BACKGROUND TO THE INVENTION
[0001] With the advent of containerization, the use of shipping pallets has become a necessity
insofar as the shipping of most commodities is concerned, and vast numbers of pallets
are in use.
[0002] The simplest form of pallet comprises upper and lower decks fabricated using wooden
planks, there being wooden blocks between the upper and lower decks. The blocks not
only connect the decks but also hold them apart so that the tines of forklift trucks
can be inserted between them.
[0003] Wooden pallets are normally constructed near where they are to be loaded with goods
and make a one-way journey. This is because it is, generally speaking, not economical
to return empty pallets to their source. Furthermore, mechanical handling of the pallets
often results in them being damaged so that they are not fit for re-use.
[0004] Applicant is aware of a pallet which comprises two components which are identical
to one another and which are fabricated using wood waste in chip and/or shaving and/or
sawdust form which is mixed with a binder. The resultant material is then pressed
to the desired shape. Because composite wood of this nature is weak, such pallet components
have to be of considerable thickness. The pallet components are for shipping purposes
placed in a stack and nest with one another so that they occupy minimum space. When
a pallet is to be erected, one of the components is inverted and fastening elements
such as nails or screws are driven through to secure the components together. Each
component has a generally planar deck and has a plurality of raised areas. When said
one pallet component is inverted its raised areas become depressed areas and engage
with the top surfaces of the raised areas of the uninverted pallet component. Thus,
a plurality of columns are formed which space the decks of the components apart.
[0005] Experience with pallets of this form has shown that because of the thickness of material
which must be used, the components do not nest very satisfactorily and the space which
is saved by nesting the components is not as substantial as users would like. Furthermore,
it is difficult to secure the components to one another sufficiently strongly to resist
damage should one pallet component be urged laterally with respect to the other. The
screws, nails, or other fastening devices which are inserted simply tend to rip out.
OBJECTS OF THE PRESENT INVENTION
[0006] The main object of the present invention is to provide a pallet constructed of components
which, when all the same way up, can be nested and two of which, when one is inverted,
interlock to provide a pallet which is sufficiently strong to resist forces imposed
thereon during mechanical handling thereof.
[0007] A further object of the present invention is to provide a pallet comprising two components
which are of synthetic plastics material.
BRIEF DESCRIPTION OF THE INVENTION
[0008] According to the present invention there is provided a pallet comprising first and
second components moulded in synthetic plastics material, each component comprising
a horizontally extending deck and connectors standing proud of the deck, the connectors
of the upper deck protruding downwardly and abutting the connectors of the lower component
which protrude upwardly, thereby to form columns which space the decks apart vertically,
the connectors having formations which mesh with one another and resist any forces
tending to move the pallet components relatively to one another in the horizontal
plane.
[0009] In one constructional form said formations comprise spigots and sockets. In this
constructional form each of said connectors of one of said pallet components comprises
a frusto-conical wall, the larger diameter end of which merges with said deck and
the smaller diameter end of which is closed by a horizongal end wall, said sockets
being in the outer faces of said end walls, and each of the connectors of the other
pallet component comprises a frusto-conical wall, the larger diameter end of which
merges with the deck and the smaller diameter end of which is closed by a transverse
end wall, each spigot being part of one of said end walls.
[0010] In another constructional form said connectors of one pallet each comprise a frusto-conical
wall, the larger diameter end of which merges with said deck and the smaller diameter
end of which is closed by a horizontal end wall, said formations being on the outer
faces of said end walls. In this constructional form each formation comprises two
raised wedges which are at diametrically opposed positions on said outer face and
the apices of which point towards one another.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] For a better understanding of the present invention, and to show how the same may
be carried into effect, reference will now be made, by way of example, to the accompanying
drawings, in which
FIGURE 1 is a top plan view of a pallet component moulded in synthetic plastics material;
FIGURE 2 is an elevation showing two components of the form illustrated in Figure
1, stacked with the top component inverted;
FIGURE 3 is a pictorial view of a connector;
FIGURE 4 is an elevation illustrating two nested connectors;
FIGURE 5 is a pictorial view of a pallet with box retaining edge pieces;
FIGURE 6 is an 'exploded' pictorial view of a further form of pallet;
FIGURE 7 shows how an insert is connected to the pallet deck;
FIGURE 8 and 9 show high friction inserts;
FIGURE 10 is a pictorial view of a further connector;
FIGURE 11 is a top plan view of the connector of Figure 10;
FIGURE 12 is a section on the line XII-XII of Figure 11;
FIGURE 13 to 15 are a pictorial view, a top plan view and a section on line XV-XV
of Figure 14, and show a connector which is compatible with the connector of Figures
10 to 12;
FIGURE 16 is a section showing the connectors of Figures 10 to 12 and 13 to 15 meshed;
FIGURE 17 shows connectors of the form illustrated in Figures 10 to 12 stacked; and
FIGURE 18 shows connectors of the form illustrated in Figures 13 to 15 stacked.
[0012] The pallet component 10 shown in Figure 1 is moulded in synthetic plastics material.
It comprises a peripheral frame 12, two intersecting cross ribs 14 and 16, and four
areas 18 which are thinner than the frame 12 and ribs 14 and 16. The frame, ribs and
areas form a deck. On one face of the deck are nine connectors 20.
[0013] Each connector 20 is hollow (see particularly Figure 4) and is of generally frusto-conical
form. Its top surface, as viewed in Figure 3, comprises two diametrically opposed
depressed areas 22 of wedge shape and two diametrically opposed raised areas 24 also
of wedge shape.
[0014] The component 10 can be used as a stillage for unitized loads. Its primary function,
however, is as part of a pallet (see Figure 2) in which event two of the pallet components
10, the upper one inverted, are employed. The configuration of connectors 20 is such
that as the upper pallet component 10 is placed on the lower pallet component 10,
the raised areas 24 enter the depressed areas 22. Engagement between the depressed
and raised areas 22, 24 prevents sideways movements of the pallet components 10 with
respect to one another. As will be explained in more detail hereinafter, fastening
elements can be driven through the components 10 to secure them together.
[0015] For shipping purposes, pallet components 10 can be stacked on one another, the pallet
components all being the same way up as shown in Figure 4. Thus, each connector 20
of a lower pallet component 10 enters a connector 20 of the superposed pallet component
10.
[0016] If desired, each pallet component can have recesses 26 (see Figures 5 and 6) in the
edges of the face thereof opposed to the connectors 20. The recesses 26 are generally
rectangular in form and receive edge pieces 28. Each edge piece 28 includes two downwardly
protruding pins 30 which are inserted into holes 32 of the pallet component 10.
[0017] Each edge piece is of right-angled configuration when viewed in section. The horizontals
of the edge pieces 28 are received in the recesses 26, the top surfaces of the horizontals
being flush with the top surface of the pallet component. Similarly, the outer face
of ther vertical part of each edge piece 28 is flush with the edge of the pallet component
10. The edge pieces inhibit sideways movement of boxes on the pallet top decks.
[0018] In a modified constructional form the areas 19 are omitted so that the pallet component
has holes in it. Each of these holes can, if desired, be closed off by a removable
insert which has a pattern of ventilation holes in it. A pallet of this form is illustrated
in Figures 6 and 7 where an insert is shown at 34 and its ventilation holes at 36.
The edges of the deck which surround the holes in the pallet component can be configured
as shown in figure 7, so that the inserts 'snap' into the deck with the ribs 38 of
the insert in grooves 40 of the deck.
[0019] It will be understood that the tines of a forklift truck are inserted between the
pallet components 10 when it is desired to move the pallet. To prevent the pallet
slipping off the tines, an additive can be introduced into the plastics material from
which the pallet is manufactured to cause its surface coefficient of friction to increase.
Alternatively, the surface of each pallet component can be moulded with roughened
surfaces or can have a pattern of ridges and valleys or other protrusions. In other
forms, the pallet component is moulded with sockets for receiving components having
a high coefficient of friction. For example, sockets 42 (Figure 8) which are slightly
more than semi-cylindrical in extent can be provided for receiving tubular friction
elements 44. In the form of Figure 9, the friction elements are shown at 46 and 'snap'
into sockets 48 provided therefor.
[0020] Turning now to Figures 10, 11 and 12, these Figures show a connector 50 which forms
part of a pallet component designated 52. The pallet component 52 can have nine connectors
50 arranged in the same way that the connectors 20 are arranged in Figure 1.
