Note: Descriptions are shown in the official language in which they were submitted.
WO 2012/012363 CA 02805429 2013-01-14PCT/US2011/044432
METALLIC PALLET WITH IMPROVED CORNER CONSTRUCTION
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Provisional Patent Application No.
61/365,409 filed
July 19, 2010, the entire disclosure of which is hereby incorporated by
reference and relied upon.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The invention relates generally to horizontally supported planar
surfaces such as
industrial platforms having a support surface provided with supporting means
whereby a load
may be supported relatively close to a floor and having means to receive
handling means beneath
said surface or load and wherein the support surfaces are made of metal.
Related Art
[0003] Pallets are commonly used to support and transport bundled objects or
loads in
applications like that shown in Figure 1. Traditionally, pallets have been
constructed from wood
members assembled together. However, wooden pallets are subject to many
drawbacks,
including a relatively short lifespan, chemical contamination, insect
infestation, and fire hazard,
to name a few. More recently, pallets have been constructed from plastic
materials which can be
more durable than wood and are typically insect resistant, however are still
subject to chemical
contamination, fire hazards and other shortcomings. While additives can be
used to make a
plastic pallet more fire retardant, such additives are costly and generally
disfavored in situations
where food handling is required. There is a desire within the material
handling industry to
identify new materials suitable for manufacturing cargo carrying pallets which
will provide
superior functionality at a cost competitive price with other options.
[0004] Some examples of pallet constructions representative of prior art
teachings may be
found in US Patent No. 5,367,960 to Schleicher granted November 29, 1994, US
Patent No.
5,522,325 to Knauer granted June 4, 1996, US 2002/0078863 to Marr et al.
published June 27,
2002 and US 2005/0178299 to Rasmussen et al. published August 18, 2005. These
examples of
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prior art illustrate various approaches in mixed forms of construction which
include at least some
metallic components. In these examples, the pallets include a top deck or load
engaging surface
which may be composed of parallel top slats or decking attached to a
surrounding frame made
from plastic or wood.
[0005] One drawback found in prior art constructions relates to the general
lack of strength of
the pallet in terms of resisting damage due to rough handling. Excessive
damage most typically
manifests when a pallet experiences a laterally applied force to one of its
corners. This may
occur during transport such as when a forklift is moving a pallet, or when the
pallet is stationary
but some object collides with it. It will be appreciated that metallic pallets
are substantially more
expensive to manufacture than wooden pallets. The cost proposition for a
metallic pallet
therefore only becomes favorable when the metallic pallet can enjoy a
substantially longer
service life than the typical wooden pallet or other available alternatives.
Accordingly,
constructing a metallic pallet that has the ability to withstand rough
handling and other stressful
conditions is imperative to the business proposition for such objects.
[0006] Accordingly, metallic pallets have inherent benefits and are being
increasingly accepted
within an industry accustomed to utilizing cheap wooden pallets. Nevertheless,
there remains
opportunity to further improve pallet designs and constructions with the
objectives to reduce
severe damage resulting from corner impacts, and thus to enhance service life.
SUMMARY OF THE INVENTION
[0007] A metallic pallet is provided of the type for supporting objects for
storage and transport.
The pallet comprises a generally planar top side having a substantially
rectangular configuration
defining four corners. The top side includes four elongated outer top frame
members. The top
side also includes a plurality of decking members arranged parallel to one
another and parallel to
two of the outer frame members. A generally planar bottom side is provided
having a
substantially rectangular configuration defining four corners. The bottom side
includes four
elongated outer bottom frame members. The bottom side is disposed below the
top side so that
its corners are vertically aligned with the corners of the top side in
corresponding pairs.
