U.S. patent application number 10/935299 was filed with the patent office on 2006-03-09 for reduced profile, improved-strength, improved-ridgity, plastic one-way pallet.
This patent application is currently assigned to TriEnda, a Wilbert Company. Invention is credited to Patrick J. Quigley.
Application Number | 20060048687 10/935299 |
Document ID | / |
Family ID | 35994923 |
Filed Date | 2006-03-09 |
United States Patent
Application |
20060048687 |
Kind Code |
A1 |
Quigley; Patrick J. |
March 9, 2006 |
Reduced profile, improved-strength, improved-ridgity, plastic
one-way pallet
Abstract
A plastic pallet is thermoformed from a sheet of light-weight
plastic material having a reduced thickness or gauge relative to
conventional plastic pallets and is lighter than
correspondingly-sized wood and conventional plastic pallets. The
pallet includes support legs that give the pallet a profile height
that is less than that of a correspondingly-sized wood or plastic
pallet. The support legs have a variety of different sizes and/or
shapes, such as rectangular or annular. The support legs are
generally evenly distributed over the surface of the pallet and can
include one or more pairs of protrusions. The total support leg
area is generally larger than a conventional similarly-sized
plastic pallet, while the area within each individual support leg
opening is generally smaller than a similarly-sized conventional
plastic pallet. Items on the plastic pallet that extend over a
support leg will be better supported due to the reduced size and/or
protrusions.
Inventors: |
Quigley; Patrick J.;
(Portage, WI) |
Correspondence
Address: |
LATHROP & CLARK LLP
740 REGENT STREET SUITE 400
P.O. BOX 1507
MADISON
WI
537011507
US
|
Assignee: |
TriEnda, a Wilbert Company
2913 Gardner Road
Broadview
IL
60155
|
Family ID: |
35994923 |
Appl. No.: |
10/935299 |
Filed: |
September 7, 2004 |
Current U.S.
Class: |
108/57.28 |
Current CPC
Class: |
B65D 19/004 20130101;
B65D 2519/00407 20130101; B65D 2519/00268 20130101; B65D 2519/00034
20130101; B65D 2519/00069 20130101; B65D 2519/00298 20130101; B65D
2519/00338 20130101; B65D 2519/00412 20130101 |
Class at
Publication: |
108/057.28 |
International
Class: |
B65D 19/38 20060101
B65D019/38 |
Claims
1. A pallet, comprising: a support deck made of a first material; a
plurality of support structures extending away from the support
deck and formed of the first material, each of the plurality of
support structures extending to a surface on which the pallet
rests, comprising: a first plurality of the support structures
positioned around the periphery of the pallet, each of the first
plurality of support structures having a pair of projections
extending into the support structure from opposite side walls of
that support structure, each of the protrusions extending from the
support deck to a bottom surface of the support structure, and at
least one additional support structure that forms a generally
annular support in a central region of the pallet, each additional
support structure having at least one pair of protrusions, each
pair of protrusions extending from opposite side walls of the
additional support structure into the interior of the additional
support structure and meeting each other in the interior of the
support structure, a connection formed between that pair of
protrusions in the interior of that additional support structure,
the protrusions extending at least part way up the sides of that
additional support structure from a bottom surface of that
additional support structure.
2. The pallet of claim 1, wherein the plurality of support
structures further includes a central support structure formed
within the bounds of the annular support.
3. The pallet of claim 1, wherein the first plurality of support
structures positioned around the periphery of the pallet includes:
at least one first support structure, having at least one of a
first size and a first shape; and at least one second support
structure having at least one of a second size that is different
from the first size and a second shape that is different from the
first shape.
4. The pallet of claim 3, wherein the first plurality of support
structures positioned around the periphery of the pallet further
includes at least one third support structure having at least one
of a third size that is different from at least one of the first
and second sizes and a third shape that is different from at least
one of the first and second shapes.
5. The pallet of claim 4, wherein the first plurality of support
structures positioned around the periphery of the pallet further
includes a fourth support structure having at least one of a fourth
size that is different from at least one of the first, second and
third sizes and a fourth shape that is different from at least one
of at least the first, second and third shapes.
6. The pallet of claim 3, wherein each at least one first support
structure has a pair of main protrusions extending from opposing
walls into the interior of that first support structure and a pair
of secondary protrusions that extend from the main protrusions and
that meet each other in the interior of the first support
structure, a connection formed between that pair of secondary
protrusions in the interior of that first support structure
7. The pallet of claim 6, wherein each at least one second support
structure that has at least one of a second size that is different
from the first size and a second shape that is different from the
first shape does not have a pair of secondary protrusions.
8. The pallet of claim 6, wherein each at least one second support
structure has a pair of main protrusions extending from opposing
walls into the interior of that second support structure and a pair
of secondary protrusions that extend from the main protrusions and
that meet each other in the interior of the second support
structure, a connection formed between that pair of secondary
protrusions in the interior of that second support structure.
9. The pallet of claim 3, wherein the at least one first support
structure comprises at least four first support structures, one
first support structure located at each corner of the pallet.
10. The pallet of claim 9, wherein the at least one second support
structure comprises a plurality of second support structures, at
least one second support structure located on each of two opposing
sides of the pallet between the first support structures located at
the corners of the pallet.
11. The pallet of claim 10, wherein the plurality of second support
structures comprises a plurality of second support structures
located on each of the two opposing sides.
12. The pallet of claim 11, wherein the plurality of second support
structures located on each of the two opposing sides comprises at
least three second support structures located on each of the two
opposing sides.
13. The pallet of claim 12, wherein: the first plurality of support
structures positioned around the periphery of the pallet further
includes at least one third support structure having at least one
of a third size that is different from at least one of the first
and second sizes and a third shape that is different from at least
one of the first and second shapes; and the at least one third
support structure comprises a plurality of third support
structures, at least one third support structure located on each of
a second pair of two opposing sides of the pallet, the second pair
being different from the two opposing sides on which the second
support structures are located, the third support structures
located between the first support structures located at the corners
of the pallet.
14. The pallet of claim 13, wherein the plurality of third support
structures comprises a plurality of the support structures located
on each of a second pair of two opposing sides.
15. The pallet of claim 14, the first plurality of support
structures positioned around the periphery of the pallet further
includes at least one fourth support structure having at least one
of a fourth size that is different from at least one of the first,
second and third sizes and a fourth shape that is different from at
least one of the first, second and third shapes; and the at least
one fourth support structure comprises a plurality of fourth
support structures, at least one fourth support structure located
on each of the second pair of two opposing sides of the pallet, the
fourth support structures located between the first support
structures located at the corners of the pallet.
16. The pallet of claim 15, wherein the fourth support structures
are located between the plurality of third support structures
located along that second pair of two opposing sides of the
pallet.
17. The pallet of claim 1, wherein: the support deck has a first
area; each of the plurality of support structures defines a cavity
having an area; and a total area of the cavities is about 20% to
about 35% of the first area.
18. The pallet of claim 17, wherein the area of the cavity of each
of the plurality of support structures is about 0.5% to about 12%
of the first area.
19. (canceled)
20. (canceled)
21. (canceled)
22. (canceled)
23. (canceled)
24. (canceled)
25. The pallet of claim 1, wherein a total profile height of the
pallet is about 3 inches to about 3.5 inches.
26. A pallet, comprising: a support deck made of a first material;
and a plurality of support structures extending away from the
support deck and formed of the first material, each of the
plurality of support structures extending to a surface on which the
pallet rests, wherein at least some of the plurality of support
structures have a pair of protrusions extending from opposing walls
into the interior of that support structure, the protrusions
forming portions of the support deck.
