U.S. patent number 3,867,806 [Application Number 05/347,873] was granted by the patent office on 1975-02-25 for process of making a stretched-wrapped package.
This patent grant is currently assigned to Lantech, Inc.. Invention is credited to Patrick R. Lancaster, III, William G. Lancaster.
United States Patent |
3,867,806 |
Lancaster, III , et
al. |
February 25, 1975 |
PROCESS OF MAKING A STRETCHED-WRAPPED PACKAGE
Abstract
This invention provides a process for making a unitary package
which comprises a load that has a band formed of plural layers of a
stretched material wrapped around it. Basically the process
comprises the steps of: placing a load on a support; locating a
rolled-up sheet of stretchable material on dispenser means adjacent
to the support; withdrawing a leading edge of the material from the
dispenser means and holding that leading edge against the load;
initiating substantially unrestricted relative movement between the
support and dispenser means to cause a sufficient amount of the
material to overwrap at least a part of the load; subsequently
continuing the relative movement but restricting it such that the
material will then be stretched and causing a sufficient amount of
the stretched material to be dispensed from the dispenser means to
provide a band comprising plural layers of the material around the
load; and fastening the trailing edge of the dispensed stretched
material to at least one of the previously dispensed band-forming
layers. The present invention is also directed toward a product
that is produced by this process and to certain apparatus which can
be utilized to perform this process.
Inventors: |
Lancaster, III; Patrick R.
(Louisville, KY), Lancaster; William G. (Louisville,
KY) |
Assignee: |
Lantech, Inc. (Louisville,
KY)
|
Family
ID: |
23365646 |
Appl.
No.: |
05/347,873 |
Filed: |
April 4, 1973 |
Current U.S.
Class: |
53/441;
53/465 |
Current CPC
Class: |
B65B
11/045 (20130101); B65B 11/585 (20130101) |
Current International
Class: |
B65B
11/04 (20060101); B65B 11/00 (20060101); B65B
11/58 (20060101); B65B 11/02 (20060101); B65b
005/06 () |
Field of
Search: |
;53/27,30,33,184,211,212,214 ;242/75.43 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: McGehee; Travis S.
Assistant Examiner: Sipos; John
Attorney, Agent or Firm: O'Donnell; Harry B.
Claims
We claim:
1. A process of making a unitary package, comprising the steps
of:
a. placing a load on a support;
b. locating a rolled-up sheet of a stretchable material on
dispenser means adjacent to said support;
c. withdrawing a leading edge of said material from said dispenser
means and holding said leading edge against said load;
d. initiating substantially unrestricted relative movement between
said support and said dispenser means to cause a sufficient amount
of said material to be dispensed from said dispenser means to
overwrap at least a part of said load;
e. subsequently continuing said relative movement but restricting
it such that said material will then be stretched and causing a
sufficient amount of said stretched material to be dispensed from
said dispenser means to provide a band comprising plural layers of
said material around said load; and
f. fastening the trailing edge of said stretched material to at
least one of the previously dispensed band-forming layers.
2. The invention of claim 1, further including an additional step,
performed prior to dispensing the outermost one of said layers of
said band, of overwrapping with a separate wrapper, a portion of
said load not overwrapped by said sheet of material.
3. The invention of claim 2, further including an additional step
of severing said material from said dispensing means after
completion of said step of fastening.
4. The invention of claim 1, further including an additional step
of severing said material from said dispensing means after
completion of said step of fastening.
5. The invention of claim 1, wherein said material is
heat-laminateable and said fastening is performed by heat
sealing.
6. The invention of claim 5, wherein said heat sealing provides a
plurality of fastening heat seals that are aligned at an angle with
respect to said trailing edge and are spaced apart from one
another.
7. The invention of claim 6, wherein said material comprises
polyethylene.
8. The invention of claim 1, wherein said material comprises
polyethylene.
9. The invention of claim 8, wherein said material is stretched in
an elongation range of 2 percent through 100 percent by said
restricting.
10. The invention of claim 1, wherein said material is stretched in
an elongation range of 2 percent through 100 percent by said
restricting.
Description
BACKGROUND OF THE INVENTION
This invention relates to packaging and, more particularly, to a
process for making a unitary package which comprises a load that
has a band formed of plural layers of a stretched material wrapped
around it. The present invention is also concerned with the product
produced by such a process and to certain apparatus which can be
utilized to perform the process.
