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Patent 2242721 Summary

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(12) Patent Application: (11) CA 2242721
(54) English Title: LIGHTWEIGHT PLASTIC PALLET
(54) French Title: PALETTE EN PLASTIQUE LEGERE
Status: Deemed Abandoned and Beyond the Period of Reinstatement - Pending Response to Notice of Disregarded Communication
Bibliographic Data
(51) International Patent Classification (IPC):
  • B65D 19/32 (2006.01)
  • B65D 19/00 (2006.01)
(72) Inventors :
  • GRONNEVIK, ODDBJORN (Norway)
  • GRANDE, HELGE (Norway)
  • KOTTERHEINRICH, ROLF (Norway)
(73) Owners :
  • BOREALIS A/S
(71) Applicants :
  • BOREALIS A/S (Denmark)
(74) Agent: MACRAE & CO.
(74) Associate agent:
(45) Issued:
(86) PCT Filing Date: 1997-01-10
(87) Open to Public Inspection: 1997-07-17
Examination requested: 1998-07-07
Availability of licence: N/A
Dedicated to the Public: N/A
(25) Language of filing: English

Patent Cooperation Treaty (PCT): Yes
(86) PCT Filing Number: PCT/NO1997/000009
(87) International Publication Number: WO 1997025250
(85) National Entry: 1998-07-07

(30) Application Priority Data:
Application No. Country/Territory Date
960128 (Norway) 1996-01-11
960910 (Norway) 1996-03-06

Abstracts

English Abstract


A lightweight pallet made of a thermoplastic material, having a deck and
integrated sheet legs underneath the deck along its longitudinal, transverse,
or both sides. The pallet being fabricated by thermoforming an extruded
plastic parison having a monolayer or multilayer structure into one
predominantly flat article and bringing the side parts of the article into a
position perpendicular to the pallet deck and affixing the sheet legs in that
position. The pallet may further be provided with appropriately designed
runners.


French Abstract

L'invention porte sur une palette plastique légère faite d'un matériau thermoplastique et comportant un plancher et des pieds en feuille intégrés placés sous ses côtés longitudinaux, transversaux ou les deux. La palette est fabriquée par thermoformage d'une préforme de plastique extrudé de structure monocouche ou multicouche. On obtient ainsi un article sensiblement plat dont les côtés sont ensuite pliés en équerre par rapport au plancher, puis bloqués dans cette position. Les palettes peuvent être munies ultérieurement de patins appropriés.

Claims

Note: Claims are shown in the official language in which they were submitted.


14
Claims
1. A pallet made of a thermoplastic material, the pallet
comprising a deck and legs disposed underneath said deck,
characterized by said pallet deck having top (2) and bottom
surfaces and a set of opposed longitudinal sides and a set of
opposed transverse sides, and sheet legs (3) integrated with
said deck and disposed along at least one of said set of sides
of said pallet deck, said pallet having been fabricated by
thermoforming an extruded thermoplastic parison having a
monolayer or multilayer structure into one predominantly flat
article having a set of opposed longitudinal sides and a set
of opposed transverse sides, and bending at least one of said
set of sides of said article into a position perpendicular to
the main part of said article to form the sheet legs and
affixing said sheet legs into said position.
2. A pallet according to claim 1, characterised by
further comprising at least two pallet deck posts formed in
the bottom surface of said pallet deck, said pallet deck posts
being situated at a longitudinal center of said pallet deck to
function as load-carrying pallet legs.
3. A pallet according to claim 2, characterized in that
said pallet deck posts (4) are block-shaped and of a height
less than the final height of the plastic pallet, and fastened
to a bottom surface of said block-shaped posts (4) separately
produced leg structures, said leg structures being of a height
such that when fastened to said pallet deck posts (4) pallet
legs of a desired height are obtained.
4. A pallet according to claim 3, characterized in that
said separately produced leg structures comprise blocks (6)
which are fastened to said bottom surface of said block-shaped
posts (4).
5. A pallet according to claim 3, characterized in that
said separately -produced leg structures comprise a separately

