GB2411638A - A stackable pallet - Google Patents

Abstract

A pallet has an upper deck surface on which goods are to be loaded for transport or storage and an underside surface that has locking formations defined thereon. The formations comprise, for example, a first rib 14 on one side of the centreline of the pallet and a second pair of ribs 16,17 that define a channel 22 therebetween and which are disposed on the opposite side of the centreline. When two such pallets are to be stacked together, the one is rotated and inverted with respect to the other so that the first rib is received in the channel in interlocking engagement. The design provides for a single pallet that can serve both as a base and a lid by simple inversion and rotation and ensures that stacked pallets are interlocked and thus restricted from moving relative to one another during transport in lateral directions.

Description

2411 638

A PALLET

The present invention relates to a pallet for the storage and carrying of goods.

Pallets are commonly used in many industries to store and transport goods in bulk. They have to be designed to withstand heavy loads and also to permit easy handling by a fork lift or pallet truck during unloading or loading of the palletised products from a vehicle, transport container, trailer or the like. Loaded pallets are often vertically stacked which risks toppling or other relative movement that can cause damage to the goods or the pallets themselves.

Once pallets have been unloaded they are ideally returned to the supplier of the goods. For the return journey the empty pallets are generally stored loosely which renders them prone to damage in transit. Moreover, they can occupy significant volume that could be used for other storage purposes and is liable to shipping costs.

It is known for stackable pallets to have interlocking features that serve to restrict relative movement. One such example is described in DE 29611420 and comprises a flat base with rear and side walls upstanding from the top surface and front and side walls depending from the underside. Corner pegs defined on the upper surface of one pallet are designed to be received in sockets defined on the underside of a pallet that is stacked on top. The pegs and sockets prevent relative movement of the stacked pallets but careful alignment is required to ensure that they are interlocked. The design of each pallet is relatively complicated and the height of the enclosed storage space is only equal to the height of the front or rear wall.

Another interlocking stackable pallet design is disclosed in US 4301743 and is intended to be compatible with standard wood pallets that are in widespread use.

Upper and lower load bearing decks are defined by spaced boards. In one embodiment stacked pallets are staggered so that the boards of the upper deck are received in the spaces between boards of the lower deck so as to interlock the pallets. In another embodiment the boards have ribs and grooves on their surfaces and the ribs on the boards of the upper deck of one pallet are designed to be received in the grooves on the boards of the lower deck. Again vertically adjacent pallets have to be laterally staggered to achieve interlocking. The design is only concerned with interlocking the pallets when in an unloaded condition and the staggering of vertically adjacent pallets is deliberately alternated so as to prevent toppling of a stack. Moreover, the interlocking arrangement only prevents relative movement of stacked pallets in one direction.

It is an object of the present invention to obviate or mitigate the aforesaid disadvantages and to provide for a pallet design that has an interlocking feature which provides stability when the pallets are stacked in both loaded and unloaded configurations. Moreover, it is an object of the present invention to provide for a pallet that offers a reduced stack volume when in the unloaded configuration. Another object of the present invention is to provide for a single pallet than can be used as a base and a cover or lid for retaining and protecting goods loaded on the pallet base.

According to a first aspect of the present invention there is provided a pallet having a centre line comprising a first substantially planar surface defining a deck on to which goods to be stored or transported are to be supported and an opposed second surface having at least one first protruding member disposed on one side of the centre line and one or more second protruding members on the other side of the centre line and defining a recess, wherein the first protruding member and the recess are substantially equidistant from the centre line so that when the pallet is presented to a second such pallet that is inverted and rotated through 180 degrees in its own plane, the first protruding member is received in the recess.

The invention thus provides for a single pallet design that enables stacking and interlocking of pallets by simple inversion and rotation.

Ideally the pallet has an upstanding edge so as to form a tray-like structure.

The first protruding member may be in the form of a rib and the second protruding members in the form of a pair of ribs that are spaced apart to define said recess between them.

The second protruding member preferably has end walls that close the recess at each end. This ensures that when the first protruding member of one pallet is received in the recess of the other relative lateral movement of the pallets is prevented in all directions.

The pallet may be formed as a unitary structure which is preferably a single wall and which may be thin-walled.

The protrusions on the second surface may be defined by channels in the upper surface.

The pallet may be provided with a reinforcing rib on its second surface.