In the past, various methods and apparatus have been utilized to
provide a unitary package comprising a load having at least a
portion of its surface overwrapped by a heat-shrunk material. Such
methods are commonly referred to as "shrink-palletizing" processes
and basically comprise unitization of a palletized package load by
first overwrapping it with a heat shrinkable material which is then
tightly shrunk against the package load by applying sufficient heat
to the overwrapped load to raise its temperature to the
heat-shrinking temperature of the overwrapping material. Our
co-pending, commonly assigned U.S. Patent application Ser. No.
295,532, filed Oct. 6, 1972, describes a most recent and efficient
form of such "shrink-palletizing" systems; while older forms
thereof have been described in detail in U.S. Pat. Nos. 3,514,920;
3,581,458; 3,590,549; 3,626,654; 3,640,048; 3,662,512; and
3,670,880.
While the aforedescribed "shrink-palletizing" systems have produced
a product which has been generally satisfactory, they require
heating means and, if a portion of the overwrapped package load is
removed after completion of the heating step, the remaining
portions tend to become loosened since the overwrapping material
becomes permanently set and loses its elasticity after the heating
has been performed.
Previous attempts have been made to overcome these disadvantages of
the "shrink-palletizing" systems by substituting non-heated
overwrapping systems, such as that described in U.S. Pat. No.
3,495,375 and another marketed by Arenco Machine Company, Inc., of
Teterboro, New Jersey. Such non-heated systems are commonly known
as "stretch-palletizing" systems, wherein the package load is
overwrapped by a single-layer band of stretchable material that is
held in tension around the package load but not heat-shrunk to it.
While eliminating the cost of the heating means and step and the
problems of loss of elasticity and load loosening which exist in
the "shrink-palletizing" systems, these prior art single-layer band
"stretch-palletizing" systems have several disadvantages of their
own. For one example, the trailing edge or edges of the
band-forming overwrapping material must be fin-sealed (as opposed
to lap-sealed) along substantially their entire width and this
requires elaborate clamping and sealing means. For another, tension
is not evenly applied to the material forming the overwrapping
band. And, for yet another, the sharp edges of the surface of the
overwrapped package load tend to pierce the single layer of the
tensioned wrapper band as it is dispensed therearound.
The present invention is particularly concerned with providing an
improved process for producing a unitary package, which is somewhat
similar to the aforenoted single-layer "stretch-palletizing"
systems in that it provides similar advantages over the
aforedescribed "shrink-palletizing" systems, but which also
eliminates the aforenoted problems which have heretofore plagued
the earlier forms of "stretch-palletizing" systems.
SUMMARY OF THE INVENTION
The present invention provides a process for making a unitary
package which comprises a load that has a band formed of plural
layers of a stretched material wrapped around it.
Basically the process comprises the steps of: placing a load on a
support; locating a rolled-up sheet of stretchable material on
dispenser means adjacent to the support; withdrawing a leading edge
of the material from the dispenser means and holding that leading
edge against the load; initiating substantially unrestricted
relative movement between the support and dispenser means to cause
a sufficient amount of the material to overwrap at least a part of
the load; subsequently continuing the relative movement but
restricting it such that the material will then be stretched and
causing a sufficient amount of the stretched material to be
dispensed from the dispenser means to provide a band comprising
plural layers of the material around the load; and fastening the
trailing edge of the dispensed stretched material to at least one
of the previously dispensed band-forming layers.
The present invention is also directed toward a product that is
produced by this process and to certain apparatus which can be
utilized to perform this process.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated in the accompanying drawings
wherein:
FIG. 1 is a somewhat schematic partly broken elevational
perspective view showing a presently preferred form of apparatus
that can be utilized in performing the novel process of the present
invention to produce its novel unitary package, which comprises a
load that has a band formed of plural layers of a stretched
material wrapped around it, and illustrates the apparatus just
following completion of the process;
FIG. 2 is a greatly enlarged fragmentary elevational view showing
in detail the construction of the presently preferred forms of the
overwrapping film dispenser means, restricting means for causing
stretching of the dispensed film, control means for selectively
adjusting the restricting means and cutter means for severing the
dispensed material from the dispenser means of the apparatus shown
in FIG. 1;
FIG. 3 is a fragmentary sectional view taken along line 3--3 of
FIG. 2;
FIG. 4 is a schematic top plan view of the apparatus of FIG. 1
illustrating it in a first condition of operation;
FIG. 5 is a view similar to that shown in FIG. 4, but showing the
apparatus in another condition of operation;
FIG. 6 is a view similar to that shown in FIGS. 4 and 5, but
showing the apparatus in yet another condition of operation;
FIG. 7 is a greatly enlarged fragmentary sectional view taken along
line 7--7 of FIG. 7;
FIG. 8 is a greatly enlarged fragmentary sectional view taken along
line 8--8 of FIG. 5; and
FIG. 9 is a greatly enlarged fragmentary sectional view taken along
line 9--9 of FIG. 6.