thermoformed runner component (9) shaped as a cross-member
(10) having at least two upward-facing runner posts (11), and
that said runner component is fastened by a top surface of
said runner posts to said bottom surfaces of said pallet deck
(4).
6. A pallet according to claim 1, characterised by
comprising one set of sheet legs (3), and further comprising a
thermoformed U-shaped profile (7) in the bottom surface of
said pallet deck in the whole length thereof in its center
longitudinally and parallel to said sheet legs, and fastened
to the bottom of said U-shaped profile, one separately
manufactured pallet leg structure comprising an upper spacer
component (8) and a lower runner component (9); said upper spacer
component (8) comprising a cross member (10) having downward-
facing posts (11); and said lower runner component (g)
comprising a cross member (10) having upward-facing posts (11);
said upper spacer component being fastened by its cross member
to a bottom surface of said U-shaped profile (7); and said
lower runner component being fastened by top surfaces of its
upward-facing posts to bottom surfaces of the matching
downward-facing posts (11) on said upper spacer component.
7. A pallet according to claim 6, characterized in that
at least one of said upper spacer component (8) and said
U-shaped profile (7) facing said upper spacer component are
formed with a longitudinal recess so that a straight open
channel (12) is created between said upper spacer component
(8) and said deck, into which a stiffening section may
optionally be inserted.
8. A pallet according to any of claims 1 to 7,
characterized in that the sheet legs (3) include openings to allow
truck forks to be inserted.
9. A pallet according to claim 8, characterized in that
said openings are expanded out through the bottom edge of said
side sheets to create at least two interspaced sheet legs (3).

16
10. The pallet of claim 9, characterized in that one
runner component is fastened to a bottom of each pair of said
sheet legs along opposite sides of said pallet deck, each said
runner component (9) being produced separately and comprising
posts (11) of heights adapted to the sheet legs (3).
11. A pallet made of a thermoplastic material, the pallet
comprising a deck and at least two runners disposed underneath
said deck, characterized by said pallet deck having top and
bottom surfaces, said runners being in the shape of a cross
member having a upward-facing runner post in each end thereof;
said runners being fastened by a top surface of said runner
posts to said bottom of said pallet deck; said pallet deck
having been produced by thermoforming an extruded plastic
parison having a monolayer or multilayer structure into one
predominantly flat article, said runners having been produced
separately by thermoforming an extruded parison identical to
the one used in the production of said pallet deck into a
predominantly flat article and bending the end parts of said
latter article into a position perpendicular to the main part of
said latter article to obtain said runners having upward-facing
posts.
12. A pallet according to any of claims 1 to 11,
characterized in that said parison is extruded from a thermoplastic
selected from polyolefins, PVC, ABS, styrene plastics (PS),
polyamides (PA) and polycarbonates (PC).
13. A pallet according to any of claims 1 to 12,
characterized in that said extruded structure is a coextruded
integrated multilayer structure comprising at least one foamed
plastic layer having a solid skin on both sides thereof.
14. A pallet according to any of claims 1 to 13,
characterized in that said extruded structure comprises at least one
polyolefin material.
15. A pallet according to claims 12, 13 or 14, characterized
in that said- thermoplastic is reinforced with a

17
reinforcing material selected from cut glass fibres and long glass
fibres.
16. A pallet according to any of claims 1 to 15,
characterised in that at least said top surface of said deck is
furnished with a plurality of parallel, raised longitudinal
sections made of a friction material.
17. A pallet according to claim 16, characterised in that
the parallel, raised longitudinal sections have a height of
about 1 mm and a width of from narrow strips to a continuous
facing.
18. A pallet according to any of claims 1 to 15,
characterised by comprising a friction material extruded onto said
top surface of said plastic pallet deck.
19. A pallet according to one or more of the above
claims, characterized by said top surface, and optionally also
said bottom surface, of said pallet deck being profiled with
impressed channels (16) and raised sections (17) of desired
dimensions.

Description

Note: Descriptions are shown in the official language in which they were submitted.


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~ '
LIGHTWEIGHT PLASTIC PALLET
FIELD OF INVENTION
This invention relates to a lightweight plastic
5 pallet, in particular a pallet having integrated sheet-like
pallet legs or runners.
PRIOR ART
Pallets are included as a part of the goods that are
o to be transported and/or stored on them, and therefore it is
important for the pallet to be lightweight, but strong and
rigid at the same time. Plastic pallets have the advantages
over wooden pallets that they are lightweight, that they do
not absorb moisture, and that they can be cleaned/disinfected,
15 which is decisive in fields where hygiene is important, e.g.,
in the food industry.
European Patent No. EP-O 400 640 discloses a plastic
pallet that is assembled from a top deck and a bottom deck
with runners, or from a deck and runners. The components are
20 formed with legs that are inserted into one another during
assembly. M~ch~n; cal fasteners in the form of metal plates
having die-cut notches, nails or the like can be employed to
ensure that the components hold together.
Swiss Patent No. CH-685549 A5 discloses a plastic
25 pallet that is injection molded in two components, namely, a
top deck and a bottom deck comprising posts and runners. The
top deck and the bottom deck, both having reinforcing ribs,
are butt-welded together so that the side edges and ribs are
welded together against one another. Directly within all four
30 side edges and along the center line longit~ n~lly there are
in the ribs semicircular openings into which steel pipes or
flat rods can be jammed for m~ch~nical reinforcement of the
pallet. The plastic pallet is preferably fabricated from poly-
ethylene.
Swedish Patent SE 501,539 relates to an injection
molded pallet runner, preferably comprising two or three sepa-
rate, hollow, closed ch~nn~ls along its entire length. The
runner is lightweight, while rigid. It can be fastened by its
top to suitable posts, which again are fastened to the bottom
.

