WO2008002007A1

WO2008002007A1 - Iron pallet

Info

Publication number: WO2008002007A1
Application number: PCT/KR2007/001471
Authority: WO
Inventors: Hi-Man Lee
Original assignee: Samjung Industries Co., Ltd
Priority date: 2006-06-28
Filing date: 2007-03-27
Publication date: 2008-01-03
Also published as: KR100817251B1; KR20080000963A

Abstract

A metal pallet is disclosed. In an embodiment thereof, the metal pallet includes an upper plate having longitudinal depressions and prominences formed through bending, and a leg/ support unit locked to the lower surface of the upper plate using a locking unit. In another embodiment, the metal pallet includes upper and lower plates, each having longitudinal depressions and prominences formed through bending, and a leg/support unit locked to the upper and lower plates using a locking unit at a location between the plates. Thus, the metal pallet, having reduced weight, can be easily and quickly produced through an automated process. Further, the metal pallet has a bent reinforced part, caps and reinforcing units, thus having increased strength. A safety means may be formed on the sharp ends of the upper and lower plates through coating, or may be formed on the leg/support units through bending, thus covering the sharp ends of the upper and lower plates and protecting workers from the sharp ends. Further, prong holes are formed in the leg/support units so that the prongs of a forklift truck can be inserted into the prong holes.

Description

[DESCRIPTION]

[invention Title]

IRON PALLET [Technical Field] The present invention relates, in general, to metal pallets, and more particularly, to a metal pallet, which comprises a plurality of upper and lower plates and a plurality of leg/support units, made of thin steel sheets which are repeatedly bent to form prominences and depressions to increase the strength thereof, with caps installed in the open ends of each leg/support unit, reinforcing units installed in the middle portion of each leg/support unit, and a safety means provided on the opposite ends of each of the upper and lower plates through coating or along the upper edge of an outer wing of each leg/support unit through bending, in which the elements of the pallet are locked to each other through caulking using a press, thus reducing the pallet production time, reducing the pallet production cost, automating the pallet production process, and remarkably reducing the weight of the metal pallet to accomplish lightness of the pallet, and in which the strength of the pallet increases due to reinforced parts and reinforcing units having prominences and depressions, and the opposite ends of each of the upper and lower plates are provided with a safety means, which is formed through coating, or are covered with a safety means of the leg/support unit, thus protecting workers from the sharp ends of the plates and protecting the ends of the plates from damage and deformation.

[Background Art]

Generally, in various industrial fields, pallets are preferably used for easily, quickly and safely handling products for shipping and delivery. Most conventional pallets, used for shipping and delivery of products in the related art, are wood pallets, which are typically produced by arranging a plurality of wood frames, having a predetermined thickness, length and width, in a lattice structure and by locking the wood frames to each other using locking members, such as nails, fastened to the intersections in the lattice structure. However, the conventional wood pallets are problematic in that the strength is low and the lifespan is short.

Particularly, when the wood pallets are used as supports for bricks or stones in the open air, the wood frames of the pallets are exposed to moisture or water, thus getting wet and being deformed. Further, the wet wood pallets may rot and gather mold, thus giving off odors and causing damage to the products loaded on the pallets. In most countries, wood, used as the material of the wood pallets, must be imported, so that the wood pallets cause excessive foreign trade in those countries. Further, the wood pallets also waste natural resources and cause environmental pollution. Thus, in an effort to prevent the corrosion of wood pallets and increase the strength of pallets, plastic pallets are proposed and used.

The conventional plastic pallets can be produced in large quantities and have increased strength. In comparison with the conventional wood pallets, the conventional plastic pallets have an increased lifespan due to their increased strength. However, because the conventional plastic pallets are produced as integrated structures through injection molding processes, they are heavy and reduce shipping and delivery efficiency, thus remarkably increasing shipping and delivery costs. Further, the worn or broken plastic pallets cannot be recycled, are discarded as waste, thus causing environmental pollution.

Thus, in an effort to overcome the problems of the wood pallets and the plastic pallets, in recent years, metal pallets have been proposed and used. However, the conventional metal pallets comprise many elements, thus increasing the pallet production cost. The large number of elements also makes it difficult to produce the conventional metal pallets in large quantities. Further, the conventional metal pallets are configured such that the elements are assembled with each other into a pallet through welding or bolting. However, the welding process increases the cost of producing the metal pallets, while the bolting process causes problems in that the bolts may be easily loosened due to vibration and load when the metal pallets are used for a lengthy period of time, so that the bolted metal pallets may not be easy to use, and may have a reduced lifespan.