DETAILED DESCRIPTION
Referring now to the drawings and more particularly to FIG. 1
thereof, there is illustrated, with parts broken away for purposes
of illustration, a typical product, a unitary package 10, which can
be produced in accordance with the novel process that is provided
in accordance with the present invention. While it should be
understood that various means could be employed, FIGS. 1-9 of the
drawings illustrate a form of apparatus 11 that has been used with
good results in carrying out the novel process of the present
invention to produce the product 10.
As further shown in FIG. 1, the product 10 comprises a palletized
load of plural boxes 12 built upon a skid 13 and has its generally
vertically arranged portion overwrapped by a band 14 formed of
plural layers of a stretched sheet of stretchable material 15
wherein the trailing edge 16 of the stretched material 15 is
fastened to at least one of the previously wrapped band-forming
layers of the material 15. Preferably, the material 15 is of a type
that is heat laminateable and this fastening is performed by heat
sealing means 17a (FIG. 6) which provides a plurality of fastening
heat seals 17 that are aligned at an angle with respect to the
trailing edge 16 of the sheet of material 15 and are spaced apart
from one another.
As illustrated in FIGS. 1-9, the presently preferred form of
apparatus 11 that can be employed to perform the process of the
present invention to produce the product 10 basically includes a
support means 18 for supporting the package load 12; dispenser
means 19 for locating a rolled-up sheet of the material 15 for
movement relative to the support means 18; drive means 20 for
initiating substantially unrestricted relative movement between the
support 18 and dispenser means 19 to cause a sufficient amount of
the material 15 to be dispensed from the dispenser means 19
overwrap at least a part of the load 12 (FIG. 4); and restricting
means 21, such as a brake best shown schematically in FIGS. 4-6 for
restricting continuation of the relative movement such that the
material 15 will then be stretched (FIG. 6) but permitting a
sufficient amount of the stretched material 15 to be dispensed from
the dispenser means 19 to provide the band 14 comprising plural
layers of the material 15 around the load 12 (FIGS. 1, 6 and
9).
As best shown in FIGS. 1 and 4, the support means 18 preferably
comprises a generally horizontally arranged platform 22 which can
support the skid 13 for rotary movement about a generally
vertically arranged axis. As schematically illustrated in FIG. 4,
the platform 22 is supported on a vertical axle 23 journaled in a
bearing 24 centrally located in a base 25 for the support means 18
and is suitably interconnected to the drive means 20, which can
comprise a rotary electric motor 26 or other suitable means, for
substantially unrestricted rotary movement around the generally
vertical axis of the axle 23 (in a clockwise direction as viewed in
FIGS. 4-6).
And, as best illustrated in FIGS. 1-6, the dispenser means 19
comprises a generally vertically arranged member or shaft 27 that
is mounted on a base frame 28 located adjacent to the support means
20 for substantially unrestricted rotary movement relative thereto
about a generally vertical axis. The upper end of this shaft 27
removably receives the lower end of and generally vertically
supports a rolled-up sheet of the stretchable material 15, while
the upper end of the rolled-up sheet is rotatably journaled by an
upper journal member 29 which is mounted for slidable vertical
movement relative to the base frame 28. This illustrated
construction provides the dispenser means 19 with height adjustable
means for mounting overwrapping material of various widths to thus
accomodate overwrapping of package loads 12 of various heights.
While it should be understood that various other substantially
equivalent means could be substituted, such as clutch means, etc.,
the presently preferred form of the restricting means 21 that are
employed in the apparatus 11 comprise brake means which are
provided adjacent the lower end of the dispenser means rotary shaft
27. As best shown in FIGS. 4-6, these illustrated restricting means
21 comprise a brake drum 30 which is fixed on the lower end of the
dispenser means shaft 27 for rotation therewith and that can be
engaged and disengaged by a brake shoe 31 which is carried by a
brake lever 32 that is pivotally mounted to the dispenser means
frame 28. As shown, the brake shoe 31 that is carried by the lever
32 is yieldably urged out of engagement with the brake drum 30 by a
first tension spring 33 (FIGURE 4) to thus permit substantially
unrestricted rotary movement of the dispenser means shaft 27.
However, the yieldably urging of this first spring 33 can be
overcome and the brake lever 32 can be pivoted to engage the brake
shoe 31 carried by it with the brake drum 30 through movement of a
cable 34 which has one of its ends connected to the pivoted brake
lever 32. The brake cable 34 has its other end connected to a brake
operating arm 35 that is pivotally mounted with respect to the
dispenser means frame 28. The brake cable operating arm 35 is, in
turn, yieldably urged by a second tension spring 36 in a direction
causing the brake cable 34 to move the brake lever 32 with
sufficient force to overcome the urging of the first spring 33 and
thus cause engagement of the lever-carried brake shoe 31 with the
brake drum 30.
As further shown, this second tension spring 36 is connected
between the dispenser frame 28 and the brake cable operating arm 35
by adjustable control means, such as the illustrated jack screw 37
and wire 38 and pulley 39 arragement, whereby the brake engaging
counter-force which it provides with respect to the brake
disengaging force of the first spring 33 can be readily adjusted.
As further illustrated, a brake release device 40 is also pivotally
mounted to the dispenser frame 28 which can be releasably engaged
with the brake cable operating arm 35 to completely overcome the
counter of the second spring 36 and allow the first spring 33 to
fully release the lever-carried brake shoe 32 from engagement with
the brake drum 30 (FIG. 4 ).
However, it should be understood that barring engagement of the
brake release device 40 with the brake cable operating arm 35, as
shown in FIG. 4, or the exertion of some other releasing force
thereupon, the second spring 36 will exert sufficient force to
overcome that provided by the first spring 33 and the brake shoe 32
and drum 30 will remain engaged and movement of the dispenser
roller shaft 27 will consequently be so restricted, as shown in
FIGS. 5 and 6. 4).
In particular accordance with the present invention, the brake
cable operating arm 35 rotatably journals a generally vertically
arranged roller 41 over which the leading edge of the rolled-up
sheet of material 15 can be first threaded prior to its engagement
with the package load 12 at the commencement of the process of the
present invention. And, during the initial part of the process of
the present invention, the brake or restricting means release
device 40 is preferably engaged with the brake cable operating arm
35 as shown in FIG. 4, to thus permit substantially unrestricted
relative movement between the support 18 and dispenser 19 means
upon energization of the drive means 20. However, once a portion of
the package load 12 has been overwrapped, the brake release device
40 is pivoted, as shown in FIG. 5, out of engagement with the brake
cable operating arm 35 and continued operation of the drive means
20 will cause relative movement between the support 18 and
dispenser 19 means only when the pull of the drive means 20 as
exerted through the portion of the dispensed sheet 15 passing over
the brake cable operating arm roller 41 is sufficient to partially
overcome the counter-force of the second spring 36 and thus permit
sufficient movement of the wire 38, arm 35, cable 34 and lever 32
to allow the first spring 33 to partially release the brake shoe 31
from engagement with the dispenser shaft-carried brake drum 30.
This restriction of relative movement by the restricting means 21
will, of course, cause the dispensed sheet of material 15 to then
be stretched.
While it should be understood that various stretchable materials
may be employed for the sheet of overwrapping material 15, good
results can be obtained in accordance with the present invention by
employing a polyethylene film having thickness in a range between
0.00075 and 0.004 inches and a specific gravity in a range from
0.915 through 0.922 which can be stretched in an elongation range
of from 2 percent through 100 percent under from 600 to 2,000 P.S.I
of force. And, while it should be similarly understood that various
forms of equipment can be utilized for the heat-sealing means 17a
(FIG. 6) to perform the fastening step without departing from the
true spirit and scope of the present invention, good results have
been obtained by employing an inexpensive commercially available,
electrically-powered hand-size heat sealer when the aforedescribed
polyethylene film was utilized for the material 15. It should also
be understood that this fastening might be accomplished other than
by heat sealing, as by use of an adhesive or mechanical means, such
as staples and the like, or other forms of fastening means.
Basically, the novel process that is provided in accordance with
the present invention comprises the steps of: placing a load on a
support; locating a rolled-up sheet of stretchable material on
dispenser means adjacent to the support; withdrawing a leading edge
of the material from the dispenser means and holding that leading
edge against the load; initiating substantially unrestricted
relative movement between the support and dispenser means to cause
a sufficient amount of the material to overwrap at least a part of
the load; subsequently continuing the relative movement but
restricting it such that the material will then be stretched and
causing a sufficient amount of the stretched material to be
dispensed from the dispenser means to provide a band comprising
plural layers of the material around the load; and fastening the
trailing edge of the dispensed stretched material to at least one
of the previously dispensed band-forming layers.
To produce a product, such as the illustrated unitary package 10,
by the novel process of the present invention with the illustrated
apparatus 11, an operator first mounts a rolled-up sheet of the
material 15 having a width sufficient to cover at least the
vertical portion of the package load 12 on the shaft 27 and upper
journal member 29 of the dispenser means 19.
