Information
-
Patent Grant
-
6293074
-
Patent Number
6,293,074
-
Date Filed
Friday, February 20, 199826 years ago
-
Date Issued
Tuesday, September 25, 200122 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Ostrager; Allen
- Hong; William
Agents
- Finnegan, Henderson, Farabow, Garrett & Dunner, L.L.P.
-
CPC
-
US Classifications
Field of Search
US
- 053 399
- 053 441
- 053 556
- 053 587
- 053 588
- 053 210
- 053 211
-
International Classifications
-
Abstract
A leading end of packaging material is attached to a retainer to hold the leading end of the packaging material as the retainer moves toward the load. The retainer is positioned adjacent the load and packaging material is dispensed from a packaging material dispenser, and relative rotation is provided between the dispenser and a load to wrap packaging material around the load. The packaging material is released from the retainer in response to force applied to the retainer to withdraw it from the wrapped load.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for wrapping a load with packaging material.
Loads have been stretch wrapped with stretch wrap packaging material by dispensing the packaging material, securing a leading end of the packaging material to the load or a turntable clamp, and providing relative rotation between the load and a packaging material dispenser to cause the load to be enveloped by the packaging material. The relative rotation can be provided several different ways. Either the load can be rotated on a turntable, or the dispenser can be rotated around the stationary load. Stretch wrapping usually employs a web of stretch film as the packaging material.
Semi-automatic stretch wrapping machinery requires the operator to attach a leading end of the packaging material to the load. This is typically accomplished by forming a rope in the leading end of the film and then inserting this end between the layers of the load or tying the end of the packaging material to the edge of the supporting wood pallet or any suitable outcropping on the load. This attachment must be relatively strong since it provides the resistance to pulling the film from the film dispenser during the initiation of the relative rotation between the load and the film dispenser. The attachment or tying of the film makes film removal more difficult after the load has been shipped to its destination.
Automatic stretch wrapping machines typically use film clamps that grip the film web between two opposed surfaces and use electrical or pneumatic actuators to open and close the clamps. Such film clamps create a “tenting” effect during wrapping due to the distance between the clamp and the load during wrapping, resulting in wasted film and loosely wrapped loads. Such clamps are expensive and may require costly maintenance for the electrical and mechanical actuators.
In light of these drawbacks, there is a need for a method and apparatus for wrapping a load with packaging material that operates as effectively as those previously developed but which can be manufactured at a lower cost.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a method and apparatus for wrapping a load with packaging material which provides advantages and obviates a number of problems in earlier methods and apparatus for wrapping a load.
To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described, the invention includes an apparatus for wrapping the sides of a load with packaging material including a load support surface for supporting the load during wrapping, a dispenser for dispensing packaging material, means for providing relative rotation between the dispenser and the load to wrap packaging material around the sides of the load, a packaging material holder for selectively holding and releasing a leading end of packaging material, and a support arm moveable above the load support surface for moving the packaging material holder between a radially outward position distant from the sides of the load and a radially inward position near the sides of the load.
According to another aspect of the present invention, the invention includes an apparatus for wrapping the sides of a load with packaging material including a dispenser for dispensing packaging material, means for providing relative rotation between the dispenser and the load to wrap packaging material around the load, and a packaging material holder with at least one vacuum cup for selectively holding and releasing a leading end of the packaging material.
According to a further aspect of the present invention, the invention includes an apparatus for wrapping a load with packaging material including a load support surface for supporting the load during wrapping, a dispenser for dispensing packaging material, means for providing relative rotation between the dispenser and the load to wrap packaging material around the load, a packaging material holder for selectively engaging and releasing a leading end of the packaging material, and a support arm connected to the packaging material holder for moving the packaging material holder and leading end of the packaging material from a packaging material engaging position distant from the sides of the load to a wrapping position near the sides of the load to wrap the packaging material about the sides of the load and the packaging material holder.
