CA1071552A

CA1071552A - Pallet construction

Info

Publication number: CA1071552A
Application number: CA257,959A
Authority: CA
Inventors: Ferdinand M. Svirklys
Original assignee: Extrados Co Ltd
Current assignee: Extrados Co Ltd
Priority date: 1975-05-14
Filing date: 1976-07-28
Publication date: 1980-02-12
Also published as: GB1544661A; DE2621546A1; DE2621546B2; JPS51139043A; DE7615404U1; CA997690A; CA997689A; AU507599B2; JPS5416090B2; NL7708353A; BE857277A; SE7708556L; AU1786876A; DE2621546C3; CH613666A5

Abstract

PALLET CONSTRUCTION
ABSTRACT OF THE DISCLOSURE
A knock-down pallet is constructed of a plurality of releasably interlocking aluminum members of one of two types. A unique fastening device is used to achieve, in simple manner without special tools or skill, the inter-locking of a plurality of spaced-parallel deck-forming members to two, three or more spaced and parallel stringer members of rectangular cross-section to provide a one- or two-deck two-way or four-way pallet construction. A stop means prevents longitudinal movement of the deck members transverse of the stringer members.

Description

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This invention relates to cons~ructions formed of releasably interlockable members, particularly pallets and fences.

Pallets for warehousiny use and material handling typically have been constructed of wood and provided in a permanent structure. Pallets generally have one or two decks and are provided in 2-way entry or 4-way entry types.
Wooden pallets although used almost universally in material handling suffer from considerable drawbacks.
In view of the permanence of the structure, wooden pallets occupy considerable storage area during shipping from the manufacturer to the consumer and when not in use. Wooden pallets cannot be stored out-of-doors as moisture is readily absorbed, increasing its weight, altering its dimension, promoting fungal and bacterial growth, and leading to degradation of the material on prolonged exposure.
The bulk size and the necessity to store wooden pallets in a sheltered area gives rise to considerable shipping and storage costs.
2G Further, wooden pallets typically are quite heavy and can be used only with considerable difficulty in certain industries, such as the food industry, in which cleanliness and corrosion resistance are essential. Effec-; tive sterilization of wooden pallets is extremely difficult.
Construction of palle$s from wood constitutes a potential fire hazard due to the ready flammability of wood.