Next, the operator utilizes a fork-lift truck or other suitable
conveyor means to place the package load 12 and its skid 13 atop
the platform 22 of the support means 18 to align its center
generally over that of the platform axle 23.
Then, the operator moves the brake release device 40 into
engagement with the brake cable operating arm 35 as shown in solid
lines in FIG. 4 and in shadow lines in FIG. 3 to fully release the
restricting means 21 and permit substantially unrestricted rotary
movement of the dispenser means shaft 27 and upper journal member
29.
Next, the operator withdraws the leading edge of the rolled-up
sheet of the material 15 from the dispenser means 19 and, having
first threaded it over the brake cable operating arm roller 41 as
shown in solid lines in FIG. 4 and in shadow lines in FIG. 3, holds
that leading edge against the vertical surface of the package load
12 either manually or with fastener means (not shown).
Then, the operator energizes the drive means 20 in a well-known
manner through closure of switch means (not shown) which cause the
drive means motor 26 to initiate rotation of the support means
platform 22 and the package load 12 and skid 13 carried by it about
the generally vertical axis of the platform shaft 23. This, in
turn, causes substantially unrestricted relative movement between
the support means 18 and the dispenser means 19 such that a
sufficient amount of the rolled-up material 15 will be unwound or
dispensed from the dispenser means 19 through the substantially
unrestricted rotary movement of the support means platform 22 and
the dispenser means shaft 27 and upper journal member 29 to
overwrap at least a part of the package load 12. As illustrated,
this substantially unrestricted movement is allowed to continue
approximately one revolution of the support platform 22 and the
package load 12 carried by it whereby a band comprising a single
unstretched layer of the material 15 is overwrapped around the
generally vertically arranged portion of the package load 12.
Now, as best shown in FIGS. 5 and 8, the operator can with a
separate wrapper, such as an overcapping sheet 43, overwrap a
portion of the package load 12 (the top of the package load 12 as
illustrated) not previously overwrapped by the sheet of material
15.
Next, the operator pivots the brake release device 40 out of
engagement with the brake cable operating arm 35, as shown in solid
lines in FIGS. 3, 5 and 6, activating the restricting means 21 as
previously described above, and continues energization of the drive
means 20 and thus provides continuous but now restricted relative
movement between the support 18 and dispenser means 19 such that
the dispensed sheet material 15 will then be stretched and causing
a sufficient amount of the stretched material 15 to be dispensed
from the dispenser means 19 to provide the band 14 which comprises
plural layers, including at least one outer stretched layer, as
shown in FIG. 1, of the material 15 around the package load 12.
Then, as best shown in FIGS. 1 and 6, while maintaining the
stretching of the dispensed sheet 15 through continued energization
of the drive means 20, the operator fastens the trailing edge 16 of
the stretched dispenser material 15 in an overlapping seal to at
least one of the previously dispensed band-forming layers. As
illustrated, this fastening is preferably performed by heat
sealing, assuming the material is a heat laminateable material such
as polyethylene, and the heat-sealing step is performed manually by
the operator with means such as the illustrated heat-sealing device
17a to provide the plurality of fastening heat seals 17 that are
aligned at an angle (approximately a 90 degree angle) with respect
to the width of the trailing edge of the dispensed material sheet
15 and are spaced apart from one another therealong.
Next, upon completion of this fastening step, the operator now
severs the overwrapped package from the dispenser means, as by
employing the illustrated drop-knife cutter means 44 which is
preferably mounted adjacent the support means 19 and finally
de-energizes the drive means 20. The novel overwrapped product 10
(FIG. 1) that is produced by the novel process of the present
invention can now be removed from the support means platform 22 by
a fork-lift or other suitable conveyor means.
The operator can selectively adjust the restrictive effect of the
restricting means 21 through operation of the jack screw 37 of the
aforedescribed control means to thereby selectively alter the
degree of elongation of the stretched dispensed material 15.
It should be apparent that while there has been described what is
presently considered to be a presently preferred form of the
present invention in accordance with the Patent Statues, changes
may be made in the disclosed process and product produced thereby
without departing from the true spirit and scope of this
invention.
For example, other equivalent forms of apparatus might be
substituted for the illustrated apparatus 11. Various materials
might be used for the material 15, so long as they are of a type
that is stretchable. And, the optional overcapping sheet 43 could
be installed either before or after the actuation of the
restricting means 21 to cause the stretching of the sheet 15; it
being necessary only that such optional installation of the
separate overcapping sheet 43 be performed prior to the dispensing
of the outermost one of the plural layers of the sheet 15 which
form the multi-layered band 14. It is, therefore, intended that the
appended claims shall cover such modifications and applications
that may not depart from the true spirit and scope of the present
invention.
* * * * *