Likewise, the outer top and outer bottom frame members are arranged in
opposing pairs. Four
generally hollow corner pieces are provided. Each corner piece extends between
a respective
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aligned pair of corners of the top and bottom sides. The corner pieces each
interrupt the
generally planar top and bottom sides such that the top and bottom sides do
not overlie the corner
pieces. Each the corner piece comprises a pair of adjoining perpendicular back
walls in direct
abutting contact with the top and bottom sides. Each corner piece further
comprises an upper
plate and a lower plate respectively affixed to the back walls. The upper
plate is generally planar
with the top side, and the lower plate is generally planar with the bottom
side. Each corner piece
includes a separately formed cover. The cover is configured to simultaneously
engage the back
walls and the upper and lower plates.
[0008] The subject invention is distinguished from prior art designs by
providing a unique
corner construction that is robust and easily manufactured. This design, which
represents a
departure from prior art techniques, increases the ability of a metallic
pallet to resist damage
caused by undesirable impact forces to the corners, which thereby favorably
extends the service
life and hence cost benefit of a metallic pallet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] These and other features and advantages of the present invention will
become more
readily appreciated when considered in connection with the following detailed
description and
appended drawings, wherein:
[0010] Figure 1 is an environmental view showing a pallet constructed in
accordance with one
embodiment of this invention utilized to support cargo and poised for
transport via a common
forklift vehicle;
[0011] Figure 2 is a perspective view of the subject pallet;
[0012] Figure 3 is a perspective view showing the bottom of the pallet
according to Figure 2;
[0013] Figure 4 is a top view of the subject pallet;
[0014] Figure 5 is a bottom view of the subject pallet;
[0015] Figure 6 is an end view of the subject pallet;
[0016] Figure 7 is a cross-sectional view taken generally along lines 7-7 in
Figure 6;
[0017] Figure 8 is a cross-sectional view of an exterior spacer block taken
generally along
lines 8-8 in Figure 6;
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[0018] Figure 9 is a perspective view of a corner piece according to an
embodiment of the
invention;
[0019] Figure 10 is an exploded view of the corner piece of Figure 9;
[0020] Figure 11 is a cross-sectional view taken generally along lines 11-11
of Figure 9;
[0021] Figure 12 is a perspective view of the cover for the corner piece of
Figure 10;
[0022] Figure 13 is a schematic view illustrating tracking capabilities for
the subject pallet
when configured to include an RFID tag;
[0023] Figure 14 is a perspective view of a first alternative corner piece
construction;
[0024] Figure 15 is a fragmentary perspective view showing a second
alternative corner piece
in partially exploded fashion and including an optional RFID tag in the hollow
space therein; and
[0025] Figure 16 is a perspective view of a third alternative corner piece
design.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] Referring to the figures, wherein like numerals indicate like or
corresponding parts
throughout the several views, a pallet constructed in accordance with
embodiments of this
invention is generally shown at 20. Standard pallet dimensions are given as 48
inches x 40
inches x 5.6 inches, however the specific dimensional properties of the pallet
20 are subject to
alteration to suit any given application.
[0027] As perhaps best shown in Figures 2-7, the pallet 20 includes a
generally planar top side,
generally indicated at 22. The top side 22 establishes a generally horizontal
surface for
supporting objects such as cargo for storage and transport. The top side 22 is
elevated above the
floor or other supporting structure so that the tines of a forklift 24 (Figure
1) can be inserted
under the top side 22 in the customary fashion. The top side 22 has a
substantially rectangular
configuration as suggested by the dimensions suggested above, however this is
subject to
variation depending upon design choice. The top side 22 defines four corners
which, in the
preferred embodiment, are represented by notches 26. The top side 22 also
includes four
elongated outer top frame members comprised of two long rails 28 and two short
rails 30. The
long 28 and short 30 rails are arranged about the perimeter of the top side 22
and extend each
into the notches 26 thus establishing a generally rectangular shape for the
top side 22. The long
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28 and short 30 rails are preferably made from extruded aluminum having any
desirable and
suitable cross-sectional shape such as, for example, shown in the cross-
section of Figure 7.
[0028] A plurality (seven in the examples shown) of decking members 32 are
arranged parallel
to one another and parallel to the two short rails 30 with generally equal
spacing therebetween.