27. The pallet of claim 26, wherein the plurality of support
structures comprises: a first subset of the plurality of support
structures that have the pair of protrusions; and a second subset
of the plurality of support structures that lack the pair of
protrusions.
28. The pallet of claim 27, wherein each of at least some of the
first subset of the plurality of support structures comprises at
least one pair of second protrusions that extend from the
protrusions and that meet each other in the interior of that
support structure, wherein, for each pair of second protrusions, a
connection is formed between that pair of second protrusions in the
interior of that support structure.
29. The pallet of claim 27, wherein the first subset of the
plurality of support structures comprises a first sub-subset of the
first subset of the plurality of support structures that have the
at least one pair of second protrusions; and a second sub-subset of
the first subset of the plurality of support structures that lack
the at least one pair of second protrusions.
30. The pallet of claim 29, wherein, in each of the second
sub-subset of the first subset of the plurality of support
structures, the protrusions extending from opposing walls into the
interior of that support structure are spaced from each other.
31. The pallet of claim 29, wherein each of at least some of the
second subset of the plurality of support structures comprises at
least one pair of second protrusions that extend from opposing
walls into the interior of that support structure and that meet
each other in the interior of that support structure, wherein, for
each pair of second protrusions, a connection is formed between
that pair of second protrusions in the interior of that support
structure.
32. The pallet of claim 28, wherein the protrusions extend into the
support structure a distance that is at least about 10% of the
distance between the walls from which the protrusions extend.
33. The pallet of claim 32, wherein the second protrusions extend
the remaining distance between the walls from which the protrusions
extend.
34. The pallet of claim 32, wherein the protrusions extend into the
support structure a distance that is at most about 40% of the
distance between the walls from which the protrusions extend.
35. The pallet of claim 28, wherein the protrusions extend into the
support structure a distance that is at most about 40% of the
distance between the walls from which the protrusions extend.
36. The pallet of claim 27, wherein the second subset of the
plurality of support structures comprises a first sub-subset of the
second subset of the plurality of support structures that have the
at least one pair of second protrusions; and a second sub-subset of
the second subset of the plurality of support structures that lack
the at least one pair of second protrusions.
37. The pallet of claim 36, wherein, in each of the second
sub-subset of the second subset of the plurality of support
structures, the second protrusions do not extend to the support
deck.
38. The pallet of claim 26, wherein the plurality of support
structures comprises at least one support structure that forms a
generally annular support in a central region of the pallet, each
at least one support structure having at least one pair of second
protrusions, each pair of second protrusions extending from
opposite walls of that support structure into the interior of that
support structure and meeting each other in the interior of that
support structure, a connection formed between that pair of
protrusions in the interior of that support structure.
39. The pallet of claim 38, wherein the plurality of support
structures further comprises a central support structure formed
within the bounds of the generally annular support.
40. The pallet of claim 38, wherein, for each pair of second
protrusions of a particular support structure, the pair of second
protrusions extend at least part way up the sides of that support
structure from a bottom surface of that support structure.
41. The pallet of claim 38, wherein the plurality of support
structures further comprise a plurality of the support structures
arranged around the at least one support structure that forms the
generally annular support.
42. The pallet of claim 38, wherein the at least one support
structure that forms a generally annular support comprises a single
continuous support structure.
43. The pallet of claim 42, wherein the single continuous support
structure is a rectangular annulus support structure.
44. The pallet of claim 26, wherein: the support deck has a first
area; each of the plurality of support structures defines a cavity
having an area; and a total area of the cavities is about 20% to
about 35% of the first area.
45. The pallet of claim 44, wherein the area of the cavity of each
of the plurality of support structures is about 0.5% to about 12%
of the first area.
46. (canceled)
47. (canceled)
48. (canceled)
49. (canceled)
50. (canceled)
51. (canceled)
52. The pallet of claim 26, wherein a total profile height of the
pallet is about 3 inches to about 3.5 inches.
53. A pallet, comprising: a support deck made of a first material;
a plurality of support structures extending away from the support
deck and formed of the first material, each of the plurality of
support structures extending to a surface on which the pallet
rests, comprising: a first plurality of the support structures
positioned around the periphery of the pallet, each of the first
plurality of support structures having a plurality of projections
extending into the support structure from opposite side walls of
that support structure, each of the protrusions extending from the
support deck to a bottom surface of the support structure, at least
one additional support structure that forms a generally annular
support in a central region of the pallet, each additional support
structure having a plurality of protrusions, the protrusions
extending at least part way up the sides of that additional support
structure from a bottom surface of that additional support
structure, the plurality of protrusions extending from opposite
side walls of the additional support structure into the interior of
the additional support structure, and a central support structure
formed within the bounds of the annular support.
54. The pallet of claim 53, wherein the first plurality of support
structures positioned around the periphery of the pallet includes:
at least one first support structure, having at least one of a
first size and a first shape; and at least one second support
structure having at least one of a second size that is different
from the first size and a second shape that is different from the
first shape.
55. The pallet of claim 54, wherein the at least one first support
structure comprises at least four first support structures, one
first support structure located at each corner of the pallet.
56. The pallet of claim 55, wherein the at least one second support
structure comprises a plurality of second support structures, at
least one second support structure located on each of two opposing
sides of the pallet between the first support structures located at
the corners of the pallet.
57. The pallet of claim 56, wherein the plurality of second support
structures comprises a plurality of second support structures
located on each of the two opposing sides.
58. The pallet of claim 57, wherein the plurality of second support
structures located on each of the two opposing sides comprises at
least three second support structures located on each of the two
opposing sides. pallet.
59. The pallet of claim 53, wherein: the support deck has a first
area; each of the plurality of support structures defines a cavity
having an area; and a total area of the cavities is about 20% to
about 35% of the first area.
60. The pallet of claim 59, wherein the area of the cavity of each
of the plurality of support structures is about 0.5% to about 12%
of the first area.
61. The pallet of claim 53, wherein a total profile height of the
pallet is about 3 inches to about 3.5 inches.
62. The pallet of claim 53, wherein the at least one support
structure that forms a generally annular support comprises a single
continuous support structure.
63. The pallet of claim 1, wherein the at least one support
structure that forms a generally annular support comprises a single
continuous support structure.
64. The pallet of claim 63, wherein the single continuous support
structure is a rectangular annulus support structure.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention is directed to plastic pallets that are
usable for shipping and storing goods.
[0003] 2. Related Art
[0004] Pallets are commonly used to store and transport goods in
many industries. Using wooden pallets has become problematic when
transporting goods across national boundaries. For example, several
countries have imposed regulations requiring wooden pallets to be
fumigated before entering those countries. Wooden pallets can act
as homes to various bacteria, fungi, insects and/or other
single-celled or multi-cellular organisms. These countries require
wooden pallets to be fumigated because they are concerned that such
bacteria, fungi, insects or the like carried by wooden pallets
could become significant environmental and/or health threats in
these countries.
[0005] However, fumigation adds costs and also requires
documentation to be maintained for the wooden pallets, so that the
shipper can establish that the pallets were treated within a
certain time frame. Thus, for a shipper, not only must the shipper
maintain a proper set of documentation for the goods being shipped,
but the shipper must also maintain proper sets of documentation for
the wooden pallets on which the goods are being shipped.
Maintaining such records for the wooden pallets, which provides no
economic return to the shippers, can be a significant cost to the
shippers. Additionally, the fumigation process itself adds costs
and down time to the wooden pallets.
[0006] Because of the cost of returning empty wooden pallets to the
goods' producer, wooden pallets are not usually returned,
especially after having crossed country borders. As a consequence,
pallets used when shipping goods across country borders are usually
low-cost wood pallets that have been used and/or repaired. Such
pallets frequently have broken and/or splintered boards, and/or
loose nails, any of which can damage the goods placed onto such
pallets.
[0007] Nevertheless, wooden pallets do have a number of
advantageous features. In particular, wood pallets are rigid, can
support significant product weight and are easily accessed by a
variety of transporting and/or lifting systems such as, for
example, forklifts having different distances between the
forks.
[0008] A number of pallets have been designed using materials other
than wood that attempt to maintain, as best as possible, the
advantages provided by wood pallets while attempting to avoid the
disadvantages of wooden pallets. Various forms of these
conventional plastic pallets are described in U.S. Pat. Nos.
3,702,100; 3,709,162; 4,263,885; 5,606,921; 5,813,355; and
6,289,823. In general, the pallets disclosed in these references
are formed using a plastic material. This material is typically
injection-molded plastic, while at least one of these references
discloses using pairs of thermoformed sheets as the plastic
material.
SUMMARY OF THE DISCLOSED EMBODIMENTS
[0009] Typically, as shown, for example, in the '355 and '823
patents, an array of widely but evenly spaced support legs is used
to support the pallet, while the planar "deck" surface of the
pallet is designed to minimize the surface area of the pallet that
is within the bounds of the supporting leg structures. Most of
these conventional pallets are formed using an injection molding
process so that various small structures can be formed to provide
the pallet with sufficient rigidity and structural strength against
bending and twisting. However, such small detailed structures can
generally only be formed using injection molding techniques. Thus,
such designs would not be appropriate for a thermoforming
process.
[0010] Additionally, conventional pallet designs tend to
concentrate the surface area of the pallet consumed by the legs. As
a result, prior art pallets tend to use nine legs which are fairly
evenly distributed over the surface of the pallet and which are
relatively large in size. Such large support leg openings often
make it difficult to adequately support a particular good in areas
of the deck surface of the pallet where such large support legs are
formed. Additionally, by spacing the legs far from each other, the
designers have determined that large loads of goods on the deck
surface of the pallet between the legs can cause the deck surface
to deform under the load of the goods.
[0011] This invention provides a plastic pallet that is lower in
weight than conventional plastic pallets.
[0012] This invention separately provides a plastic pallet that has
a reduced height between the product support surface of the pallet
and the support surfaces of the legs of the pallet relative to
conventional plastic pallets.
[0013] This invention separately provides a plastic pallet having a
smooth, durable surface that does not cause damage or injury to
either workers or goods being carried by the pallets.
[0014] This invention separately provides a plastic pallet having
structures that can be created by thermoforming a plastic
material.
[0015] This invention separately provides plastic pallets that have
structures that allow the pallets to be nested without jamming.
[0016] This invention provides a plastic pallet that is resistant
to moisture and humidity.
[0017] This invention separately provides plastic pallet having
increased durability over wooden pallets.
[0018] This invention separately provides plastic pallet having
reduced distances between the support legs.
[0019] This invention separately provides plastic pallets having an
improved ratio of deck surface area to support surface area.
[0020] This invention separately provides a plastic pallet
structure that has improved resistance to bending and/or
twisting.
[0021] This invention separately provides a plastic pallet having a
design that has reduced deflection along the deck of the
pallet.
[0022] In various exemplary embodiments of plastic pallets
according to this invention, the pallet is formed of a light-weight
plastic material. In various exemplary embodiments, the pallet is
formed by thermoforming a sheet of the light-weight plastic
material having a reduced thickness or gauge relative to
conventional plastic pallets. In various exemplary embodiments, the
light-weight pallet is lighter than a correspondingly-sized wood
pallet and is lower in weight than conventional plastic
pallets.
[0023] In various exemplary embodiments of the plastic pallet
according to this invention, the pallet provides low profile
support legs that reduce the distance between the surface on which
the pallet is resting and the product support or deck surface of
the pallet. In various exemplary embodiments, this distance or
profile is less than that of a correspondingly-sized wood pallet.
In various exemplary embodiments, this profile is less than a
typical conventional plastic pallet.
[0024] In various exemplary embodiments, pallets according to this
invention are formed by thermoforming a single sheet of
thermoformable plastic material. In various exemplary embodiments,
this plastic material is recyclable and durable, and is resistant
to moisture, humidity and/or other liquids, fluids or semi-solids
which tend to reduce the usefulness and/or the life of wood or
paper-based pallets.
[0025] In various exemplary embodiments, pallets according to this
invention use a relatively large number of relatively smaller
support legs to provide a relatively larger amount of support area
in the support legs, as well as to provide a relatively larger
number of support columns, which may be distributed over the
surface of the pallet, that support the pallet load. In various
exemplary embodiments, up to around 18 support legs or columns are
provided in pallets according to this invention. In various
exemplary embodiments, the support legs or columns have a variety
of different sizes. In various exemplary embodiments, the plurality
of support legs or columns have a variety of shapes and/or sizes.
In various exemplary embodiments, the support legs or columns are
generally evenly distributed over the surface of the pallet. In
various exemplary embodiments, the total deck surface area is less
than the total deck surface area in a similarly-sized conventional
plastic pallet. In various exemplary embodiments, the total support
leg area is larger than in a conventional similarly-sized plastic
pallet, while the area within each individual support leg opening
is smaller than that of a similarly-sized conventional plastic
pallet. This is advantageous when the load is a number of smaller
items, such as boxes. The boxes that extend over a support leg will
have better support if the support leg area is small. This is also
an advantage when stacking a loaded pallet on top of another pallet
that is loaded with corrugated boxes or the like. In that
situation, the load is more evenly distributed over a greater
number of the corrugated boxes or the like.
[0026] In various exemplary embodiments of the pallet according to
this invention, a number of the support legs or columns are
provided around the periphery of the pallet.
[0027] These and other features and advantages of various exemplary
embodiments of apparatus and structures according to this invention
are described in, or are apparent from, the following detailed
descriptions of various exemplary embodiments of the apparatus and
structures according to this invention.
BRIEF DESCRIPTION OF DRAWINGS
[0028] Various exemplary embodiments of the apparatus and
structures of this invention will be described in detail, with
reference to the following figures, wherein:
[0029] FIG. 1 is a top perspective view of one exemplary embodiment
of a pallet structure according to this invention;
[0030] FIG. 2 is a top plan view of the pallet structure shown in
FIG. 1;
[0031] FIG. 3 is a bottom plan view of the pallet structure shown
in FIG. 1;
[0032] FIG. 4 is a bottom perspective view of the pallet structure
shown in FIG. 1;
[0033] FIG. 5 is a first side cut-away view, cut through some
support structures, of the pallet structure shown in FIG. 1;
[0034] FIG. 6 is a second side cutaway view, cut through some of
the support structures, of the pallet structure of FIG. 1;
[0035] FIG. 7 is a third side cutaway view, cut through some of the
support structures, of the pallet structure shown in FIG. 1;
[0036] FIG. 8 is a side plan view of a longer edge of the pallet
structure shown in FIG. 1; and
[0037] FIG. 9 is a side plan view of a shorter edge of the pallet
structure shown in FIG. 1.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0038] Pallets greatly facilitate storing and transporting a wide
variety of goods. Pallets allow different items to be stored and
transported using forklift trucks as a common material handling
system. General purpose pallets generally share several basic
structural properties, including a generally flat upper deck
surface or product support surface that is used to support boxes,
canisters, crates or other goods or packaging, as well as two or
more openings through which the lift tines of a forklift can be
inserted under the generally flat upper deck.
[0039] Pallets that allow the forklift tines to enter from all four
sides of the pallet tend to be more useful. The forklift tine
openings may be formed between a pallet top deck and pallet bottom
deck, such as with wood pallets. Alternatively, the pallet may have
only a single product support surface, with an array of support
legs extending down from the deck surface to space the deck surface
from a support surface, thus allowing the forklift tines to be
inserted underneath the deck surface.
[0040] Traditionally, most pallets were constructed of hardwoods,
due to their low cost, ready availability, and high compressive
strength. Wood pallets are still widely used in the industry.
However, as discussed above, wood pallets are subject to
splintering, moisture absorption, and colonization by various
unicellular microorganisms, insects, fungi and the like. Thus, as
discussed above, using wood pallets in export situations becomes
highly problematic. This is true when shipping pallets in one
direction across national borders. This problem becomes even
greater when such pallets are to be returned to the originating
country.
[0041] Because plastic pallets are lighter and more durable than
traditional wooden pallets, plastic pallets are replacing wooden
pallets in many industries. Lighter plastic pallets are easier to
move than wooden pallets and add less weight to a shipment of the
product that is being stored and transported using the pallet,
resulting in decreased transportation costs and/or increased
transportable load capacity. Plastic pallets are also better suited
to export situations than wood pallets by allowing the fumigation
and record-keeping aspects of wood pallets in export situations to
be avoided.
[0042] While wood pallets have various drawbacks, as discussed
above, wood pallets do provide significant advantages in terms of
cost, load-bearing capacity, and rigidity. Traditionally, these
advantages of wood pallets are offset by the greater durability and
design options available with plastic pallets. However, plastic
pallets are traditionally less competitive with wood pallets on a
straight cost basis, unless the greater durability of the plastic
pallets is taken into account. While the greater durability of
plastic pallets can be taken into account when using the plastic
pallets locally or within national borders, this is often not the
case with pallets used when exporting goods across national
borders. Due to the distances involved and the lack of reciprocal
trade channels, such pallets used in export situations are rarely
returned to the exporter. Thus, the exporter has less ability to
recoup the costs of more expensive plastic pallets, because the
exporter cannot make use of the longer useful lifetimes and
recycling capabilities of the plastic pallets.
[0043] Additionally, especially in export situations, shipping
considerations are of primary importance. Thus, the size,
load-bearing capacity, and weight of the pallets become even more
important. For example, because exporters expect that the pallets
used for export goods will not be returned, exporters traditionally
employ low-cost used wood pallets that are nearing the end of their
useful lifetimes and/or have been previously repaired. Other types
of pallets that are not "wooden" have also been proposed. For
example, U.S. Pat. No. 5,448,956 to Ong et al. discloses a one-way,
light-weight pallet that is formed using corrugated paper. While
such corrugated paper pallets are light-weight, they are of limited
usefulness, as they are not as rigid as wood and are significantly
adversely affected by humidity and/or moisture. Additionally, these
pallets are also made from, if not of, wood, and thus can also
provide the same infestation problems as wooden pallets.
[0044] FIGS. 1-9 show one exemplary embodiment of a low-cost,
low-profile and/or low-weight plastic pallet that is particularly
suitable for export or one-way use. One-way or export use implies
that the shipper or goods manufacturer who has purchased the pallet
and placed the goods onto the pallet for transport to the customer
does not expect to have the pallet returned. Thus, a one-way pallet
having improved load carrying capacity, reduced cost considerations
and improved durability with respect to, for example, corrugated
paper pallets, would be desirable to such a shipper or
manufacturer.
[0045] The cost considerations to the shipper or manufacturer
include not only the cost of the pallet to the shipper or
manufacturer, but also the costs of using a particular pallet. For
example, if a particular pallet has poor load carrying
capabilities, the shipper or manufacturer will be required to use
more pallets for a given weight of goods to be shipped. Likewise,
the shipper or manufacturer will not only have to pay for shipping
the weight of his goods, but will also have to pay for the cost of
shipping the pallets. Thus, lighter-weight pallets reduce the
shipper's or manufacturer's shipping costs. Additionally, the
shipper's or manufacturer's costs are not only a function of
weight, but are also a function of volume consumed by the goods to
be shipped. Thus, any unused space in a tractor-trailer or shipping
container raises the shipping costs to the shipper or manufacturer.
Consequently, lower-profile pallets, which do not consume as much
shipping volume as higher-profile pallets, tend to reduce the
shipper's or manufacturer's costs by permitting more goods to be
shipped within a given volume.
[0046] FIGS. 1-9 show one exemplary embodiment of a pallet 100
having improved load carrying capacity, reduced profile, and/or
lower weight. As shown in FIGS. 1-9, the pallet 100 is formed from
a single sheet of thermoformable material and comprises a deck
surface or product support surface 102 having a long side 104 and a
short side 106, in which a relatively larger number of relatively
smaller support legs, such as the support legs 110, 120, 130, 140,
150 and 160, are formed. Each of the support legs 110-160 defines
an upwardly opening cavity in the deck surface 102. As shown in
FIGS. 1-8, the support legs 110 are located at the corners where
the long sides 104 meet the short sides 106. The support legs 120
are located between the support legs 110 along the long sides 104,
while the support legs 130 and 140 are located between the support
legs 110 along the short sides 106. The support leg 160 is located
generally at the center of the pallet 100, with the
rectangular-shaped annular support leg 150 surrounding the central
support leg 160.
[0047] It should be appreciated that, in the exemplary embodiment
of the pallet 100 shown in FIGS. 1-9, each of the support legs
110-160 has a different shape and/or a different size. However, it
should be appreciated that, in various other exemplary embodiments,
these different shapes for the support legs 110-160 need not be
used. Thus, fewer different shapes, or even a single shape, could
be used for the support legs 110-140 and 160. It should also be
appreciated that any appropriate shape for the annular support leg
150 can be used, such as any polygon having either sharp or rounded
vertices, a circle, an ellipse or any other open or closed curve.
Likewise, it should be appreciated that more than six different
types of shapes for the various support legs could be
implemented.
[0048] As shown in FIGS. 1-9, there are 16 support legs 110-140
distributed around the periphery of the pallet 100 and there are
two more-centrally-located support legs 150 and 160 located in the
interior of the pallet 100. It should be appreciated that fewer or
more of the support legs 110, 120, 130, 140 and/or 160 could be
implemented in a particular exemplary embodiment of the pallet 100
without departing from the spirit and/or scope of this invention.
Similarly, the annular support leg 150 can be a single structure or
a plurality of separate structures, such as separate sections that
correspond to each of the sides of the annular support leg 150.
[0049] The pallet 100 shown in FIGS. 1-9 also includes a variety of
non-support-leg structures 170 formed in the deck surface 102 of
the pallet 100. These include a variety of laterally extending
channels 172 and 174, edge portions 175, web structures 176 formed
in the lateral channels 172 and 174, and indented portions 178
formed in the periphery of the deck surface 102 and the edge
portions 175. Additionally, it should be appreciated that the
positions and orientations of the support legs 110-150 cooperate to
define a pair of forklift tine passages 182 extending between the
long sides 104 of the pallet 100 and a pair of forklift tine
passages 184 extending between the short sides 106 of the pallet
100.
[0050] As shown in FIGS. 1-6, each of the corner support legs 110
includes a relatively short side wall 112 and a relatively long
side wall 114. In various exemplary embodiments, the short side
wall 112 is roughly parallel to the short side 106, while the long
side wall 114 is generally parallel to the long side 104 of the
pallet 100. It should be appreciated, as shown in FIGS. 5 and 6,
that each of the side walls 112 and 114 generally slopes inwardly
into the support leg 110 as the side walls 112 and 114 extend from
the deck surface 102 to a support surface 115 that lies at the
bottom of the support leg 110. That is, in such exemplary
embodiments, the upwardly opening cavity defined by the support leg
110 tapers inwardly from the deck surface 102 to the support
surface 115.
[0051] It should also be appreciated that, as shown in FIGS. 1-6,
each support leg 110 has a pair of protrusions 116 that extend into
the support leg 110 from the long walls 114. These protrusions 116
tend to increase the area of the deck surface 102, and are
sufficiently sized that the protrusions 116 will provide support to
a load placed on the deck surface 102 of the pallet 100. That is,
the top surfaces of the protrusions 116 form portions of the deck
surface 102. The protrusions 116 also tend to prevent the walls 114
from spreading or buckling, thus tending to increase the load
capacity of the support legs 110. In various exemplary embodiments,
each of the protrusions 116 extends into the cavity formed by the
support leg 110 by about 10% to about 40% of the distance between
the walls 114. In general, for a typically-sized leg, the
protrusions 116 should extend about 1 to about 3 inches into the
leg 110 from the side walls 114. Of course, it should be understood
that these dimensions might not apply to legs having extremely
narrow or extremely wide separations between the side walls. In
some exemplary embodiments, each of the protrusions 116 extend to
no more than about 30% to about 40% of the distance between the
walls 114.
[0052] In addition, as shown in FIGS. 1-6, a pair of secondary
protrusions 118 extend out of the bottom portions of the
protrusions 116. In particular, as shown in FIGS. 1-6, these
secondary protrusions 118 extend the rest of the way across the
bottom surface 115 between the protrusions 116 and contact each
other within the support leg 110 such that a web or other linking
structure 119 is provided between the two protrusions 116. The
secondary protrusions 118 act as anti-jam features that tend to
prevent another pallet 100 that has been nested into this pallet
100 from becoming struck or jammed into this pallet 100. That is,
the secondary protrusions 118 act as anti-jam shoulders to prevent
nested pallets and tapered parts to stick together when attempting
to separate the pallets 100. The second protrusions 118 also
effectively divide each support leg 110 into two lateral sections,
increasing the rigidity of the support leg 110 while also
increasing its support capacity That is, the secondary protrusions
118 tend to prevent the lower portion of the support leg 110 from
buckling, which tends to increase the support capacity of the
support leg 110. The web 119 tends to prevent the walls 114 from
spreading or buckling, thus tending to increase the load capacity
of the support legs 110.
[0053] Similarly, as shown in FIGS. 1-4 and 6, the support legs
120, which are arranged along the long side 104 of the pallet 100,
each includes a pair of walls 122 that are generally parallel to
the short side 106 and a pair of walls 124 that are generally
parallel to the long side 104 of the pallet 100. In various
exemplary embodiments, the sizes of the walls 122 and 124 can be
roughly equal. In various other exemplary embodiments, the side
walls 122 can be longer than the side walls 124.
[0054] It should be appreciated that, in various exemplary
embodiments, while the length of the side wall 122 of the support
leg 120 is generally about the same dimension as the length of the
side wall 112 of the support leg 110, the length of the side wall
124 of the support leg 120 is shorter than the side wall 114 of the
support leg 110, and, in some exemplary embodiments, is
substantially shorter.
[0055] As with the support legs 110, each of the support legs 120
has a pair of projections 126 extending out from the side walls 124
into the interior of the support leg 120. As with the support leg
110, these projections 126 tend to increase the area of the support
deck 102 and increase the load capacity of the support leg 120. In
general, the protrusions 126 are sufficiently sized that the
protrusions 126 will provide support to a load placed on the deck
surface 102 of the pallet 100. That is, the top surfaces of the
protrusions 126 form portions of the deck surface 102. The
protrusions 126 also tend to prevent the walls 124 from spreading
or buckling, thus tending to increase the load capacity of the
support legs 120. In various exemplary embodiments, each of the
protrusions 126 extends into the cavity formed by the support leg
120 by about 10% to about 40% of the distance between the walls
124. In general, for a typically-sized leg, the protrusions 126
should extend about 1 to about 3 inches into the leg 120 from the
side walls 124. Of course, it should be understood that these
dimensions might not apply to legs having extremely narrow or
extremely wide separations between the side walls. In some
exemplary embodiments, each of the protrusions 126 extend to no
more than about 30% to about 40% of the distance between the walls
124.
[0056] However, unlike the support leg 110, the projections 126 do
not have secondary projections that contact each other. Further,
like the support leg 110, the side walls 122 and 124 of the support
leg 120 slope inwardly into the interior of the support leg 120
from the support deck 102 to a bottom surface 125 that lies at the
bottom of the support leg 120. That is, in such exemplary
embodiments, the upwardly opening cavity defined by the support leg
120 tapers inwardly from the deck surface 102 to the bottom surface
125.
[0057] As shown in FIGS. 1-5, each of the support legs 130 includes
a pair of side walls 132 that, in various exemplary embodiments,
are generally parallel to the short side 106 and a pair of side
walls 134 that, in various exemplary embodiments, are generally
parallel to the long side 104. As with the support legs 110 and
120, the side walls 132 and 134 generally slope toward the interior
of the support leg 130 from the deck surface 102 to a bottom
surface 135 of the support leg 130. That is, in such exemplary
embodiments, the upwardly opening cavity defined by the support leg
130 tapers inwardly from the deck surface 102 to the bottom surface
135.
[0058] Also similarly to the support legs 110 and 120, the support
leg 130 includes a pair of protrusions 136 that extend into the
support leg 130 from the side walls 134, which tend to increase the
support capacity of the support legs 130. In general, the
protrusions 136 are sufficiently sized that the protrusions 136
will provide support to a load placed on the deck surface 102 of
the pallet 100. That is, the top surfaces of the protrusions 136
form portions of the deck surface 102. The protrusions 136 also
tend to prevent the walls 134 from spreading or buckling, thus
tending to increase the load capacity of the support legs 130. In
various exemplary embodiments, each of the protrusions 136 extends
into the cavity formed by the support leg 130 by about 10% to about
40% of the distance between the walls 134. In general, for a
typically-sized leg, the protrusions 136 should extend about 1 to
about 3 inches into the leg 130 from the side walls 134. Of course,
it should be understood that these dimensions might not apply to
legs having extremely narrow or extremely wide separations between
the side walls. In some exemplary embodiments, each of the
protrusions 136 extend to no more than about 30% to about 40% of
the distance between the walls 134.
[0059] However, like the support legs 110, and unlike the support
legs 120, the protrusions 136 contain secondary protrusions 138.
These secondary protrusions 138 are located at the bottom of the
protrusion 136 and extend fully across the support surface 135 of
the support leg 130 to contact each other. As with the support leg
110, the secondary protections 138 act as anti-jam features and
tend to increase the bottom capacity of the support leg 130. As
with the support leg 110, a weld or web 139 is formed connecting
the secondary protrusions 138. The webs 139 tend to prevent the
walls 134 from spreading or buckling, increasing the load capacity
of the support leg 130.
[0060] As shown in FIGS. 1-4 and 6, the support legs 140 include a
pair of side walls 142 that, in various exemplary embodiments, are
generally parallel to the short side 106 and a pair of side walls
144 that, in various exemplary embodiments, are generally parallel
to the long side 104. Like the support legs 110-130, the side walls
142 and 144 slope generally into the interior of the support leg
140 from the deck surface 102 to a bottom surface 145 of the
support leg 146. That is, in such exemplary embodiments, the
upwardly opening cavity defined by the support leg 140 tapers
inwardly from the deck surface 102 to the bottom surface 145.
[0061] Like the support legs 110-130, the support leg 140 includes
protrusions 146 extending into the interior of the support leg 140
from the side walls 144, which tend to increase the support
capacity of the support legs 140. In general, the protrusions 146
are sufficiently sized that the protrusions 146 will provide
support to a load placed on the deck surface 102 of the pallet 100.
That is, the top surfaces of the protrusions 146 form portions of
the deck surface 102. The protrusions 146 also tend to prevent the
walls 144 from spreading or buckling, thus tending to increase the
load capacity of the support legs 140. In various exemplary
embodiments, each of the protrusions 146 extends into the cavity
formed by the support leg 140 by about 10% to about 40% of the
distance between the walls 144. In general, for a typically-sized
leg, the protrusions 146 should extend about 1 to about 3 inches
into the leg 140 from the side walls 144. Of course, it should be
understood that these dimensions might not apply to legs having
extremely narrow or extremely wide separations between the side
walls. In some exemplary embodiments, each of the protrusions 146
extend to no more than about 30% to about 40% of the distance
between the walls 144. Like the support legs 120, and unlike the
support legs 110 and 130, the protrusions 146 do not have any
secondary protrusions nor do they meet in the interior of the
support leg 140.
[0062] It should also be appreciated that, in various exemplary
embodiments, the portions of the deck surface 102 extending between
the side walls 112 and 122 of the support legs 110 and 120 and
between side walls 122 of adjacent support legs 120 can be beveled
or chamfered. That is, some or all of the corners between the deck
surface 102 and the various side walls 112, 114, 122, 124, 132,
134, 142, 144, 152, 154, 162 and/or 164 can be rounded, radiused,
beveled, chamfered or the like. When used, the chamfered corners
allow a more uniform wall thickness to be obtained during the
thermoforming process. In various other exemplary embodiments, the
portions of the deck surface 102 between the side walls 112 and 122
of the support legs 110 and 120 can be square, as shown in FIG. 1,
similar to the deck surface 102 between the side walls 114 and 134,
and 134 and 144.
[0063] As shown in FIGS. 1-4 and 7, a central rectangular-shaped
annular support leg 150 comprises an inner wall 152 and an outer
wall 154. Each of the inner and outer walls 152 and 154 each
contain four portions that, in various exemplary embodiments, are
generally parallel to each of the two sides 104 and two sides 106
of the pallet 100. Adjacent portions of the inner and outer walls
152 and 154 are generally perpendicular to each other, although
they do not need to meet at sharp angles. Rather, as shown in FIGS.
1-4, the corners of at least the outer wall 154 can be curved or
rounded, although they do not need to be. As shown in FIG. 1, the
tops of the corners of the inner wall 152 where the inner wall 152
meets the deck surface 102, contain beveled surfaces 156.
Additionally, the walls 152 and 154 generally slope inwardly toward
the interior of the annulus of the support leg 152 from the deck
surface 102 to the bottom surface 155 in the same manner that the
side walls of the support legs 110-140 slope toward the interior of
those support legs 110-140. It should be appreciated that these
walls slope due to the required draft angles for forming the
pallets 100 and for nesting the pallets 100.
[0064] As shown in FIGS. 2-4 and 7, at various points around the
circumference of the side walls 152 and 154, at opposing positions,
protrusions 158 extend from the side walls 152 and 154 toward each
other and meet at a weld or rib 159 and tend to prevent spreading
or buckling of the walls 152 and 154 of the support leg 150. It
should be appreciated that the protrusions 158, like the secondary
protrusions 118 and 138, extend only part way up the side walls 154
and 152 from the support surface 155 of the support leg 150 and
tend to increase the support capacity of the support leg 150, as
well as tend to prevent jamming between nested pallets.
[0065] It should be appreciated that any number of the protrusions
158 can be formed along the circumference of the side walls 152 and
154. In the particular exemplary embodiment illustrated in FIGS.
2-4 and 7, two protrusions 158 extend from each of the four
portions of the side walls 152 and 154. In various exemplary
embodiments, such as the one shown in FIGS. 2-4 and 7, the
protrusions 158 on one of the four portions of the side walls 152
and 154 are offset from the protrusions 158 in the other portion of
the side walls 152 and 154 that is parallel to that first portion.
It should also be appreciated that, in various exemplary
embodiments, such as the exemplary embodiment shown in FIGS. 2-4
and 7, the protrusions 158 are equally and regularly spaced around
the circumference of the side walls 152 and 154. However, it should
be appreciated that, in various other exemplary embodiments, the
protrusions 158 formed in the two portions of the side walls 152
and 154 that are parallel to each other do not need to be
offset.
[0066] It should also be appreciated that the protrusions 158 do
not need to be evenly or regularly spaced around the circumference
of the side walls 152 and 154. It should also be appreciated that
different numbers of protrusions 158 can be provided in different
portions of the side walls 152 and 154. It should further be
appreciated that the protrusions 158 need not be all the same
shape.
[0067] It should also be appreciated that, while the above-outlined
discussion describes the annular support leg 150 as being
rectangularly shaped, the annular support leg 150 need not be
rectangularly shaped. Rather, the support leg 150 can be an annulus
of any particular desired shape, from circular to polygonal to any
closed curve. It should also be appreciated that, for polygonal
shapes, the vertices can be sharp or rounded. However, it should be
appreciated that shapes that are 180.degree. rotationally
symmetrical are particularly useful.
[0068] It should further be appreciated that, rather than being a
continuous, annular shape, as shown in FIGS. 1-4, the support leg
150 could comprise a plurality of distinct segments that are spaced
or separated from each other. For example, the support leg 150
could comprise four straight segments that correspond to each of
the sides of the rectangular annulus 150 shown in FIGS. 1-4, where
the segments are spaced from each other.
[0069] As shown in FIGS. 1-4 and 7, the central support leg 160
includes a pair of side walls 162 that, in various exemplary
embodiments, are generally parallel to the short side 106 and a
pair of side walls 164 that, in various exemplary embodiments, are
generally parallel to the long side 104. As with the support legs
110-140, the side walls 162 and 164 generally slope toward the
interior of the support leg 160 from the deck surface 102 to a
bottom surface 165 of the support leg 160. Unlike any of the
support legs 110-150, there are no protuberances or protrusions
extending from the side walls 162 or 164 into the interior of the
support leg 160. It should be appreciated that, in various
exemplary embodiments, such as the one shown in FIGS. 1-9, the
central support leg 160 is centered on the geometrical center point
of the pallet 100 and is laterally symmetrical about that center
point relative to both the sides 104 and 106. However, in various
other exemplary embodiments, the central support leg 160 need not
be located at the center point of the pallet 100 nor need be
laterally symmetrical relative to either of the sides 104 or
106.
[0070] It should also be appreciated that, while the central
support leg 160 shown in FIGS. 1-4 is square in shape, any desired
shape for the central support leg 160 could be used. Thus the
central support leg 160 can be circular, oval, polygonal or any
other closed curve. When the central support leg 160 is polygonal,
the vertices can be sharp or rounded. It should further be
appreciated that the walls 162 and 164 of the central support legs
160 may have protrusions similar to the protrusions 116, 118, 126,
136, 138, 146 and/or 158, and/or other structures. It should
further be appreciated that such protrusions can have the same
shape or can have a plurality of shapes.
[0071] It should also be appreciated that, in use, various ones of
the pallet 100 can be stacked together, with each of the support
legs 110-160 of one such pallet 100 nesting into the corresponding
support legs 110-160 of another such pallet 100. It should be
appreciated that, to insure that the two pallets 100 do not become
jammed together, the secondary protrusions 118, 138 and 158 act as
an "anti-jamming" feature to insure that the upper pallet 100 does
not become too deeply forced into the lower pallet 100. Similarly,
along with the protrusions 118, 138 and 158, the slope applied to
the side walls 112, 114, 122, 124, 132, 134, 142, 144, 152, 154,
162, and 164 allows the upper pallet 100 to nest into the lower
pallet 100 without the side walls actually engaging to such an
extent that the upper pallet 100 becomes jammed into or stuck in
the lower pallet 100. However, limiting the slope tends to allow
for smaller openings for the support legs 110-160 at the deck
surface 102.
[0072] As shown in FIGS. 1-7, the pallet 100 also includes a first
plurality of channels 172 that, in various exemplary embodiments,
extend parallel to the side 106 and a second plurality of channels
174 that, in various exemplary embodiments, extend parallel to the
side 104. In general, the channels 172 and 174 cross each other.
However, it should be appreciated that some of the channels 172 and
some of the channels 174 do not extend all the way across the deck
surface 102 of the pallet 100.
[0073] As shown in FIGS. 1-7, in addition to the channels 172 and
174, at various locations within the channels 172 and 174, paired
protrusions 176 extend from each side wall of the channels 172 and
174. The protrusions 176 contact each other to form a web or weld
extending across the channels 172 and 174. In various exemplary
embodiments, such as the one shown in FIGS. 1-9, there is at least
one such web for each portion of a channel 172 or 174 that extends
between either a pair of channels 172 or 174, respectively, between
adjacent ones of the support legs 110-160, or between the side wall
of one of the support legs 110-150 and a channel 172 or 174,
respectively. The channels 172 and 174, and the corresponding webs
or welds 176, tend to make the deck surface 102 of the pallet 100
stiffer and/or more rigid.
[0074] As shown in FIGS. 1-7, a plurality of depressions 178 are
formed in the periphery of the deck surface 102 of the pallet 100
along the sides 104 and 106. It should be appreciated that these
depressions 178 can take any desired shape or form. It should be
appreciated that, in the particular exemplary embodiment shown in
FIGS. 1-9, there is one such depression for each of the exterior
side walls 112, 132 and 142, and two depressions, one on each side
of the protuberances 116 and 126, for each of the exterior side
walls 114 and 124. However, in various other exemplary embodiments,
different numbers of depressions 178 could be formed. It should
also be appreciated that, for the depressions 178 formed in the
exterior side walls 112, 132 and 142, in the exemplary embodiment
shown in FIGS. 1-7, these depressions 178 are generally circular
shaped, while the depressions formed in the exterior side walls 114
and 124 are generally rectangular or square in shape. However, it
should be appreciated that any desired shape could be used for each
of the depressions 178. The depressions 178 help stiffen the
portion of the deck 102 that lies outside of the support legs
110-140. The depressions 178 also tend to reduce any warp that may
occur in the outer vertical walls 175. The rectangularly-shaped
depressions 178 are used on the narrow portions of the side walls
114 and 124 of the support legs 110 and 120 to obtain the same
depth as the semi-circularly-shaped depressions 178 in less space.
The semi-circularly-shaped depressions 178 are used on the wider
portions of the side walls 112, 132 and 142 of the support legs
110, 130 and 140 because such semi-circularly-shaped depressions
178 are easier to process during thermoforming and will result in a
more uniform material distribution in the thermoformed plastic
pallet.
[0075] Finally, it should be appreciated that the portions of the
deck surface 102 that lie between the various support legs 110-160,
and/or between the various channels 172 and/or 174, are treated to
provide a pattern or texture to the deck surface 102. This pattern
or texture tends to better hold the goods placed on the pallet 100
in place, especially during transport.
[0076] FIGS. 8 and 9 are side plan views of the pallet 100 shown in
FIGS. 1-7. In particular, FIGS. 8 and 9 illustrate how the various
support legs 110-150 combine to form the forklift tine passages 182
and 184.
[0077] It should be appreciated that the type of pallet 100 shown
in FIGS. 1-9 can come in various sizes and dimensions. In general,
common dimensions include pallets that are 40''.times.48'',
42''.times.48'', 45''.times.48'', 48''.times.54'',
48''.times.63.times., and 48''.times.75''. In general, the
dimensions of the pallet will be selected based on the type of good
to be loaded onto the pallet, as well as the internal dimensions of
the tractor-trailer or shipping container into which the palletized
goods are to be loaded. For example, if the palletized goods are to
be loaded onto a standard semi tractor-trailer, which has an
internal width of 96'' and an internal length of 47.5' or 52.5',
pallet sizes of 40''.times.48'' and 48''.times.48'' allow an
integer number of pallets to be loaded into the tractor trailer
with minimal wasted space.
[0078] For the exemplary embodiment shown in FIGS. 1-9, for a
pallet measuring 48'' along the sides 104 and 40'' along the sides
106, typical dimensions for the support legs 110 are 7''.times.4'',
4''.times.4'' for the support legs 120, and approximately 3.75'' by
approximately 7'' for the support legs 130, approximately 4.5'' by
7'' for the support legs 140, approximately 20'' along the sides
104 and 18.5'' along the sides 106 for the annular support leg 150
and approximately 6'' along the sides 104 and 5'' along the sides
106 for the central support leg 160.
[0079] Additionally, the support legs 120 are spaced approximately
5.75'' from the support legs 110 and approximately 3.75'' from each
other along the side 104. Similarly, the support legs 130 are
spaced about 5.6'' from the support legs 110 and approximately
3.75'' from the support legs 140. The annular support leg 150 is
spaced about 5.5'' from both the support legs 120 and the support
legs 140. Similarly, the central support leg 160 is spaced 5.5''
from the annular support leg 150 along the side 104, while it is
spaced about 5'' from the annular support leg 150 along the edge
160. The annular support leg 150 is about 2'' wide around the
annulus.
[0080] The protuberances 116, 126, 136 and 146 are generally
semi-circular shaped and extend into their respective support legs
110-140 approximately 1''. The protrusions 118, 138 and 158 are
also generally semi-circularly shaped and all are about 1.75''
below the deck surface 102 of the pallet 100. The channels 172 and
174 are generally 1.5'' deep and approximately 0.5'' wide at their
widest. However, it should be appreciated that, at the locations
where the protuberances 176 occur, the channels 172 and 174 tend to
be slightly narrower.
[0081] It should be appreciated that these dimensions are exemplary
only and are meaningful only with respect to the exemplary 40'' by
48'' pallet corresponding to the exemplary embodiment of the pallet
100 shown in FIGS. 1-9. Thus, it should be appreciated that, for
pallets 100 having different dimensions, the sizes of the various
features outlined above may shrink and/or stretch. However, it
should be appreciated that, for the channels 172 and 174, the
dimensions of the structures are more likely to remain the same, as
these structures are not generally tied to the size of the pallet
100.
[0082] It should be appreciated, as outlined above, that in the
pallet 100 shown in FIGS. 1-7, the total amount of surface area of
the deck surface 102 that lies within the cavities defined by the
support legs 110-160, and thus the total amount of the surface area
of the support surfaces 115, 125, 135, 145, 155 and 165 is
relatively greater than the total amount of support surface that
lies within the cavities defined by the relatively larger support
legs used in the conventional plastic pallets. In particular, in
various exemplary embodiments, for a 40''.times.48'' pallet, the
total amount of surface area of the deck surface 102 that lies
within the cavities defined by the support legs 110-160, as a
percentage of the total surface area of the deck surface 102 is
between about 20% and about 35%. It should be appreciated that, as
the pallet dimensions increase, these percentages drop.
[0083] At the same time, the amount of surface area of the deck
surface 102 that lies within a cavity defined by one of the support
legs 110-160 is relatively less than the surface area that lies
within a cavity defined by the relatively larger support legs used
in the conventional plastic pallets. In particular, in various
exemplary embodiments, for a 40''.times.48'' pallet, the amount of
surface area of the deck surface 102 that lies within the cavity
defined by one of the support legs 110-160, as a percentage of the
total surface area of the deck surface 102 is between about 0.5%
and about 12%. It should be appreciated that, as the pallet
dimensions increase, these percentages also drop.
[0084] It should be appreciated that the exemplary embodiment of
the pallet 100 shown in FIGS. 1-9 as outlined above, is merely one
exemplary embodiment of a light-weight and/or low-profile pallet
according to this invention. That is, many of the specific details
discussed above with respect to the pallet 100 are optional and can
be omitted or altered. In general, a plastic pallet according to
this invention has a relatively large number of relatively small
support legs that are located generally closer to each other and/or
each take up less area of the deck surface upon which the goods to
be palletized are placed. Such relatively larger number of
relatively smaller legs support the load better by providing more
evenly distributed support under the entire load.
[0085] In contrast, most conventional light-weight plastic pallets
have support legs in only nine locations, with larger distances
between the legs. In such conventional light-weight pallets, heavy
loads tend to cause the pallet deck to sag between the legs where
the load is unsupported. In contrast, in various exemplary
embodiments of the pallet according to this invention, the distance
between the support legs is reduced, which consequently reduces the
downward deflection of the support deck for a given load. At the
same time by, reducing the size of the opening of each of the
support legs 110-160 on the support deck 102 relative to the
opening sizes of the conventional support legs, the goods carried
on the deck surface 102 are better supported and less likely to
adversely interact with the openings of the support legs
110-160.
[0086] The greater total support surface area provided by the
support surfaces 115, 125, 135, 145, 155 and 165 tends to more
evenly distribute, to the floor or other load-bearing surface, the
load of the goods that are stacked onto a pallet. The increased
total surface area within the support legs 110-160 also allows the
load to be more evenly distributed when a pallet is stacked upon
the goods carried by another pallet. Such double stacking occurs
when loads are stored in a warehouse, or are placed onto a tractor
trailer or a shipping container.
[0087] In general, as shown in FIGS. 1-9, the protrusions 116, 126,
136 and 146 are generally semi-circular in shape, as are the
protrusions 118, 138 and 158. However, it should be appreciated
that any desired and appropriate shape, such as a part of a circle,
a part of an oval or an ellipse, or a section of a polygon can be
used for the various protrusions 116, 126, 136 and 146 and/or the
various secondary protrusions 118, 138 and 158. It should also be
appreciated that the protrusions 116, 126, 136 and 146 and/or the
secondary protrusions 118, 138 and 158 do not need to all have the
same shape. It should be appreciated that any desired shape that
can be appropriately connected to the side walls of the support leg
or to the primary protrusions 116, 126, 136 and 146 can be used for
the primary protrusions 116, 126, 136 and 146 or the secondary
protrusions 118, 138 and 158, respectively. If a polygonal shape is
used, the vertices can be either sharp or rounded.
[0088] It should be appreciated that the protrusions 116, 126, 136
and 146 help the pallet resist bending of the walls of the support
legs when the pallet is loaded. These protrusions also increase the
deck surface area. As outlined above, some of the support legs,
such as the support legs 110, 130 and 150, have a web formed
between the secondary protrusions. This tends to increase strength
by preventing the support leg walls from flexing when a load is
applied to the pallet. The secondary protrusions and/or the webs
also can act as anti-jam elements that keep empty pallets from
sticking together when nested. The narrow annular support leg 150
generally stiffens the support deck and decreases deflection of the
support deck. The relatively narrow channels 172 and 174 act as
stiffening ribs near the center of the pallet.
[0089] It should also be appreciated that, while various ones of
the support legs 110-140 are described as having various shapes and
structures, these support legs 110-140 need not have the exact
shapes shown in the embodiment outlined with respect to FIGS. 1-4.
Thus, it is possible that different ones of the support legs have
the lower protrusions and/or are positioned in different locations
around the periphery of a pallet.
[0090] It should further be appreciated that the support legs
110-160 are configured such that the tines of a forklift may access
the pallet 100 near the periphery. This forces the majority of the
unsupported load to be carried between the two tines of the
forklift, which is the stiffer section of the pallet due to the
narrow leg mentioned above. This results in a more stable load, as
the strongest portion of the pallet carries the majority of the
weight. Any deflection of the pallet is thus likely to be toward
the center of the pallet, forcing the load to shift toward the
center of the pallet rather than outward away from the pallet. The
various channels 172 and 174 create bridges between the support
legs 110-160. These bridges or channels 172 and 174 are positioned
such that they will tend to resist bending when the pallet 100 is
resting on the floor or is being transported by a forklift.
[0091] Test pallets that are 40 inches wide by 48 inches long were
made according to the embodiment shown in FIGS. 1-9 out of
thermoformable plastic sheets having initial nominal thicknesses of
0.150 inches and 0.200 inches. In these test pallets, the fork
clearance, i.e., the height between the ground on which the support
legs 110-160 rest and the bottom of the channels 172 and 174 and/or
the edge 175, whichever is lower, is about two inches. The distance
between the tops of the channels 172 and 174 and the top of the
deck surface 102 and the height of the edge 175 are both about 1.5
inches. Accordingly, the total profile height of the test pallets
is about 3 inches to about 3.5 inches, which is less than the total
profile height of similarly-sized conventional plastic pallets and
the total profile height of similarly-sized conventional wood
pallets, which have total profile heights of about 4.5 inches and
about 6 inches, respectively.
[0092] While this invention has been described in conjunction with
the exemplary embodiments outlined above, various alternatives,
modifications, variations, improvements and/or substantial
equivalents, whether known or that are or may be presently
foreseen, may become apparent to those having at least ordinary
skill in the art. Accordingly, the exemplary embodiments of the
invention, as set forth above, are intended to be illustrative, not
limiting. Various changes may be made without departing from the
spirit or scope of the invention. Therefore, the invention is
intended to embrace all known or earlier developed alternatives,
modifications, variations, improvements and/or substantial
equivalents.
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