Damaged wooden pallets generally are not repair-able and represent a considerable disposal problem. Re-clamation of the wood generally is not practical or feasible due to the various nails, screws or other fasteners used in the construction and the damage~ pallets have to be dis-posed of by burning or as land-fill. The former manner of disposal generally is impractical, due to air pollution control requirements, and the latter manner is expensive, both i.n terms of haulage costs to a suitable dump and space occupied at the land-fill.
Further, wooden pallets generally are not readily color-keyed for various uses, since suitable paints for this purpose either lack the strength to withstand ex-tensive use and hence are easily removed during use of the pallets, or are so expensive as to be prohibitiveO
In view of these difficulties, attempts have been .-made to use other construction materials for the provision of pallets, typically plastics. However, plastic pallets suffer from several drawbacks, such as, the plastic materialsinvolved are quite expensive, the pallets must be molded as -a single unit again giving rise to a bulk size problem, a minor crack in the structure is sufficient to seriously impair the strength of the pallet, the pallets are severely affected by extremes of temperature, the plastic generally is degraded by exposure to sunlight, and damaged pallets are difficult to dlspose of economically.
The present invention seeks to overcome the disadvantages of the prior art structures by providing a plurality of pallet structures wherein the elements are constructed wholly of aluminum in assemblable and disassem-.~. ............. ~blable form and a combination.of~elements~constructed of. -~
various materials of cons.truction, including aluminum.
- In accordance with one aspect of the present invention, there is provided a pallet construction comprising:
at least two spaced-apart substantially parallel '!' . , ~ - 3 -Si2 longitudinally-extending aluminum members; a pluralit~ of deck-forming aluminum members contacting and extending at least between the at least two longitudinally-extending mem~ers generally transverse thereto in spaced-apart rèlation; each of the plurality of deck-forming members having at least one planar portion cooperating with the at least one planar portion of the others of the plurality of deck-forming members to provide a planar pallet deck surface which extends substantially the length of the longitudinally-extending members; snap fit means' releasably interconnecting the at least two longitudinally-extending members with each of the plurality of deck-forming memhers at the intersections thereof; at each intexsection, the anap-fit means includes a first part integral with the longitudinally-extending member and a second cooperating part integral with the deck-forming member; and stop means located at each intersection and preventing movement of each of the plurality of deck-forming members longitudinally thereof and transverse to the at least two longitudina~ly-extending mem~ers while normally permitting movement of the plurality of deck-forming members out of contact with the longitudinally-extending members upon release of the snap-fit means to allow disassembly of the pallet; the stop means at each intersection including cooperating elements integral with the longitudinally-extending member and integral with the deck-forming member; the snap-fit means including a first and second pair of spaced channels ' ' ''situated on the longitudin'a~'ly-extending member, in eàch ''''`
pair the channels opening in opposite directions in the direction of extension of the longitudinally-extending member, and channel-engaging members formed on each of the deck-forming members constructed to snap-fit into the pairs of spaced channels; the stop means at each intersection comprising two projections OII each of the longitudinally-extending members engaginy respective openings in the deck-forming members.
In accordance with a second aspect of the pres~nt invent.ion, there is provided a pallet construction comprising:
at least two spaced-apart substantially parallel longitudinally-extending aluminum members; a plurality of deck-forming aluminum members contacting and extending at least between the at least two longitudinally-extending members generally transverse thereto in spaced~apart relation; ea~h of the plurality of deck-forming members having at least one planar portion cooperating with the at least.one planar portion of the others of the plurality of deck-forming members to provide a planar pallet deck surface -~ -.-.
which extends substantially the length o the longitudinally-extending members; snap-fit means releasa~ly interconnecting the at least two longitudinally-extending ~
members with each of the plurality of deck-forming members . at the intersections thereof; at each ~nterSeGtiOn, the snap-fit means includes a first part integral with the longitudinally-extending member and a second cooperating part integral with the deck-forming member; and stop means located at each intersection and preventing movement of each of the plurality of deck-forming members longitudinally thereof and transverse to the at least two longitudinally-?. ~-~r~ extending members while normally:permitti~g moveme~t~of~-the:
plurality of deck-formin~ members out of contact with the 30 . longitudinally-extending members:upon release of the snap-fit means to allow disassembly of the pallet; the stop means ".s"~ ;,, at each intersection including cooperatin~ elements-integral with the longitudinally-extending mell~er and integral with the deck-forming member; each of the plurality of deck-forming members including a wholly planar portion spaced from the longitudinally-extending members at the intersections and spacer means depending from the planar portion into engagement with the longitudinally-extending members at the intersections.
In accordance with a third aspect of this invention, there is provided a pallet construction comprising:
at least two spaced-apart substantially parallel longitudinally-extending aluminum members; a plurality of deck-forming aluminum members contacting and extending at least between the at least two longitudinally-extending members generally transverse thereto in spaced apart relation; each of the plurality of deck-forming members having at least one planar portion cooperating with the at least one planar portion of the others of the plurality of deck-forming members to provide a planar pallet deck surface which ex~ends substantially the length of the longitudinally-- extending members; snap~fit means releasably interconnecting the at least two longitudinally-extending members with each of the plurality of deck-forming members at the intersections thereof; at each intersection, the snap-fit means includes a first part integral with the longitudinally-extending member and a second aooperating part integral with the deck-forming member; and stop means located at each . -- , inters-ect~on and preventing movement of each'of'the`plurality'''' of deck-forming members longitudinally thereof and transverse to the at least twa longitudinally-extendi'ng members while normally permitting movement of the plurality of deck-forming ~'~
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members out of conf~ct with the longitudinally-extending members upon release oE the snap-fit means to allow disassembly of the pallet; the stop means at each inter-section including cooperating elements integral with the longitudinally-ext~nding member and integral with the deck-forming member; each of the longitudinally-extending members including a continuous generally rectangularly cross-sectioned portion and a plurality of short continuous portions received in sliding fit relationship with the continuous portion longitudinally-spaced apart from each other to provide openings for receiving fork-lift tines through the longitudinally-eXtending members transverse thereof; the continuous portion and the short portions having identical cross-sectional shapes. -The pallets of this invention, therefore, are formed only from a plurality of one type of member and a plurality of a second type of member, the types of member being interlocked by a unique locking structure. The interlocking of the two types of member to provide the pallet and the disassembly oi the interlock are achieved 1, ~ - 5b/c -s~æ

without the necessity for any special~tools or skills.
In accordance with a ~t~raspect of the present invention, there is provided in combination, a flrst substantially rigid elonga~e member having a flat surface;
a second elongate member having a planar portion spaced from the flat surface and at least one web depending from the planar portion into engagement with the flat surface; first and second projections upstanding from the flat surface of the first member, each of the projections having a shoulder projecting therefrom in opposite directions to each other generally parallel to the flat surface and defining an undercut with the flat surface; first and second shoulder engaging members integrally joined to the planar portion of the second elongate member and projecting towards the at least one web, the shoulder-engaging members being positioned one in each of the undercuts in engagement with the respective shoulder; the second elongate member being capable of limited flexure about its centre line for release of at least one of the shoulder-engaging members from its respective undercut to allow separation of the second elongate member from the first elongate member; a third projection upstanding from the flat surface of the first elongate member, and a vertically-extend1ng slot formed in the at least one web receiving the third projection therethrough preventing movement of the second elongate member transverse of the first elongate oember and normally permitting the separation of the second elongate member from the first elongate member upon the limited fiexure. - . ~ ..
The invention is described further by way of illustration with referencè to the accompanying drawings, in which:

- Sd --Figure.l is a perspective view of a single deck two-way pallet construction provided in accordance with the invention;
Figure 2 is a perspective view of a two-deck two-way pallet construction provided in accordance with the invention;
Figure 3 is a close up view of one side of the pallet of Figure 1, partly exploded, showing the interlocking of the pallet-forming members;