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WO 97/25250 PCT/NO97/OOOO9
of a pallet deck.
International Application W0 93/18906 relates to a
blow-mold device for producing one-piece, externally smooth,
double-walled plastic plates with internal spaces formed dur-
S ing blow-molding. The high bending resistance of the manufac-
tured plate makes it suitable for making plastic pallets.
Prior art plastic pallets are fabricated by injection
molding of components that are then joined together. The com-
ponents will typically have reinforcing ribs at required
o places in order to attain a lightweight rigid construction. In
the injection molding of such large objects, very large and
expensive injection molding tools are used that require large
injection molding machines having great clamping forces. Con-
sequently, it would be desirable to be able to make plastic
15 pallets by a simpler and more economical method. A possible
means of attaining this object is to thermoform the pallet
from an extruded plastic sheet or from a parison, like the
blow molding of large objects such as barrels, gasoline tanks,
etc. To attain a lightweight and rigid construction it is
20 o-ften desirable to employ a coextruded multilayer structure
where one of the layers is at least partially foamed. For in-
stance, US Patent No. 4,874,649 discloses a method for the
blow molding of a coextruded parison comprising at least two
layers, one of which, perhaps more, is at least partially
25 foamed.
Applicant's contemporary Norwegian patent application
N0-A-960128, the disclosure of which is hereby incorporated by
reference, relates to a pallet manufactured by thermoforming a
parison of the type disclosed in US Patent 4,874,649. This
30 parison is formed into a pallet deck and spacer and runner
components, which are assembled in a subse~uent separate oper-
ation. Thus, a lightweight, however strong and rigid construc-
tion, is att~i n~ . The pallet may be reinforced by introducing
rlgid sections into cavities formed between the pallet deck
35 and spacers.
For many purposes especially lightweight pallets,
often of a smaller size than standard normal sized pallets,
are desired. It has now been found that it is possible to fab-
ricate a lightweight pallet having pallet legs and runners of

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W O 97/25250 PCT~N097/00009
a simpli~ied construction compared with the pallet disclosed
in Applicant's above mentioned patent application.
The pallet's smooth and even surface makes it very
simple and easy to clean and disinfect. The pallet is there-
5 fore especially well suited ~or use in the food industry andallied industries. The pallet has a great strength/weight
ratio because of its design. As a result, it is well suited
for purposes where low weight is important, e.g. in air
freight, and where manual handling of pallets occur frequent-
~o ly.
SUMMARY OF THE INVENTION
The present invention provides a pallet made of athermoplastic material, the pallet comprising a deck and legs
15 disposed underneath the deck. The pallet deck has top and bot-
tom sur~aces and a set of opposed longit~l~;n~l sides and a set
of opposed transverse sides, and sheet legs integrated with
the deck and disposed along at least one of said set of sides
of the pallet deck. The pallet is fabricated by thermoforming
20 an extruded thermoplastic parison having a monolayer or multi-
layer structure into one pr~om;n~ntly flat article having a
set of opposed longitudinal sides and a set of opposed trans-
verse sides, and then bending at least one of said set of
sides o~ the article into a position perpendicular to the main
25 part thereof to form the sheet legs, and affixing the sheet
legs into said position.
The invention also provides a pallet, made of a
thermoplastic material, comprising a deck and at least two
runners disposed underneath said deck. The pallet deck, having
30 top and bottom surfaces, and the runners, being in the shape
of a cross member having a upward-facing runner post in each
end thereo~, are fastened by a top surface of said runner
posts to the bottom of the pallet deck. The pallet deck is
produced by thermoforming an extruded plastic parison having a
35 monolayer or multilayer structure into one predominantly flat
article. The runners are produced separately by thermoforming
an extruded parison identical to the one used in the produc-
tion of said pallet deck into a prA~om;nantly flat article and
bending the end parts of this article into a position perpen-
-