Further, in the related art, another type of metal pallet, which is integrated with legs to form a single structure, has been proposed. However, the metal pallets having integrated legs are problematic in that they require expensive production facilities. Further, the metal pallets having integrated legs are heavy, incur high pallet production costs, and cause many problems in the practical use thereof .

Thus, in an effort to overcome the problems experienced in the conventional metal pallets, the inventor of the present invention proposed new techniques related to metal pallets in Korean Patent Application Nos. 10-2004-108331, 10- 2005-51713, 10-2005-51714, 10-2005-51715, 10-2005-51716 and 10-2005-64652.

Korean Patent Application No. 10-2004-108331 proposes a surface treatment technique for preventing the slippage of metal pallets and increasing the corrosion resistance and abrasion resistance of the pallets. Korean Patent Application No. 10-2005-51713 proposes a technique for increasing the strength of metal pallets using a middle support unit. Korean Patent Application No. 10-2005-51714 proposes a technique for generating anions and far-infrared rays from pallets by- coating the surfaces of the metal pallets with specific materials. Korean Patent Application No. 10-2005-51715 proposes a safety metal pallet with a safety means on its side surface, such that the upper and lower plates of the pallet can be locked to each other without using a separate locking means. Korean Patent Application No. 10-2005-51716 proposes a metal pallet structure, in which locking depressions and locking protrusions are formed in the middle members of a pallet, so that the elements of the pallet can be jointed together without using separate elements. Korean Patent Application No. 10-2005-64652 proposes a metal pallet structure, in which the elements can be assembled with each other through compression-locking.

However, in the metal pallets disclosed in the above Korean Patent Applications, the legs, which function as elements for connecting the upper and lower plates to each other, have cubic column shapes, so that each of the pallets must include the upper and lower plates. Further, because the upper and lower plates must be connected to each other using the plurality of legs, the number of elements of the pallet and the number of joints of the elements are increased, thus complicating the pallet production process and increasing the pallet production cost.

Further, in the prior art metal pallets, the upper plate, the lower plate and the middle plate may be locked to each other to form a pallet using locking pieces. Alternatively, the upper plate, the lower plate and the middle plate may be integrated into a single structure through welding or riveting. However, the locking method using the locking pieces is problematic in that it is difficult to execute the process and consumes excessive labor, and, furthermore, the produced pallets raise many problems in practical use.

Described in detail, the locking method for fabricating the conventional metal pallets using the locking pieces can provide high locking strength in the produced metal pallets. However, this locking method requires excessive labor cost and is difficult to automate and, further, the produced pallets cannot effectively resist vibrations. The welding method may cause many problems according to the working conditions and, furthermore, when the process is automated, high installation costs are incurred. Further, the other methods for producing the conventional metal pallets are disadvantageous with respect to the production cost and quality of products. Further, in the conventional metal pallets, the legs cannot support all of the upper and lower plates, but support only part of support plates, which support the upper and lower plates at locations below the upper and lower plates. Thus, the upper and lower plates have reduced bending strength and require corresponding support plates, thereby- increasing the number of elements, complicating the assembly process, and increasing the production cost of the pallets.

Further, in the conventional metal pallets, the free ends of the upper and lower plates, which are repeatedly bent to form zigzag structures, are exposed outside the opposite sides of the pallet at the upper and lower sides of the pallet, so that workers may be injured by the sharp ends of the upper and lower plates while handling the pallets. Further, when a variety of products loaded on the metal pallets are moved by forklift trucks, the prongs of a forklift truck come directly into contact with the lower surface of the upper plate of a metal pallet or with the lower surface of a support plate of the upper plate. Thus, the jointed parts between the upper plate, the support plate and the legs are overloaded, so that the upper plate and the support plate may be bent, or the jointed parts may be damaged, thus causing inconvenience while using the pallets and reducing the lifespan of the pallets. [Disclosure] [Technical Problem]

Accordingly, the present invention has been made in an effort to solve the problems occurring in the related art, and an object of the present invention is to provide a metal pallet, which can be produced through an automated process and has a reduced number of elements, thus reducing the pallet assembly time and the pallet production cost, and which has reduced weight, thus accomplishing lightness of the pallets, and in which the elements have increased strength due to both reinforced parts and reinforcing units, each having depressions and prominences and provided in the elements, and which includes a safety means formed on the sharp ends of each of the upper and lower plates through coating, or formed on a leg/support unit, thus covering the sharp ends of the upper and lower plates and protecting workers from the sharp ends of the plates, and in which the upper and lower plates are supported by the leg/support units having caps and reinforcing units, thus being prevented from deformation, and in which prong holes are formed in each leg/support unit for allowing the prongs of a forklift truck to be inserted into the prong holes, with a reinforcing flange formed around each prong hole through bending, thus preventing the upper and lower plates or the leg/support units from being bent and preventing the jointed parts of the elements from being damaged when a product loaded on the pallet is moved by the forklift truck, thereby increasing the lifespan of the metal pallet .