The decking members 32 are preferably made from an extruded aluminum material
and may
have a cross-sectional like that shown for example in Figure 7. Each decking
member 32 is
welded at its ends to the inside edge of the two long rails 28. The top side
22 in one embodiment
further includes a backbone 34 disposed directly underneath each of the
decking members 32.
The backbone member 34, perhaps best seen in Figures 3 and 7, extends parallel
to the two long
rails 28 to provide mid-span support for the top side 22 for increased weight
bearing capacity for
the pallet 20.
[0029] Turning now to Figures 3 and 5, the pallet 20 is shown including a
generally planar
bottom side 40. The bottom side 40, like the top side 22, also has a
substantially rectangular
configuration having corners defined by notches 42. The outer dimensional
properties of the
bottom side 40 are substantially identical to that of the top side 22 so that
the notches 26, 42 can
be directly aligned one over the other. The bottom side 40 also includes four
elongated outer
frame members comprised of long 44 and short 46 rails. The short rails 46 of
the bottom side 40
are generally congruent with the short rails 30 of the top side 22, and
likewise the long rails 44 of
the bottom side are generally congruent with the long rails 28 of the top side
22. Unlike the rails
28, 30 of the top side 22, however, in the preferred embodiment shown in
Figures 5 and 7, the
rails 44, 46 of the bottom side 40 are significantly wider (measured
laterally) than their long 28
and short 30 rail counterparts of the top side 22. As a result, the long 44
and short 46 rails of the
bottom side 40 may, in one embodiment, directly connect to one another at
their terminal ends
via a truncated miter joint 40. This miter joint 48 may be welded to provide
direct fixed
connection between the long 44 and short 46 rails. The bottom side 40 further
includes a first
inner bottom frame member 50 and a second inner bottom frame member 52. The
second inner
bottom frame member 52 perpendicularly bisects the first inner bottom frame
member 50 at a
bottom intersection joint 54 which may be welded to secure the frame members
50, 52 to one
another. Additionally, the terminal ends of each of the first 50 and second 52
inner bottom frame
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members may be attached at their respective ends to the inner edges of the
long 44 and short 46
rails such as by welding to establish a strong matrix or skeletal
construction.
[0030] Four generally identical, hollow corner pieces are generally indicated
at 56. The corner
pieces 56 each extend between a respective aligned pair of corners of the top
22 and bottom 40
sides as represented by their respective notches 26, 42. In other words, the
corner pieces 56 fit
into each of the notches 26, 42 and are there securely attached such as by
welding so as to rigidly
join the top side 22 to the bottom side 40 via the corner pieces 56. Thus,
because the corner
pieces 56 are set into the notches 26, 42, it may be seen that the corner
pieces 56 each interrupt
the generally planar top 22 and bottom 40 sides so that the top 22 and bottom
40 sides do not
overlie the corner pieces 56. As a result, corner impacts to the pallet 20 may
be absorbed
entirely by deformation of the hollow corner pieces 56 without distorting the
planar
configurations of the top 22 and bottom 40 sides.
[0031] Various configurations for corner pieces 56 may be found by reference
to the
applicant's co-pending US 2010/0218705, published September 2, 2010, the
entire disclosure of
which is hereby incorporated by reference and relied upon. Figures 9-12
illustrate one preferred
embodiment of the corner pieces 56 designed for optimal performance, low cost,
ease of
construction, as well as the ability to safely contain an RFID tag 58 or other
tracking features.