According to a second aspect of the present invention there is provided a pallet comprising a deck defining a first substantially planar upper surface on which goods to be carried or stored are supported and an opposed second lower surface on which there are defined locking members for interlocking engagement with the locking members of a second such pallet when stacked, the interlocking members comprising a first projection and a second projection, the first and second projections being disposed on opposite sides of a centre line of the pallet such that when the pallet is stacked with a second such pallet that is inverted and rotated through 180 degrees in its main plane with respect to the pallet, the first projection interlocks with the second projection such that lateral movement is prevented in all directions.

The invention provides for a single pallet design that enables multiple pallets to be stacked and interlocked against lateral movement in all directions.

Ideally the second projection defines a recess having a wall at least part of which is complementary to the shape of the first projection so that when two such pallets are stacked the recess receives the first projection in interlocking engagement.

The first projection may be in the form of a rib and the second projection in the form of a wall that defines a recess that corresponds to the shape of the first projection.

The wall of the second projection preferably comprises two parallel spaced ribs that define a channel between them, the channel being closed at each end by end walls.

Ideally the pallet has an upstanding edge so as to form a tray-like structure.

The pallet may be formed as a unitary structure such as a single wall and ideally a thin-walled structure.

The protrusions on the second surface may be defined by recesses in the upper surface.

The pallet may be provided with a reinforcing rib on its second surface.

According to a third aspect of the present invention there is provided a pallet system comprising a plurality of pallets as defined above.

A specific embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a plan view of a pallet according to the present invention; Figure 2 is a side view of the pallet of figure 1 in the direction of arrow B.; Figure 3 is an end view of the pallet of figure 1 in the direction of arrow C; Figure 4 shows a sectioned view of the pallet along line A-A of figure I next to a similar view of an inverted pallet rotated through 180 degrees; and Figure S is a schematic sectioned view showing four pallets according to figures I to 4 arranged in a stacked and loaded configuration, the pallets serving as bases and covers.

Referring now to the drawings, the exemplary pallet 10 is a single thinwalled structure that can be manufactured, for example, by moulding from plastics material or by press-forming a steel sheet, although other suitable materials and manufacturing methods may be used.

The pallet is generally in the form of a tray with a substantially planar upper surface 11 that defines a loading deck and a lower surface 12 on which are defined protruding locking features. The edges of the tray on all four sides have a lip 13 that serves in use to retain goods loaded on to the deck.

The pallet 10 has four parallel channels 14, 15, 16, 17 in its upper surface 11 which serve to define four ribs 18, 19, 20, 21 on the lower surface 12. The ribs extend across the majority ofthe width (labelled at the X axis in figure 1) of the pallet but fall short at each side. A first rib 18 is disposed at a position slightly offset from the centre line Z. a second rib 19 is disposed towards a first end of the pallet and third and fourth ribs 20, 21 are disposed close to one another towards the opposite end. The third and fourth ribs define a channel 22 between them which is closed at each end by end walls 23. The distance b from the centre line Z of the pallet to the centre of the second rib 19 is equal to the distance c from the centre line Z to the centre line of the channel 22 (i.e. a line that is equidistant from the two ribs 20, 21). The width of the second rib 19 is designed to be just less than the width of the channel 22. Ah

Figure 4 illustrates the manner in which two such pallets iG, 10 are presented to each other so as to interlock when stacked one above the other. The lower pallet 10' is inverted and rotated through 180 degrees in its own plane in comparison to the upper pallet 10 so that the single second ribs 19, 19' on each pallet are received in the channel 22', 22 defined between the third and fourth ribs 20', 21' and 20, 21 on the opposing pallet. In this configuration the central first ribs 18, 18' are offset relative to one another such that they do not interfere with the stacking action.

In figure 5 four pallets are shown in a loaded configuration comprising first and second tiers T1 and T2. A first pallet 10 is used as a base and supports a first row of three goods containers 30 between the edge lips 13. A second row of containers 31 is placed directly on top of the first row and an inverted and rotated pallet 10' then serves as a cover to retain the first tier T1 between the edge lips 13' thereof. Securing members such as straps or bands may be wrapped around the stacked goods containers 30, 31 to prevent relative movement thereof. A second base pallet 10 is then placed directly above the cover pallet lO' and interlocked therewith in the manner described above. A further two rows of containers 30', 31' are loaded on to the second base 10 to form the second tier T2 and a second cover pallet 10' is placed over the top of the second tier T2.

At the interface of the first and second tiers, the location of the ribs 19, 19' in the channels of the first cover and second base lO prevents relative movement of the pallets and therefore the tiers of goods in both the X and Y directions.