Figure 4 is a perspective view of one element used in the pallet construction of Figure 2; and Figure 5 is a perspective view of another element used in the pallet construction of Figure 1 or 2;
Figures 6 and 7 are views of the interlocking of the members to form the pallet construction of Figures 1 and 2;
Figure 8 is a sectiona]L view of part of the inter-lock taken on line 8-8 of Figure 7 in a permanently-locked position;

Figure 9 is a perspective view of a one-deck four-way pallet construction provided in accordance with the invention~
Figure 10 is a perspective view of a two-deck four-way pallet construction provided in accordance with the invention;
Figure 11 is an end view of one of the pallet-forming members used in the pallet of Figure 10;
,Figure 12 is.a perspective-~iew o~ the~en~portion of a modification of the element shown in Figure 4;

, Figure 13 is a close up of one side-of-a pàllet structure, similar to Figure 3, showin~ the interlocking of the pallet-forming memb~rs, wherein one of the mem~ers ' ' ~ .
~j. > - 5e -is as illustrated in Figure 12 and the other is a modifica tion of the structure shown in Figure 5; and Figure 14 is an end view of modified elements of the four-way pallet illustrated in Figures 10 and 11.
Referring to the drawings, Figures 1 and 2 illus-trate single- and double-deck one-way entry pallet construc-tions respectively which utilize basically the same units and assembly principle, with the exception of modifications required to provide a single- or double~deck construction.
A pallet lO constructed of aluminum parts includes three hollow elongate members or stringer elements 12 of rectangular cross-section and arranged with their longer dimension upright so that the outer surface 13 of the shorter dimension provides a supporting surface. The rectangularly cross-seckioned members 12 are arranged parallel to each other.
While the pallet of Figures 1 and 2 is illustrated as having three elongate members or stringer elements 12, this number is not essential but rather is preferred. ~wo or four or more such elements 12 may be used, depending on the size a~d strength of pallet desired.

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- 5f -A plurality of deck-forming elongate extrusions 14 are supported on the outer surfaces 13 and are releasably connected to the rectangularly cross sectioned members 12 in spaced parallel relation generally perpendicular to the rectangularly cross-sectioned member 12 and cooperate to provide a deck 16 on one side only or on both sides of the pallet 10, depending on the type desired~
The deck-forming members 14 are releasably connected to the rectangularly cross-sectioned members 12 in such a manner as to prevent movement of the deck-forrning members 14 longitudinally thereof and laterally to the rectangularly cross-sectioned members 12, in a manner descrihed in more detail below, so that the structure is stable~
Each rectangularly cross.-sectioned member 12 includes a plurality of sets of protrusions 18, extending either from the top outer surface 13 only, in the case of ~.
the pallet construction of Figure 1 or from the top and bottom outer surfaces 13, in case of the pallet construction of Figure 2. The longitudinal dimension of each set of pro~
trusions 18 is substantially equal to the width of each deck-forming member 14.
: The number of the sets of protrusions 18 is equal to the number of deck-forming members 14 to be attached to the rectangularly cross-sectioned member 12 and the number is the same for each of the rectangularly cross-sectioned members 12~
The spacing apart of the sets of protrusions 18 from each other on the surface 13 of the rectangularly cross-sectioned merf~er 12 may vary widely, depending on the spacing desired between the deck-forming extrusions in the ~o~

pallet 10, wh.ich in turn is dependent on the desired end use and desired strength of the pallet 10.
Each of the sets of protrusions 18 includes a central member 20, a left hand member 22 and a right hand member 24. Each member of the set 18 extends upwardly generally perpendicular to the surface 13 and extends in straight line alignment with the other members of the set and with the members in other sets longitudinally of the surface 13. Each member is thin laterally.
The left and right hand member 22 and 24, which have mirror-image shapes, are undercut at their ends remote from the central member 20 to define shoulders 26 and 28 respectively and undercuts 30 and 32 respectively.
In Figures 1 to 11, a single set of protrusions 18 for each intersection is illustrated.upstanding from surface 13.. For improved pallet strength, two sets of such protrusions 18 may be provided for each intersection, as shown in Figures 12 and 13, the sets being provided one adjacent each longitudinal edge of the surface 13.
Each of the deck-forming members 14 includes first and second elongate parallel coplanar eiements 34 and 36 intended to cooperate with the elements 34 and 36 of the other deck-forming members 14 to define a planar load-supporting surface.
The coplanar elements 34 and 36 are joined by an integral member defining a channel 40 therebetween and including a first elongate portion 42 situated in a plane parallel to the plane of the coplanar elements 34 and 36 and intended to engage the outer s~rface 13 of the rec-tangularly cross-sectioned element 12 and first and second upright elements 44 and 46 integrally joining the elongate portion 42 and the coplanar elements 34 and 36.

The elon~ate portion 42 has three slots 48 formed therethrough of length and dimension sufficient to receive the central member or tab 20 of each set of protru-sions therethrough.
Three slots 48 are used corresponding to the three rectangularly cross-sectioned members 12 used to form the pallet constructions of Figures 1 and 2 and the central slot is spaced equally from the two ends. Where two or more than three such rectangularly cross-sectioned members 12 are used, then the corresponding number of slots 48 may be provided.
The slots 48 adjacent the ends of each member 14 are spaced inwardly a distance corresponding to the distance of the tabs 20 from the edge of the surface 13, so that, when the pallet is assembled, the ends of the deck-forming members are flush with the outer surfaces of the rectangularly cross-sectioned element 12, as illustrated in Figures 1 and 2.
If desired, the end slots 48 may be positioned a further distance from the ends of the member 14, so that the assembled pallet has the outer rectangularly cross-sectioned elements 12 recessed with the deck or decks 16 overhanging the outer elements 12.
The deck-forming elements 14 also include integral skirt portions 50 and 52 depending from the coplanar elements 34 and 36 generally perpendicularly thereto at the sides of the dec]c~forming elements 14. ~he skirt portions S0 and 52 extend a distance substantially equal to the depth of the channel 40.
At the lower end of each skirt portion 50 and 52 is a shoulder-engaging member 54 and 56 respectively.

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Each shoulder-engaging member includes a portion projecting inwardly of the skirt 50 or 52 towards the first elongate portion 42 and a shoulder-face-engaging portion.
Generally shoulder-engaging mem~er 54 projects inwardly in yreater di.stance than shoulder-engaging member 56 and a distance substantially equal to the depth of the undercut 30.
While the undercuts 30 and 3.2 have the same dimen~
sions and depth approximately equal to the extremity of the shoulder-engaging member 54, this arrangement is for con-venience in assembly of the pallet, allowing the longer shoulder-engaging member 54 to be inserted in either under~
cut to engage both the shoulder and the end wall of the undercut, so that the arrangement shown in Figures 6 and 7 with respect to the relative positions of shoulder-engaging members 54 and 56 and undercuts 30 and 32 may ~e reversedO Further, not all the extrusions 14 need to be connected to extrusions 12 by the illustrated arrangement~
However, if desired, the undercuts 30 and 32 may be dimensioned such that undercut 30 has a depth at least equal to the maximum distance of extension of the shoulder engaging member 54 and the undercut 32 has a lower depth a~ least equal to the maximum distance of extension of the shoulder-engaging member 54 and.less than the maximum dis-tance of extension of the shoulder~engaging member 56~
Each shoulder 26 and 28 has a sloping outer surface 58. The surface of the shoulder-engaging member 56 intended to engage the sloping surface 58 during assem-bly, as described below, is also curved at 600 Where it is desired to provide a pallet deck which does not possess channels 40, then the deck-forming g members 14 may be provided in the modified form illustrated in Figure 130 As seen therein, the deck-forming member 14 has a continuous planar surface 100 which cooperates with other like surfaces to provide the deck surface. Integral skirt portions 50 and 52 with associated shoulder-engaging members 54 and 56 are provided depending from the lateral extremities of the planar surface 100.
A pair of webs 102 depend from the planar surface 100 parallel to the skirt portions 50 and 52 for engagement with the surface 13 of the rectangulax cross-sectioned member 13. One only such web 102 may be used, if desired, although it is preferred to provide the pair of such webs for strength and stability. Greater numbers of such webs 102 may be used, if desired.
Slots 104 are provided in each of the webs 102 for receiving the central member 20 of each of the set of protrusiolls 18 to prevent longitudinal displacement of the deck-forming members 14 relative to the rectangularly cross-sectioned elements 12 in an assembled pallet, in analogous manner to the proj~ction of the central member 20 through the slots 48.
In Figure 13, the modified deck-forming member 14 is shown assembled with the modified rectangularly cross-sectioned member 12 of Figure 12, with the ends of the members 14 overhanging the member 12~ Clearly, the modi-fied deck-forming member 14 may be assembled with the rectangularly cross-sectioned member 12 as illustrated in Figure 4, with the ends of the members 14 lying flush with or overhanging the members 12, by appropxiate positioning of the slots 104.

Each of the deck-forming members 14 has a thickness and size allowing limited flexibility when bent about its longitudinal centre line. This flexibility, the dimensioning of the deck-forming members 14 and the set of protrusions 18, the shape of the members 22 and 24 and the dimensioning of the shoulder-engaging members 54 and 56 combine to provide snap-fit means, readily~releasable inter-locking of the deck-forming member 14 and the rectangularly cross-sectioned member 12. Further, ~he interlocking and releasing of the pallet-forming elements 12 and 14 is achievable without the use of special tools or skills.
As seen particularly in Figures 6 and 7, the pallet of Figure 1 and 2 is assembled by, at each inter-section of deck-forming member 14 and rectangularly cross~
sectioned m~mber 12, inserting the longer shoulder-engaging member 54 into the undercut 30 and pushing the shorter shoulder engaging member 56 against the upper and outer surface of the shoulder 28, causing the member 14 to flex slightly about its centre line, thereby moving the shoulder~
engaging members 54 and 56 a greater distance apart, so that the curved surface 60 of the shoulder engaging member 56 rides on and round the surface 58 of shoulder 28 and snap-fits into the undercut 32 in engagemen~ with the underside of the shoulder 28.
Disassembly of the interlock is readily achieved by flexing the member 14 about its centre line until the shoulder-engaging members 54 and 56 are spaced apart a distance sufficient to remove the shoulder-engaging member 56 from the undexcut 32.
The interaction of the central member or tab 20 and the walls of the slot 48 or of the slot 104 constitutes -- 11 --.

stop means and prevents longitudinal movement of the member 14, so that a stable pallet construction is provided,.
and permits release of the members 12 and 14 for pallet disassembly.
In some instances, it may be desired to provide the pallet in-a permanent form, in which case the central members or tabs 20 may be twisted or bent over, as seen in the cross-section of Figure 6, to prevent withdrawal of the tabs 20 through the slots 48.
While the three members of each set of protru-sions is illustrated as being provided in a straight line, this construction is for convenience of formation of the extrusion 12. However, the members may be offset from straight line alignment, with the slots 48 being appropriate-ly positioned.
Furtherl while the sets of protrusions 18 are illustrated as constituted by a central member 20 which is located between left and right hand members 22 and 24 respectively~ it is possible to provide the central member 20 integral with the left and right hand members 22 and 24, so that the set of protrusions 18 is constituted by a single protrusion extending generally perpendicular from the surface 13, with shoulders at each longitudinal end defining undercuts with the surface 13.
The latter form of the protrusion 18 has particular utility with the modified form of deck-forming member 14 shown in Figure 13 and is simpler to form than the three-member sets 18. The continuous protrusion also may be used with the type of deck-forming member 14 shown in Figures 3 and 5 by suitable lateral extension of the slot 48 and the formation of appropriate vertical slots i.n the side walls 44 and 46.

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The interlock which is used in the provision of the pallets of the invention and as illustrated above has a variety of other uses, where it is desired to interconnect two elements, one of which has limited flexibility along a line generally transverse to the other extrusion and forms another embodiment of the invention. The use of ~his inter-lock in a fence structure is descri~ed in more detail below with respect to Figures 15 to 18.
It will be seen from the above description of Figures l to 8 and 12 and 13, that the present invention pro~ides a pallst construction which is in a knock-down form and which is formed from only two types of aluminum members, the members of each type being completely inter-changeable one with another. The pallet may be assembled without any special tool or skills.

Turning now to consideration of Figures 9 to ll and 14, there are shown modifications of the two-way pallet constructions of Figures l and 2 to provide a four-way pallet construction.

2~ Figures 9 and lO illustrate respectively single-deck and t~lo-deck versions of a four-way pallèt 62 having the same deck-forming members 14 as the pallets of Figures l and 2 releasably connected to elongate members or s~ringer elements 64 using snap-fit means and s~op means in the same manner as described above for the releasable interconnection of the deck-forming members 14 and the stringer elements 12 of the pallets lO of Figures l and 2.
As in the case of the pallet of Figures l and 2, three stringer elements 64 are illustrated in the pallet of Figures 9 and lO. Two or four or more such elements 64, howeverl may be used, depending on the size and strength of pallet desired.

s~æ

Each of the stringer elements 64 includes a first continuous generally rectangularly-shaped elongate member 66 extending adjacent the upper deck of the pallet 10 for the length thereof.
The continuous elongate member 66 includes a horizontal element having a supporting surface 68 and down-wardly depending parallel skirt elements 70 and 72 defining a channel with the horizontal element and opening down-wardly. The sets of protrusions 18 extend from the supporting surface 68~
The lower edge of each skirt element 70 and 72 is bent inwardly and is integral with a channel element 74 and 76 respectively, the channels 74 and 76 opening towards the horizontal element and extending the length of the elongate member 66.
Each stringer element 64 also includes three spaced members 78 slidably connected to the elongate member 66. Each of the spaced members 78 includes a horizontal element 80 having a supporting surface from which the set ~0 or sets ~f protrusions 18 extend, such sets of protrusions 18 being absent in the case of the single-deck pallet of Figure 9 and two upwardly-extending skirt elements 82 and 84 spaced apart the same distance as the skirt elements 70 and 72 and defining a channel with the horizontal element - 80 opening upwardly.
The skirt elements 82 and 84 are integral with channel elements 86 and 88 respectively extending inwardly of the skirt elements 22 and 84 and extending the length of the respective spaced member 78.
The channel elements 86 and 88 are constructed to cooperate with the channel elements 74 and 76 respec-tively to provide an interference fit sliding relationship therebetween, whereby the individual spaced members 78 may be positioned in slidable relation to the elongate member 66.
The skirt members 82 and 84 extend into engage-ment with the lower edge of the skirt members 70 and 72 respectively to give an appearance of a continuous outar surface to the stringers 64 in the region of the spaced members 78.
~enerally, the spaced members 78 are spaced apart equidistantly with one of the members 78 being at each end of the stringer 64 to provide fork lift truck tine-receiving openings 90. This arrangement, however, is for convenience and may be varied as desired, such as by omission of the centre one of the spaced members 78.
The opposed channels defined by the elements of the elon~ate member 66 and the spaced members 78 provide a generally rectangular cross-secti.on enclosure, of similar dimension to the rectangular cross-section of the stringer 2~ elements 12.
Figure 14 illustrates an alternative form of the stringer elements 64 from that shown in Figure 11.
In the structure of Figure 14, the stringer elements 64 are formed of identically cross-sectioned members~ making formation and assembly simpler~
The continuous elongate member 66 and ~he spaced members 78 include a supporting surface 106 having protrusions 18 thereon, downwardly depending parallel skirt elements 108 and a cross member 110 defining a generally rectangularly-shaped cavity 112.