Figure 10 is an exploded view of the corner piece 56. The corner piece 56
shown here comprises
a cast aluminum body establishing perpendicular back walls 60 in direct
abutting contact with
the top 22 and bottom 40 sides. Upper and lower plates 62, connect the upper
and lower ends of
the back walls 60 into a somewhat box-like structure. As a result, the upper
plate 62 is generally
planar with the top side 22 and the lower plate 62 is generally planar with
the bottom side 40
thereby contributing to the load carrying capacity. A cover 64 is formed
separately from the
back walls 60, and preferably made from a non-metallic materials such as
plastic or hard rubber
in an injection molding process. The cover 64 is configured to simultaneously
engage the back
walls 60 and the upper and lower plates 62 to provide a solid, secure exposed
area for the corner
piece 56. The cover 64 includes an outer edge 66 establishing the leading or
terminal corner for
the pallet 20, which is expected to receive the initial and most frequent
impacts during rough
handling of the pallet 20. The material composition selected for the cover 64
should therefore be
impact resistant and durable yet somewhat resilient.
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[0032] The corner pieces 56 may further include internal webbing 70 formed
integrally with
the back walls 60 and plates 62 during the casting process for both strength
and controlling
deformation. The cover 64 may include notches 92 for receiving or engaging
with the outer
edges of the webbing 70 which, as shown in Figure 10, is formed as three
vertical ribs and one
horizontal rib. The upper and lower plates 62 are also formed with chamfers
94. The outer edge
66 of the cover 64 is configured with short extensions to directly engage the
chamfers 94 as
perhaps best shown in Figure 11. Through this design, the cover 64 and cast
aluminum
components become mechanically interlocked so that the corner pieces 56 may
absorb and
partially collapse in response to impact forces without stressing the top 22
or bottom 40 sides and
thereby helping to maintain their planar nature for an extended service life
of the pallet 20. The
hollow corner pieces 56 resist infiltration by liquids or other unwanted
substances.
[0033] As mentioned and shown in Figure 15, a small RFID tag 58 may be sealed
inside one or
more of the corner pieces 56 to provide pallet 20 locating and tracking
capabilities. An adhesive
may be used to anchor and seal the RFID tag 58 inside the corner piece 56.
Alternatively, the
RFID tag 58 may be securely stationed in a pocket or receptacle formed
integrally with or
subsequently attached to the inside of the corner piece 56. In this way, the
RFID tag 58 can be
contained in a protected enclosure so as to provide long term service life and
functionality for
purposes of tracking the pallet 20. If the RFID tag 58 is installed into a
corner piece 56 prior to
assembly of that corner piece 56 with the top 22 and bottom 40 sides, the RFID
tag 58 is
preferably retained in a position spaced as far as possible from each of the
back walls 60 where
welding occurs during attachment to the top 22 and bottom 40 sides. This will
help protect the
RFID tag 58 from damage due to excessive heat that occurs during welding
operations.
Conversely, the RFID tag 58 is also located as far as possible from the outer
edge 66 where the
majority of deformation is expected to occur in use. This will help protect
the RFID tag 58 from
damage for a longer service life.
[0034] Figure 13 shows an exemplary, highly schematic method by which the RFID
tag 58
may be used to triangulate the position of a pallet 20 which has been lost or
possibly stolen.
Using known RFID technology, the exact position of a pallet 20 with respect to
a digital map 76
can be determined. Of course, the map 76 may be specific to a particular
warehouse or
manufacturing facility, or used more generally to track pallets 20 which may
be stolen or
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misplaced in a much wider geographic area. Additional functionality may be
incorporated into
the RFID tag 58 according to known techniques.
[0035] Returning to Figures 2-8, the pallet 20 is shown including a plurality
of extruded
aluminum spacer blocks 78, 80. Each spacer block 78, 80 extends
perpendicularly between the
top 22 and bottom 40 sides for holding the top 22 and bottom 40 sides in
generally parallel
spaced and aligned relation to one another so that the notched corners 26, 42
remain vertically
aligned and so that the corresponding pairs of long 28, 44 and short 30, 46
rails remain aligned.
Furthermore, the spacer blocks 78, 80 increase the weight force loading with
which the pallet 20
is capable of supporting. Each spacer block 78, 80 may include at least one
internal web. Four
spacer blocks 78 comprise exterior spacer blocks 70 arranged about the outer
periphery of the
pallet 20. Two exterior spacer blocks 78 extend between the respective pairs
of long rails 28, 44,
whereas another two exterior spacer blocks 78 extend between opposing short
rails 30, 46.