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WO 97/252~0 PCTA~097/~0009
dicular to the main part thereof to obtain the runners having
upward-facing posts.
B~IEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective sketch of a fabricated pallet
comprising sheet legs and a leg structure consisting of block-
shaped posts located in the center lonytitudinally.
Fig. 2 indicates the principle of constructing the
sheet legs.
o Figs. 3 and 4 are sectional views showing alternative
designs of the plate-shaped legs.
Fig. 5 is a sectional view through the center long-
itudinally of a pallet having legs consisting of deep-drawn
posts.
15 ~ Fig. 6 is a sectional view through a block-shaped
pallet leg of an alternative design.
Fig. 7 is a perspective sketch of a pallet deck and
runner components prior to joining together.
Fig. 8 is a sectional view through a part of the
20 pallet deck and spacer and runner components fastened to the
bottom of the deck along its center longitudinally.
Fig. 9 is a top view of a pallet where the pallet
deck has raised sections.
Fig. 10 is a side view of the pallet in Fig. 9.
a5
DETAILED DESCRIPTION OF THE INVENTION
The present pallet is manufactured by a process that
comprises a number of steps. The first step consists in extru-
ding a parison, preferably as disclosed in the above mentioned
30 US 4,874,649. The extrudate can have various wall thicknesses
around its periphery, obtained by the use of an extrusion die
of a suitable configuration. Thus, different parts of the pal-
let can be given different wall thicknesses. The extruded par-
ison is flattened, and, when still hot, shaped in a mold to a
35 substantially flat article. Parts of the article can be given
a desired shape, e.g. profiled structures, deep-drawn posts,
etc. by utilizing combinations of compressed air and vacuum.
When the parison is laid flat, those parts of the insides
forced into contact with each other will become welded to-

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W O 97/25250 PCT~N097/0~009
gether and form a do~ble sheet. The principles of extrusion
and forming are well known to persons skilled in the art.
In its simplest embodiment the parison consists of a
homogeneous (solid) material. In order to make the extruded
S structure lighter, the parison can be coextruded with several
layers, where at least one layer is at least partially foamed.
Present-day coextrusion technology permits a number of options
for the shape and structure of the parison. For instance, the
extruded structure can in one specific embodiment of the in-
o vention consist of a foamed plastic layer having a solid skinon just one side thereof. The foamed layer should preferably
have a closed-cell structure, however, this is not an obliga-
tory feature. In practice, a foam having a density of down to
about 100 kg/m3 can prove useful. The skin will form the pal-
15 let's outsides, so that a wear-resistant and easy-to-clean
surface is attained.
In another specific embodiment of the invention, the
extruded structure comprises a foamed layer having a solid
skin on both sides, or optionally multiples of such a multi-
20 layer structure. Such a sandwich structure will, it is ~om~o~knowledge, have high torsional rigidity and produce a light-
weight construction. The foam layer typically comprises about
70~ of the sheet structure's thickness, and each skin layer
about 15%, more preferably about 80% and about 10~, respecti-
25 vely. When the foam has a closed-cell structure, in some cases
it can even constitute the entire wall thickness. The foam can
have a density within the range of from the density of a solid
material down to as far as it is practicable possible to pro-
duce a stable polymer foam. There has to be very good adhesion
between the foam and the skin layer in order to attain an op-
timal rigid structure. Consequently, the foam and skin have to
be coextruded in such a way that an integrated multilayer
structure is produced.
Suitable materials for producing the extruded parison
3~ having a monolayer or multilayer structure comprise in prin-
ciple all extrudable thermoplastics having sufficient rigi-
dity. Especially suited thermoplastics are polyolefins such as
polyethylene (PE) and polypropylene (PP), polyvinyl chloride
(PVC), acrylonitrile butadiene (ABS), styrene plastics, poly-
, .