While one set of centrally-located protrusions 18 is illustrated, it is possible in this structure and in the structure of Figure 11 to provide two parallel sets of protrusions, as illustrated in Figure 12.

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A generally L-shaped elongate protrusion 114 is formed at one lateral side of the cross member 110 while an elongate channel 116 is provided at the other lateral side of the cross r,lember 110 shaped to receive the L-shaped protrusion 114 in sliding relation therewith to achieve sliding assembly of the stringer element 64.
As in the case of the structure illustrated in Figure 11, there is an appearance of a continuous outer surface to the stringers 64 in the region of the spaced members 78. This i5 achieved by providing a shoulder 118 on the protrusion 114 which is engaged by the outer wall 120 of the elongate channel 116.
As in the case of the embodiments of Figures 1 to 8, 12 and 13, the four-way entry pallet construction of Figures 9 to 11 and 14 is in a knock-down form and is formed from only two types of aluminum extrusions, the members of each type being completely interchangeable one with another. The pallet may be assembled and disassembled without any special tools or skills.
The pallet construction of the present invention has a number of advantages over the prior ar~ constructions mentioned above. Since the pallet is provided in a knock-down form and hence may be shipped and stored in compact form, initial shipping cost, storage cost and inventory cost are ~ecreased as compared with wooden and plastic pallets. The user can make up the pallet as and when required, in the type and size required, givin~ consider-able flexibility of choice. Unskilled labor can be used to assemble and disassemble the pallet and no special tools are re~uired for either operation, also providing a cost advantage to the user.

Further, since aluminum is not readily corroded or damaged by exposure to the elements or extremes of tem-perature, moisture cannot be absorbed, and the dimensions of the pallet remain the same on external exposure, the com-ponent parts of the pallet or the made up pallet may be stored exteriorally, further decreasing storage costs.
This advantage also contrasts with the prior art wooden and plastic pallets. Since aluminum is inflammable and spark proof, no fire or safety hazard is attendant the use or storage of the pallets, also in contrast to the wooden and plastic pallets.
Broken or damaged pallets have considerable ~;
scrap value as alumlnum metal and hence are 100% recyclable, thereby avoiding the considerable disposal problems and disposal costs of wooden and plastic pallets. Further, since the various elements are of only two types and the members of each type are wholly interchangeable, it is un-likely that the pallet would be Idamaged to the extent that the whole pallet would require replacing. Repair to one or more damaged parts is readily achieved by substituting a new part for the damaged part, thereby prolonging the overall effective life of the pallet. This advantage also contrasts markedly with the wooden and plastic pallets which usually have to be disposed of in their entirety.
A corrosion resistant finish may be provided to the aluminum surface, typically by anodizing when the pallet is to be used where high corrosion materials occur.
Further, a highly resistant colour coating may be applied inexpensively to the aluminum, to provide color-keying for 30 various uses, if desired. These treatments are not feasible with wooden pallets, as mentioned above~

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-Since the aluminum pallets of the invention do not promote fungal or bacterial growth, are very easily cleaned and sterilized, generally are non-corrodable and can be easily provided with corrosion-resistant finishes for specialist corrosion problems, are not affected by exkremes of temperature, do not split or crack, or use nails, screws or other separable fasteners, are not affected by ultra-violet rays, and are light in weight, the pallets have awide flexibility of use and may be used in many industries, including industries where wooden and plastic pallets can be used only with difficulty, or not at all.
Industries where wooden and plastic pallets can be used only with difficulty or not at all and in which the pallets of the present invention may be used include meat processing plants, dairy plants, canning factories, any any food processing plant where cleanliness and health factors are essential, pharmaceutical industries , chemical industries with corrosion problems, chemical industries with explosive and fire hazards, petrochemical industries, in-dustries where exposure to high moisture levels or liquids is frequent.and warehousing or storaye under rèfrigeration.
Further, the pallets may be.used for outside storage with exposure to extreme weather conditions, in transportation industries where pallet weight is a factor, such as shipment by air cargo, in any processing or storage facility where contamination of pallets is a problem, in material handling in the Arctic region or under other extensive cold weather conditions in material handling at elevated temperatures, and in.various military and emer-gency uses.

~ 18 '. .-3, '',,'' f~

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The present inventlon, therefore, provides pallet constructions which are formed of readily-assembled and replaced parts. Modifications are possible within the scope of the invention.

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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A pallet construction comprising:
at least two spaced-apart substantially parallel longitudinally-extending aluminum members, a plurality of deck-forming aluminum members con-tacting and extending at least between the at least two longitudinally-extending members generally transverse thereto in spaced-apart relation, each of said plurality of deck-forming, members having at least one planar portion cooperating with the at least one planar portion of the others of said plurality of deck-forming members to provide a planar pallet deck surface which extends substantially the length of said longitudinally-extending members, snap fit means releasably interconnecting said at least two longitudinally-extending members with each of said plurality of deck-forming members at the intersections thereof, at each said intersection, said snap-fit means includes a first part integral with said longitudinally-extending member and a second cooperating part integral with said deck-forming member, and stop means located at each said intersection and preventing movement of each of said plurality of deck-forming members longitudinally thereof and transverse to said at least two longitudinally-extending members while normally permitting movement of said plurality of deck-forming members out of contact with said longitudinally-extending members upon release of said snap-fit means to allow disassembly of said pallet, said stop means at each said intersection inclu-ding cooperating elements integral with said longitudinally-extending member and integral with said deck-forming member, said snap-fit means including a first and second pair of spaced channels situated on said longitudinally-extending member, in each pair the channels opening in opposite directions in the direction of extension of the longitudinally-extending member, and channel-engaging members formed on each of said deck-forming members con-structed to snap fit into said pairs of spaced channels, said stop means at each said intersection com-prising two projections on each of the longitudinally-extending members engaging respective openings in said deck-forming members.

2. The pallet construction of claim 1, wherein each of said longitudinally-extending members has a planar supporting surface supporting said deck-forming members, and said pairs of channels and said two projections are located at the lateral extremities of said supporting surface.

3. The pallet construction of claim 2 wherein each pair of said channels are defined by first and second pro-trusions extending from said supporting surface and each including a shoulder projecting in opposite directions generally parallel to and spaced from said supporting surface to define an undercut therewith, and said projec-tions comprise third protrusions extending from said supporting surface between said first and second protrusions.

4. The pallet construction of claim 2, wherein each of said pair of said channels and said projections are defined by first and second continuous elongate protrusions extending from said supporting surface and each including shoulders projecting in opposite directions generally parallel to and spaced from said supporting surface to define an undercut therewith.

5. The pallet construction of claim 1 wherein each of said plurality of deck-forming members includes a wholly planar portion spaced from said longitudinally-extending members at said intersections and spacer means depending from said planar portion into engagement with said longi-tudinally-extending members at said intersections and having said openings formed therein.

6. The pallet construction of claim 5 wherein each of said plurality of deck-forming members further includes first and second skirt members depending one from each lateral extremity of said planar portion and carrying said channel engaging members, said spacer means comprises a pair of webs depending from said planar portion parallel to each other and to said skirt members and said openings comprise vertically-extending slots formed in said webs.

7. The pallet construction of claim 1, wherein each of said longitudinally-extending members includes a continuous generally rectangularly cross-sectioned portion and a plurality of short continuous portions received in sliding fit relationship with said continuous portion longitudinally spaced apart from each other to provide openings for receiving fork-lift tines through the longi-tudinally-extending members transverse thereof.

8. The pallet construction of claim 5 wherein said continuous portions and said short portions have identical cross-sectional shapes and each includes an elongate generally L-shaped protrusion and an elongate channel for receiving said protrusion in sliding fit relationship therewith.

9. A pallet construction comprising:
at least two spaced-apart substantially parallel longitudinally-extending aluminum members, a plurality of deck-forming aluminum members con-tacting and extending at least between the at least two longitudinally-extending members generally transverse thereto in spaced-apart relation, each of said plurality of deck-forming members having at least one planar portion cooperating with the at least one planar portion of the others of said plurality of deck-forming members to provide a planar pallet deck surface which extends substantially the length of said longitudinally-extending members, snap fit means releasably interconnecting said at least two longitudinally-extending members with each of said plurality of deck-forming members at the intersections thereof, at each said intersection, said snap-fit means includes a first part integral with said longitudinally-extending member and a second cooperating part integral with said deck-forming member, and stop means located at each said intersection and preventing movement of each of said plurality of deck-forming members longitudinally thereof and transverse to said at least two longitudinally-extending members while normally permitting movement of said plurality of deck-forming members out of contact with said longitudinally-extending members upon release of said snap-fit means to allow disassembly of said pallet, said stop means at each said intersection inclu-ding cooperating elements integral with said longitudinally-extending member and integral with said deck-forming member, each of said plurality of deck-forming members including a wholly planar portion spaced from said longitudinally-extending members at said intersections and spacer means depending from said planar portion into engage-ment with said longitudinally-extending members at said intersections.

10. The pallet construction of claim 9 wherein each of said plurality of deck-forming members further includes first and second skirt members depending one from each lateral extremity of said planar portion, and said spacer means comprises a pair of webs depending from said planar portion parallel to each other and to said skirt members.

11. The pallet construction of claim 10 including at least one vertical slot formed in each said web at each said intersection to constitute said cooperating element of said stop means integral with said deck-forming member and for receiving a protrusion integral with said longitudinally-extending member and constituting said cooperating element integral with said longitudinally-extending member.

