Pallet with non-slip load-carrying and ground-engaging surfaces

A pallet having a load-carrying surface (2) constructed of a substantially flat impervious material having a multiplicity of upstanding projections to prevent slippage on the surface while permitting cleaning of the surface. A ground-engaging part (8) of the pallet has at its underside an array of apertures so configured that when two like pallets are arranged in stacked configuration the projections on the load-carrying surface of a lower one of the pallets will engage within the apertures in the ground-engaging part of the upper of the two pallets to prevent slippage of the upper pallet relative to the lower pallet. Preferably, the ground engaging part of the pallet includes an array of substantially parallel reinforcing ribs (10) and the apertures are defined between adjacent ribs.

The present invention relates to pallets and more particularly to pallets 
which can easily be cleaned. 
Most pallets currently in use are constructed of wood, with the 
load-carrying platform of the pallet being defined by a series of spaced 
wooden planks. Conventional wooden pallets are liable to accumulate dirt 
and other contaminants during use which can become embedded into the 
surface structure of the wood with the result that it can be very 
difficult to properly clean the pallet by a normal housing or steam 
cleaning operation after use. This is unsatisfactory when the pallet is 
used to carry foodstuffs, pharmaceutical, or medical products or other 
products sensitive to contamination by dirt or bacteria. 
In our International patent application No. PCT/AU95/00690 there is 
disclosed a pallet of one-piece moulded plastics construction having a 
solid load-carrying platform with a plurality of upstanding projections. 
The projections are intended to grip onto the surface of for example a 
cardboard container or a shrink wrapped plastics container to prevent 
slippage on the platform. The projections are also so arranged on the 
platform as to permit thorough cleaning of the platform including the 
projections by hosing or steam cleaning. The underside configuration of 
the pallet is also such as to permit ease of cleaning. Although this 
pallet operates effectively and is capable of being effectively cleaned, 
when several of the pallets are stacked one on top of another there is a 
risk slippage of individual pallets of the stack when the stack is being 
moved, for example on the tines of a forklift truck. 
According to the present invention, there is provided a pallet having a 
load-carrying surface which is constructed of a substantially flat 
impervious material having a multiplicity of upstanding projections to 
prevent slippage on the surface while permitting cleaning of the surface, 
and a ground-engaging part of the pallet has at its underside an array of 
apertures so configured that when two like pallets are arranged in stacked 
configuration the projections on the platform of a lower one of the 
pallets will engage within the apertures in the ground-engaging surface of 
the upper of the two pallets whereby to prevent slippage of the rubber 
pallet relative to the lower pallet. 
In the preferred embodiment of the invention the ground-engaging part of 
the pallet is defined by two or more struts with ribs at their underside 
to provide reinforcement, the apertures being defined between adjacent 
ribs. 
In the preferred embodiment the upstanding projections are defined by a 
series of raised lips which form a polygonal shape or a rounded shape or a 
mixture of rounded and polygonal shapes. 
In the preferred embodiment the projections are distributed uniformly 
throughout the load-carrying surface, and the apertures are distributed 
throughout the ground-engaging part.

As shown in the accompanying drawings a pallet in accordance with the 
preferred embodiment of the invention is constructed of plastics and has a 
continuous, substantially flat, load-carrying platform 2. The 
load-carrying platform 2 is provided with a multiplicity of upstanding 
projections 4, uniformly distributed over its entire surface, the 
projections 4 being formed integrally with the platform 2. The projections 
4 on the otherwise flat and smooth load-carrying platform 2 enable the 
projections to grip the surface of a container on the platform, for 
example a cardboard container or a shrink wrapped plastics container. 
The load-carrying platform 2 is supported by an underlying support 
structure consisting of a series of parallel beams 6, the two outer beams 
6 defining outside walls of the pallet. The lower edges of the beams 6 are 
interconnected by a series of transverse struts 8 which define the 
ground-engaging surface of the pallet. The beams 6 are spaced to define an 
access for the tines of the forklift truck from either of the two open 
ends of the pallet. The beams 6 defining the opposed outer side walls of 
the pallet may be apertured to permit entry of the forklift tines from 
either of the two opposed sides thereby providing four-way entry for the 
tines. The outer edges 8a of the outermost struts 8 are included to define 
ramps to facilitate movement onto the upper surface of the struts of 
wheels at the underside of the tines of a hand operated forklift trolley. 
Preferably, the overall pallet consisting of the load-carrying platform 2 
and the supporting structure defined by the beams 6 and transverse struts 
8 is moulded in one piece in a suitable plastics, for example 
post-consumer recycled plastics, although other plastics may also be used. 
The underside of each of the struts 8 is formed with a series of 
longitudinally-extending parallel ribs 10 to provide increased rigidity 
against bowing of the struts and hence bowing of the pallet in a direction 
transversely to the beams 6. It will be noted from FIG. 3 that the 
adjacent ribs 10 at the underside of each strut 8 are interconnected by a 
series of transverse webs to provide a pattern of apertures 12. It will 
also be noted from FIG. 1 and 2 that the upstanding projections 4 on the 
load-carrying platform 2 define a continuous upstanding lip in the form of 
a four sided figure which as shown is either a parallelogram or a 
trapezium, the continuous lip bounding flat internal area 4a of the 
platform. The apertures 12 defined within the ribs 10 of the underside of 
the struts 8 are so configured that when two like pallets are stacked one 
on another the upstanding lips of the projections 4 on the platform 2 of 
the lower pallet will engage within the recesses 12 at the underside of 
the struts 8 of the upper pallet, with the ribs 10 are interconnecting 
webs of the struts 8 lying in contact with the flat surface areas of the 
platform surrounding the projections 4. As a result, the two pallets are 
interlocked sufficiently to prevent slippage. 
Although as shown the upstanding lips on the platform are in the form of 
four sided figures of parallelogram or trapezium shape, they may be of 
other shape for example other polygonal shape or a rounded shape such as a 
circular, elliptical, or oval shape. Although as shown each of the 
upstanding lips is continuous it may alternatively be interrupted. 
As will be apparent, when other shapes of lips are used on the upper 
surface of the platform 2, the apertures 12 defined between the ribs 10 at 
the underside of the struts 8 are appropriately configured to receive the 
differently shaped lips. It will be apparent in this regard that the 
apertures 12 within the ribs 10 do not have to be of the same shape as the 
upstanding lips but merely have to be such as to receive those lips and 
co-operate with them to prevent slippage. For example in the case of lips 
which are of circular shape, apertures within the ribs of an appropriately 
sized square shape can receive the circular lips of an underlying pallet 
and engage them at four diametrically-opposed points in order to prevent 
slippage. 
In the pallet of the invention the upstanding lips on the load-carrying 
surface of the platform provide gripping characteristics for the surface 
without impeding the ability to effectively clean the surface due to the 
substantial flat areas of the platform which surround and lie within the 
individual lips. However these lips also enable a substantial non-slip 
stacking characteristic by co-operation with the formation of apertures 
incorporated within the array of reinforcing ribs at the underside of the 
pallet. 
The embodiment has been described by way of example only and modifications 
are possible within the scope of the invention.