[Technical Solution]

In order to achieve the above object, according to the first embodiment of the present invention, there is provided a metal pallet, comprising: a plurality of longitudinal upper plates, each repeatedly bent to form a plurality of longitudinal depressions and longitudinal prominences alternately arranged, the upper plates being arranged on a plurality of longitudinal leg/support units at regular intervals and locked thereto using a plurality of locking units; and the longitudinal leg/support units arranged below the upper plates at regular intervals and locked thereto using the locking units, the leg/support units individually comprising opposite sidewalls, which are inclined downwards and inwards and are repeatedly bent to form a plurality of reinforced parts having vertical prominences and vertical depressions, with a wing provided along the upper edge of each of the opposite sidewalls of the leg/support unit, so

that the leg/support unit has a \—' -shaped cross-section.

Further, the metal pallet may be provided with a plurality of prong holes in the sidewalls thereof, thus receiving the prongs of a forklift truck therein, with a reinforcing flange formed around the edge of each of the prong holes through bending.

Further, a cap, repeatedly bent to form a vertical reinforced part having depressions and prominences, may be installed in each open end of the leg/support unit. Further, a reinforcing unit may be installed around each of the prong holes of the opposite sidewalls of the leg/support unit. The reinforcing unit may comprise a horizontal plate part and a wing part bent downwards from each end of the horizontal plate part, with reinforced parts longitudinally formed on the horizontal plate part and the opposite wing parts.

The metal pallet may further comprise: a safety means having a cubic bar shape formed along the edge of the outer wing of the leg/support unit through bending, thus covering the sharp ends of the upper plate.

According to the second embodiment of the present invention, there is provided a metal pallet, comprising: a plurality of longitudinal upper and lower plates, each repeatedly bent to form a plurality of alternately arranged longitudinal depressions and longitudinal prominences, the upper and lower plates being arranged on and below a plurality of longitudinal leg/support units at regular intervals and locked thereto using a plurality of locking units; and the longitudinal leg/support units arranged between the upper and lower plates at regular intervals and locked thereto using the plurality of locking units, the leg/support units individually comprising opposite sidewalls arranged at a constant interval, with a wing provided along each of the upper and lower edges of each of the opposite sidewalls, so that the leg/support unit has a t=-shaped cross-section, and caps locked to the opposite ends and to an intermediate portion of the leg/support unit using a plurality of locking units.

Further, a reinforcing unit may be installed in the leg/support unit at a location around each of the prong holes of the opposite sidewalls of the leg/support unit. The reinforcing unit may comprise a horizontal plate part and a wing part bent downwards from each end of the horizontal plate part, with reinforced parts longitudinally formed on the horizontal plate part and the opposite wing parts.

The metal pallet may further comprise: a safety means having a cubic bar shape formed along the edge of each of the upper and lower wings of the outer sidewall of the leg/support unit through bending, thus covering the sharp ends of the upper and lower plates. In the metal pallet, the opposite sidewalls and the caps of the leg/support unit may be repeatedly bent to form respective reinforced parts having vertical prominences and vertical depressions. Further, in the first and second embodiments of the present invention, the opposite ends of the upper plate and/or the lower plate may be coated with rubber or synthetic resin to a predetermined thickness, thus forming a safety means . Further, the opposite edges of each cap and the opposite edges of each reinforcing unit may be provided with respective locking flanges through bending, so that the caps and the reinforcing units can be locked to the leg/support units or to the upper and lower plates using the locking units.

Further, the locking units, which lock the upper plates to the leg/support units, lock the upper and lower plates to the leg/support units, and lock the caps and the reinforcing units to the leg/support units, may be formed through a caulking process, in which a punch and a die are located on and below the junctions of neighboring elements and the punch is moved downwards to the die, so that a locking protrusion is formed in one element, a locking depression is formed in another element, the locking protrusion is inserted into the locking depression, and the locking protrusion and the locking depression are compressed and deformed together, thus being locked to each other.

Further, each of the upper and lower plates may be provided with a reinforcement, which is formed on the inner surface of each end of the upper and lower plates by folding the end inwards.

