U.S. patent application number 12/409407 was filed with the patent office on 2009-09-24 for wrapping apparatus having top loading and threading film dispenser.
Invention is credited to Richard L. Johnson, Patrick R. Lancaster, III, Philip R. Moore, Joseph D. Norris.
Application Number | 20090235617 12/409407 |
Document ID | / |
Family ID | 40732261 |
Filed Date | 2009-09-24 |
United States Patent
Application |
20090235617 |
Kind Code |
A1 |
Moore; Philip R. ; et
al. |
September 24, 2009 |
WRAPPING APPARATUS HAVING TOP LOADING AND THREADING FILM
DISPENSER
Abstract
A film dispenser is provided, including an open top roll
carriage having a base plate on which a film dispensing assembly,
including an upstream roller and a downstream roller, may be
mounted. A film path for film traveling through the film-dispensing
assembly may be at least partially defined by a surface of the
upstream roller and a surface of the downstream roller. The film
path may be accessible via the open top of the roll carriage. The
film dispenser may also include a drive assembly for the upstream
roller and the downstream roller mounted below the base plate.
Inventors: |
Moore; Philip R.; (Mt.
Washington, KY) ; Norris; Joseph D.; (Pleasureville,
KY) ; Johnson; Richard L.; (La Grange, KY) ;
Lancaster, III; Patrick R.; (Louisville, KY) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT & DUNNER;LLP
901 NEW YORK AVENUE, NW
WASHINGTON
DC
20001-4413
US
|
Family ID: |
40732261 |
Appl. No.: |
12/409407 |
Filed: |
March 23, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61038846 |
Mar 24, 2008 |
|
|
|
Current U.S.
Class: |
53/461 ;
53/203 |
Current CPC
Class: |
B65B 2210/20 20130101;
B65B 2011/002 20130101; B65B 11/025 20130101; B65B 11/045 20130101;
B65B 11/006 20130101 |
Class at
Publication: |
53/461 ;
53/203 |
International
Class: |
B65B 11/00 20060101
B65B011/00 |
Claims
1. A film dispenser comprising: an open top roll carriage having a
base plate on which a film dispensing assembly, including an
upstream roller and a downstream roller, is mounted; and a film
path for film traveling through the film-dispensing assembly, the
film path being at least partially defined by a surface of the
upstream roller and a surface of the downstream roller, the film
path being accessible via the open top of the roll carriage; and a
drive assembly for the upstream roller and the downstream roller
mounted below the base plate.
2. The film dispenser of claim 1, wherein the upstream roller is
cantilevered from the base plate of the roll carriage.
3. The film dispenser of claim 1, wherein the downstream roller is
cantilevered from the base plate of the roll carriage.
4. The film dispenser of claim 1, wherein the roll carriage further
includes a first support connecting an upper end of the upstream
roller to the base plate of the roll carriage, and a second support
connecting an upper end of the downstream roller to an upper
portion of the roll carriage.
5. The film dispenser of claim 1, wherein the upstream roller is
supported by a first support, the first support extending in a
first direction from a fixed end to a free end, and the downstream
roller is supported by a second support, the second support
extending in a second direction from a fixed end to a free end, the
second direction substantially opposing the first direction.
6. The film dispenser of claim 1, wherein the upstream roller and
the downstream roller are coupled to a serpentine drive belt, the
serpentine drive belt being coupled to a drive means, and being
configured to rotate the upstream roller and the downstream
roller.
7. The film dispenser of claim 1, wherein the roll carriage further
includes a roll support for supporting a roll of film, the roll
support being vertically offset downward from the base plate of the
roll carriage.
8. The film dispenser of claim 7, wherein a top surface of the
roller support lies in a plane extending through a drive housing of
the drive assembly.
9. The film dispenser of claim 1, further including a selectively
tiltable film drive down roller, the selectively tiltable film
drive down roller driving the film from a first elevation to a
second elevation, lower than the first elevation, when the
selectively tiltable drive down roller is in a tilted position.
10. The film dispenser of claim 1, further including a roping
assembly, the roping assembly forming at least a portion of the
film into a cable during wrapping of the load.
11. A film dispenser comprising: a roll carriage having a base
plate on which a film dispensing assembly is mounted, and an open
top opposite the base plate; a film path for film traveling through
the film-dispensing assembly, wherein the open top includes one or
more passageways configured to receive a length of film for
insertion downward into the film path; and a drive assembly for
driving the film dispensing assembly, wherein the drive assembly is
mounted below the base plate.
12. The film dispenser of claim 11, wherein the film dispensing
assembly includes an upstream roller and a downstream roller.
13. The film dispenser of claim 12, wherein at least one of the
upstream roller and the downstream roller is cantilevered from the
base plate of the roll carriage.
14. The film dispenser of claim 12, wherein the drive assembly is
low-profile, and includes at least one sprocket, a serpentine drive
belt operatively coupled to the at least one sprocket, and a
housing.
15. The film dispenser of claim 1, wherein the roll carriage
further includes a roll support for supporting a roll of film, the
roll support being vertically offset downward from the base plate
of the roll carriage.
16. A method for wrapping a load, comprising: inserting a length of
film downward into a film path of a film dispensing assembly
mounted on a base plate of a roll carriage; providing relative
rotation between the film dispensing assembly and the load; and
driving the film dispensing assembly to dispense film for wrapping
the load using a drive assembly mounted below the base plate.
17. The method of claim 16, wherein inserting the length of film
downward includes inserting the length of film through one or more
passageways above the film dispensing assembly, wherein the one or
more passageways are configured to receive a continuous length of
film for insertion downward into the film path.
18. The method of claim 16, further including wrapping a bottom
portion of the load.
19. The method of claim 16, wherein driving the film dispensing
assembly includes rotating an upstream dispensing roller and a
downstream dispensing roller of the film dispensing assembly with
the drive assembly.
20. The method of claim 19, further including roping a portion of
the film prior to the film upstream of the upstream dispensing
roller.
Description
[0001] This application claims priority under 35 U.S.C. .sctn. 119
based on U.S. Provisional Application No. 61/038,846, filed Mar.
24, 2008, the complete disclosure of which is incorporated herein
by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to a wrapping apparatus for
wrapping a load with packaging material, and more particularly, to
a wrapping apparatus having a top load packaging material
dispenser.
BACKGROUND
[0003] Various packaging techniques have been used to build a load
of unit products and subsequently wrap them for transportation,
storage, containment and stabilization, protection and
waterproofing. Products may be stacked as a load on a pallet to
simplify handling of the products. The load is commonly wrapped
with stretch wrap packaging material. One system uses stretch
wrapping machines to stretch, dispense and wrap stretch packaging
material around a load. Stretch wrapping can be performed as an
inline, automated packaging technique that dispenses and wraps
packaging material in a stretch condition around a load to cover
and contain the load. Stretch wrapping, whether accomplished by a
turntable, rotating arm, or vertical rotating ring, typically
covers the four vertical sides of the load with a stretchable film
such as polyethylene film. In each of these arrangements, relative
rotation is provided between the load and the packaging material
dispenser to wrap packaging material about the sides of the
load.