The ribs 19, 19' may be a friction fit with the walls of the ribs defining the corresponding channel so as to prevent the stacked pallets working loose during, for example, transport over uneven ground.

The central ribs add stability and strength to the structure and in particular prevent the base pallet from sagging or otherwise deforming significantly under load.

The present invention thus provides for a single pallet that can serve both as a base and a lid by simple inversion and rotation. It also provides for a stable stacked load in which the components of the load are restricted from moving relative to one another during transport in all lateral directions, but in particular the major directions X and Y. al It will be appreciated that when the goods are unloaded after transportation the empty pallets can be stacked and interlocked by overlaying them in the manner shown in figure 4. Altematively, if the ribs are Conned with slightly tapered walls the pallets can be stacked together in the same orientation (unlike in figure 4). In such an arrangement the rib 19 of one pallet is received in the corresponding channel 14 in the deck of an underlying pallet, rib 18 is received in channel lS and ribs 21, 22 in channels 17, and respectively. Such an arrangement occupies a reduced volume such that less space is required for storage and thereby reducing shipping costs on the return journey.

The pallet design is such that when stacked and interlocked a vertical clearance, e, between them provides access for the forks of a fork lift truck or pallet truck.

The pallet is designed to be re-usable so providing both environmental and economic benefits.

It will be appreciated that numerous modifications to the above described design may be made without departing from the scope of the invention as defined in the appended claims. For example, the ribs and channels can be replaced with other suitable interlocking formations and can take be of any appropriate number whilst still using the same principle. \

Claims (21)

1. A pallet having a centre line comprising defining an first substantially planar surface defining a deck on to which goods to be stored or transported are to be supported and an opposed second surface having at least one first protruding member disposed on one side of the centre line and one or more second protruding members on the other side of the centre line and defining a recess, wherein the first protruding member and the recess are substantially equidistant from the centre line so that when the pallet is presented to a second such pallet that is inverted and rotated through 180 degrees in its own plane, the first protruding member is received in the recess.

2. A pallet according to claim 1 having an upstanding peripheral edge so as to form a tray-like structure.

3. A pallet according to claim 1 or 2, the first protruding member being in the form of a rib and the second protruding member in the form of a pair of ribs that are spaced apart to define said recess between them.

4. A pallet according to claim 3, wherein the ribs are substantially parallel.

5. A pallet according to claim 3 or 4, wherein the second protruding member has end walls that close the recess at each end.

6. A pallet according to any preceding claim being in the form of a unitary structure.

7. A pallet according to claim 6, wherein the pallet is formed from a single wall.

8. A pallet according to claim 7, being a thin-walled structure.

N

9. A pallet according to any preceding claim, wherein the protrusions on the second surface are defined by channels in the upper surface.

10. A pallet according to any preceding claim, further comprising a reinforcing rib on its second surface.

11. A pallet comprising a first substantially planar upper surface defining a deck on which goods to be carried or stored are supported and an opposed second lower surface on which there are defined locking members for interlocking engagement with the locking members of a second such pallet when stacked, the interlocking members comprising a first projection and a second projection, the first and second projections being disposed on opposite sides of a centre line of the pallet such that when the pallet is stacked with a second such pallet that is inverted and rotated through 180 degrees in its main plane with respect to the pallet, the first projection interlocks with the second projection such that lateral movement is prevented in all directions.

12. A pallet according to claim 11, wherein the second projection defines a recess having a wall at least part of which is complementary to the shape of the first projection so that when two such pallets are stacked the recess receives the first projection in interlocking engagement.

13. A pallet according to claim 11 or 12, wherein the first projection is in the form of a rib and the second projection in the form of a wall that defines a recess that corresponds to the shape of the first projection.

14. A pallet according to claim 13, wherein the wall of the second projection comprises two parallel spaced ribs that define a channel between them, the channel being closed at each end by end walls. r

15. A pallet according to any one of claims 11 to 14, further comprising an upstanding peripheral edge so as to form a tray-like structure.

16. A pallet according to any one of claims 11 to 15, wherein the pallet is a unitary structure.

17. A pallet according to claim 16, wherein the pallet is conned from a single wall structure.

18. A pallet according to claim 17, wherein the structure is thin-walled.

19. A pallet according to any one of claims 11 to 18, wherein the protrusions on the second surface are defined by recesses in the upper surface.

20. A pallet according to any one of claims 11 to 19, further comprising a reinforcing rib on its second surface.

21. A pallet system comprising a plurality of pallets according to any one of the preceding claims.