[0021] Each connector 50 has an upwardly tapering frusto-conical wall designated 54 and
a generally cylindrical portion 56 which is closed by a circular top wall 58. The
portion 56 has a smaller diameter than the smaller diameter end of the wall 54, and
an annular surface 60 encircles the portion 56.
[0022] In Figures 13 to 15 there is illustrated a connector 62 which forms part of a pallet
component 64. The connector 62 includes a frusto-conical wall 66, the smaller diameter
end of which is closed by a circular end wall 68. In the top surface of the end wall
68 there is a circular recess 70. An annular surface 72 encircles the recess 70.
[0023] When a pallet component 52 and a pallet component 64 are brought into co-operating
relationship with one of the components inverted (as shown in Figure 16), the portion
56 enters the recess 70 and the surfaces 60 and 72 engage with one another. A screw
74 is shown passing through both pallet components, thereby to secure them to one
another.
[0024] It will be understood that when the pallet is loaded, the component 52 bears down
on the component 64. Should any force be exerted which tends to shift the components
52, 64 literally with respect to one another, movement is prevented as the peripheral
walls of the portion 56 and the recess 70 are in engagement with one another.
[0025] The components 64 does not have to be attached in a very secure manner to the underside
of the component 52. The only time that the component 64 can drop away from the component
52 is when the tines of a forklift truck are inserted between the pallet components
(into the space designated S) and the pallet lifted. The screws 74 must be sufficient
to prevent the pallet component 64 dropping away from the component 52.
[0026] The components 52 stack (as shown in Figure 17) with the lower faces of the portions
56 engaging the peripheries of the top walls 58. The components 64 stack (as shown
in Figure 18) with the surfaces 72 in engagement with the underfaces of the end walls
68.
[0027] It will be understood that a pallet of the form shown in Figure 16 requires two different
types of pallet component and hence two different moulds. A pallet of the form shown
in Figure 2 can be constructed from two identical pallet components. If the pallet
component 10 is fabricated with the areas 18 omitted, and inserts such as are shown
in Figure 6 inserted into the generally rectangular openings provided, then only a
single pallet mould is needed together with a smaller mould or moulds for the inserts.
The inserts can have ventilation holes 36 in them or they can be unapertured.
[0028] The screws 74 can be replaced by other mechanical fastening elements or by adhesive,
or mechanical fastening elements can be supplemented by adhesive. For example, a hole
can be drilled in one pallet component and hot melt adhesive injected into the gap
between the components.
[0029] Two pallet components, as shown in Figure 1, can be secured together using any of
the methods described.
1. A pallet comprising first and second components (10), each of which comprises a
horizontally extending deck and connectors (20, 50, 62) standing proud of the deck,
the connectors of the upper deck protruding downwardly and abutting the connectors
of the lower component which protrude upwardly thereby to form columns which space
the decks apart vertically, characterized in that the connectors (20) have formations
(22, 24 : 56, 70) which mesh with one another and resist any forces tending to move
the pallet components (10) relatively to one another in the horizontal plane.
2. A pallet according to Claim 2, characterized in that said formations comprise spigots
(56) and sockets (70).
3. A pallet according to Claim 2, characterized in that each of said connectors (62)
of one of said pallet components comprises a frusto-conical wall (66), the larger
diameter end of which merges with said deck and the smaller diameter end of which
is closed by a horizontal end wall (68), said sockets (70) being in the outer faces
of said end walls, and each of the connectors (50) of the other pallet component comprises
a frusto-conical wall (54), the larger diameter end of which merges with the deck
and the smaller diameter end of which is closed by a transverse end wall (58), each
spigot (56) being part of one of said end walls.
4. A pallet according to Claim 1, characterized in that said connectors (20) of one
pallet each comprise a frusto-conical wall, the larger diameter end of which merges
with said deck and the smaller diameter end of which is closed by a horizontal end
wall, said formations (24) being on the outer faces of said end walls.
5. A pallet according to Claim 4, characterized in that each formation comprises two
raised wedges (24) which are in diametrically opposed positions on said outer face
and the apices of which point towards one another.
6. A pallet according to Claims 1 to 5, and including elements (28) mounted along
the edges of the upper component and standing proud of the upper deck to inhibit lateral
movement of goods placed on the pallet.