US3882796A

US3882796A - Metal pallet

Info

Publication number: US3882796A
Application number: US485693A
Authority: US
Inventors: Joseph I Andreini; David P Riley
Original assignee: METAL PALLETS CO
Current assignee: METAL PALLETS CO
Priority date: 1974-07-02
Filing date: 1974-07-02
Publication date: 1975-05-13
Anticipated expiration: 1992-05-13

Abstract

A metal pallet having a top deck of generally rectangular form, a plurality of runners, a plurality of legs and a bottom deck, said top deck consisting of a top skin of sheet metal having therein a plurality of elongate embossments, elongate reinforcing means cooperating with said embossments and rigidly attached to said top skin and a rim extending around the entire periphery of said top skin and rigidly attached to said top skin and to said reinforcing means, said runners being arranged in spaced parallel relationship transversely of said elongate reinforcing means and being rigidly attached to said top deck, said legs being rigidly attached to said runners and extending from said runners downwardly away from said top deck and said bottom deck being rigidly attached to the lower end of said legs.

Description

Andreini et al.

1 METAL PALLET [75] Inventors: Joseph I. Andreini, Troy, Mich;

David P. Riley, Fairfield, Ohio [73] Assignee: Metal Pallets Company, Cincinnati,

Ohio

[22] Filed: July 2, 1974 21 Appl. 1 10.; 485,693

[52] U.S. Cl 108/51; 108/58 [51] Int. Cl B65d 19/28 [58] Field of Search 108/51, 55, 58

[56] References Cited UNITED STATES PATENTS 3,531,855 10/1970 Spring 1 108/51 3,616,766 11/1971 Weiss 108/51 3,719,157 3/1973 Arcocha et al.. 108/51 3,720,176 3/1973 Munroe 108/51 3,762,344 10/1973 Chez 108/51 1 1 May 13,1975

Primary Examiner-Roy D. Frazier Assistant E.\'aminerDarrell Marquette Attorney, Agent, or FirmLadas, Parry, Von Gehr, Goldsmith & Deschamps [57] ABSTRACT A metal pallet having a top deck of generally rectangular form, a plurality of runners, a plurality of legs and a bottom deck, said top deck consisting of a top skin of sheet metal having therein a plurality of elongate embossments, elongate reinforcing means cooperating with said embossments and rigidly attached to said top skin and a rim extending around the entire periphery of said top skin and rigidly attached to said top skin and to said reinforcing means, said runners being arranged in spaced parallel relationship transversely of said elongate reinforcing means and being rigidly attached to said top deck, said legs being rigidly attached to said runners and extending from said runners downwardly away from said top deck and said bottom deck being rigidly attached to the lower end of said legs.

10 Claims, 5 Drawing Figures PATENTED 3W5 3882;796

sum 1 or s PATENTED MAY I975 SHEET 2 OF 5 NUE PATENTED RAY I 3 I973 SHEET Q [If 5 YOK METAL PALLET The present invention relates to a metal pallet and, in particular, to a four-way entry non-reversible pallet suitable for engagement by the tines of a fork-lift type truck thereby to facilitate the transportation of goods supported on the pallet.

A very substantial proportion of pallets in common use today are constructed of wood. These wooden pallets are unhygienic, easily damaged, relatively heavy and, although relatively inexpensive in terms of initial cost, uneconomical to use in view of their short working life. A number of attempts have been made to produce an effective substitute for the wooden pallet. These attempts have involved the use of both metals and plastics and have until the present invention failed to produce a pallet having the necessary attributes to compete favorable with the conventional wooden pallet.

Prior art designs of metal pallet have failed to be competitive with the conventional wooden pallet for a wide variety of reasons, for example:

a. Unsuitability for mass production;

b. Excessive cost;

c. Excessive weight;

(1. Insufficient strength, stiffness and/or resilience;

e. Insufficient durability;

f. A tendency to warp or deform due to the stresses and strains of every day use;

g. Inadequate versatility (For example, having twoway or one-way entry only for the tines of a forktype lift truck);

h. Insufficient load capacity;

i. Inconvenient design features;

Designs of pallets involving the use of plastics materials have failed to provide a design capable of economical mass production coupled with the necessary requisites of strength, resilience and durability. Designs of pallets constructed of plastics materials known to the applicants all fail to exhibit the necessary durability to stand up to the stresses imposed by normal every day use of a pallet.