[0004] Such a stretch wrapping apparatus performs admirably in
accomplishing its intended goal of wrapping a load with a stretched
web of film. However, the procedure of threading the film web
through the series of rollers in the film web dispenser prior to
operation of the stretch wrapping apparatus has been found to be
time consuming and difficult. Conventional stretch wrapping
apparatuses employ a film web dispenser having two closely spaced
rollers to stretch between them a web of thermoplastic stretch film
packaging material.
[0005] It is preferable that a stretch wrapping apparatus with
pre-stretch rollers have the following features. The upstream and
downstream pre-stretch rollers should be closely spaced during
operation to prevent neckdown of the film web as it is being
substantially stretched in the dispensing direction. Since the
forces exerted on a wide web of stretch film between the
pre-stretch rollers is very significant, in the order of 50 pounds
of force, the frame and the mounting of the pre-stretch rollers
should be required to be very sturdy. The surface of the
pre-stretch rollers should be covered by the stretch film over a
sufficient extent such that the stretch film does not slip on the
pre-stretch rollers. The rotational inertia of the pre-stretch
rollers should not be so high as to require excessively high power
to vary their velocity. To accommodate these requirements, a series
of idle rollers are used to support the stretch film proximate to
the pre-stretch rollers. As a result, the film web follows a
tortuous path around the closely spaced pre-stretch and idler
rollers. The downstream pre-stretch roller has a faster surface
speed than the upstream pre-stretch roller. This stretches the
packaging material between the upstream and downstream pre-stretch
rollers in the dispensing direction.
[0006] The increased numbers of rollers in the film dispenser for
pre-stretch and the close spacing of such rollers with their
effective interconnection for pre-stretching the film web prior to
dispensing the film web on the load makes it very difficult to
thread the film web through the pre-stretch portion of the film
dispenser. Before operating a stretch wrapping apparatus having
pre-stretch rollers, it is necessary to thread the stretch film
along the tortuous path. This threading operation is difficult and
time consuming since, due to the close spacing of the rollers, an
operator cannot manually carry the stretch wrap packaging material
between the rollers. Rather, the operator must feed the stretch
wrap packaging material from one side of each roller nip with one
hand and pull the stretch film from the other side of the roller
nip with the other hand. This procedure is rendered considerably
more difficult because of the large widths of the stretch wrap
packaging material which are used commercially. Such webs generally
have a width in the range of 10 to 30 inches. Other problems in
threading resulted from the fact that the operator was required to
place his fingers proximate to the nip of the rollers and blindly
feed the film from the rear of the frame which carried the rollers,
which made the threading operation difficult and more time
consuming.
[0007] This threading problem was addressed in U.S. Pat. No.
4,747,254 to Lancaster, issued May 31, 1988, and entitled "Web
Threading Device," the entire disclosure of which is incorporated
herein by reference. This earlier arrangement reduced the
difficulty of threading a web along a tortuous path by using a
retractable leader which ran generally parallel to the path of the
film web around the rollers to lead the film along the path.
However, this arrangement required the leading end of the film web
to be attached to the leader and the leader to be slowly pulled
through the tortuous path while rotating the pre-stretch rollers,
releasing the film web from the leader and retracting the
leader.
[0008] Pre-stretch roll carriages include at least two coated
pre-stretch rollers and additional rollers which are necessary for
achieving the necessary film path. The pre-stretch rollers are
mounted on shafts through bearings on each end. One end has a
sprocket or pulley for connecting the rollers to each other and to
the drive motor. The guiding rollers are also supported at both
ends. Many prior art pre-stretch roll carriages "split" either
vertically or horizontally to facilitate film threading around
these multiple rollers. Examples of such prior art can be seen in
numerous issued patents. Virtually all prior art pre-stretch roll
carriages utilize a "W" threading pattern around the pre-stretch
rollers which rotate in the same direction.
[0009] For example, a convention pre-stretch roll carriage includes
first and second upper frame portions, first and second lower frame
portions, and first and second side frame portions. The first frame
portions form a first side of a frame, and the second frame
portions form a second side of the frame. The first and second
sides of the frame are pivotable relative to one another around a
hinge. This "split frame" is necessary to permit threading of the
film between the first and second sides of the frames and the
rollers supported therein. However, splitting or opening the frame
each time a roll is loaded, or each time that threading of the film
is to be carried out, can be laborious, and can lead to increases
in machine downtime.
[0010] An attempt to simplify the threading process is exemplified
in very early pre-stretch roll carriage produced by Lantech. The
roll carriage utilized two pre-stretch rollers cantilevered and
supported only at the top of the roll carriage, such that the
bottoms of the rollers were unsupported and unconnected to any
structure. This prior art device utilized an "S" threading pattern
around the pre-stretch rollers, which rotated in opposite
directions. This roll carriage could be threaded from the bottom
without the necessity for additional idle rollers or mechanical
split of the roller supports. This design was unsuccessful due to
very significant problems in dealing with the forces exerted on the
unsupported rollers. The forces caused deformation of the rollers
and the misalignment of the gears used to maintain relative speeds
of the two pre-stretch rollers.
[0011] One way to address deformation and misalignment problems is
described in U.S. Patent Application Publication No. 2006/0254225
A1, entitled "Stretch Wrapping Apparatus Having Film Dispenser With
Pre-stretch Assembly," filed Mar. 9, 2006, and published Nov. 16,
2006, the entire disclosure of which is incorporated herein by
reference. That disclosure describes a roll carriage frame
including a drive plate, and a pre-stretch assembly including first
and downstream pre-stretch rollers. A first end of each of the
pre-stretch rollers is connected to the drive plate, while a second
end of each of the pre-stretch rollers is connected to the second
end of the other pre-stretch roller. The connection between the
second ends helps to maintain the alignment of the pre-stretch
rollers under the high forces generated during the pre-stretching
of film. A cantilevered idle roller is positioned between the
pre-stretch rollers. A space between the pre-stretch rollers and
the idle roller forms a film path that is accessible for threading
from the second ends of the pre-stretch rollers and a free end of
the idle roller.
SUMMARY
[0012] In accordance with this disclosure, embodiments of a
packaging material dispenser including a pre-stretch portion for
pre-stretching packaging material as it is dispensed is provided.
An apparatus for stretch wrapping a load including a packaging
material dispenser having a pre-stretch portion for pre-stretching
film as it is dispensed also is provided.
[0013] In accordance with this disclosure, a film dispenser is
provided. The film dispenser may include an open top roll carriage
having a base plate on which a film dispensing assembly, including
an upstream roller and a downstream roller, is mounted. A film path
for film traveling through the film-dispensing assembly may be at
least partially defined by a surface of the upstream roller and a
surface of the downstream roller. The film path may be accessible
via the open top of the roll carriage. The film dispenser may also
include a drive assembly for the upstream roller and the downstream
roller mounted below the base plate.
[0014] In accordance with another aspect of this disclosure, a film
dispenser is provided. The film dispenser may include a roll
carriage having a base plate on which a film dispensing assembly is
mounted, and an open top opposite the base plate. The film
dispenser may also include a film path for film traveling through
the film-dispensing assembly. The open top may include one or more
passageways configured to receive a length of film for insertion
downward into the film path. The film dispenser may also include a
drive assembly for driving the film dispensing assembly. The drive
assembly may be mounted below the base plate.