[Advantageous Effects]

As described above, the metal pallet according to the present invention is advantageous in that, first, the elements of the metal pallet can be produced through an automated process and the number of elements is reduced, thus reducing the pallet assembly time and the pallet production cost, second, the weight of the metal pallet is remarkably reduced, thus accomplishing lightness of the metal pallets, third, the elements of the metal pallet, made of thin steel sheets, are provided with bent reinforced parts having prominences and depressions and the leg-support units are provided with caps and reinforcing units, thus having increased strength, fourth, a safety means may be formed on the sharp ends of each of the upper and lower plates through coating, or may be formed on the leg/support units through bending, thus covering the sharp ends of the upper and lower plates and protecting workers from the sharp ends. Fifth, the upper and lower plates are supported by the leg/support units having the caps and the reinforcing units, thus being prevented from deforming. Sixth, prong holes are formed in each leg/support unit for allowing the prongs of a forklift truck to be inserted into the prong holes, with a reinforcing flange formed around each prong hole through bending, so that, when a product loaded on the pallet is moved by the forklift truck, the upper and lower plates or the leg/support units can be prevented from being bent and the jointed parts of the elements can be prevented from being damaged, thereby remarkably increasing the lifespan of the metal pallets .

[Description of Drawings]

FIG. 1 is a perspective view illustrating a metal pallet according to the first embodiment of the present invention;

FIG. 2 is a perspective view illustrating the metal pallet according to the first embodiment of the present invention, with a safety means provided on the upper surface of a leg/support unit of the pallet;

FIG. 3 is a perspective view illustrating a metal pallet according to the second embodiment of the present invention;

FIG. 4 is a perspective view of the metal pallet according to the second embodiment of the present invention, with a safety means provided on a side surface of a leg/support unit of the pallet;

FIGS. 5 (a) and 5 (b) are perspective views of an upper plate and a lower plate used in respective metal pallets according to the first and second embodiments of the present invention;

FIG. 6 is a partially exploded perspective view of the leg/support unit used in the metal pallet of FIG. 1;

FIG. 7 is a partially exploded perspective view of the leg/support unit used in the metal pallet of FIG. 2;

FIG. 8 is a partially exploded perspective view of the leg/support unit used in the metal pallet of FIG. 3;

FIG. 9 is a partially exploded perspective view of the leg/support unit used in the metal pallet of FIG. 4; and FIGS. 10 (a) through 10 (d) are sectional views illustrating the operation of a punch and a die for forming a locking unit used for locking the elements of the metal pallet of the present invention to each other and illustrating the shape of the locking unit.

[Best Mode]

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view illustrating a metal pallet according to the first embodiment of the present invention. FIG. 2 is a perspective view illustrating the metal pallet according to the first embodiment of the present invention, with a safety means provided on the upper surface of a leg/support unit of the pallet. FIG. 3 is a perspective view illustrating a metal pallet according to the second embodiment of the present invention. FIG. 4 is a perspective view of the metal pallet according to the second embodiment of the present invention, with a safety means provided on the side surface of a leg/support unit of the pallet.

FIGS. 5 (a) and 5 (b) are perspective views of an upper plate and a lower plate used in respective metal pallets according to the first and second embodiments of the present invention. FIG. 6 is a partially exploded perspective view of the leg/support unit used in the metal pallet of FIG. 1. FIG. 7 is a partially exploded perspective view of the leg/support unit used in the metal pallet of FIG. 2. FIG. 8 is a partially exploded perspective view of the leg/support unit used in the metal pallet of FIG. 3. FIG. 9 is a partially exploded perspective view of the leg/support unit used in the metal pallet of FIG. 4. FIGS. 10 (a) through 10 (d) are sectional views illustrating the operation of a punch and a die for forming a locking unit used for locking the elements of the metal pallet of the present invention to each other and illustrating the shape of the locking unit. As shown in the drawings, the metal pallet according to the first embodiment of the present invention comprises a plurality of longitudinal upper plates 1, each of which is repeatedly bent to form a plurality of alternately arranged longitudinal depressions 11 and a plurality of longitudinal prominences 12. The upper plates 1 are arranged on a plurality of longitudinal leg/support units 3 at regular intervals and are locked thereto by a plurality of locking units 5. The longitudinal leg/support units 3, which are arranged below the upper plates 1 at regular intervals and are locked thereto using the plurality of locking units 5, individually comprise opposite sidewalls, which are inclined downwards and inwards and are repeatedly bent to form a plurality of reinforced parts 31 having vertical prominences and vertical depressions. A wing 32 is provided along the upper edge of each of the opposite sidewalls of the leg/support unit 3 , so that the leg/support unit 3 has a