Examples of prior art pallets may be found in the following patents:

U.S. Pat. Nos. 3,405,666; 1,597,820; 1,797,874; 2,232,991; 3,531,855; 3,235,040; 2,741,390; 1,904,193; 1,665,799; 2,152,086; 2,634,931 and 3,776,146; Swedish Pat. No. 166,360 and French Pat. No. 1,121,113.

In relation to the prior art the metal pallet of the present invention provides a light-weight, four-way entry, economical to mass produce and use, durable metal pallet capable of supporting a 3,000 pound dynamic and a 10,000 pound static load without permanent deformation and having a high resistance to warpage, sufficient resilience to provide adequate resistance against impacts encountered in use and to limit the transmission of such impacts to goods supported by the pallet, and an economy of use on a cost/life basis superior to that of wooden pallets.

The light weight and strength combination found in the present invention stems from the unique and advanced constructional features incorporated while the suitability for economic mass production stems from the design of components to provide the necessary strength while at the same time being easy and economical to mass produce and from a design which permits rapid and easy assembly and welding of components to one another utilizing a minimum of production steps and which substantially eliminates the need for jigs to position components relative to one another during assembly. In this connection, the components have been designed to be self-locating in relation to one another during assembly in order that they, in substance, act as their own jigs. The above mentioned design features permit the pallet to be produced using only a form rolling mill, a press, a resistance welding machine and a fusion welding machine.

Applicants are unaware of any design in the prior art that provides the advantageous combination of design features of the present invention and believe that the metal pallet of the present invention is the first pallet capable of meeting the requirements of industry with respect to durability, strength and economy of production and use.

According to the present invention there is provided a metal pallet having a top deck of generally rectangular form, a plurality of runners, a plurality of legs and a bottom deck, said top deck consisting of a top skin of sheet metal having therein a plurality of elongate embossments, elongate reinforcing means cooperating with said embossments and rigidly attached to said top skin and a rim extending around the entire periphery of said top skin and rigidly attached to said top skin and to said reinforcing means, said runners being arranged in spaced parallel relationship transversely of said elongate reinforcing means and being rigidly attached to said top deck, said legs being rigidly attached to said runners and extending from said runners downwardly away from said top deck and said bottom deck being rigidly attached to the lower end of said legs.

One embodiment of metal pallet according to the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

. FIG. 1 is a perspective view of the pallet;

FIG. 2 is a fragmentary sectional elevation along section line 22 shown in FIGS. 1 and 3;

FIG. 3 is a fragmentary sectional elevation taken along section line 3-3 shown in FIGS. 1 and 2;

FIG. 4 is a fragmentary sectional plan view taken along section line 44 shown in FIGS. 1, 2 and 3; and

FIG. 5 is a fragmentary sectional view taken along section line 5-5 shown in FIGS. 2 and 3.

With reference to the drawings a pallet 1 comprises a top deck 2, three runners 3 attached to the underside of the top deck 2, nine legs 4 (5 only being shown in FIG. 1) and three bottom deck members 5 extending transversely of runners 3 and together forming a bottom deck of the pallet l.

The top deck 2 comprises three types of component, namely a top skin 6, seven stringers 7 (two only being shown) and a rim 8. The top skin 6 is constructed from steel sheet 0.018 inches thick, is of rectangular form with down turned lips 9 (one only being shown) on one pair only of opposed edges and has five embossments, of generally rectangular cross-section, extending across the top skin 6 parallel to one another and parallel to the edges of the top skin 6 having the down turned lips 9. The embossments 10 are equally spaced apart and the outer two embossments are spaced equally from their respective adjacent top skin edges. The embossments 10 extend across the full width of the top skin 6 and are three-sixteenths of an inch deep and three-fourths of an inch wide.

The stringers 7 are constructed from steel sheet 0.036 inches thick and have a top-hat cross-section, extending from the outer edges of which, parallel to the sides 12 of the section are flanges 11. The flanges 11 have a width of three-sixteenths of an inch and the stringers have a depth of three-fourths of an inch. Five of the stringers 7 form reinforcing means for the five embossments and the other two of the stringers 7 are utilized to stiffen the edges of the top skin 6 along the lips 9.

The five stringers 7 utilized to reinforce the top skin 6 at the embossments 10 fit tightly over the sides of the embossments 10 on the under side of the top skin 6 and are resistance welded thereto at a plurality of points along the length of the embossment. These five reinforcing stringers extend across the full width of and three-eighths inch beyond each side edge of the top skin 6.

