Note: Descriptions are shown in the official language in which they were submitted.
WO 92/12~?06 2 0 7 ~ PCl'/AU92/00018
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n PAI.LET "
TECHNICAL FIELD
The present invention relates to pallets for
shipping purposes and is especially concerned with the
5 shipment of coils of metal strip but the invention may be
equally applicable to the shipment o~ other products
particularly in coil form but not necessarily so~
BAC~GROUND ART
During transportation, a pallet may be subjected to
severe forces duo to impact when the pallet and its load
is picked up and deposited by a forkli~t truck and
furthermore during transportation forces aro imposed due
to substantial accelerat~ons and decelerations~ For
e~ample, when the pallet is being moved by rail, during
shun~ing operations to prevent damage to the product on
the pallet, the pallet must support the product and
restrain movement.
Substantial economic loss occurs, for esample, in
relation to coils of thin aluminium strip where movement
of the coil occurs on a conventional pallet thereby
damaging the coil. It has been now found that strapping
the coil onto a pallet, with tha a~is of the coil being
vertical, does not adeguately restrain movement of the
coil and damage has easily occurred. The user of the coil
will typically be intending to manufàcture aluminium cans
for beverages and any damage to the strip must be removed .
since such damaged strip cannot be used in precision
machinery. Not only is there a loss of valuable aluminium
strip but also machine down~-time and labour cost
contribute to the economic loss~ ~ `
Thus, there has been a long standing problem of `
damage to coils of aluminium which typically weigh around
si~ tonnes, have a diameter of around 1.4 meters and a .
width of around 1~5 meters. Attempts to protect the coil
from movement on a timber pallet have included nailing
timber battens to the upper surface of the pallet to
attempt to restrict movement of the coil and also placing
a thick rubber mat under the coil before it is placed on
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WO92~1290~ 2 Q 7 8 ~13 ~ PCT/AU92/~
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the pallet. In an attempt to further protect the coil it
has been wrapped in plastic sheet material and strapped to
the pallet.
Another approach that has been proposed involves
the formation of a pallet from two moulded plastic halves
which interengage and have an upstanding lip. The
periphery of the pallet is secured by a steel band which
pulls the two halves towards one another so that the lip
engages around the periphery of the coil~ However these
pallets are e~pensive, heavy and only a very small range
of adjustment is possible to accommodate coils of
different diameter~ This results in substantial capital
investment for a range of pallet sizes ~or a typical
aluminium strip product plant as significant variation in
coil diameter occurs in practice~ The capital cost o
such pallets is a serious disadvantage as, for many
consignments involving esport, it is not practicable or
feasible to return the pallets for further use~ The
pallets are of special purpose design and would have not
general utility for shipment~
DISCLOSURE OF INVENTI~N
The present invention consists in one aspect, in a
pallet suitable for shipment of coils of metal strip or
similar products and comprises a base for supporting the
product, support means connected to the base and shaped
and dimensioned for supporting the base and providing a
clearance under the base for the insertion of forks of a
forklift truck, and a centrally located dowel connected to
the base and projecting upwardly therefrom for`engaging
within a central cavity in tha product for restraining
movement of the product in a plane parallel to the base.
P~eferably the dowel is of circular shape and
tapered upwardly to facilitate location and engagement of
the cavity in the product. Advantageously the dowel can
be of the order of 25mm to 75mm in height~ When the
invention is used $or transporting coils of metal strip,
the dowel typically will have a diameter of about 250mm
and a taper of a few percent over the height of the dowel
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W092/l2906 2 0 7 ~ d ~ ~ PCT/A~192/~
has proven to be convenient and satisfactory.
Advantageously, embodiments of the invention are
formed ~ith the base of circular shape whereby a high
density of packing of pallets can be achieved.
Alternatively the base could be of polygonal shape of at
least five sides again to achieve high density pac~ing.
For example it has been found that a standard shipping
container will accommodate onl~ three conventional timber
pallets but four pallets in accordance with the present
invention can be accommodated in the same space thereby
offering substantial economic advantage~
In a preferred embodiment, the support means
comprises a mult~plicity of lQgs in spacad array and most
proferably the array permits the forks of a forklift truck
to be insert~d from any one of four directions~
Most preferably the array of leqs includes a
central space for accommodating the dowel of another
pallet so that an interengaged stack can be formed.
In a preferred embodiment, the pallet is formed as `
a single plastic moulding and it has been found that this
can be achieved economically by low pressure injection
moulding in polypropylene. For the purpose of shipping
six ton coils of aluminium strip, it has been found that a
relatively cheap, lightweight and durable pallet can be
formed. Typically the pallet will weigh only about 16KG
and the pallet is of competitive price having regard to ~
its durability compared to timber pallets. Such a pallet i
is considered to be economic for e~port where return of
the pallet is not feasible and in any event the pallet is
of valuable plastic material which can be recycled to form
other products after shipment of the coil.