CA 02242721 1998-07-07
W O 97n5250 PCT~N097/O0009
amides (PA) and polycarbonates (PC). Among these, polyolefin
materials are preferred. However, there is nothing to prevent
the foam material and the skin layer(s) from being made of
different materials. For instance, an inside layer of high
S density polyetylene (HDPE) and an outside layer of ultrahigh
molecular weight high density polyethylene (HMW-HDPE) and an
intermediate layer of a foamed polyethylene will comprise a
suited structure. Another structure has an inside layer of PP
homopolymer, an outside layer of PP block copolymer, and an
o intermediate layer of foamed PP. Of course, other structures
are also possible and fall within the scope of the invention.
The materials constituting the solid part of the ex-
truded multilayer structure can, if desired, be reinforced
with cut glass fibers and/or long glass fibers in the direc-
tion of extrusion.
During extrusion of the parison and forming of thecomponents of the pallet, manufacturing waste will be produced
which, for economic reasons, should be returned to production.
This can be done by incorporating the waste materlal into one
20 or more layers in the coextruded multilayer structure. Conse-
quently, in a practical embodiment of the invention, it will
be advantageous to use materials that can be mixed with one
another. Polyolefin materials are excellently suited in this
respect, especially certain types of polypropylene (PP) and
2s high-density polyethylene (HDPE). Smaller amounts of glass
fibers in the skin layers can after grinding o~ the material
be re-extruded and without problems included in the skin
layers, and even in the foam layer(s).
It is also possible to add to the thermoplastics
30 crosslinking agents in order to crosslink the material in the
pallets produced. ~he disadvantage is that this kind of manu-
facturing waste cannot be recycled. Another disadvantage is
that the pallets then as a rule can be joined together only
m~h~n; cally, though there do exist silane-based crosslinking
35 agents that can be crosslinked after the finished pallet has
been made.
Because articles made from plastic materials have a
slippery surface, and especially articles made from polyole-
fins like HDPE and PP, it will often be desirable to add to
-

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_
the pallet deck a friction-increasing material. This can be
done by extruding on the outside of the parison an extra layer
with a friction material in a width from narrow strips to a
continuous facing around the entire periphery of the parison
5 or around parts of its periphery. The friction material on the
top of the pallet deck will prevent goods from sliding off the
pallet, while the ~riction strips on the bottom will prevent
the pallet from sliding easily off truck forks when the pallet
is being handled. Alternatively, the friction material coating
o may be applied onto the pallet deck of already fabricated pal-
lets. This can easily be performed by extrusion coating, for
instance by conveying the pallets underneath a stationary ex-
truder in a coating line.
Pre~erably, the friction material is applied to the
15 pallet in the form of parallel, raised longitudinal sections
having a height of about 1 mm and in a width from narrow
strips to a continuous facing. When the pallet is fabricated
from a polyolefin material, a suitable friction material is
selected among polyolefin-containing materials such as EVA,
20 EBA and the like.
It is of course possible to add to the plastic mater-
ials the additives and auxiliary agents that are customary for
thermoplastics, such as antistatic agents, heat and UV stabil-
izers, colorants, etc. The various layers of the multilayer
2~ structure can be of dissimilar colors, as desired. It is also
possible that pallets intended for dissimilar purposes can
have different colors.
The pallet deck and the sheet pallet legs along the
sides of the pallet are formed in one forming step into one
30 pr~om~nantly flat article. The side parts of this article are
then brought into a position perpendicular to the main sheet
and fastened, e.g. by welding, in this position. The fastened
side sheets will thus constitute one set of integrated pallet
sheet legs made from the same sheet structure as the rest of
35 the article, i.e. the pallet deck.
In one embodiment of the pallet, it has sheet legs
only along two opposite sides. To stabilize the legs it may be
convenient to provide runners fastened to the bottoms of two
corresponding opposite sheet legs. This is particularly appro-

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priate when the sheet legs have openings cut through their
edges, e.g. three separate sheet legs along each longitudinal
side of the pallet and runners fastened to the bottoms of each
pair of opposite sheet legs in the transverse direction of the
5 pallet.
In its simplest embodiment the pallet has sheet-like
legs both along its longitudinal and transverse sides, and no
legs in the center on the bottom. The sheet-like legs are
joined together in the corners where they meet to obtain a
o rigid construction. The fields of use of such a pallet will
normally not re~uire any additional pallet legs.
Any combination of sheet-like legs in the longitudin-
al and/or transverse directions of the pallet is contemplated
by the present invention.
15 ~ When the pallet shall carry greater loads, additional
legs intended for carryiny the substantial part of the load
must be provided, usually fastened to the bottom of the pallet
deck at e~ual dist~nc~-~ from and parallel to the sheet legs.
Such legs may be of various constructional designs.
zo
Detailed descriPtion of drawinqs ~
Preferred embodiments of the pallet will now be
explained in more detail with reference to the attached draw-
ings.
2S Fig. 1 shows one particular embodiment of the finish-
ed pallet, 1, with the pallet deck, 2, sheet legs, 3, and leg
members comprising more block-shaped pallet legs, of which
only one is seen in the figure.
Fig. 2 demonstrates the principle of forming the
30 sheet legs. During the forming of the parison V-shaped
grooves, 5, are impressed into the sheet in its whole length
in the direction of extrusion and/or in its transverse direc-
tion at specific distances from the side edges of the sheet.
These grooves are given a bottom angle of approximately 90 ~,
35 and a suitable depth; however, the wall thickness in the bot-
tom of the grooves must be sufficient to avoid that the mater-
ial break during the subse~uent manufacturing steps. After
that the formed sheet has been removed from the mold, the side
parts, 3, of the sheet are bended along the V-shaped grooves