[0015] In accordance with yet another aspect of this disclosure, a
method for wrapping a load is provided. The method may include
inserting a length of film downward into a film path of a film
dispensing assembly mounted on a base plate of a roll carriage. The
method may also include providing relative rotation between the
film dispensing assembly and the load. The method may also include
driving the film dispensing assembly to dispense film for wrapping
the load using a drive assembly mounted below the base plate.
[0016] Additional objects and advantages of the disclosed
embodiments will be set forth in part in the description that
follows, and in part will be obvious from the description, or may
be learned by practice of the embodiments. The objects and
advantages of the embodiments may be realized and attained by means
of the elements and combinations particularly pointed out in the
appended claims.
[0017] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only and are not restrictive of the features
claimed.
[0018] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate embodiments of
the disclosure and together with the description, serve to explain
the principles of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is an isometric view of a rotating arm of a wrapping
apparatus and shows an embodiment of a packaging material dispenser
mounted on the arm, according to an aspect of the disclosure;
[0020] FIG. 2 is an enlarged isometric view of the packaging
material dispenser of FIG. 1;
[0021] FIG. 3 is a top view of the packaging material dispenser of
FIG. 2;
[0022] FIG. 4 is a bottom view of the packaging material dispenser
of FIG. 2;
[0023] FIG. 5 is a front view of the packaging material dispenser
of FIG. 2;
[0024] FIG. 6 is a side view of the packaging material dispenser of
FIG. 2;
[0025] FIG. 7 is an isometric view of the packaging material
dispenser of FIG. 2 from a different angle;
[0026] FIG. 8 is an isometric view of another embodiment of a
packaging material dispenser, according to an aspect of the
disclosure;
[0027] FIG. 9 is a top view of the packaging material dispenser of
FIG. 8;
[0028] FIG. 10 is a front view of the packaging material dispenser
of FIG. 8; and
[0029] FIG. 11 is a side view of the packaging material dispenser
of FIG. 8.
DETAILED DESCRIPTION
[0030] Reference will now be made to the present exemplary
embodiments of the disclosure, examples of which are illustrated in
the accompanying drawings. Wherever possible, the same reference
numbers will be used throughout the drawings to refer to the same
or like parts.
[0031] In accordance with the present disclosure, embodiments of an
apparatus are provided, the apparatus being provided for wrapping a
load with packaging material. The apparatus includes a packaging
material dispenser having a pre-stretch assembly configured to
pre-stretch the packaging material, and means for providing
relative rotation between a load and the dispenser to wrap the
pre-stretched packaging material around the load. The means may
include a horizontal rotatable ring assembly, a vertical rotatable
ring assembly, a rotatable turntable assembly, or a rotating arm
assembly. The rotatable turntable assembly may include a
low-profile turntable. As used herein and generally understood in
the art, a low profile turntable is a rotatable turntable having a
load support surface that is less than or equal to 3 inches above a
floor surface supporting the turntable.
[0032] As embodied herein and shown in FIGS. 1-7, a stretch
wrapping apparatus (not shown) includes a packaging material
dispenser 100. Packaging material dispenser 100 may dispense a
sheet of packaging material 102 in a web form. Packaging material
dispenser 100 may include a roll carriage 104. Packaging material
dispenser 100 may contain a roll 106 of packaging material 102 to
be dispensed. A roll support 108 may be mounted on roll carriage
104 for this purpose. Roll support 108 may be constructed to
rotatably support roll 106 as packaging material 102 unwinds,
moving from roll 106 to a pre-stretch assembly 110.
[0033] In one embodiment, roll support 108 may include a
cylindrical member 112 extending vertically therefrom, cylindrical
member 112 being sized to be received within an aperture 114
extending axially through the center of roll 106. Roll 106 may
rotate freely about cylindrical member 112 when packaging material
102 is being dispensed. Roll support 108 may be top-loaded, such
that roll 106 may be loaded into packaging material dispenser 100
from above packaging material dispenser 100 by sliding roll 106
over a free end of cylindrical member 112. Roll support 108 may
support a bottom end of roll 106 once roll 106 is loaded. It is
also contemplated that roll support 108 may be offset vertically
from roll carriage 104, to assist with roping a portion of
packaging material 102.
[0034] In an exemplary embodiment, stretch wrap packaging material
is used, however, various other packaging materials such as
netting, strapping, banding, or tape can be used as well. As used
herein, the terms "packaging material," "film," "web," and "film
web" are interchangeable.
[0035] As embodied in FIGS. 1-7, packaging material dispenser 100
may include pre-stretch assembly 110. Pre-stretch assembly 110 may
include an upstream pre-stretch roller 118 and a downstream
pre-stretch roller 120. "Upstream" and "downstream," as used in
this application, are intended to define the direction of movement
relative to the flow of packaging material 102 from packaging
material dispenser 100. Thus, since packaging material 102 flows
from packaging material dispenser 100, movement toward packaging
material dispenser 100 and against the flow of packaging material
102 from packaging material dispenser 100 is defined as "upstream,"
and movement away from packaging material dispenser 100 and with
the flow of packaging material 102 from packaging material
dispenser 100 is defined as "downstream." Upstream pre-stretch
roller 118 and/or downstream pre-stretch roller 120 may be
connected to a power source (not shown), such as a drive motor;
however, they do not need to be, and upstream pre-stretch roller
118 and/or downstream pre-stretch roller 120 therefore may be
powered or unpowered.
[0036] Upstream pre-stretch roller 118 and downstream pre-stretch
roller 120 may be the same size, and each may have, for example, an
outer diameter of approximately 2.5 inches. Alternatively, upstream
pre-stretch roller 118 and downstream pre-stretch roller 120 may
have different sizes, as shown in FIGS. 1-3, 5, and 7. Each of
upstream pre-stretch roller 118 and downstream pre-stretch roller
120 may have a sufficient length to carry a twenty (20) inch wide
web of packaging material 102 along their working lengths. In one
exemplary embodiment, rollers used for conventional conveyors were
used to form upstream pre-stretch roller 118 and downstream
pre-stretch roller 120.
[0037] As shown in FIGS. 2, 5, and 6, upstream pre-stretch roller
118 and downstream pre-stretch roller 120 may be mounted on shafts
122 and 124, respectively, which may be hex shafts. Bearings 126,
128, 130, and 132, for supporting shafts 122 and 124, may be
press-fit or welded into each end of upstream pre-stretch roller
118 and downstream pre-stretch roller 120, and shafts 122 and 124
may be placed therethrough, such that shafts 122 and 124 may be
centrally and axially mounted through the lengths of upstream
pre-stretch roller 118 and downstream pre-stretch roller 120.
Shafts 122 and 124 may act as the rotational axes of upstream
pre-stretch roller 118 and downstream pre-stretch roller 120.
Upstream pre-stretch roller 118 and downstream pre-stretch roller
120 may be cantilevered rollers, in that a first end of each of
shafts 122 and 124 may be fixed to or supported by a base plate of
roll carriage 104, while a second end of each of shafts 122 and 123
may be unsupported, or supported by first and second supports 134
and 136. In the latter case, shafts 122 and 123 are supported in
such a way as to provide a film path for packaging material 102 to
be brought into engagement with upstream pre-stretch roller 118 and
downstream pre-stretch roller 120 that is freely accessible from
above upstream pre-stretch roller 118 and downstream pre-stretch
roller 120 despite the supports.