In another aspect the invention estends to a lid of
suitable form for use on a coil supported on a pallet and
the invention also estends to a method of shipment using
such items~
BRIEF DESCRIPTION OF DRAWINGS
For illustrative purposes only, an embodiment of
the invention will be described with reference to the
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W092/12~6 PCT/AU92/~18
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accompanying drawinqs of which:-
Figure l is a perspective view from above of a
pallet;
Figure 2 is a side elevation of the pallet;
Figure 3 is a sectional side elevation of the
pallet taken along the line A-A in Figure 4;
Figure 4 is a plan view of the pallet;
Figure 5 is an inverted plan view of the pallet;
Figure 6 is a plan view of a complimentary lid to
be used with the pall~t of FiqurQs l to 5; and
Figure 7 is a cross sectional vie~ taken along the
line ~-B of Figure 6~
MODES FOR CARRYING OUT THE INVENTION
The pallet and lid illustrated are each integrally
formed in polypropylene by low pressure injection moulding
in a single operation. The pallet comprises a circular
base lO, having an upstanding peripheral lip 9, an
integral upstanding dowel ll and array of twelve support
legs 12. The dowel is slightly tapered, has an internal
cross-shaped strengthening wall 17, and is of the order of
50mm hiyh. The pallet diameter is 1590mm and thus can
accommodate a wide range of coil sizes. Each of the
support legs is hollow and slightly tapered and stiffened
by a set of radially outwardly e~tending buttress walls
15, and a cross-shaped interior webbing 16. In the case
of the buttress walls 15A reaching the periphery o~ the
base, the buttress is the full depth of the support legs
but the other buttress walls 15 terminate short of the
bottom of the support leg.
As illustrat~d in figure 5 by arrows a forklift
truck can insert its forks in any one of four directions
under the pallet~ This facilitates pallet handling is an ,
advantage over many one-trip pallets where strip-like
supports for the base are used thereby restricting access ``
of forks to two directions. Furthermore the array of legs `
provides a high degree of stability irrespective of
direction of any loads or forces during transportation.
The base also includes a series of four notches 13
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WO92/12906 2 ~ 7 ~ fl 3 ~:~ PCT/AUg2/~18
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each defined by respective pairs of parallel walls 14 for
accommodating strapping which can facilitate holding in
place protective plastic sheeting.
Referring now to the lid of Figures 6 and 7, the
lid 20 is of the same overall diametar as the pallet 10.
The lid comprises a thin plastic disc-shaped portion 21
with a downwardly extending peripheral skirt 22
interrupted at our equally spaced locations ~3, a central
depending collar 24 and, e~tending from tha upper surface,
a central smaller location collar 2~ and an array of
location rings 26.
Tho location rings 26 are dimensioned to accomodate
and locate the bases of the support legs 1~ o another
pallet which may be placad on top of tha lid to ~orm a
stack. Similarly the collar ~5 is dimensioned and located
to cooperate with the rings and depending collar 24 of
another lid so lids may be stacked and located for
shipment and storage.
A series of four identical tie locators 27 are
provided equally spaced around the lid, the radially outer
portion of each locator being where there is an ` `
interruption 23 in the peripheral skirt 22. Each locator
comprises a pair o~ spaced upstanding walls 28 e~tending
substantially radially so that a tiedown strap passes
between the walls and over the edge of the lid to secure
the lid and a coil onto a supporting pallet. A series of
transverse grooves or slots 29 are provided in the plastic
material between the walls 28 thereby providing lines of
weakening. When a strap-like tie is tensioned over a coil
having an e~ternal diameter less than the full diameter of
the lid, the plastic material can shear along one or more ``
of the grooves to tighten the tie so as to bear on the
edge of the coil. `
A further feature which may be utilised is the
provision of packing rings, the e~ternal dimension of the
upstanding dowel 11 on the pallet being chosen to
represent the smallest diameter used on a coiliny
machine. If machines providing a greater coil diameter
WO92/1~6 2 ~ 7 8 -~ 3 ~ PCT/AU92/~18 _
are used then packing rin~s are simply inserted to make
the coil a snug fit.
The present invention can be applied in plastics
material such as polypropylene which readily can be
recycled when pallets become damaged. It is envisaged
that a multiplicity of trips will be completed before
pallet damage is likely. It is then a simple matter to
reuse the material to make further lids and pallets.
Embodiments of the inv~ntion can be utilised with
plastic wrapping materials so that a completely weather
tight package is providQd to protect valuable products
such as thin aluminium strips when in transit from the
place of manuacturQ to the placa of utilisation.
Embodiments o~ the in~ention permit fast, safe and
reliable handling with minimal chance of coil damage and
wastage compared with conventional palletisation and
delivery systems~
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