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.
until a position perpendicular to the main sheet and then fas-
tened in this position. This operation is indicated by the
dotted lines in figure 2. Thus, the main sheet, 2, will con-
stitute the pallet deck and the side parts, 3, will constitute
the sheet legs. The thickness of the main sheet, 2, is prefer-
ably greater than the thickness of the side sheet parts, 3.
This difference in thicknesses is achieved by regulating the
circumferential thicknesses of the parison, as explained
above, and make the final ~;m~ion adjustments in the forming
o tool. This thickness difference will contribute to obtain a
rounded off transitional part between the pallet deck and the
sheet legs.
The pallet normally requires openings in the sheet
legs to allow truck forks to be easily inserted so the pallet
L5 can be easily lifted and transported. Figure 3 shows one em-
bodiment of the sheet legs, 3, provided with approximately
rectangular openings having rounded off corners. Obviously,
the openings can be of any suitable shape. Another embodiment
of the sheet legs is shown in figure 4, where said openings
20 are expanded out through the bottom edge of the side sheet,
resulting in three separate sheet legs, optionally two inter-
spaced sheet legs. The desired openings in the side sheets are
marked during the forming in the mold by impressing the con-
tours of the openings and after the pallet has been formed the
25 indicated parts are forced out.
In the embodiment of the pallet shown in figure 1,
posts which will constitute one set of pallet legs are deep-
drawn in the bottom of the pallet deck in its center long-
itudinally and parallel to the sheet legs. In fig. 1 only one
30 post at one end of the pallet can be seen. Normally, there are
three deep-drawn posts evenly distributed along the center
line o~ the pallet, one post at each end of the pallet and one
in the middle. This is indicated in figure ~, which is a sec-
tional view which runs through the pallet at section A-A in
~5 ~igure 1. The posts, 4, can be deep-drawn in one operation to
their final depths, thus constituting one set of ~inal block-
shaped pallet legs. The disadvantage of deep-drawing said pal-
let legs to full depths is that the wall thicknesses in the
bottom corners of the posts will become small. The properties

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W O 97/25250 PCTA~0~7/OO009
of the material from which the pallet is manufactured deter-
mine the allowed deep-draw ratios, wall inclinations~ shape of
corners, etc. The problems related to deep-drawing thermoplas-
tics are common knowledge to persons skilled in the art.
An optional embodiment of the block-formed pallet
legs is shown in figure 6. Each post, 4, is deep-drawn to a
depth less than the final depth, for example to half the
height of the final pallet leg. To the bottom of said half-
sized post, 4, a separately produced block, 6, is then
o fastened in a particular operation. In principle, such blocks
may be of any shape and produced from any material, provided
that they can be permanently fastened to the bottoms of the
half-sized posts. The blocks, 6, must have such a height that
they, when combined with the deep-drawn posts, 4, produce
p~allet legs of correct heights. The advantages of this em-
bodiment is that the necessary deep-draw ratios of the posts
become smaller, and the pallet legs will become stronger.
Instead of using such blocks, all of them can be re-
placed by one runner component, such as the one, 9, shown in
20 fig. 7. This runner component consists of a cross member, 10,
having two or more upward-facing posts, 11, which are fastened
by their tops to the bottoms of the posts, 4, deep-drawn in
the deck, 2.
In another embodiment similar runner components may
25 be fastened to the bottom surfaces of sheet legs along oppo-
site sides of the pallet. The height of a possible deep-drawn
leg structure in the center of the pallet must then be adapted
to the particular design of the runner. Such a runner may be
similar to the runner, 9, shown in figure 7. In a preferred
~o embodiment half-sized posts, 4, as shown in figure 6, are
deep-drawn in the bottom of the deck, and the runners are fur-
nished with a center post that matches post 4 of the pallet,
while the posts at the ends of the runners must have a height
adapted to the sheet legs, 3. Thus, the bottom part of the
35 C~OSS member of the runner component, 10, will face the floor.
Figure 7 shows an embodiment of the pallet where a
continuous U-shaped profile, 7, is thermoformed in the bottom
side of the deck in the whole length thereof in its center
longitl7~7. 1 n~ 1 ly and parallel to the sheet legs, 3. The upper

CA 02242721 1998-07-07
W O 97/25250 PCTA~097/00009 11
spacer component, 8, is fastened by its cross member, 10, to
the bottom of the U-shaped profile, 7. The lower runner com-
ponent, 9, is ~astened by the tops of its posts, 11, to the
bottom of the matching posts, 11, on the upper spacer compon-
5 ent, 8. Each spacer and runner is manufactured in a particularoperation by forming a parison into a cross member, 10, with
posts, 11.
Fig. 8 is a sectional view through the finished pal-
let, 1, at section B-B in Fig. 7. The section runs through the
o pallet deck, 2, the U-shaped profile, 7, and posts, 11, on the
upper spacer component, 8, and lower runner component, 9. The
U-profile, 7, is formed into a channel, 12, and two closed
hollow spaces, 14. The upper spacer component, 8, is shaped so
that a channel formed on the top of the cross member and long-
15 itudinally has the same width as the channel, 12, in the bot-
tom of the U-profile. Consequently, a closed ~.h~nn~l, 12, ex-
tending longitudinally along the pallet is created when the
pallet deck, 2, and the upper spacer component, 3, are joined
together. The channel's length, width and depth can be made to
20 fit the requirements. The U-profile, 7, and the upper spacer
component, 8, are formed so that each channel, 12, is sealed
at each end so that a closed hollow space is created. Option-
ally, the forming can be such that the channel is open at both
ends. The lower runner component, 9, is in principle formed
Z5 like the upper spacer component, 8, but so that the cross mem-
ber, 10, constitutes the surface facing the floor. Each post
on the upper spacer component, 8, and lower runner component,
9, is formed as a symmetric profile so that two like-shaped
hollow spaces, 15, and a channel, 13, are created, that will
30 also create a closed hollow space. The shape of the pallet's
posts can differ designwise from that sketched in Fig. 8 by
variations in the dimensions of the channel, 12, and hollow
- spaces, 13 and 15. However, the bearing walls in the posts
must be formed so that a sufficiently rigid structure is at-
35 t~i~d.
A suitable stiffening section can be inserted into
the ch~nn~l, 12, in Fig. 8, to ensure that the pallet does not
deflect at its center under great stress. Preferably, sections
made of a lightweight metal, plywood, reinforced thermoset

CA 0224272l l998-07-07
WO 97/2S250 PCT~N097/00009
12
-
plastics (e.g. GRP), or other suitable plastic materials or
composites are used in order to keep down the pallet's un-
loaded weight.
As mentioned above, pallets having sheet legs along
5 two opposite sides may have runners fastened to the bottoms of
corresponding pairs of opposite legs. Such runners are made
by laying flat the extruded parison and shaping it into a
flat, double sheet. During this forming there are impressed
V-shaped grooves at a certain distance from each end, as
o explained a~ove. Finally, the end parts are bent along said
V-shaped grooves into a desired angle (e.g. 90 ~) to the main
cross member and fastened in such a position. Each runner is
then fastened by the top surfaces of its ends to the bottoms
of the appropriate sheet legs of the pallet. However, this
15 embodiment involves a number of welding operations for each
pallet: the integrated sheet legs of the pallet are fastened
in their correct positions by welding, as explained above; the
end parts of each runner are welded in their correct posi-
tions, usually in a perpendicular position, to the cross mem-
20 ber; and finally the runner are fastened by its end top sur-
faces to the bottom surfaces of said sheet legs. To simplify
the assembly of such a pallet the sheet legs of the pallet may
be deleted and each runner fastened by the top surfaces of its
ends directly to the bottom of the pallet deck.
The individual components of the pallet can be ~oin-
ted together most expediently by welding, preferably by butt
welding, but other methods of joining like extrusion welding,
the use of glue or adhesive, and mechanically joining, can
a7so be employed.
30 - The pallet deck can have a flat surface or a profiled
surface. A particularly preferred embodiment of a pallet hav-
ing a profiled deck is shown in figures 9 and 5.
Fig. 9 is a top view of a pallet, 1, having ch~nnelq,
16, impressed into the pallet deck, thus creating raised sec-
35 tions, 17, running in the transverse direction of the pallet.
Fig. 1~ is a side view showing the longitudinal sideof the pallet in Fig. 9.
The ~ime~qions of such raised sections and impressed
ch~nnels~ i.e. thair lengths, widths and heights, can be chos-