[0038] As embodied in FIGS. 4 and 5, a sprocket 138 may be mounted
on/attached to upstream pre-stretch roller 118, and similarly, a
sprocket 140 may be mounted on/attached to downstream pre-stretch
roller 120. Sprockets 138 and 140 may be housed in a drive housing
142 below roll carriage 104. This creates a low-profile drive
design, which allows packaging material dispenser 100 to move
through a wide range of vertical positions. Additionally,
positioning roll carriage 104 above drive housing 142 allows roll
carriage 104 to be used to prevent debris from entering into drive
housing 142.
[0039] Upstream pre-stretch roller 118 and downstream pre-stretch
roller 120 (and sprockets 138 and 140) may be connected to each
other through a drive belt 144, and also to a drive motor (not
shown). Drive belt 144 may include, for example, a belt, a chain, a
cable, one or more gears, and/or any other suitable connection. As
shown in FIGS. 4-6, drive belt 144 may be looped around sprockets
138 and 140, with one side of drive belt 144 engaging sprocket 138,
and another side of drive belt 144 engaging sprocket 140. As a
result of this arrangement, upstream pre-stretch roller 118 and
downstream pre-stretch roller 120 rotate in opposite directions.
Sprockets 138 and 140 may be selected to produce a desired level of
pre-stretch in packaging material 102. For example, sprockets 138
and 140 may be selected such that pre-stretch assembly 110 may
maintain a surface speed of downstream pre-stretch roller 120 at a
speed that is faster than the speed of upstream pre-stretch roller
118, to stretch packaging material 102 between upstream pre-stretch
roller 118 and downstream pre-stretch roller 120. It is
contemplated that a clutch mechanism (not shown) may be provided to
allow an operator to manually rotate upstream pre-stretch roller
118 and/or downstream pre-stretch roller 120, when the drive motor
is not running.
[0040] Positioning the low-profile drive components, such as drive
housing 142, sprockets 138 and 140, and drive belt 144 below roll
carriage 104 allows the top of roll carriage 104 to be open, thus
making the film path freely accessible from above upstream
pre-stretch roller 118 and downstream pre-strech roller 120.
Attempting to use conventional drive components to provide the open
top, instead of the low-profile drive components, may not be
feasible for a few reasons.
[0041] Impacts between bottom-mounted drive components and an
object, such as, for example, the ground, a conveyor, or a machine
part, may cause damage, resulting in machine downtime. Thus, a
clearance must be maintained between the drive components and the
object, so that impacts can be avoided. Providing that clearance
requires moving the drive components vertically higher relative to
a load wrapping surface to provide a clearance distance between the
drive components and the object. The packaging material dispensing
components on the roll carriage, being positioned above the drive
components, must also be moved vertically higher by at least the
sum of the clearance distance and the thickness of the drive
components. The thicker the drive components, the farther away the
packaging material dispensing components are from the load wrapping
surface.
[0042] If the packaging material dispensing components are too high
relative to the load wrapping surface, they may have difficulty
wrapping the bottom surfaces of a load on the load wrapping
surface. Even greater difficulties arise if roping assemblies are
used to rope up the packaging material before it reaches the load,
since roping assemblies may drive the packaging material even
higher away from the load wrapping surface. While the use of drive
down rollers may help drive the packaging material downward, its
capacity to drive down has a limit. When that limit is exceeded, it
may not be able to drive the packaging material down any further,
or may fail to operate in a desired manner.
[0043] One way to avoid such problems associated with
bottom-mounted drive components is by eliminating mechanical drive
components, so that packaging material dispensing rollers mounted
on the roll carriage are driven by separate motors controlled by a
microprocessor unit. Such an arrangement, however, would increase
the complexity and cost of a system.
[0044] The overall vertical thickness of low-profile drive
components, such as drive housing 142, sprockets 138 and 140, and
drive belt 144, allows those components to be mounted below roll
carriage 104 (enabling the open top), while avoiding the
above-described drawbacks. This is because the vertical thickness
of the low-profile drive components is less than that of
conventional components. Thus, packaging material 102 can be
dispensed at a height closer to the bottom surfaces of a load than
would be possible using conventional components. In addition,
offsetting the height of roll support 108 relative to roll carriage
104 helps to compensate for the vertical thicknesses of drive
housing 142, sprockets 138 and 140, and drive belt 144.
[0045] As embodied in FIGS. 1-3 and 5-7, first and second supports
134 and 136 may extend from roll carriage 104, or from any other
suitable structure that is fixed relative to roll carriage 104. In
one embodiment, first support 134 may include a bent plate or
bracket with a fixed end coupled to a surface on or near an upper
portion of roll carriage 104, and a free end configured to receive
shaft 122; and second support 136 may include a vertical support
146 coupled to and extending from the base plate of roll carriage
104, and a horizontal support 148 having a fixed end coupled to
vertical support 146. A free end of horizontal support 148 may be
configured to receive shaft 124. Mounting the first ends of shafts
122 and 124 to roll carriage 104, and providing first and second
supports 134 and 136 to support the second ends of shafts 122 and
124, may help to ensure that upstream pre-stretch roller 118 and
downstream pre-stretch roller 120 maintain their alignment even
under high forces that may be generated during pre-stretching of
packaging material 102. This design may also permit easy threading
of packaging material fully around upstream pre-stretch roller 118,
downstream pre-stretch roller 120, an upstream idle roller 150, a
first downstream idle roller 152, a second downstream idle roller
154, and a third downstream idle roller.
[0046] Upstream idle roller 150, first downstream idle roller 152,
second downstream idle roller 154, and third downstream idle
roller, may each be cantilevered from the base plate of roll
carriage 104, as shown in FIGS. 1-7. Any or all of upstream idle
roller 150, first downstream idle roller 152, second downstream
idle roller 154, and third downstream idle roller 156 may be the
same diameter as or smaller in diameter than upstream pre-stretch
roller 118 or downstream pre-stretch roller 120. Upstream idle
roller 150, first downstream idle roller 152, second downstream
idle roller 154, and third downstream idle roller 156 may be coated
or uncoated. As with upstream pre-stretch roller 118 and downstream
pre-stretch roller 120, upstream idle roller 150, first downstream
idle roller 152, second downstream idle roller 154, and third
downstream idle roller 156, should have a sufficient length to
carry a twenty (20) inch wide web of packaging material 102 along
their working lengths. It is contemplated that upstream idle roller
150 and first downstream idle roller 152 may be cantilevered
rollers, in that upstream idle roller 150 and first downstream idle
roller 152 may be supported at a first lower end by roll carriage
104, but may not be supported at a second upper end, opposite the
first lower end, by additional support structure. This arrangement
allows packaging material 102 to be easily threaded through
pre-stretch assembly 110 from the open top of roll carriage 104.
Second downstream idle roller 154 and third downstream idle roller
156 may be supported on one or both ends by other structures in
packaging material dispenser 100.
