit 11(a) and (b) were formed for 1^st strut (11) to be folded inward.

Each inner plate (8) is also provided with a pair of slits (9) (9) in the middle of the bottom edge thereof in a longitudinal direction. In addition, the portion that is to be latched with struts between a pair of slits (9) (9) is set in such a manner that the longitudinal position of the bottom ends of struts (21) (21) is set higher than both sides such that the portion that is to be latched with struts via a pair of slits (9) (9) contacts the upper surface of linking (base) plate (22) described later. Guiding taper (10) is provided in the vicinity of slits (9) (9) to be coupled to struts.

Figure 7 is a plan view of a pair of struts (21) (21) in an extended state: a pair of struts (22) (22) are foldably connected to the side edges of linking plate (22) that are facing each other via folding lines (f) (f), and flaps (23) (23) are also foldably connected to side edges thereof via folding lines (g) (g) wherein flaps (23) (23) work as load-bearing portions.

The size of each strut (21) is set such that both side edges thereof contact the inner surfaces of outer plates (6) (6) of square prisms which correspond to ends of side edges, and slit (24) to be latched with the inner plate of a square prism is provided in the center of the upper end in the vertical direction. In the vicinity of the upper end of slit (24) to be latched with the inner

CA 02484040 2004-09-17 plate of a square prism, guiding tapers (25) (25) are provided such that inner plate (8) of a square prism can be easily engaged with slit (24).

The tip of each flap (23), the load-bearing portion, as illustrated in Figure 3, contacts corresponding inner plate (8), and the size of flaps (23) (23) that are housed in the square prisms (3) or (4) is set such that the tips of flaps (23) (23) interfere with each other. In addition, the bottom edges are set such that they contact linking plates (22) (22) as illustrated in Figure 4. On the upper end of flap (23), guiding taper (26) is provided such that inner plate of square prism inner plate (8) of a square prism can be easily engaged with slit (24) in a manner similar to guiding taper (25) described above.

Beam member (1) in the extended state is assembled to make a desired square prism shape in the following maimer (See Figure 5): first, let a pair of struts (21) (21) that are connected to each other via linking plate (22) stand out from linking plate (22); fold each of the struts (23) (23) (23) (23) inside in such a manner that, in one square prism (3) or (4), one half body of strut (21) and flap (23) that are folded inward at the end of strut (21) is followed by inward folding of the other half body of strut (21) and flap (23) that are folded inward at the end of the half body strut (21) so as to form a “M” shape, which can clearly be observed in a cross section of a finished beam illustrated in Figure 3.

Next, a pair of struts (21) (21) are latched with inner plates inner plates (8) (8) of 1^stsquare prism while maintaining the M shape with flaps (23) (23) as illustrated in Figure 8. In other words, slits (9) (9) of 1^st square prism are latched with slits (24) (24) of strut (21) to link struts (21) (21) and inner plate (8) of 1^st square prism (3).

Struts (21) (21) and 1^st square prism (3) thus connected are folded inward on beam base platform (5) as illustrated in Figure 9. Then, a given portion of 2^nd square prism (4) is folded in a manner that slits (9) (9) on inner plate (8) and slits (24) (24) of struts (21) are latched together, thereby leveling top platform (7) of 1^st square prism (3) and top platform (7) of 2nd square prism (4) .

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Finally, 1^st strut (11)... to be folded inward and 2^nd strut (12) ... to be folded inward are folded into the edge of square prisms (3) and (4) such that engagement portions (1 lb) (12b) are latched with struts (11) (11) to be folded inward. More specifically, first of all, 1^st strut (11) to be folded inward is folded into the edge of square prism (3) and 2^nd strut (12) to be folded inward is folded into the edge of the same square prism (3). As folding 2^nd strut (12) inward, the free end thereof touches 1^st strut (11) in such a manner that 1^st strut (11) pushes against 2^nd strut (12). As 2^nd strut is further pushed inward against the resistance from 1^st strut (11), engagement portions (1 lb) (12b) meet on back of struts (12) (11) over slits (12a) (1 la). Both struts (11) (12) to be folded inward are thus locked therein. The assembly of beam member (1) is thus completed.

Presence of flaps (11)(12) that are folded inward and locked into both ends of square beam members (3) (4) makes beam member (1) and ensures prevention of top platform (7) from popping up. Consequently, the need for bonding inner plates (8) (8) of square prisms (3) (4) is eliminated.

Top pallet deck plate (18) is bonded on top of a given number of beam members (1) (1)

.. .and bonding bottom pallet deck plate (19) onto the bottom of beam members (1) (1)..., finishes assembly of corrugated cardboard pallet (A) of the present invention illustrated in Figure

1. During the bonding process, top platform does not inadvertently pop up, making bonding of the top pallet deck plate (18) easier as well.

The corrugated cardboard pallet of this embodiment is constructed with 16 beam members (1) 95mm high arranged between top and bottom pallet deck plates (18) (19) of 1100 mm length x 1100 mm width. These beam members (1) (1)... are arranged in a manner illustrated in Figure 1.

The resulting corrugated cardboard pallet (A) was tested for its compression resistance in a comparative test and a comparative analysis of the present invention and a conventional corrugated cardboard pallet(control). The control was constructed in the same manner as that of the present invention except that it did not have flaps to be folded inward: the top and bottom

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CA 02484040 2004-09-17 pallet deck plates of controls had the size and used the same material as the present invention;

beam members of controls had the size and used the same material as the present invention; ways to arrange top and bottom pallet deck plates are further analyzed. It was proven that the corrugated cardboard pallet of the present invention tested in this embodiment had a significantly better compression resistance than that of the controls (See Table 1).

The objective of this comparative test was to measure how much load is required to deform the corrugated cardboard pallet. The compression test method was in compliance with the Japan Industrial Standard (JIS) Rule 0212:1998.

In this comparison test, the initial load was 200N (20.4 kgf) and it took 5 minutes and 30 seconds until the maximum load was applied to the corrugated cardboard pallet.

Table 1

<td></td><td> Sample</td><td> LoadN (kgf)</td><td> Amount Deformed (mm)</td><td> Maximum Load N (kgf)</td><td> Amount Deformed (mm)</td>

<td rowspan="3"> Sample</td><td> 1</td><td> 73000 (7450)</td><td> 25</td><td> 116000 (11800)</td><td> 38</td>

<td> 2</td><td> 75600 (7710)</td><td> 25</td><td> 115000 (11700)</td><td> 38</td>

<td> 3</td><td> 72300 (7380)</td><td> 25</td><td> 116000 (11800)</td><td> 39</td>

<td rowspan="3"> Control</td><td> 1</td><td> 37200 (3800)</td><td> 25</td><td> 56000 (5710)</td><td> 36</td>

<td> 2</td><td> 40100 (4090)</td><td> 25</td><td> 56900 (5810)</td><td> 37</td>

<td> 3</td><td> 41300 (4210)</td><td> 25</td><td> 54700 (5580)</td><td> 35</td>

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INDUSTRIAL USE

As described above, the corrugated cardboard of the present invention has an improved pressure resistance and water resistance taking advantage of its configuration in which a part of cut-open surface of the corrugated cardboard is not exposed in the beam member’s height direction. Water absorption through the cut-open surface of a corrugated cardboard is thus prevented. The present invention has a wide variety of uses in industrial applications.