V-/ -shaped cross-section. A plurality of prong holes 33 is formed in the sidewalls of the leg/support unit 3, so that the prongs of a forklift truck can be inserted into the prong holes 33. A reinforcing flange 34 is formed around the edge of each of the prong holes 33 through bending. A cap 6, which is provided with a vertical reinforced part 61, is locked to each open end of the leg/support unit 3. A reinforcing unit 7 is securely installed around the facing prong holes 33 of the opposite sidewalls of the leg/support unit 3. The reinforcing unit 7 comprises a horizontal plate part 71 and a wing part 72, which is bent downwards from each end of the horizontal plate part 71, with reinforced parts 711 and 721 longitudinally formed on the horizontal plate part 71 and the opposite wing parts 72.

Further, to cover the sharp ends of the upper plate 1, a safety means 35, which has a cubic bar shape, may be formed along the edge of the outer wing 32 of the leg/support unit 3 through bending.

Meanwhile, the metal pallet according to the second embodiment of the present invention comprises a plurality of longitudinal upper and lower plates 1 and 2, each of which is repeatedly bent to form a plurality of longitudinal depressions 11, 21 alternately arranged with a plurality of longitudinal prominences 12, 22. The upper and lower plates 1 and 2 are arranged on and below a plurality of longitudinal leg/support units 4 at regular intervals and are locked thereto using a plurality of locking units 5.

The longitudinal leg/support units 4, which are arranged between the upper and lower plates 1 and 2 at regular intervals and are locked thereto using the plurality of locking units 5, individually comprise opposite sidewalls 4a and 4b, which are arranged at a constant interval and are repeatedly bent to form a plurality of reinforced parts 41 having vertical prominences and vertical depressions. A wing 42 is provided along each of the upper and lower edges of each of the opposite sidewalls 4a and 4b of the leg/support unit 4, so that the leg/support unit 4 has a ^-shaped cross- section. Caps 8, each of which has a rectangular shape and has a vertical reinforced part 81, are locked to the opposite open ends and to an intermediate portion of the leg/support unit 4 using a plurality of locking units 5.

Further, a plurality of prong holes 43 is formed in the sidewalls 4a and 4b of the leg/support unit 4, so that the prongs of a forklift truck can be inserted into the prong holes 43. A reinforcing flange 44 is formed around the edge of each of the prong holes 43 through bending. A reinforcing unit 9 is securely installed around the facing prong holes 43 of the opposite sidewalls 4a and 4b of the leg/support unit 4. The reinforcing unit 9 comprises a horizontal plate part 91 and a wing part 92, which is bent downwards from each end of the horizontal plate part 91, with reinforced parts 911 and 921 longitudinally formed on the horizontal plate part 91 and the opposite wing parts 92.

Further, to cover the sharp ends of the upper and lower plates 1 and 2, a safety means 45, which has a cubic bar shape, may be formed along the edge of each of the upper and lower wings 42 of the outer sidewall 4b of the leg/support unit 4 through bending.

Further, rubber or synthetic resin may be applied on each end of the upper plate 1, used in the pallet of the first embodiment of the present invention, or may be coated on each end of each of the upper and lower plates 1 and 2 used in the pallet of the second embodiment of the present invention, thus forming a safety means 10 having a predetermined thickness. Further, the opposite edges of the cap 6, 8 and the opposite edges of the reinforcing unit 7, 9 are provided with respective locking flanges 62, 82 and 73, 93 through bending so that the caps 6, 8 and the reinforcing units 7, 9 can be locked to the leg/support units 3, 4 or to the upper and lower plates 1 and 2 using the locking units 5.

Further, the locking units 5, which lock the upper plates 1 to the leg/support units 3, lock the upper and lower plates 1 and 2 to the leg/support units 4, and lock the caps 6 and 8 and the reinforcing units 7 and 9 to the leg/support units 3 and 4, are formed through a caulking process, in which a punch P and a die D are located on and below the junctions of neighboring elements and, thereafter, the punch P is moved downwards to the die D, so that a locking protrusion 51 is formed in one element and a locking depression 52 is formed in another element, and, at the same time, the locking protrusion 51 is inserted into the locking depression 52. In the above state, the locking protrusion 51 and the locking depression 52 are compressed and deformed together, thus being locked to each other. Further, the opposite ends of each of the upper and lower plates 1 and 2 are provided with reinforcements 13 and 23 through folding.

