TECHNICAL FIELD

The application relates generally to material handling and, more particularly, to metal pallets, such as aluminum and galvanized steel pallets.

BACKGROUND OF THE ART

While most pallets are made of wood, some pallets are also made of plastic and metal. Each material has advantages and disadvantages relative to the others.

Presently, metal pallets represent less than 1 % of the market. Metal pallets are generally costly compared to wooden pallets. Some metallic pallets are subject to oxidation, the use thereof for outside storage may thus be problematic. Also metal and plastic pallets typically offer less adherence for the stack of goods to be carried than wooden pallets, which may result in stability problems. Finally, conventional metal pallets are generally heavy. Accordingly, there is a need for a new metallic pallet design.

SUMMARY

In accordance with a general aspect of the present invention, there is provided a metal pallet comprising a deck mounted on a plurality of laterally spaced-apart beams, at least peripheral ones of said beams having a one-piece sheet metal body including a pair of legs extending upwardly from a bottom end, the legs defining therebetween a hollow internal volume, the one-piece sheet metal having at least one die formed portion protruding into said hollow internal volume between longitudinally opposed ends of the one-piece sheet metal body, each of said at least one die formed portion defining an arched opening across the one-piece sheet metal body.

In accordance with another general aspect, there is provided a metal pallet comprising a deck, a base and a plurality of beams therebetween, each beam having a one-piece sheet metal body folded into a V-shaped elongated member including a pair of legs extending upwardly from a flat bottom end, the legs defining therebetween an internal volume, the flat bottom end having at at least one location therealong a plastically deformed portion die pressed into the internal volume between the legs of the one-piece sheet metal body so as to define a corresponding transversal arched opening between opposed longitudinal ends of the beam, the plastically deformed portion being fully accommodated within the internal volume.

In accordance with a further general aspect of the invention, there is provided a galvanized steel pallet has a deck, a base and a plurality of beams therebetween. The deck, the base and the beams are formed from lightweight galvanized steel sheet. The galvanized steel sheets are folded into the desired shape to respectively form the beams, and panels and slats for the deck and the base. The panels and the slats are corrugated and the opposed side edges thereof may be folded upon themselves to provide for robust multi-ply edge constructions. Different types of corrugations may be provided over the panels and the slats to locally reinforce the pallet.

Further details of these and other aspects of the present invention will be apparent from the detailed description and figures included below.

DESCRIPTION OF THE DRAWINGS

Reference is now made to the accompanying figures, in which:

Fig. 1 is a perspective top view of a galvanized steel palette in accordance with an embodiment of the present invention;

Fig. 2 is a perspective bottom view of the palette shown in Fig. 1 ;

Fig. 3 is a side view of the palette shown in Fig. 1 ;

Fig. 4 is an exploded view of the palette illustrating the panels, the beams and the slats forming the palette;

Fig. 5 is an enlarged side view of the palette illustrating details of the corrugation pattern of the top panels of the palette;

Fig. 6 is a bottom perspective view of a V-shaped beam forming part of the pallet; Fig. 7 is a cross-section view of the V-shaped beam taken along line 7-7 in

Fig. 6;