These exterior spacer blocks 78 are preferably made from extruded aluminum
materials and
welded in place.
[0036] As perhaps best shown in Figure 8, the exterior spacer blocks 78 have a
generally D-
shaped profile when viewed in cross-section. This D-shaped profile includes an
outer convex
portion 82 that is oriented outwardly from the pallet 20. In other words, as
perhaps best shown
in Figures 2 and 6, the convex portions 82 of the exterior spacer blocks 78
face outwardly and so
that if contacted by the tines of a forklift 24, they will gently direct the
tines to the side usually
with little to no damage. Preferably, although not necessarily, at least one
spacer block 80
comprises an interior spacer block 80 disposed for direct contact between the
backbone 34 and
bottom inner section joint 54 to provide column strength in the center of the
pallet 20. The
interior spacer block 80 may have a generally rectangular profile in cross-
section. Like the
exterior spacer block 78, the interior spacer block 80 is also preferably made
from extruded
aluminum material and securely welded in place at each end.
[0037] Figure 14 shows an exploded view of a first alternative embodiment of
the corner piece
156, wherein like or corresponding parts are indicated with reference numerals
offset by 100. In
this example, the back walls 160 are formed of extruded aluminum and the upper
and lower
plates 162 are made from stamped aluminum sheet stock then subsequently
affixed to the back
walls 160 by welding or by other suitable fixation technique. Once assembled,
the upper plate
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162 is generally planar with the top side 22 and the lower plate 162 is
generally planar with the
bottom side 40. The cover 164 in this example is formed integrally with the
back walls 160
during the extrusion process. The cover 164 is configured to simultaneously
engage the back
walls 160 and the upper and lower plates 162 to provide a solid, secure
exposed area for the
corner piece 156. The cover 164 includes an outer edge 166 establishing the
leading or terminal
corner for the pallet 20. Generous deformation grooves 168 may be formed in
the cover 164
laterally on either side of the outer edge 166 to provide controlled collapse
in the event of
impact. The corner pieces 156 may further include internal webbing 170 formed
integrally
during the extrusion process to join the cover 164 and back walls 160 for both
strength and
controlling deformation. The corner pieces 156 are designed to absorb and
deform when
impacted without upsetting the top 22 or bottom 40 sides. The upper and lower
plates 162
provide an enclosed space, i.e., hollow, in the corner pieces 56 to resist
infiltration by liquids or
other unwanted substances. Each plate 162 may include a small hole 172 aligned
over an
intersection point 174 of the webbing 170. During the assembly process, the
plates 162 are
positioned over the extruded body section with the holes 172 providing a
convenient location
through which to place a small tack weld to the webbing 170 and thereby secure
the plates 162 in
position
[0038] Figure 15 shows a second alternative embodiment of the corner piece
256, wherein like
or corresponding parts are indicated with reference numerals offset by 200. In
this example, a
simplified version of the corner piece 256 includes a less sophisticated
separate cover 264 which
may be secured in position to a cast aluminum back wall 260 and upper/lower
plate 262
construction. A single horizontal web 70 and optional intersecting vertical
web may be formed
therein to improve crush resistance. An RFID tag 58 can be placed inside the
hollow corner
piece 256 and secured with a suitable adhesive or by other means as described
previously.
[0039] Figure 16 shows yet another alternative construction for a corner piece
356, with like or
corresponding parts being identified with similar reference numbers offset by
300. In this
example, the corner piece 356 is made from cast aluminum and omits the cover
altogether so as
to present an open cellular hollow corner for the pallet. In all other
respects, the corner piece 356
functions similarly to that described above.
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[0040] The foregoing invention has been described in accordance with the
relevant legal
standards, thus the description is exemplary rather than limiting in nature.
Variations and
modifications to the disclosed embodiment may become apparent to those skilled
in the art and
fall within the scope of the invention.
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