The operational effect of the metal pallet according to the present invention will be described hereinbelow. The metal pallets according to the present invention are configured as two types, one comprising a plurality of leg/support units 3, which are arranged below a plurality of upper plates 1 at regular intervals and are locked thereto, the other comprising a plurality of leg/support units 4, which are arranged between a plurality of upper and lower plates 1 and 2 at regular intervals and are locked thereto.

In the present invention, the sheet materials of the upper and lower plates 1 and 2 and the leg/support units 3 and 4 are selected from galvanized steel sheets, pre-painted steel sheets, stainless steel sheets, aluminum sheets and cold-rolled steel sheets 0.3-1.2 mm thick. The sheet materials are formed into desired shapes through forming, pressing and cutting.

As shown in FIGS . 5 (a) and 5 (b) , the upper plate 1 and/or the lower plate 2, used in the first or second embodiment of the present invention, is fabricated by bending a sheet such that the plurality of longitudinal depressions 11 and the plurality of longitudinal prominences 12 are alternately formed on the sheet. In the present invention, rubber or synthetic resin may be coated on each end of the upper and lower plates 1 and 2 to a predetermined thickness and width (for example, 5 mm thickness and 5-20 mm width) , thus forming a safety means 10 capable of preventing workers from being injured by the sharp ends of the plates 1 and 2. Further, in order to prevent workers from being injured by the sharp ends of the upper and lower plates 1 and 2 of the present invention and prevent the ends of the upper and lower plates 1 and 2 from being damaged or deformed by external shock or pressure, reinforcements 13 and 23 are formed on the inner surfaces of the ends of the upper and lower plates 1 and 2 by folding the ends inwards.

Unlike a conventional pallet, which comprises integrated upper and lower plates, the metal pallet according to the first embodiment of the present invention comprises upper plates 1 with no lower plate. Further, the leg/support units 3, which are arranged below the upper plates 1 and are locked thereto using the locking units 5, are configured as a tapered cross-section rather than a rectangular cross- section, wherein the opposite sidewalls of the tapered structure are inclined downwards and inwards. Described in detail, as shown in FIG. 1 and FIG. 6, the opposite sidewalls of each of the leg/support units 3, used in the metal pallet according to the first embodiment of the present invention, are inclined downwards and inwards and are repeatedly bent to form reinforced parts 31 having vertical prominences and vertical depressions. Further, the wings 32 are formed along the upper edges of the opposite sidewalls of each leg/support unit 3, so that the leg/support unit 3 has

the XV_f/--,shaped cross-section. Further, the prong holes 33 are formed in the sidewalls of each of the leg/support units 3 , so that the prongs of a forklift truck can be inserted into the prong holes 33. Further, a reinforcing flange 34 is formed around the edge of each of the prong holes 33 through bending. Thus, when freight loaded on the metal pallet is raised using a forklift truck, the reinforcing flanges 34 prevent the sheets of the leg/support units 3 and the edges of the prong holes 33 from being deformed or damaged.

Further, the cap 6, which is provided with the vertical reinforced part 61 and the locking flanges 62, is locked to each open end of the leg/support units 3. Thus, the

leg/support units 3 can maintain the i—' -shaped cross- sections thereof without being bent inwards or outwards or opening. Further, the reinforcing unit 7, which comprises the horizontal plate part 71 and the wing parts 72, bent downwards from the opposite ends of the horizontal plate part 71, with both the locking flanges 73 and the reinforced parts 711 and 721 longitudinally formed on the horizontal plate part 71 and the opposite wing parts 72, is securely installed around the prong holes 33 of the opposite sidewalls of the leg/support unit 3. Thus, the parts of the leg/support units

3, having the prong holes 33, can maintain the \-J -shaped cross-sections, without being bent inwards or outwards or being opened.

Further, as described above, when the upper plates 1 are arranged on and locked to the leg/support units 3, each of which has both the caps 6 in the opposite ends thereof and the reinforcing units 7 at locations around the prong holes 33, with the wings 32 formed along the upper edges of the opposite sidewalls of the leg/support unit 3 through bending, the sharp ends of the upper plates 1 may be exposed outside the edges of the outer wings 32 of the leg/support units 3, so that workers may be injured by the exposed sharp ends of the upper plates 1 while handling the pallets.

However, in the present invention, as shown in FIG. 2 and FIG. 7, a safety means 35, which has the cubic bar shape, may be formed along the edge of the outer wing 32 of the leg/support unit 3 through bending, thus covering the sharp ends of the upper plates 1 and preventing workers from being injured by the sharp ends of the upper plates 1 when handling the pallets.

Unlike the first embodiment of the present invention, the leg/support units 4 according to the second embodiment of the present invention are arranged between the upper and lower plates 1 and 2 and are locked thereto using the locking units 5. As shown in FIG. 3 and FIG. 8, to fabricate each of the leg/support units 4, two sidewalls 4a and 4b, which have both the wings 42 formed along the upper and lower edges of each sidewall 4a, 4b and the reinforced parts 41 having vertical prominences and vertical depressions, thus having the τ= -shaped cross-section, are arranged at a constant interval. Thereafter, the caps 8, which have the rectangular shape and have the respective vertical reinforced parts 81, are locked to the two sidewalls 4a and 4b in the opposite open ends and in the intermediate portion of the leg/support unit 4 using the locking units 5.

Further, in the same manner as that described for the first embodiment of the present invention, the prong holes 43 are formed in the sidewalls 4a and 4b of each leg/support unit 4 according to the second embodiment of the present invention, so that the prongs of a forklift truck can be inserted into the prong holes 43. Further, the reinforcing flange 44 is formed around the edge of each of the prong holes 43 through bending. Thus, when freight loaded on the metal pallet is raised using a forklift truck, the reinforcing flanges 44 prevent the sheets of the leg/support units 4 and the edges of the prong holes 43 from being deformed or damaged.

Further, the reinforcing units 9 are locked to the opposite sidewalls 4a and 4b of the leg/support unit 4 at locations around the prong holes 43. Each of the reinforcing units 9 comprises the horizontal plate part 91 and the wing part 92, which is bent downwards from each end of the horizontal plate part 91 and has the two locking flanges 93, with the reinforced parts 911 and 921 longitudinally formed on the horizontal plate part 91 and the opposite wing parts 92. Thus, the sidewalls 4a and 4b of the leg/support units 4 can remain horizontal without being bent inwards or outwards or being opened in the portions having the prong holes 43.

Further, the safety means 45, which has the cubic bar shape, may be formed along the edge of each of the upper and lower wings 42 of the outer sidewall 4b of the leg/support unit 4 through bending, thus covering the sharp ends of the upper and lower plates 1 and 2 and preventing workers from being injured by the sharp ends of the upper and lower plates 1 and 2 while handling the pallets.

Further, the locking units 5, which lock the upper plates 1 to the leg/support units 3 in the first embodiment of the present invention, lock the upper and lower plates 1 and 2 to the leg/support units 4 in the second embodiment of the present invention, and lock the caps 6 and 8 and the reinforcing units 7 and 9 to the leg/support units 3 and 4 in the first and second embodiments of the present invention, are formed through a caulking process.

Described in detail, when the elements of the metal pallets are automatically fed to a caulking stage on an automatic production line for the metal pallets, a punch P and a die D are located on and below the junctions of neighboring elements (for example, on a depression 11, 21 of an upper or lower plate 1, 2 and below a wing 42 of a leg/support unit 4), as shown in FIG. 10 (a) . Thereafter, the punch P is moved downwards to the die D, as shown in FIG. 10 (b) , so that a locking protrusion 51 is formed in one element, which is placed up, and a locking depression 52 is formed in another element, which is placed down and, at the same time, the locking protrusion 51 is inserted into the locking depression 52. In the above state, part of the locking protrusion 51 is compressed and deformed to match the shape of a cavity of the die D when the locking protrusion 51 enters the locking depression 52. In other words, the locking protrusion 51 is deformed in the locking depression 52 in response to the deformation of the locking depression 52, so that the locking protrusion 51 and the locking depression 52 are locked to each other, as shown in FIG.

10 (c) .

Thus, the present invention can automatically produce metal pallets and provides increased locking force between the elements of the pallet, thus preventing the locked parts in the pallet from being undesirably separated from each other while the pallet is used. Further, the present invention simplifies the pallet production process, thus increasing the operational reliability of the pallet and reducing the production cost of the pallet. In the present invention, the material of the metal pallet may be selected from steel, iron, etc.

Although preferred embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims .

[industrial Applicability]

As described above, the present invention provides a metal pallet. To produce the pallet, thin steel sheets are repeatedly bent to form a plurality of prominences and depressions, thus having increased strength. Upper and lower plates and leg/support units are made of the steel sheets, with caps installed in the open ends of each leg/support unit and reinforcing units installed in the middle portion of the leg/support unit. Further, a safety means may be provided along the ends of the upper and lower plates through coating, or may be provided along the upper edge of an outer wing of each leg/support unit through bending. The elements of the pallet are locked to each other through caulking using a press. Thus, the present invention saves pallet production time, reduces the pallet production cost, and automates the pallet production process. Further, the present invention remarkably reduces the weight of the metal pallet, thus accomplishing lightness of the pallet. Further, due to the reinforced parts and reinforcing units, each having prominences and depressions, the pallet of the present invention has increased strength. The opposite ends of each of the upper and lower plates may be provided with a safety means, which is formed through coating, or may be covered with a safety means of the leg/support unit, so that the present invention protects workers from the sharp ends of the plates and protects the ends of the plates from damage or deformation.