Fig. 8 is a side elevation view of a stack of pallets, the pallets being nested one into each other; and Figs. 9a-9d are sequential views schematically illustrating the sheet metal forming process used to form transversal arched openings in the beams.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Fig. l illustrates an example of a 48"x 40"x 5" (1000m x 1200mm x 102mm) weldless galvanized steel pallet 10. The pallet 10 generally comprises a load supporting deck 12, a base 14 and a set of beams 16 (three in the illustrated embodiment) interconnecting the deck 12 to the base 14. The deck 12, the base 14 and the beams 16 may all be made from galvanized steel sheets. According to one example, the components of the deck 12, the base 14 and the beams 16 are made from a lightweight gauge of galvanized steel, such as lightweight gauges typically used in the ventilation industry. For instance, the components of the pallets could be made from standard 24 gauge galvanized steel sheets (ASTM 653B G90). It is understood that different gauges of steel could be used. For instance, any combination of 10 gauge galvanized steel sheet to 24 gauge galvanized steel to 24 gauge could be used. Referring concurrently to Figs. 1 to 4, it can be appreciated that the deck 12 of the pallet 10 may be composed of a front corrugated panel 18, a central corrugated slat 20 and a rear corrugated panel 22. It is understood that the number of panels and slats may vary. Referring more particularly to Fig. 3, it can be appreciated that slat 20 is narrower than the panels 18, 22. For instance, the panels 18, 22 may have a width (W) equal to 500mm whereas the slat 20 may have a width (w) of 100mm. The slat 20 may be spaced-apart from the front and rear panels 18, 22 so as to define front and rear gaps 24 therewith. The central slat 20 and the panels 18, 22 are coterminous in the transversal direction of the pallet 10. The corrugations of the panels 18, 22 and slat 18 extend transversally to the longitudinal axis of the pallet 10. In the embodiment illustrated in Figs. 1-4, the panels 18, 22 and the central slat 20 are mounted on top of three laterally spaced-apart longitudinal beams 16. In the illustrated embodiment, the beams 16 are identical. However, they could be different. According to the illustrated embodiment, all the beams 16 have a V-shaped open-top section with longitudinally extending lateral flanges 28 at the top. The deck panels 18, 22 and the central slat 20 may be riveted or otherwise suitably attached to the lateral flanges 28 of the beams 16. The beams 16 may extend longitudinally the full extent of the pallet 10. The bottom end of the beams 16 is flat to provide a suitable mounting surface 30 for the base 14. According to the illustrated example, the base 14 is composed of three corrugated bottom slats 32. The bottom slats 32 are uniformly distributed along the length of the beams 16 and oriented transversally with respect thereto. The bottom slats 32 comprise a front bottom slat, a central bottom slat and a rear bottom slat. The front, central and rear bottom slats 32 may be identical and are coterminous to the deck panels 18, 22 and the deck central slats 20 in the transversal direction of the pallet 10. According to the illustrated example, each bottom slat 32 has three pairs of laterally extending mounting flanges 34 distributed along the length thereof. The mounting flanges 34 of the bottom slats 32 may be riveted or otherwise suitably attached to the flat bottom end 30 of each beam 16. As best shown in Fig. 5, the front and rear panels 18, 22 of the deck 12 each have two different types of corrugations: central corrugations 38 and edge corrugations 40. The central and the edge corrugations 38, 40 may have a trapezoidal shape and a same depth (e.g. 19mm). However, the pitch of the corrugations 38 in the central area is greater than the pitch of the corrugations 40 in the lateral edge areas of the panels 18, 22. For instance, the pitch of the central corrugations 38 may be twice that of the edge corrugations 40. In accordance with one example, the pitch of the central corrugations 38 is 54mm and the pitch of the edge corrugations 40 is 27mm. The central corrugations 38 are designed to maximize the top bearing surface area of the pallet 10 while offering an adequate load bearing surface capability relative to the weight of the panel. According to one example, the central corrugations 38 have an 88 degrees opening angle. In contrast, the edge corrugations 40 may have a 26 degrees opening angle. The edge corrugations 40 have a smaller pitch and have almost vertical sides or legs extending between top and bottom webs, thereby providing for better mechanical properties with greater vertical load bearing capabilities at the lateral edges of the panels 18, 22.

Multi-ply edges portions may be provided at the opposed lateral sides of the panels. For instance, a 3 -ply edge portion 42 may be formed along the front edge of the front panel 18 by folding the front edge portion of the panel 18 twice upon itself. A 3-ply edge portion 44 may be similarly formed along the rear edge of the rear panel 22. The folding of the edge portions of the panels 18, 22 at the front and the back of the pallet 10 eliminates the presence of sharp edges that would otherwise be present at the periphery of the pallet 10 and that could potentially be harmful for an operator when manually handling the pallet 10. Furthermore, the multi-ply edge structures at the front and rear of the pallet 10 also act as front and rear bumpers to better resist potential lateral impacts of the forks of a forklift truck or other pallet handling equipment at the front and rear fork entries of the pallet 10.

A 2-ply edge portion 46 may also be formed along the rear edge of the front panel 18 and along the front edge of the rear panel 22 adjacent to the central slat 20. The 2-ply edge portions are formed by folding the edge portion of each panel upon itself. This also provides for smoother rounded edge at the top surface of the pallet 10.

A non-slip or anti-skid treatment surface may be applied on the top facing surface of the deck panels 18, 22 and of the central slat 20 (i.e. the deck surface in contact with the merchandise to be carried on the pallet). The anti-skid treatment may take the form of small convex embossments or protrusions on the top web surface of the corrugations as for instance shown at 48 in Fig. 5. Arrays of spaced-apart elongated embossments 48 may be formed along the top web of selected corrugations. According to one example, the embossments have a 1mm height and a 5mm length. According to one embodiment, more than 550 embossments are distributed over the deck of the pallet 10 to provide a better adherence and, thus, a better stability of the merchandise on the pallet 10. Like the top panels 18, 22, the top slat 20 is corrugated. The corrugations of the slat 20 may also have a generally trapezoidal shape. According to one embodiment, the pitch of the corrugations of the slat 20 is equal to 27mm. The slat 20 may have opposed longitudinal downwardly sloping edge portions 50. The sloping edge portions 50 may define a 45 degrees slope. The sloping edge portions 50 may be folded upon themselves to provide a 2-ply edge structure as described above with respect to the panels 18, 22.

The corrugations of the bottom slats 32 forming the base 14 of the pallet 10 may be generally similar to the corrugations of the top slat 20 and the side corrugations 40 of the panels 18, 22 (similar depth and pitch). As can be appreciated from Fig. 4, downwardly sloping wing-like projections 52 extend between the mounting flanges 34 along the opposed longitudinal sides of each slat 32. The winglike projections 52 extend downwardly at an appropriate angle (e.g. 45 degrees) to form raceways to facilitate the entry of pallet handling equipment (e.g. forks of a forklift truck) in the end entries of the pallet. The wing-like projections 52 may have a 2-ply configuration by folding over a portion of the lateral edge portions of the slats 32 upon themselves. This provides for a more robust raceway construction for absorbing impact forces. The mounting flanges 34 also contribute to render the winglike projections 52 more robust. As mentioned hereinbefore, each beam 16 has a V-shaped open-top section.