[0047] Third downstream idle roller 156 may be selectively tiltable
from the vertical position shown in FIGS. 1-5 and 7, to a tilted
position, such that an angle is formed between the longitudinal
axis of third downstream idle roller 156 in the vertical position,
and the longitudinal axis of third downstream idle roller 156 in
the tilted position. Third downstream idle roller 156 may be
actuated into a tilted position, thus driving down packaging
material 102 from a first elevation to a second elevation, lower
than the first elevation, before applying packaging material 102 to
the load being wrapped. By driving down packaging material 102,
third downstream idle roller 156 may position at least a portion of
packaging material 102 at an elevation lower than the bottom of a
load and the top of a pallet supporting the load, thus helping to
secure the load to the pallet. Thus, packaging material dispenser
100 does not have travel as low vertically to secure the load to
the pallet, which may be beneficial, since drive housing 142 should
be kept above the ground or any other support surfaces. One example
of how third downstream idle roller 156 can be actuated into the
tilted position can be found in U.S. Patent Application Publication
No. 2007/0209324 A1, entitled "Method and Apparatus for Securing a
Load to a Pallet With a Roped Film Web," filed Feb. 23, 2007, and
published Sep. 13, 2007, the entire disclosure of which is
incorporated herein by reference.
[0048] A film path is defined by and between the surfaces of
upstream pre-stretch roller 118, downstream pre-stretch roller 120,
upstream idle roller 150, first downstream idle roller 152, second
downstream idle roller 154, and third downstream idle roller 156.
The film path is easily accessible via the top of pre-stretch
assembly 110, as shown in FIGS. 1-3 and 7. A rope of packaging
material 102 may be pulled from roll 106, around upstream idle
roller 150, between upstream idle roller 150 and upstream
pre-stretch roller 118, around upstream pre-stretch roller 118,
between upstream pre-stretch roller 118 and downstream pre-stretch
roller 120, around downstream pre-stretch roller 120, in between
downstream pre-stretch roller 120 and first downstream idle roller
152, around first downstream idle roller 152, between first
downstream idle roller 152 and second downstream idle roller 154,
over second downstream idle roller 154, over third downstream idle
roller 156, and to the load. As shown in FIG. 3, the portion of the
film path between upstream idle roller 150 and first downstream
idle roller 152 has an S-configuration. It is contemplated that at
least one of first, second, and third downstream idle rollers 152,
154, and 156, may be mounted as a "dancer" and may be used to sense
any slack in packaging material 102 caused by a change in the size
or shape of the load being wrapped, or a break in packaging
material 102.
[0049] As embodied in FIGS. 1-7, packaging material dispenser 100
may also include an upstream roping assembly 158, and a downstream
roping assembly 160. Upstream roping assembly 158, assisted by the
offset between roll carriage 104 and roll support 108, may form a
rope from bottom portion of packaging material 102 before packaging
material 102 enters pre-stretch assembly 110. Downstream roping
assembly 160 may create another rope, or reinforce the rope, after
packaging material 102 leaves pre-stretch assembly 110. Thus, it
should be apparent that by using the offset between roll carriage
104 and roll support 108, and upstream roping assembly 158, more of
packaging material 102 may be formed into the rope than if the
offset and upstream roping assembly 158 were not used.
Additionally, if the offset was not used, and roll support 108 was
level with the base plate of roll carriage 104, then roping up with
upstream roping assembly 158 would drive the bottommost edge of
packaging material 102 farther upward, thus requiring third
downstream idle roller 156 to drive packaging material 102 farther
downward in response to ensure that packaging material 102 can be
wrapped around the bottom of the load and/or the top of a pallet
supporting the load.
[0050] Roping may be carried out at any time during a wrapping
cycle, including near the end of a wrapping cycle, to secure the
bottom of the load to a pallet (not shown), or during an
intermediate portion of a wrapping cycle, to wrap a roped web of
packaging material 102 around the sides of the load. A rope may
include a portion of packaging material 102 that is concentrated in
a tightly compacted, and preferably somewhat round, shape. A rope
may be a conventional rope of packaging material, which is
gathered, compacted or compressed; or may be a rolled cable of
packaging material 102. A more detailed explanation of the general
structure, operation, and benefits of various roping assemblies can
be found in U.S. Patent Application Publication No. 2007/0209324
A1, entitled "Method and Apparatus for Securing a Load to a Pallet
With a Roped Film Web," filed Feb. 23, 2007, and published Sep. 13,
2007, the entire disclosure of which is incorporated herein by
reference.
[0051] Downstream roping assembly 160 may be placed immediately
downstream of second downstream idle roller 154. This positioning
of downstream roping assembly 160 creates a rolled cable of
packaging material 102 that is capable of maintaining its
structural integrity as a rope structure during and after wrapping
of a load. Downstream roping assembly 160 and second downstream
idle roller 154 may form a "rolled cable rolling means" for rolling
a portion of packaging material 102 into a rolled cable. The rolled
cable rolling means rolls an outer edge of packaging material 102
inward upon itself and toward the center of packaging material 102.
The film is rolled upon itself to form a tightly rolled cable of
film, or a high tensile rolled cable of film along an edge of the
packaging material 102. Further, by placing downstream roping
assembly 160 immediately downstream of second downstream idle
roller 154, the rolling of packaging material 102 into a rolled
cable may begin at a point upstream from second downstream idle
roller 154. Additionally, downstream roping assembly 160 may serve
to elevate the bottom edge of packaging material 102 before it is
driven down by the tilting of third downstream idle roller 156,
thus helping to prevent packaging material 102 from sliding off the
bottom of third downstream idle roller 156, and causing other
malfunctions. A more detailed explanation of the rolled cable
rolling means can be found in U.S. Patent Publication No.
2005/0044812, entitled "Method and Apparatus for Securing a Load to
a Pallet With a Roped Film Web," filed Jan. 30, 2004, and published
Mar. 3, 2005, the entire disclosure of which is incorporated herein
by reference. It is contemplated that second downstream idle roller
154 may be coated to assist with roping.
[0052] According to one aspect of the disclosure, means for
providing relative rotation between a load and packaging material
dispenser 100 may be provided. The means for providing relative
rotation may include, for example, a rotatable turntable (not
shown). In such an embodiment, packaging material dispenser 100 may
be mounted on a stationary mast (not shown) upon which packaging
material dispenser 100 can be vertically driven and positioned to
dispense packaging material 102 to spirally wrap the load, as the
load rotates on the turntable. In such an embodiment, the
low-profile design of drive housing 142, and the elements contained
therein, provides packaging material dispenser 100 with the ability
to wrap a bottom portion of the load, including a top portion of a
pallet if the load is supported by a pallet, while remaining high
enough above the turntable and/or a floor surface (not shown)
supporting the turntable, to avoid interference with/from the
turntable and/or the floor surface.
[0053] Alternatively, packaging material dispenser 100 may be
vertically driven on a rotating arm 116, shown in FIG. 1, to
dispense packaging material 102 spirally about the load, as
rotating arm 116 rotates about the load, and packaging material
dispenser 100 moves vertically along rotating arm 116. It is also
contemplated that packaging material dispenser 100 may be mounted
on horizontal wrapping ring (not shown) to dispense packaging
material 102 spirally about the load, as packaging material
dispenser 100 rotates with the wrapping ring relative to the load.