Claims

[CLAIMS]

[Claim l]

A metal pallet, comprising: an upper plate with a plurality of longitudinal depressions and prominences alternately formed in the upper plate through bending; and a leg/support unit arranged below the upper plate and locked to the upper plate using a locking unit.

[claim 2]

A metal pallet, comprising: an upper plate and a lower plate, with a plurality of longitudinal depressions and prominences alternately formed in each of the upper and lower plates through bending; and a leg/support unit arranged between the upper and lower plates and locked to the upper and lower plates using a locking unit .

[claim 3] The metal pallet according to claim 1 or 2, wherein each of the upper and lower plates further comprises : safety means formed along opposite ends of each of the upper and lower plates by coating rubber or synthetic resin on the ends to a predetermined thickness.

[claim 4]

The metal pallet according to claim 1 or 2, wherein each of the upper and lower plates is provided with a reinforcement formed on an inner surface of each end of the upper and lower plates by folding the end inwards.

[claim 5]

The metal pallet according to claim 1, wherein the leg/support unit comprises: opposite sidewalls inclined downwards and inwards and repeatedly bent to form a reinforced part having vertical prominences and vertical depressions, with a wing provided along an upper edge of each of the opposite sidewalls of the leg/support unit.

[claim 6]

The metal pallet according to claim 5, wherein the

leg/support unit has a \—' -shaped cross-section.

[claim 7]

The metal pallet according to claim 5, wherein the leg/support unit is provided with a plurality of prong holes in the sidewalls thereof, thus receiving prongs of a forklift truck therein, with a reinforcing flange formed around an edge of each of the prong holes through bending.

[claim 8]

The metal pallet according to claim 7, further comprising: a cap installed in each open end of the leg/support unit, the cap being provided with a vertical reinforced part having depressions and prominences formed through bending.

[claim 9] The metal pallet according to claim 7, further comprising: a reinforcing unit installed around each of the prong holes of the opposite sidewalls of the leg/support unit, the reinforcing unit comprising a horizontal plate part and a wing part bent downwards from each end of the horizontal plate part, with reinforced parts longitudinally formed on the horizontal plate part and the opposite wing parts.

[claim lθ] The metal pallet according to claim 8, further comprising: safety means having a cubic bar shape formed along an edge of the outer wing of the leg/support unit through bending, thus covering sharp ends of the upper plate. [claim ll]

The metal pallet according to claim 2, wherein the leg/support unit comprises : opposite sidewalls arranged at a constant interval and repeatedly bent to form reinforced parts having vertical prominences and vertical depressions, with wings provided along upper and lower edges of the opposite sidewalls of the leg/support unit, thus making the leg/support unit have a tr- shaped cross-section, with rectangular caps having a vertical reinforced part locked to opposite open ends and to an intermediate portion of the leg/support unit using a plurality of locking units.

[claim 12] The metal pallet according to claim 11, wherein the leg/support unit is provided with a plurality of prong holes in the sidewalls thereof, thus receiving prongs of a forklift truck therein, with a reinforcing flange formed around an edge of each of the prong holes through bending.

[claim 13]

The metal pallet according to claim 12, further comprising: a reinforcing unit installed in the leg/support unit at a location around each of the prong holes of the opposite sidewalls of the leg/support unit, the reinforcing unit comprising a horizontal plate part and a wing part bent downwards from each end of the horizontal plate part, with reinforced parts longitudinally formed on the horizontal plate part and the opposite wing parts.

[claim 14]

The metal pallet according to claim 11, further comprising: safety means having a cubic bar shape formed along an edge of each of the upper and lower wings of the outer sidewall of the leg/support unit through bending, thus covering sharp ends of the upper and lower plates.

[claim 15]

The metal pallet according to claim 1 or 2, wherein the locking unit is formed through a caulking process, in which a punch and a die are located on and below junctions of neighboring elements and the punch is moved downwards to the die, so that a locking protrusion is formed in one element and a locking depression is formed in another element and the locking protrusion is inserted into the locking depression, and the locking protrusion and the locking depression are compressed and deformed together, thus being locked to each other.