The V shape of the beams provides added resistance to buckling under high-stacking loads. The V-shaped beams provide a rigid and sturdy bridge between the top and bottom sections of the pallet 10. According to an embodiment, an angle of about 30 degrees is defined between the sidewalls of each beam 16. Still according to this embodiment, the height of each beam is equal to 90mm. The top lateral flanges 28 used to attach the beams 16 to the top panels 18, 22 and the top central slate 20 may have a 2-ply configuration. As described above with respect to the panels 18, 22 and the slates 20, 32, the 2-ply configuration may be obtained by folding over the side edge portions of the sheets of galvanized steel used to form the beams 16. As shown in Figs. 1 , 3 and 6, a pair of elongated arched openings 58 may be defined in the sides of each beam 16 for providing side entries for pallet handling equipment. The pallet shown in Fig. 1 with the side entries and the end entries is a four-way entry pallet that can be lifted from any sides thereof. As can be appreciated from Figs. 6 and 7, the openings 58 may be provided by pressing or deep drawing a portion of the material of the flat bottom end 30 of the beams between the diverging sides or legs of the beams. The material pressed into the V-shaped section of the beams (i.e. the die formed portions) can be seen at 60 in Fig. 7. The die formed portions may include a central arch 60a and a pair of secondary arches 60b, 60c on opposed sides of the central arch 60a. These die formed portions also contribute to strengthen the beams 16. A shape transformation process that can be used to form the transversal arched openings 58 in the beams 16 is shown in Figs. 9a to 9d. First, a sheet metal workpiece W is folded into a V-shaped elongated beam member. Then, as shown in Fig. 9a, the pre-folded sheet metal workpiece W is seated face down on a die D and held thereon by a blank-holder H. Thereafter, as shown in Fig. 9b, a central punch CP is lowered to press the underlying portion of the flat bottom end of the inverted- V-shaped workpiece W into a corresponding central cavity defined in the die D, thereby providing for the formation of the central arched 60a. As can be appreciated from Fig. 7, the central arch 60a is fully accommodated within the internal volume defined between the legs of the cold formed V-shaped beam 16. In the illustrated example, the height of the central arch 60a corresponds to the height of the legs (i.e. the top surface of the central arch is leveled with the mounting flange 28). It is understood that the central arch 60a must not project out of the top open end of the beam in order not to interfere with the mounting of the deck to the flanges 28. In order to further increase the height of the arched openings 58, a pair of secondary punches SP disposed on opposed sides of the central punch CP are pushed into the workpiece material to draw the material adjacent to the previously formed central arch 60a into corresponding cavities defined in the die D. This result in the formation of secondary arches 60b, 60c on opposed sides of the central arch 60a. As can be appreciated from Fig. 7, the height of the secondary arches 60b, 60c is less than that of the primary arch 60a. The central arch 60a and the secondary arches 60b, 60c cooperate to further strengthen the beam. Finally, as shown in Fig. 9d, the central punch CP and the secondary punches SP are withdrawn from the workpiece W to permit subsequent removal of the so cold formed arched beam from the die D.

The above shape transformation process with material retention provides for the formation of strong beams with lateral entry features for the pallet. It is understood that other suitable stamping or press forming processes could be used to form the arched openings with material retention of the plastically deformed zones within the internal volume between the legs of the beam.

The remaining land of material between the adjacent arched openings 58 and at the outer ends thereof provide the required mounting surfaces for the transversal slats 32 of the base 14.

As shown in Fig. 6, the edge portions 62 at the opposed longitudinal ends of the legs of each beam may be folded inwardly at right angles to provide additional protection to the beams 16 against collisions. As shown in Fig. 8, similar pallets 10a, 10b, 10c l Od, l Oe ... may be stacked one upon another with the downwardly projecting ridges of the corrugations formed in the bottom slats 32 fitting in corresponding troughs of the side corrugations 40 of the deck panels 18, 22 and of the central top slat 20. This nesting engagement between the corrugations of the pallets provides for added stacking stability. It also provides for a more compact stacking arrangement than conventional wooden pallets.

Advantages of the above described metal pallet constructions comprise: load bearing capability, durability, recyclable, sanitary, easy to clean, light weight and robust, fire resistant, thermally stable and re-usable.

The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the invention disclosed. For instance, any suitable metal material, such aluminum could be used to form the pallet. Also, depending on the size of the pallets, a different number of arched openings could be formed in the beams 16 to permit side entries of material handling equipment. Also, only the peripheral beams (the one along the sides of the pallet) could be provided with the side openings. It is also contemplated to manufacture a pallet without the corrugated bottom slat. Other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims.