U.S. patent number 3,788,462 [Application Number 05/118,664] was granted by the patent office on 1974-01-29 for unitized palletless load.
This patent grant is currently assigned to Owens-Illinois, Inc.. Invention is credited to John H. Meincer.
United States Patent |
3,788,462 |
Meincer |
January 29, 1974 |
UNITIZED PALLETLESS LOAD
Abstract
A unitized, palletless plurality of articles grouped and
arranged in transportable or storable units. A first layer of
articles is built atop a strip of heat-shrinkable thermoplastic
material. Subsequent layers, all of an equal circumference and of
greater circumference than the first layer, are built atop the
first layer. At least two free ends of the bottommost strip are
tucked beneath one of the subsequent layers. When the layers have
reached the desired height, a heat-shrinkable thermoplastic
material, preferably in the form of a bag, is placed around the
entire load. The load, so enclosed, is exposed to heat to cause the
material to shrink, also causing the bottom strip to fuse into the
overall wrapping. The result is a tightly confined unitized and
stabilized load suitable for storage or shipment. The load may be
lifted and transported by a fork lift at the ledge defined by the
overhang of all of the upper layers over the first layer.
Inventors: |
Meincer; John H. (Toledo,
OH) |
Assignee: |
Owens-Illinois, Inc. (Toledo,
OH)
|
Family
ID: |
22379997 |
Appl.
No.: |
05/118,664 |
Filed: |
February 25, 1971 |
Current U.S.
Class: |
206/595; 53/442;
206/597; 53/399; 206/497; 414/802 |
Current CPC
Class: |
B65D
71/0088 (20130101); B65D 2571/00092 (20130101); B65D
2571/00067 (20130101); B65D 2571/00024 (20130101); B65D
2571/00061 (20130101) |
Current International
Class: |
B65D
71/00 (20060101); B65d 065/20 (); B65d 071/00 ();
B65d 085/62 () |
Field of
Search: |
;206/65S,65B,45.33
;53/30,184 ;229/DIG.12,87R ;214/1.5R |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Dixson, Jr.; William T.
Attorney, Agent or Firm: McLary; Steve M. Holler; E. J.
Claims
I claim:
1. The method of forming a unitized, stable load of a plurality of
objects comprising, placing at least one elongated sheet of
thermoplastic material on a support, assembling a first layer of
objects on said sheet in a regular pattern, said sheet having ends
thereof which extend beyond the perimeter of said layer, assembling
a second layer of objects on said first layer, said second layer
having a perimeter greater than said first layer to provide
overhangs at opposed sides thereof, assembling a plurality of
additional layers having a perimeter equal to that of said second
layer in overlying relation thereto to form a complete load,
enclosing the side walls of said load with a continuous sheet of
heat-shrinkable thermo-plastic material, positioning the extending
ends of said elongate sheet in contacting relation to said
continuous sheet, retaining said sheet in contacting relationship,
heat-shrinking said sheet material about said load and
simultaneously therewith fusing said enclosing material to said
first sheet to thereby form a stabilized, unitized load capable of
being handled by a fork lift engaging the overhang, and removing
said unitized load from said support.
2. The method of claim 1 further including, the step of placing an
additional elongated sheet of thermoplastic material in cross-wise,
overlying relationship to said first sheet prior to assembling said
first layer, said additional sheet having ends extending beyond the
perimeter of said first layer, positioning the ends of said second
sheet in contacting relation to said continuous sheet and retaining
said second sheet in contacting relationship.
3. The method of claim 1 further comprising, the step of placing at
least one stabilizing strip of a thermoplastic material across the
top of at least one of said additional layers prior to enclosing
and heat-shrinking, said stabilizing strip being of sufficient
length to hang vertically downward to an extent sufficient to
provide a fused connection with the enclosing material during said
heat shrinking.
4. The method of forming a unitized, stable load of a plurality of
objects comprising, placing at least one elongated sheet of
thermoplastic material on a support, assembling a first layer of
objects on said sheet in a regular pattern, said sheet having ends
thereof which extend beyond the perimeter of said layer, assembling
a second layer of objects on said first layer, said second layer
having a perimeter greater than said first layer to provide
overhangs at opposed sides thereof, assembling a plurality of
additional layers having a perimeter equal to that of said second
layer in overlying relation thereto to form a complete load,
raising the extending ends of said elongated sheet into generally
parallel relationship to the sides of said load, retaining said
ends in their raised position, enclosing the side walls of said
load with a continuous sheet of heat-shrinkable thermoplastic
material, heat-shrinking said sheet material about said load and
simultaneously therewith fusing said enclosing material to said
first sheet to thereby form a stabilized, unitized load capable of
being handled by a fork lift engaging the overhang, and removing
said unitized load from said support.
5. The method of claim 4 further including, the step of placing an
additional elongated sheet of thermoplastic material in cross-wise,
overlying relationship to said first sheet prior to assembling said
first layer, said additional sheet having ends extending beyond the
perimeter of said first layer, raising the extending ends of said
additional elongated sheet into generally parallel relationship to
the sides of said load, and retaining said ends in their raised
position.
6. The method of claim 4 further comprising, the step of placing at
least one stabilizing strip of a thermoplastic material across the
top of at least one of said additional layers prior to enclosing
and heat-shrinking, said stabilizing strip being of sufficient
length to hang vertically downward to an extent sufficient to
provide a fused connection with the enclosing material during said
heat shrinking.
7. A method for unitizing a plurality of articles into a load
suitable for storage and shipment comprising the steps of
positioning at least one strip of a heat-shrinkable thermoplastic
material of from 0.001 inch to 0.015 inch in thickness on a
suitable base, placing a first layer of articles to be unitized on
top of said strip, said strip having portions thereof extending
beyond said first layer on either side of said first layer, placing
at least one additional layer of said articles atop said first
layer, said additional layer having a perimeter greater than the
perimeter of said first layer, said additional layer being centered
with respect to said first layer, and positioned with an overhang
provided at at least two opposed sides of said first layer, raising
and placing the free ends of said strip horizontally across the top
of said additional layer, adding subsequent layers of articles
having a perimeter equal to the perimeter of said additional layer
until the desired height of load is reached, said first, additional
and subsequent layers of articles serving to define the sidewalls
of said load, enclosing at least the sidewalls of said load with a
heat-shrinkable thermoplastic material of from 0.001 inch to 0.015
inch in thickness, heat-shrinking said heat-shrinkable
thermoplastic material about said load and fusing said underlying
strip to said enclosing material, to thereby form a unitized load
capable of being handled with lifting means positioned under the
overhang, and removing said unitized load from said base for
storage or shipment independently of said base.
8. The method of claim 7 further comprising the step of placing at
least one stabilizing strip of a thermoplastic material across the
top of at least one of said additional layers prior to enclosing
and heat shrinking, said stabilizing strip being of sufficient
length to hang vertically downward to an extent sufficient to
provide a fused connection with the enclosing material during said
heat shrinking.
9. The method of claim 7, wherein said heat-shrinkable
thermoplastic material is polyethylene.
10. A unitized, palletless load of articles comprising, a stack of
articles formed of a plurality of layers of a plurality of
articles, the lowermost layer of said stack being formed of lesser
horizontal dimension than the other layers and providing access to
opposed lifting ledges, a strip of heat shrunk thermoplastic
material underlying said lowermost layer and having opposed ends
folded up and interposed said overlying layers, and a heat shrunk
thermoplastic material completely enclosing said stack of articles
and fused to said strip.
11. As an article of manufacture, a unitized palletless load of a
plurality of articles suitable for storage and shipment comprising,
a substantially rectangular first layer of said articles, a second,
substantially rectangular layer of said articles, having a
perimeter greater than that of said first layer, overlying said
first layer, a third, substantially rectangular layer of said
articles, having a perimeter substantially equal to that of said
second layer, overlying said second layer, a strip of heat shrunk
thermoplastic material underlying said first layer, extending up
the side and interposed said second and third layers, a plurality
of substantially rectangular subsequent layers of substantially
equal perimeter overlying said third layer, and a heat shrunk
thermoplastic material completely enclosing said first, second,
third and subsequent layers and fused to said underlying strip.
12. The article of manufacture as defined in claim 11 further
comprising, at least one strip of thermoplastic material laid
horizontally across the top of at least one of said subsequent
layers, having sufficient length to hang vertically at least the
height of said subsequent layer and fused to said enclosing
material.
Description
BACKGROUND OF THE INVENTION
The use of heat-shrinkable plastic films such as polyethylene and
polyvinyl chloride to stabilize and protect loads of articles,
particularly stacks of boxes, has become an important method of
material handling. Such stacks of articles are commonly referred to
in the industry as unit loads. To date, unit loads, which have been
shrink-wrapped (the term applied to loads which have been covered
with the heat-shrinkable plastic films mentioned), have been built
on pallets. Palletless loads, such as the well-known slip sheet
loads, have not been shrink-wrapped because of the problems
involved in handling such loads when encased in plastic film.
However, it is often desirable to avoid the use of pallets but
still retain the advantages of shrink-wrapped unit loads, such as
better load stability, product protection and lower cost of
stabilizing materials. That is, in some cases, loads are shipped
great distances, making return freight costs for pallets
prohibitive. Often, customers do not wish to have pallets in their
plants, while the shipper desires to have the ease of handling and
economies of unit loads inhis plant. Finally, there is frequently
an unexplained and nearly uncontrollable "shrinkage" in the
quantity of pallets returned, thus causing the shipper losses in
the cost of replacing pallets thus lost. The present invention
presents a unitized load and a method for making the same which
will give a stable, palletless unit load that may be handled in
much the same manner as a load built on a pallet, but, since the
load is palletless, without the problems attributed to shipping
unit loads with pallets.
SUMMARY OF THE INVENTION
This invention relates generally to shrink-wrapping unit loads.
More specifically, this invention relates to a palletless,
shrink-wrapped, unit load and the method for making said load.
In practicing the invention, at least one strip of a thermoplastic
material is laid on a suitable base. On this strip is built a first
layer of articles to be unitized, most commonly, multiple
individual boxes or cartons. A second layer is then built atop the
first layer, the second layer having a slightly larger perimeter
than the first layer. The difference in perimeter is equally
distributed (although, if the size of the layers, so dictate, the
overhang may be distributed over only two opposite sides of the
first layer), the second layer thus overhanging the first layer on
all four sides. Subsequent layers, of the same circumference, are
then built atop the second layer until the load is of the desired
height. The strip of heat-shrinkable material upon which the first
layer was built will be raised vertically and laid horizontally
across the top of one of the layers built on top of the first
layer. The subsequent layers will then tend to secure the strip in
position. After the load has been built to the desired height, the
entire load is covered with a heat-shrinkable thermoplastic
material. This step is accomplished most easily if the
heat-shrinkable material is in the form of a bag, although sheets
of material could be used. As a final step, the entire load is
subjected to heat sufficient to cause the overall thermoplastic
wrap to shrink and also cause the lower strip to both shrink and
fuse into the overall wrap. The result is a very stable unitized
load which does not require a pallet for handling. The load may be
picked up by inserting the forks of a fork lift truck under the
ledge defined by the overhang of the upper layers over the first
layer. The load may be handled in this manner for both storage and
shipment.
IN THE DRAWINGS
FIG. 1 is a perspective view illustrating the first step of placing
lower load strips to begin the building process;
FIG. 2 is a perspective view, similar to FIG. 1, illustrating the
building to a height of two layers;
FIG. 3 is a perspective view showing a stabilizing strip or shelf
in place on the load;
FIG. 4 is a perspective view of the completed load before the
overall plastic wrap is applied;
FIG. 5 illustrates the method of handling the completed load after
the shrinking process; and
FIG. 6 is a perspective view showing the completed load of the
invention in the form it assumes for storage or shipment.
DETAILED DESCRIPTION OF THE DRAWINGS
It should be apparent that FIGS. 1, 2, 3, 4 and 6 are a series of
views illustrating the various stages of the process of making the
palletless load of the invention. The load is built on a
conventional material handling pallet 10. The pallet 10 is used to
handle the load until the completed load has been through the final
heating process to shrink the plastic film and thus make the load
stable. Until this process is completed, the load is very unstable
and must be handled on the pallet 10. After the process, the load
is removed from the pallet 10, allowing immediate reuse of the
pallet 10. FIG. 1 illustrates how the load is begun. Two strips 12
and 14 of a thermoplastic material are laid atop the pallet 10 in
an overlying manner to form a cross having arms of substantially
equal length. While FIG. 1 illustrates the preferred embodiment of
the invention in the use of two strips 12, 14, a suitable load
could be constructed using either the strip 12 or the strip 14. A
preferred material for the strips 12, 14, is heat-shrinkable
polyethylene of from 0.002 inch to 0.005 inch in thickness.
However, any heat-shrinkable thermoplastic material of from 0.001
inch to 0.015 inch in thickness could be successfully utilized. The
length of the strips is not a critical factor, but the length of
each of the arms of the cross formed by the overlying strips 12,
14, should be greater than the height of two of the articles to be
unitized.
The objects to be unitized will most typically be boxes or cartons.
As seen in FIG. 2, a first layer 16 consisting of a plurality of
objects is assembled on the pallet 10 on top of the strips 12, 14.
A second layer 18 of a plurality of objects is then assembled atop
the first layer 16. The second layer 18 contains more of the
objects to be unitized than does the first layer 16, and,
consequently, the second layer 18 has a larger perimeter than the
first layer 16. In the preferred embodiment, as shown in FIG. 2,
the difference in perimeters is on only two sides, and is equally
distributed to form ledges 20 overhanging the first layer 16.
However, the perimeter of the second layer 18 could be larger than
that of the first layer 16 on all four sides, thereby giving four
overhanging ledges 20. As a final step in this initial portion of
the preferred load building process, the arms of the strips 12, 14,
are raised to the top of the second layer 18 and laid one atop
another as shown in FIG. 2. It should be kept in mind, however,
that the arms of the strips 12, 14, could be retained in their
raised position by means other than placing them on the second
layer and holding them in place with subsequent layers. For
example, the arms of the strips 12, 14, could be taped to the
exterior of the layers and not laid over the top of the second
layer. Furthermore, the arms of the strips 12, 14, could be left
lying flat until the completed load is ready to be enclosed with a
heat-shrinkable thermoplastic material, as discussed later. The
arms of the strips 12, 14, in that case, would be raised to the
desired vertical position and, for example, taped in place in
touching relationship with the load-enclosing wrap.
Turning now to FIG. 3, it can be seen that subsequent layers 22 are
assembled atop the second layer 18. The subsequent layers 22 are
identical in size to the second layer 18. Although a straight up
stack of objects is shown in FIG. 3, the objects could be arranged
in an interlocking pattern for additional stability. An added
measure of stability may be imparted to the completed load if a
stabilizing strip 24 is placed as shown in FIG. 3. Preferably, the
stabilizing strip 24 should be no wider than the width of a
subsequent layer 22 and should be long enough to lie completely
across the top of a subsequent layer 22 and hang down at either end
at least the height of a subsequent layer 22. Furthermore, the
strip 24, while serving as a lateral tensioning member to aid in
load stabilization, also has the function of being a shelf. It can
readily be seen that the unitized load may tend to sag in the
center when elevated as a unit. The strip 24, particularly when
several additional tiers of objects are positioned thereabove, will
serve as a shelf and transfer some of the load or weight thereabove
to the edges with the outside objects acting as columns, therefore
lessening the load concentration supported by the forks on the
center of the unitized load. The material of the stabilizing strip
24 should be the same as that of the strips 12, 14. The subsequent
layer 22 upon which the stabilizing strip 24 is placed is not
critical, but, as shown in FIG. 4, at least one subsequent layer 22
must be placed on top of the stabilizing strip 24 to hold it in
position.
With specific reference to FIG. 4, there is shown a completed load
ready to be enclosed with a heat-shrinkable thermoplastic material.
This material should be the same as that used for the strips 12,
14, and the stabilizing strip 24, although the thickness may be
varied as desired. The encapsulation or covering step is most
easily accomplished with the thermoplastic material being in the
form of a bag which can be slipped over the entire load.
Alternatively, the load could be over-wrapped with the use of
sheets of heat-shrinkable thermoplastic material. It should be kept
in mind that the load-enclosing thermoplastic material should not
be allowed to drape over the edges of the pallet 10, for reasons to
be explained later.
The pallet 10, still supporting the now covered load, is next
placed in a conventional shrink oven of a size sufficient to
receive such loads. In the oven, sufficient heat is applied to
cause the load-enclosing wrap to shrink and tightly hold the
objects making up the load. The strips 12, 14, will experience some
degree of shrinkage and thus tend to grip and hold the first and
second layers 16 and 18. In addition, the strips 12, 14, and
stabilizing strip 24 will become fused, by the heat, into the
load-enclosing wrap resulting in a strong unitized load. It is
important during the shrink process that the load-enclosing wrap
not extend over or below the edge of the pallet 10. If this occurs,
the load-enclosing wrap may shrink around and grip the edges of the
pallet 10 and cause incomplete fusion of the strips 12, 14, thereby
creating an unstable load. Furthermore, removal of the load from
the pallet 10 would be impossible without partial destruction of
the unitized load.
FIG. 5 illustrates the removal of the unitized load 26 from the
pallet 20 after the heating step. At this point, the unitized load
26 is suitable for storage or shipment and no longer needs to be
carried on the pallet 10. A commercial lift type truck 28 having
horizontally extending forks 30 would typically be utilized to move
the unitized load 26. The forks 30 may be inserted under the ledges
20, and the unitized load lifted with the ledges 20 resting on the
top of the forks 30. If care is used in this step, the forks 30
will not puncture the load-enclosing wrap. The load-enclosing wrap
maintains a certain degree of flexibility even after having been
shrunk. Consequently, the forks 30, when being lifted, will
normally force the load-enclosing wrap lying under the ledges 20
upward until the forks 30 contact the ledges 20 with the now
stretched load-enclosing wrap trapped between the ledges 20 and the
forks 30. Upon removal of the forks 30, by first lowering and then
retracting the load-enclosing wrap will return to substantially its
original shape.
FIG. 6 shows the unitized load 26 after removal from the pallet 10.
The first or bottom layer 16, the second layer 18 and subsequent
layers 22 are supported and stabilized in part by the tension
provided by the shrunk, load-enclosing wrap and in part by the
fusion of the strips 12, 14, to the load-enclosing wrap. When the
unitized load 26 is picked up using a fork lift truck 28, the
load-enclosing wrap may occasionally be torn under the ledges 20 by
the forks 30. These torn edges, designated as 32 in FIG. 6, do not
appreciably weaken the unitized load 26, and will not disturb the
inherent moisture barrier properties of the plastic strips. It
should be noted, though, that before the unitized load 26 is lifted
from the pallet 10, it is completely encapsulated. It is preferable
to use care in removing the load 26 from the pallet 10 as discussed
previously with reference to FIG. 5 to avoid the torn edges 32.
* * * * *