In the rotating arm and horizontal wrapping ring embodiments, a
conveyor (not shown) may convey the load into and out of a wrapping
area defined by the path of packaging material dispenser 100 around
the load. In such embodiments, during wrapping, packaging material
dispenser 100 must pass over the conveyor while rotating around the
load. The low-profile design of drive housing 142, and the elements
contained therein, as well as the offset between roll support 108
and roll carriage 104, provide packaging material dispenser 100
with the ability to wrap a bottom portion of the load, including a
top portion of a pallet if the load is supported by a pallet, while
remaining high enough above the conveyor to avoid interference
with/from the conveyor.
[0054] As embodied herein and shown in FIGS. 8-11, a stretch
wrapping apparatus (not shown) includes a packaging material
dispenser 200. Packaging material dispenser 200 may dispense a
sheet of packaging material 202 (see FIG. 10) in a web form.
Packaging material dispenser 200 may include a roll carriage 204.
Packaging material dispenser 200 may contain a roll 206 (see FIG.
10) of packaging material 202 to be dispensed. A roll support 208
may be mounted on roll carriage 204 for this purpose. Roll support
208 may be constructed to rotatably support roll 206 as packaging
material 202 unwinds, moving from roll 206 to a pre-stretch
assembly 210.
[0055] In one embodiment, roll support 208 may include a
cylindrical member 212 extending vertically therefrom, cylindrical
member 212 being sized to be received within an aperture 214
extending axially through the center of roll 206. Roll 206 may
rotate freely about cylindrical member 212 when packaging material
202 is being dispensed. Roll support 208 may be top-loaded, such
that roll 206 may be loaded into packaging material dispenser 200
from above packaging material dispenser 200 by sliding roll 206
over a free end of cylindrical member 212. Roll support 208 may
support a bottom end of roll 206 once roll 206 is loaded.
[0056] As embodied in FIGS. 8-11, packaging material dispenser 200
may include pre-stretch assembly 210. Pre-stretch assembly 210 may
include an upstream pre-stretch roller 216 and a downstream
pre-stretch roller 218, that are in many ways similar to upstream
pre-stretch roller 118 and downstream pre-stretch roller 120 of
packaging material dispenser 100. However, upstream pre-stretch
roller 216 and downstream pre-stretch roller 218 may be the same
size, and each may have, for example, an outer diameter of
approximately 2.5 inches.
[0057] Upstream pre-stretch roller 216 and downstream pre-stretch
roller 218 may be mounted on shafts 220 and 222. Shafts 220 and 222
are similar to shafts 122 and 124, described above. In packaging
material dispenser 200, upstream pre-stretch roller 216 and
downstream pre-stretch roller 218 may be cantilevered rollers, in
that a first end of each of shafts 220 and 222 may be fixed to or
supported by a base plate of roll carriage 204, while a second end
of each of shafts 220 and 222 may be unsupported. It is also
contemplated that the second end of each of shafts 220 and 222 may
be supported by a separate support member 232 coupled to an upper
portion of roll carriage 204. In that case, support member 232 may
support shafts 220 and 222 in such a way as to provide a film path
for bringing packaging material 202 into contact with upstream
pre-stretch roller 215 and downstream pre-stretch roller 218,
freely accessible from above upstream pre-stretch roller 215 and
downstream pre-stretch roller 218 despite the supports.
[0058] As embodied in FIGS. 8 and 10, a sprocket 234 may be mounted
on/attached to upstream pre-stretch roller 216, and similarly, a
sprocket 236 may be mounted on/attached to downstream pre-stretch
roller 218. Sprockets 234 and 236 may be housed in a drive housing
238 below roll carriage 204. This creates a low-profile drive
design, and prevents debris from entering into drive housing
238.
[0059] Sprockets 234 and 236 may be connected to each other through
a drive belt 240, and also to a drive motor (not shown). Drive belt
240 may include, for example, a chain, a belt, a cable, one or more
gears, and/or any other suitable connection. As shown in FIGS. 8,
10, and 11, drive belt 240 may be threaded around sprockets 234 and
236, with a first side of drive belt 240 engaging both of sprockets
234 and 236. This arrangement causes upstream pre-stretch roller
216 and downstream pre-stretch roller 218 may rotate in the same
direction. Sprockets 234 and 236 may be selected based on the same
criteria as sprockets 138 and 140. It is contemplated that a clutch
mechanism (not shown) may be provided to allow an operator to
manually rotate upstream pre-stretch roller 216 and/or downstream
pre-stretch roller 218, when the drive motor is not running.
[0060] As embodied in FIGS. 8-11, a support member 232 may extend
from the upper portion of roll carriage 204, or any other suitable
structure fixed relative to roll carriage 204. In one embodiment,
support member 232 may include a bent plate or bracket with a base
member 242, fixed relative to roll carriage 204, that joins a first
support 244 to a second support 246. A gap may exist between first
support 244 and second support 246, allowing for threading of
packaging material 202 from above upstream pre-stretch roller 216
and downstream pre-stretch roller 218, as is evident in FIG. 9.
First support 244 may be configured to receive shaft 220. Second
support 246 may be configured to receive shaft 222. Mounting the
first ends of shafts 220 and 222 to roll carriage 204, and
providing support member 232 to support the second ends of shafts
220 and 222, may help to ensure that upstream pre-stretch roller
216 and downstream pre-stretch roller 218 maintain their alignment
even under high forces that may be generated during pre-stretching
of packaging material 202. This design may also permit easy
threading of packaging material fully around upstream pre-stretch
roller 216, downstream pre-stretch roller 218, an upstream idle
roller 248, an intermediate idle roller 250, and a downstream idle
roller 252.
[0061] Upstream idle roller 248, intermediate idle roller 250, and
downstream idle roller 252, may each be cantilevered from roll
carriage 204, as shown in FIGS. 8-11. Any or all of upstream idle
roller 248, intermediate idle roller 250, and downstream idle
roller 252, may be the same diameter as or smaller in diameter than
upstream pre-stretch roller 216 or downstream pre-stretch roller
218. Upstream idle roller 248, intermediate idle roller 250, and
downstream idle roller 252 may be coated or uncoated. As with
upstream pre-stretch roller 216 and downstream pre-stretch roller
218, upstream idle roller 248, intermediate idle roller 250, and
downstream idle roller 252, should have a sufficient length to
carry a twenty (20) inch wide web of packaging material 202 along
their working lengths. It is contemplated that upstream idle roller
248, intermediate idle roller 250, and downstream idle roller 252
may be cantilevered rollers, in that upstream idle roller 248,
intermediate idle roller 250, and downstream idle roller 252 may be
supported at a first lower end by roll carriage 204, but may not be
supported at a second upper end, opposite the first lower end, by
additional support structure. This arrangement allows packaging
material 202 to be easily threaded through pre-stretch assembly 210
from the open top of roll carriage 204. Further, support member
232, being C-shaped, as shown in FIGS. 8 and 9, will not obstruct
packaging material 202 during threading of pre-stretch assembly 210
from the open top of roll carriage 204.