12. The pallet construction of claim 11 wherein said snap fit means comprises at least one continuous elongate protrusion extending from the longitudinally-extending member and in the direction of extension thereof, said continuous elongate protrusion including shoulders pro-jecting in opposite directions generally parallel to and spaced from the adjacent surface of the longitudinally-extending member to define an undercut thereof and a generally central portion constituting said received protrusion and said snap fit means further including undercut-engaging members formed on each of said deck-forming members constructed to snap fit into said undercuts.

13. The pallet construction of claim 9, wherein .
each of said longitudinally-extending members includes a continuous generally rectangularly cross-sectioned portion and a plurality of short continuous portions received in sliding fit relationship with said continuous portion longitudinally spaced apart from each other to provide openings for receiving fork-lift tines through the longi-tudinally-extending members transverse thereof.

14. The pallet construction of claim 13 wherein said continuous portion and said short portions have identical cross-sectional shapes and each includes an elongate generally L-shaped protrusion and an elongate channel for receiving said protrusion in sliding fit relationship therewith.

15. A pallet construction comprising:
at least two spaced-apart substantially parallel longitudinally-extending aluminum members, a plurality of deck-forming aluminum members con-tacting and extending at least between the at least two longitudinally-extending members generally transverse thereto in spaced-apart relation, each of said plurality of deck-forming members having at least one planar portion cooperating with the at least one planar portion of the others of said plurality of deck-forming members to provide a planar pallet deck surface which extends substantially the length of said longitudinally-extending members, snap fit means releasably interconnecting said at least two longitudinally-extending members with each of said plurality of deck-forming members at the intersections thereof, at each said intersection, said snap-fit means includes a first part integral with said longitudinally-extending member and a second cooperating part integral with said deck-forming member, and stop means located at each said intersection and preventing movement of each of said plurality of deck-forming members longitudinally thereof and transverse to said at least two longitudinally-extending members while normally permitting movement of said plurality of deck-forming members out of contact with said longitudinally-extending members upon release of said snap-fit means to allow disassembly of said pallet, said stop means at each said intersection inclu-ding cooperating elements integral with said longitudinally-extending member and integral with said deck-forming member, each of said longitudinally-extending members including a continuous generally rectangularly cross-sec-tioned portion and a plurality of short continuous portions received in sliding fit relationship with said continuous portion longitudinally spaced-apart from each other to provide openings for receiving fork-lift tines through the longitudinally-extending members transverse thereof, said continuous portion and said short portions having identical cross-sectional shapes.

16. The pallet construction of claim 15 wherein each of said portions includes an elongate generally L-shaped protrusion and an elongate channel for receiving said protrusion in sliding fit relationship therewith.

17. The pallet construction of claim 16 wherein said protrusion has a shoulder engaged by the outer wall of said channel in said sliding fit relationship to establish a continuous wall external appearance.

18. In combination, a first substantially rigid elongate member having a flat surface, a second elongate member having a planar portion spaced from said flat surface and at least one web depending from said planar portion into engagement with said flat surface, first and second projections upstanding from said flat surface of said first member, each of said pro-jections having a shoulder projecting therefrom in opposite directions to each other generally parallel to said flat surface and defining an undercut with said flat surface, first and second shoulder engaging members integrally joined to said planar portion of said second elongate member and projecting towards said at least one web, said shoulder-engaging members being positioned one in each of said undercuts in engagement with the respective shoulder, said second elongate member being capable of limited flexure about its centre line for release of at least one of said shoulder-engaging members from its respective undercut to allow separation of the second elongate member from the first elongate member, a third projection upstanding from said flat surface of said first elongate member, and a vertically-extending slot formed in said at least one web receiving said third projection therethrough preventing movement of said second elongate member trans-verse of said first elongate-member and normally permitting said separation of the second elongate member from the first elongate member upon said limited flexure.

19. The combination of claim 18 wherein said first, secnd and third projections are thin, separate from each other and extend in straight line alignment.

20. The combination of claim 18 wherein said first, second and third projections are constituted by a single continuous elongate projection having said shoulders located one at each end thereof.

21. The combination of claim 18, wherein there are two sets of said first, second and third projections, said first, second and third projections are thin, the sets of said projections is arranged in straight line alignment at opposite lateral sides of said flat surface of said first elongate member, and a vertically-extending slot is pro-vided in said at least one web to receive each of said third projections.

22. The combination of claim 21 wherein each of said sets of projections is constituted by a single continuous elongate projection having said shoulders located one at each ends thereof.

23. The combination of claim 18, wherein two webs are provided depending from said planar portion at locations adjacent the longitudinal centre line of said planar portion, and said first and second shoulder engaging members are integrally joined to said planar portion by first and second skirt portions depending one from each lateral extremity of said planar portion parallel to each other and said webs and terminating in said shoulder-engaging members.

24. The combination of claim 18, wherein one of said shoulder-engaging members extends towards said webs a distance greater than the other of said shulder-engaging members.