CA 0224272l l998-07-07
WO 97/25250 PCT/N097/00009
13
en freely within the physical limits set by the extruded pari-
son and the forming conditions. The bottom of the pallet deck
may be given a similar design as the top surface of the deck,
or it may be kept even. In principle, the raised sections in
5 the top and bottom surfaces of the pallet deck may run in any
direction, also in different directions. In the particular
embodiment of the pallet shown in Figs. 9 and lO the width of
each raised section is about 35-40 mm, and the distance bet-
ween any two ad;acent raised sections, i.e. the width of the
c impressed channels, is of approximately the same magnitude.
The height of each raised section is about lO mm.
It should be obvious that in principle the top sur-
face, optionally also the bottom surface, of the pallet deck
can be given any shape or design of patterns: the only re-
striction being the technical conditions mentioned above. All
such designs are comtemplated by the present invention.
Pallet decks having raised sections may provide a
simplified unloading of the goods that they carry. For in-
stance, the pallet indicated in Figs. 9 and lO allows speci-
zo fically designed forks to be inserted into the channels in theupper pallet deck underneath the goods, which may then be re-
moved as one unit from the pallet by the use of an adequate
lifting device. This is particularly useful when unloading
unit loads, such as goods shrink-wrapped in plastic films,
25 bottle crates, etc.
In the foregoing preferred embodiments of the pallet
have been explained in reference of pallets having a rectan-
gular shape. Obviously, the pallets may be of a square shape
or any other suitable geometrical shape. Further, references
30 to longitudinal sides and transverse sides of the pallet can
be interchanged without deviating from the scope of the inven-
tion.
- The above description is provided for a clearer
understanding of the principles of the invention. Variations
35 in designs and embodiments of the present pallets based on the
technical concepts explained above are considered being within
the scope of the present invention.
_. ~

Representative Drawing
A single figure which represents the drawing illustrating the invention.
Administrative Status

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Event History

Description Date
Inactive: IPC from MCD 2006-03-12
Inactive: Dead - No reply to s.30(2) Rules requisition 2002-09-12
Application Not Reinstated by Deadline 2002-09-12
Deemed Abandoned - Failure to Respond to Maintenance Fee Notice 2002-01-10
Inactive: Abandoned - No reply to s.30(2) Rules requisition 2001-09-12
Inactive: S.30(2) Rules - Examiner requisition 2001-03-12
Inactive: Single transfer 1999-01-14
Classification Modified 1998-11-12
Inactive: IPC assigned 1998-11-12
Inactive: First IPC assigned 1998-11-12
Inactive: Courtesy letter - Evidence 1998-09-22
Inactive: Acknowledgment of national entry - RFE 1998-09-17
Application Received - PCT 1998-09-15
Request for Examination Requirements Determined Compliant 1998-07-07
All Requirements for Examination Determined Compliant 1998-07-07
Application Published (Open to Public Inspection) 1997-07-17

Abandonment History

Abandonment Date Reason Reinstatement Date
2002-01-10

Maintenance Fee

The last payment was received on 2000-12-21

Note : If the full payment has not been received on or before the date indicated, a further fee may be required which may be one of the following

  • the reinstatement fee;
  • the late payment fee; or
  • additional fee to reverse deemed expiry.

Please refer to the CIPO Patent Fees web page to see all current fee amounts.

Fee History

Fee Type Anniversary Year Due Date Paid Date
Request for examination - standard 1998-07-07
Basic national fee - standard 1998-07-07
MF (application, 2nd anniv.) - standard 02 1999-01-11 1998-12-17
Registration of a document 1999-01-14
MF (application, 3rd anniv.) - standard 03 2000-01-10 1999-12-13
MF (application, 4th anniv.) - standard 04 2001-01-10 2000-12-21
Owners on Record

Note: Records showing the ownership history in alphabetical order.

Current Owners on Record
BOREALIS A/S
Past Owners on Record
HELGE GRANDE
ODDBJORN GRONNEVIK
ROLF KOTTERHEINRICH
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.
Documents

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Document
Description 
Date
(yyyy-mm-dd) 
Number of pages   Size of Image (KB) 
Representative drawing 1998-11-16 1 7
Claims 1998-07-07 4 178
Drawings 1998-07-07 4 67
Abstract 1998-07-07 1 49
Description 1998-07-07 13 753
Cover Page 1998-11-16 1 41
Reminder of maintenance fee due 1998-09-16 1 115
Notice of National Entry 1998-09-17 1 235
Courtesy - Certificate of registration (related document(s)) 1999-03-03 1 117
Courtesy - Abandonment Letter (R30(2)) 2001-11-21 1 171
Courtesy - Abandonment Letter (Maintenance Fee) 2002-02-07 1 182
PCT 1998-07-07 7 244
Correspondence 1998-09-22 1 28
Fees 2002-01-02 1 25