The two lip reinforcing stringers 7 are mounted along the edges of the top skin 6 having the lips 2 with the inside of each top hat section engaging the inside of the respective lip 9. These two lip reinforcing stringers 7 extend across the full width of and three-eighths inch beyond each side edge of the top skin 6. In order to provide for the accommodation of the two lip reinforcing stringers 7 within curved corners 13 of the rim 8, the outer corners of these stringers are relieved sufficiently to allow them to fit within said curvature.

The rim is constructed in two

parts

14 and 15, the ends of which abut one another to form a stiffening and protective edge around the entire periphery of the top skin 6 when assembled thereto. The rim is constructed from sheet steel of 0.036 inches thickness and has a U- shaped cross-section with one leg 16 of the U being l% inches long and the other leg 17 of the U being threefourths of an inch long. The leg 16 of the rim 8 extends over the upper surface of the top skin 6 sufficiently for the base of the U-shaped cross-section of the rim 8 to engage the outer flange 1 1 and ends of the two lip reinforcing stringers 7 and to engage the ends of the five embossment reinforcing stringers 7. In order to facilitate the formation of the curved corners 13 of the rim 8, and in order to facilitate mounting of runners 3 to the top deck 2, cut-outs 18 are formed in the legs 16 and 17 of the U-shaped cross-section of the rim 8. These cut-outs 18, when the corner has been formed, take the form of a semi-circular slot extending parallel with and adjacent to the curvature of the corner and a connecting slot extending diagonally from the center of the curved portion of the cut-out to the inner corner of the respective leg of the rim. Similar cut-outs are provided in each leg 16 and 17 of each corner 13. The leg 16 of the rim 8, top skin 6 and the coincident portions of the stringers 7 are resistance welded together at a plurality of points.

The three runners 3 are identical to one another and each is constructed from sheet steel of 0.036 inches thickness and has a top-hat shaped cross-section termimating in flanges 19 and having in the base 210 of the section two longitudinally extending spaced parallel embossments 21 of generally frusto-conical crosssection. The runners 3 extend transversely of the stringers 7, one extending across the centers of the stringers 7 and other two extending respectively adjacent the opposite ends of the stringers 7; The three runners 3 terminate three-eighths of an inch within the outer periphery of the pallet 1 as defined by the outer edge of rim 8. The outer flanges 19 of the two runners 3 adjacent the ends of the stringers '7 are located inside of the U- shaped cross-section of the rim 8 between the leg 17 and the base of the lip reinforcing stringer 7 while the inner flanges 19 of these runners and both flanges 19 of the centrally positioned runner cooperate with the outer (lower) surface of leg 17 and the bases of the five embossment reinforcing stringers 7. In order to achieve this, each corner 22 of each of the outer flanges 19 of the runners 3 adjacent the ends of the stringers 7 is caused to extend through the respective slot 18 from the outer (lower) surface of the leg 17 to the inside of the U-shaped cross-section of the rim 8 (see FIG. 5). This arrangement provides a self-jigging feature useful in the production of pallets according to the present invention and the slight flexure of the runners 3 necessary to achieve this arrangement has been found to be of no disadvantage with respect to the strength or durability of such pallets.

The runners 3, leg 17 of the rim 8 and the bases of stringers 7 are fusion welded together at a plurality of points along the lengths of the outer flanges 19 of runners 3 adjacent the ends of the stringers 7 and at the ends of the other flanges 19 of the three runners 3. In addition, the flanges 19 of the runners 3 are fusion welded to the bases of stringers 7 at points of nexus therebetween. In addition, the leg 17 of the rim 8 is fusion welded to the base of the lip reinforcing stringers 7 at a plurality of points between the ends of the runners 3. The nine legs 4 are connected three to each runner 3, one at each end of each runner and one at the center of each runner. The six legs 4 adjacent the ends of the runners 3 are all of identical size while the legs at the center of the runners have a dimension taken along the length of the runners which depends upon the size of the pallet required. Although these three central legs may vary in dimension, their constructional arrangement is the same as the six legs 4 at the ends of the runners 3.

Each leg 4 is constructed from sheet steel having a thickness of 0.036 inches. Each leg 4 (see FIG. 4) is constructed to have a base 23 of generally rectangular form extending upwardly from which are sidewalls 24 and end walls 25. Each side wall 24 has an end section 26 at each end which overlaps and extends parallel with the end walls 25 to form an end arrangement 27 at each end. Each end arrangement 27 comprising a wall of three layers of the sheet steel. The three layers of each end arrangement 27 are resistance welded together. One end section 26 of each side wall has an embossment 28 of generally semi-circular form extending along the length of the leg and each end wall 25 has an embossment 29 of generally semi-circular cross-section extending along the length of the leg, the

embossments

28 and 29 together forming a strut of generally circular cross-section and the arrangement being such that the end section 26 not having an embossment 28 extends between an end wall 25 and an end section 26 having an embossment 28, thereby to form a wall diametrically across the substantially circular strut produced by the embossments 28 and 29.

The side walls 24 of each leg have a plurality of embossments 30 of substantially semi-circular crosssection which extend along the length of the leg in an evenly spaced parallel arrangement. The legs 4 at the ends of runners 3 have three such embossments 30 on each sidewall while the legs 4 at the centers of runners 3 have a number of embossments dependent on the dimension of these legs along'the lengths of the runners 3. The base 23 of each leg forms the bottom of the leg while the top of the leg is formed by extensions 31 of the sidewalls 24. The sidewalls 24 and the extensions 31 are spaced apart by a dimension sufficient to permit the extensions 31 to cooperate with opposite sides of each runner 3 while the length of the end arrangement 27 is such that the upper end of the end arrangement 27 will abut the outer (lower) surface of the base of the runner 3 with which it is associated. Prior to assembly of the runners 3 to the top deck 2 of the pallet, the extensions 31 of the legs-4 are resistance welded at a plurality of spaced apart points to the side walls of their respective runners 3, the assembled runners and legs then being assembled and welded to the top deck 2 as above described.

It will be appreciated that the extensions 31 of the legs 4 disposed centrally of the runners 3 extend equally on either end of these legs while the extensions 31 of the legs 4 adjacent the end of the runners 3 will be cut short adjacent the periphery of the pallet as shown in FIG. 2. V

The bottom deck members extend transversely of the runners 3 across the bases 23 of legs 4 to which bases they are fusion welded at a plurality of points. The bottom deck members are constructed from sheet steel of 0.018 inches thickness, have a width corresponding to the dimension of the legs 4 parallel to the length of the runners 3 and have a plurality of corrugations of generally rectangular cross-section extending along their length. The bottom deck members 5 associated with legs 4 adjacent ends of runners 3 are of the same width while the bottom deck member 5 associated with the legs 4 which are attached to the center of the runners 3 has a width dependent upon the dimension of those central legs taken along the length of the runner 3 which as referred to above is dependent upon the size of pallet required.

The longitudinal edges 32 (see FIG. 2) of the bottom deck members comprise a horizontal flange 33 folded diagonally back from which is a diagonal flange 34 from the edge remote from flange 33 of which extends downwardly a vertical flange 35. The vertical flange 35 extends in parallel with a vertical side flange 36 of the bottom deck member. The

flanges

33, 34 35 and 36 thereby form a folded in stiffened edge section having a ramp configuration to facilitate entry of the wheeled tines of a hand dolly type truck between the lower edge of the top deck 2 and the upper surface of the bottom deck formed by the three bottom deck members 5.

The corrugations of the bottom deck members 5 have a depth of three-eighths of an inch and with the exception of the corrugations adjacent the folded in edges 32, a width of 1% inches. The ends of each bottom deck member 5 are formed into a tapered section 37 and this tapered section together with the rolled in edges of thesemembers reduces the number of raw edges exposed on the pallet.

The bottom deck member 5 associated with the legs 4 disposed centrally of the runners 3 has corrugations of identical dimension to the dimensions of the corrugations of the bottom deck members 5 associated with the legs 4 at the ends of the runners 3, the number of corrugations being increased as appropriate to provide the desired width of that member.

To facilitate easy production with a minimum of changes in tools, the dimensions and spacing of embossments on the legs 4 has also been maintained constant as between the legs 4 adjacent the ends of the runners 3 and the legs 4 at the center of the runners 3. It is envisaged that only 3 widths of bottom deck member 5 and three associated sizes of legs 4 will be required to provide the various sizes of pallet required by industry and that this standardization of size will greatly facilitate economy of manufacture in mass production quantities. Such economy of manufacture is also assisted by maintaining constant the sizes of and spacing between the embossments 10 in the top skin 6 with pallets of different sizes. Irrespective of the size of pallet required, the cross-sectional sizes of the stringer 7, rim 9 and runners 3 is maintained constant, the lengths only of these items being varied as necessary to meet with the size of pallet required.

A material particularly suited to use in the pallet of the present invention is an alloy coated sheet steel having the trade name Galvalume and produced by the Bethlehem Steel Corporation.

It will be appreciated that metals other than steel, for example, aluminum, may be used for the manufacture of pallets according to the present invention and that with the use of such other materials appropriate changes in thickness of the sheet material used may be necessary.

We claim:

1. A metal pallet having a top deck of generally rectangular form, a plurality of runners, a plurality of legs and a bottom deck, said top deck consisting of a top skin of sheet metal having therein a plurality of elongate embossments, elongate reinforcing means cooperating with said embossments and rigidly attached to said top skin and a rim extending around the entire pe' riphery of said top skin and rigidly attached to said top skin and to said reinforcing means, said runners being arranged in spaced parallel relationship transversely of said elongate reinforcing means and being rigidly attached to said top deck, said legs being rigidly attached to said runners and extending from said runners downwardly away from said top deck and said bottom deck being rigidly attached to the lower end of said legs.

2. A metal pallet according to claim 1, wherein said embossments have a substantially rectangular crosssection consisting of side walls and a base and said elongate reinforcing means have a top hat shaped cross-section consisting of a base, side walls and flanges dimensioned to fit snugly over said side walls of said embossments.

3. A metal pallet according to claim 2, wherein said top-hat shaped cross-section of said elongate reinforcing means has a greater depth than the depth of the substantially rectangular cross-section of said embossments whereby, with the reinforcing means fitted snugly over said side walls of said embossments, the bases of said embossments and said reinforcing means are spaced apart to define, together with said side walls of said reinforcing means, a tubular top deck strengthening means of generally rectangular cross-section.

4. A metal pallet according to claim 3, wherein said elongate reinforcing means have longitudinal flanges extending parallel to said side walls of said top-hat section from said flanges of said top-hat section, said flanges of said top-hat section abutting said top skin.

5. A metal pallet according to claim 3, wherein a downwardly turned lip is formed on opposed edges of said top skin parallel to said embossments and a reinforcing means substantially identical to said reinforcing means of said embossments is positioned in abutting relationship with said lip to cooperate therewith and with said rim.

6. A metal pallet according to claim 5, wherein there are three said runners disposed transversely of said reinforcing means, one runner being disposed adjacent each end of said reinforcing means, the other runner being disposed centrally of said reinforcing means, said runners having a top-hat shaped cross-section consisting of a base having longitudinally extending embossments therein, said runners being rigidly attached to said reinforcing means and said rim.

7. A metal pallet according to claim 6, wherein said rim has a U-shaped cross-section forming upper and lower legs extending inwardly toward said top skin, each leg of said rim at each corner of said top skin having a slotted configuration, to facilitate manufacture thereof, and through the slotted configuration of each lower leg a said flange of an associated runner extends from the lower side of said rim to a position between said rim and the associated reinforcing means.

9. A metal pallet according to claim 8, wherein there are nine legs, one disposed adjacent each end of each runner and one disposed centrally of each runner.

10. A metal pallet according to claim 9, wherein said bottom deck consists of three bottom deck members extending transversely of said runners and each attached rigidly to three of said legs, each bottom deck member including a plurality of longitudinally extending corrugations of generally rectangular cross-section and having edges turned inwardly to form ramps facing upwardly with respect to said pallet and to provide additional stiffness in said bottom deck members.

Claims

1. A metal pallet having a top deck of generally rectangular form, a plurality of runners, a plurality of legs and a bottom deck, said top deck consisting of a top skin of sheet metal having therein a plurality of elongate embossments, elongate reinforcing means cooperating with said embossments and rigidly attached to said top skin and a rim extending around the entire periphery of said top skin and rigidly attached to said top skin and to said reinforcing means, said runners being arranged in spaced parallel relationship transversely of said elongate reinforcing means and being rigidly attached to said top deck, said legs being rigidly attached to said runners and extending from said runners downwardly away from said top deck and said bottom deck being rigidly attached to the lower end of said legs.

2. A metal pallet according to claim 1, wherein said embossments have a substantially rectangular cross-section consisting of side walls and a base and said elongate reinforcing means have a top hat shaped cross-section consisting of a base, side walls and flanges dimensioned to fit snugly over said side walls of said embossments.

8. A metal pallet according to claim 1, wherein said legs have a generally rectangular cross-section with elongate embossments formed therein of generally semi-circular cross-section which extend vertically with respect to said pallet, said legs having end wall arrangements comprising three layers with two of the layers of each end wall arrangement including elongate vertically extending embossments which cooperate to form a generally circular strut divided by the remaining layer of material, the three layers of material being ridigly attached together.