[0062] A film path is defined by and between the surfaces of
upstream pre-stretch roller 216, downstream pre-stretch roller 218,
upstream idle roller 248, intermediate idle roller 250, and
downstream idle roller 252. The film path is easily accessible via
the top of pre-stretch assembly 210, as shown in FIGS. 8 and 9. A
rope of packaging material 202 may be pulled from roll 206, around
upstream idle roller 248, between upstream idle roller 248 and
upstream pre-stretch roller 216, around upstream pre-stretch roller
216, between upstream pre-stretch roller 216 and intermediate idle
roller 250, around intermediate idle roller 250, between
intermediate idle roller 250 and downstream pre-stretch roller 218,
around downstream pre-stretch roller 218, in between downstream
pre-stretch roller 218 and downstream idle roller 252, downstream
idle roller 252, and to the load. It should be evident from FIG. 9
that the portion of the film path between upstream idle roller 248
and downstream idle roller 252 has a W-configuration. It is
contemplated that at least one of upstream idle roller 248,
intermediate idle roller 250, and downstream idle roller 252, may
be mounted as a "dancer" and may be used to sense any slack in
packaging material 202 caused by a change in the size or shape of
the load being wrapped, or a break in packaging material 202.
[0063] According to one aspect of this disclosure, intermediate
idle roller 250 may include an idle roller hingedly connected to
roll carriage 204 and/or support member 232. As shown in FIGS.
8-10, intermediate idle roller 250 may be mounted in between
upstream pre-stretch roller 216 and downstream pre-stretch roller
218, and may be movable outward, away from one or both of upstream
pre-stretch roller 216 and downstream pre-stretch roller 218.
Movement of intermediate idle roller 250 away from upstream
pre-stretch roller 216 and/or downstream pre-stretch roller 218
provides access to the space between upstream pre-stretch roller
216 and downstream pre-stretch roller 218, to permit threading of
packaging material 202 around upstream pre-stretch roller 216 and
downstream pre-stretch roller 218.
[0064] As shown in FIG. 9, intermediate idle roller 250 may be
positioned between upstream pre-stretch roller 216 and downstream
pre-stretch roller 218, abutting one of upstream pre-stretch roller
216 and downstream pre-stretch roller 218, and spaced from the
other of upstream pre-stretch roller 216 and downstream pre-stretch
roller 218. Preferably intermediate idle roller 250 may be aligned
to provide a pinching action on upstream pre-stretch roller 216, as
shown in FIG. 9, and as disclosed in U.S. Pat. No. 5,414,979 to
Moore et al., issued May 16, 2995, and entitled "Stretch Wrapping
Apparatus," the entire disclosure of which is incorporated herein
by reference. This may reduce the amount of unsupported packaging
material 202 by 100%. Reducing the amount of unsupported packaging
material 202, reduces the amount of neckdown in the width dimension
of packaging material 202. This generates a greater area of stretch
of the film. In this embodiment, the inventors have noticed an
almost complete elimination of film slippage on upstream
pre-stretch roller 216.
[0065] Intermediate idle roller 250 may be biased against the
pre-stretch roller which it is abutting, for example, against
upstream pre-stretch roller 216. The hinged mounting of
intermediate idle roller 250 permits packaging material 202 to bias
intermediate idle roller 250 against upstream pre-stretch roller
216. This is achieved through the force vector resulting from the
geometry of the mountings and force application by packaging
material 202. Alternatively, the biasing may be achieved through
the use of a spring or similar element (not shown).
[0066] The result of this arrangement is that intermediate idle
roller 250 effectively acts like a pinch roller or press roller in
relation to upstream pre-stretch roller 216. As a pinch roller or
press roller, intermediate idle roller 250 effectively acts as an
extension of upstream pre-stretch roller 216 by offering increased
surface for traction to packaging material 202. In doing so,
intermediate idle roller 250 pinches the film between itself and
upstream pre-stretch roller 216 to offer greater traction.
Increased traction of upstream pre-stretch roller 216 reduces the
damage to packaging material 202 by decreasing the abrasion of
packaging material 202. While intermediate idle roller 250 is shown
abutting upstream pre-stretch roller 216, it is possible for
intermediate idle roller 250 to instead abut downstream pre-stretch
roller 218, or may abut neither of upstream pre-stretch roller 216
and downstream pre-stretch roller 218.
[0067] Packaging material dispenser 200 may also include an
upstream roping assembly (not shown), and/or a downstream roping
assembly (not shown), similar to those described with respect to
packaging material dispenser 100.
[0068] According to one aspect of the disclosure, means for
providing relative rotation between a load and packaging material
dispenser 200 may be provided. The means for providing relative
rotation may include, for example, a rotatable turntable (not
shown). In such an embodiment, packaging material dispenser 200 may
be mounted on a stationary mast (not shown) upon which packaging
material dispenser 200 can be vertically driven and positioned to
dispense packaging material 202 to spirally wrap the load as the
load rotates on the turntable. In such an embodiment, the
low-profile design of drive housing 238, and the elements contained
therein, provides packaging material dispenser 200 with the ability
to wrap a bottom portion of the load, including a top portion of a
pallet if the load is supported by a pallet, while remaining high
enough above the turntable and/or a floor surface (not shown)
supporting the turntable, to avoid interference with/from the
turntable and/or the floor surface.
[0069] Alternatively, packaging material dispenser 200 may be
vertically driven on a rotating arm (not shown), to dispense
packaging material 202 spirally about the load, as the rotating arm
rotates about the load, and packaging material dispenser 200 moves
vertically along the rotating arm. It is also contemplated that
packaging material dispenser 200 may be mounted on a horizontal
wrapping ring (not shown) to dispense packaging material 202
spirally about the load, as packaging material dispenser 200
rotates with the wrapping ring relative to the load. In the
rotating arm and horizontal wrapping ring embodiments, a conveyor
(not shown) may convey the load into and out of a wrapping area
defined by the path of packaging material dispenser 200 around the
load. In such embodiments, during wrapping, packaging material
dispenser 200 must pass over the conveyor while rotating around the
load. The low-profile design of drive housing 238, and the elements
contained therein, provides packaging material dispenser 200 with
the ability to wrap a bottom portion of the load, including a top
portion of a pallet if the load is supported by a pallet, while
remaining high enough above the conveyor to avoid interference
with/from the conveyor.
[0070] Several benefits may be associated with packaging material
dispensers 100 and 200. Roll carriages 104 and 204 provide for fast
and reliable loading of rolls 106 and 206 during roll changes, and
for fast and reliable loading (threading) of packaging material 102
and 202 through pre-stretch assemblies 110 and 210. One of the
reasons that loading is faster and more reliable is because
packaging material dispensers 100 and 200 do not have doors that
must be opened to load rolls 106 and 206 and to thread packaging
material 102 and 202. Rolls 106 and 206 may be loaded from the open
tops of roll carriages 104 and 204, and packaging material 102 and
202 may be threaded through the film path from the open tops. Also,
less technique is required from an operator to load rolls 106 and
206, and packaging material 102 and 202, from the open tops as
compared to conventional roll carriage assemblies. Another added
benefit of loading from the open tops is that loading may be
accomplished with packaging material dispensers 100 and 200
occupying a vertically low position, such as the usual position
occupied at the end of a wrapping cycle after a bottom portion of
the load has been wrapped. In conventional assemblies, the roll
carriage usually must be raised from the vertically lower position
to a height that is ergonomically convenient for the operator, so
that the operator can to load and thread a new roll of packaging
material. This raising can be time consuming and inconvenient. Yet
another benefit is that the open top arrangements allow for
threading of roped packaging material, which is stronger and more
resistant to breakage than a non-roped web of packaging material.
Additionally, the open top S-configuration and W-configuration
require fewer parts than conventional assemblies, which may produce
cost savings, and may reduce the weight of packaging material
dispensers 100 and 200. Further, the parts that are required are
less complex, and thus, less costly.
[0071] Additionally, roping packaging material 102 may provide
packaging material 102 with extra strength, thus helping to prevent
packaging material breaks. Further, by roping packaging material
102, if for some reason packaging material 102 is damaged (e.g.,
torn or punctured), the rope will help to carry the damaged
portions. That is, the strength of the rope allows it to resist
breaking, even when the non-roped portion of packaging material 102
is damaged. Thus, damaged portions of packaging material 102 can be
carried through by the rope and applied to the load, which prevents
the downtime associated with re-loading packaging material
dispenser 100 after a complete break occurs.
[0072] Further, by driving down packaging material 102, third
downstream idle roller 156 may help to secure the load to the
pallet, while maintaining space between drive housing 142 and the
ground or other low support surfaces. Upstream from where the
driving down occurs, downstream roping assembly 160 may rope up
packaging material 102 to prevent packaging material 102 from
sliding off the bottom of third downstream idle roller 156 during
the driving down.
[0073] One method for loading packaging material 102 in packaging
material dispenser 100 will now be described. With packaging
material dispenser 100 in a vertically low position, such as that
occupied at the end of a previous wrapping cycle, an operator may
begin loading packaging material dispenser 100 by sliding roll 106
onto cylindrical member 112 of roll support 108 from above
cylindrical member 112. The operator may grasp a leading end of
packaging material 102 from roll 106. The operator may pull the
leading end to produce a length of film. The length of film may
have a distal portion near the leading end, a proximal portion near
roll 106, and an intermediate portion between the distal portion
and the proximal portion. It is also contemplated that the operator
may form at least a portion of the length of film into a rope.
[0074] In order to thread the length of film through pre-stretch
assembly 110, the operator may bring the proximal portion into
contact with a surface of upstream idle roller 150 from above
upstream idle roller 150 or from its side. The operator may bring a
part of the intermediate portion into contact with a surface of
upstream pre-stretch roller 118 from a location proximate a top
portion of upstream pre-stretch roller 118. The operator may bring
another part of the intermediate portion into contact with a
surface of downstream pre-stretch roller 120 from above downstream
pre-stretch roller 120, or from its side. The operator may bring a
part of the distal portion into contact with a surface of first
downstream idle roller 152 from a location proximate a top of first
downstream idle roller 152, and then bring other parts of the
distal portion into contact with second downstream idle roller 154
and third downstream idle roller 156, before attaching the leading
end to a clamping assembly (not shown) and/or to a load to be
wrapped (not shown). During loading, all of the rollers coming into
contact with the length of film may remain substantially
static.
[0075] Additionally or alternatively, the method for loading may
include grasping a leading end portion of packaging material 102,
and, while grasping the leading end portion, bringing the leading
end portion into contact with a surface of upstream idle roller
150, and then into contact with a surface of upstream pre-stretch
roller 118, then into contact with a surface of downstream
pre-stretch roller 120, then into contact with a surface of first
downstream idle roller 152, and then into contact with second
downstream idle roller 154 and third downstream idle roller 156,
before attaching the leading end to a clamping assembly (not shown)
and/or to a load to be wrapped (not shown).
[0076] After clamping, the operator may ungrasp the leading end
portion. In this embodiment of the method, the operator may be
required to continually pull the leading end portion around one or
more of the contacting rollers as the leading end portion is
threaded through pre-stretch assembly 110. Thus, in this
embodiment, it may be necessary to provide upstream pre-stretch
roller 118 and downstream pre-stretch roller 120 with a clutch
mechanism that allows upstream pre-stretch roller 118 and
downstream pre-stretch roller 120 to be rotated manually as the
leading end portion is pulled by the operator.
[0077] With the leading end being clamped by the clamping assembly,
relative rotation may be provided between the load being wrapped
and packaging material dispenser 100, causing packaging material
102 to be wrapped about the load. Packaging material dispenser 100
may travel vertically from a bottom portion of the load to a top
portion of the load, and then back down to the bottom portion,
while the relative rotation is being provided, to spirally wrap
packaging material 102 about the load. During any portion of the
wrapping cycle, downstream roping assembly 160 may be actuated to
engage a bottom edge of packaging material 102 to form a bottom
portion of packaging material 102 into a rope. Packaging material
102, including the roped portion, may be applied to the load being
wrapped. Also, near the end of the wrapping cycle, third downstream
idler roller 156 may be actuated into its tilted position to drive
packaging material 102 downward, to secure a bottom portion of the
load to a pallet supporting the load.
[0078] One method for loading packaging material 202 in packaging
material dispenser 200 will now be described. With packaging
material dispenser 200 in a vertically low position, such as that
occupied at the end of a previous wrapping cycle, an operator may
begin loading packaging material dispenser 200 by sliding roll 206
onto cylindrical member 212 of roll support 208 from above
cylindrical member 212. The operator may grasp a leading end of
packaging material 202 from roll 206. The operator may pull the
leading end to produce a length of film. The length of film may
have a distal portion near the leading end, a proximal portion near
roll 206, and an intermediate portion between the distal portion
and the proximal portion. It is also contemplated that the operator
may form at least a portion of the length of film into a rope.
[0079] In order to thread the length of film through pre-stretch
assembly 210, the operator may bring the proximal portion into
contact with a surface of upstream idle roller 248 from above
upstream idle roller 248. The operator may bring a part of the
intermediate portion into contact with a surface of upstream
pre-stretch roller 216 from a location proximate a top portion of
upstream pre-stretch roller 216, or from its side. The operator may
bring another part of the intermediate portion into contact with a
surface of intermediate idle roller 250 from above intermediate
idle roller 250. The operator may bring yet another part of the
intermediate portion into contact with a surface of downstream
pre-stretch roller 218 from above downstream pre-stretch roller
218, or from its side. The operator may bring a part of the distal
portion into contact with a surface of downstream idle roller 252
from a location proximate a top of downstream idle roller 252,
before attaching the leading end to a clamping assembly (not shown)
and/or to a load to be wrapped (not shown). During loading, all of
the rollers coming into contact with the length of film may remain
substantially static.
[0080] Additionally or alternatively, the method for loading may
include grasping a leading end portion of packaging material 202,
and, while grasping the leading end portion, bringing the leading
end portion into contact with the surfaces of upstream idle roller
248, upstream pre-stretch roller 216, intermediate idle roller 250,
downstream pre-stretch roller 218, and downstream idle roller 252,
before attaching the leading end to a clamping assembly (not shown)
and/or to a load to be wrapped (not shown).
[0081] With the leading end being clamped by the clamping assembly,
relative rotation may be provided between the load being wrapped
and packaging material dispenser 200, causing packaging material
202 to be wrapped about the load. Packaging material dispenser 200
may travel vertically from a bottom portion of the load to a top
portion of the load, and then back down to the bottom portion,
while the relative rotation is being provided, to spirally wrap
packaging material 202 about the load.
[0082] Other embodiments will be apparent to those skilled in the
art from consideration of the specification and practice of the
embodiments disclosed herein. It is intended that the specification
and examples be considered as exemplary only, with a true scope and
spirit of the disclosure being indicated by the following
claims.
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