According to another aspect of the present invention, the invention includes an apparatus for wrapping a load with packaging material including a load support surface for supporting the load during wrapping, a dispenser for dispensing packaging material, means for providing relative rotation between the dispenser and the load to wrap packaging material around the load, a packaging material holder for selectively engaging and releasing a leading end of the packaging material, and a support arm connected to the packaging material holder for holding the packaging material holder and leading end of the packaging material in a wrapping position near the sides of the load to wrap the packaging material about the sides of the load and the packaging material holder and for moving the packaging material holder away from the sides of the load to release the packaging material after wrapping.
According to yet a further aspect of the present invention, the invention includes an apparatus for retaining and positioning a free end of packaging material to a load to be wrapped with a rotary stretch wrapping apparatus, including an unopposed packaging material holder moveable between a first position and a second position, a support arm for moving the packaging material holder between a position distant from the load to be wrapped and a position near the load to be wrapped, and a support frame for the support arm and configured to be mounted on or adjacent to a load support surface of a rotary stretch wrapping apparatus.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objects and other advantages of the invention will be realized and attained by the method and apparatus particularly pointed out in the written description and claims as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention, and together with the description serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a perspective view of a stretch wrap packaging apparatus according to a first embodiment of the present invention.
FIGS. 2-4
are perspective views of a stretch wrap packaging apparatus of the first embodiment of the present invention showing positioning of the packaging material holder at different points during the wrapping sequence.
FIGS. 5A and 5B
are a perspective view and a plan view, respectively, of the first embodiment of the stretch wrapping apparatus after the stretch wrap has been wrapped around the load.
FIGS. 6A and 6B
are a perspective view and a plan view, respectively, of the first embodiment of the stretch wrapping apparatus after the load has been wrapped and the stretch wrap cut.
FIGS. 7A and 7B
are a perspective view and a plan view, respectively, of the first embodiment of the stretch wrapping apparatus with the packaging material holder in the “home” position after the load has been wrapped and conveyed out of the wrapping area.
FIG. 8
is a perspective view of a stretch wrap packaging apparatus according to a second embodiment of the present invention.
FIGS. 9-11
are perspective views of a stretch wrap packaging apparatus of the second embodiment of the present invention showing positioning of the packaging material holder at different points during the wrapping sequence.
FIGS. 12A and 12B
are a perspective view and a plan view, respectively, of the second embodiment of the stretch wrapping apparatus after the stretch wrap has be wrapped around the load.
FIGS. 13A and 13B
are a perspective view and a plan view, respectively, of the second embodiment of the stretch wrapping apparatus after the load has been wrapped and the stretch wrap cut.
FIGS. 14A and 14B
are a perspective view and a plan view, respectively, of the second embodiment of the stretch wrapping apparatus with the packaging material holder in the “home” position after the load has been wrapped and conveyed out of the wrapping area.
FIGS. 15A and 15B
are perspective views of the packaging material holder of the present invention for retro-fitting a stretch wrapping apparatus used in the first and second embodiments of the present invention.
FIGS. 16-20
are perspective views of a third embodiment of the stretch wrap packaging apparatus of the present invention showing positioning of the packaging material holder at different points during the wrapping sequence.
FIGS. 21 and 22
are perspective views of a fourth embodiment of the stretch wrap packaging apparatus of the present invention showing positioning of the packaging material holder at different points during the wrapping sequence.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
According to the invention, an apparatus is provided for wrapping a load with packaging material. As embodied herein and shown in
FIGS. 1-7
and
15
, an apparatus for wrapping a load with packaging material includes stretch wrapping apparatus
100
.
According to the present invention, a packaging material holder for selectively holding and releasing a leading end of the packaging material is provided. As embodied herein and shown in
FIGS. 1-7
and
15
, packaging material holder
140
has an unopposed surface for selectively engaging and releasing a leading end
30
of packaging material
112
. As shown in
FIGS. 6B and 7B
, the unopposed surface of the packaging material holder
140
engages a single side of packaging material
112
, rather than clamping or trapping the packaging material
112
between opposing surfaces. The unopposed surface of packaging material holder
140
may be a tacky, adhesive-like surface, a prickly surface, an irregular surface, or a vacuum surface. Packaging material holder
140
may be a relatively short element, sized to contact only a portion of the width of the packaging material
112
. Alternatively, packaging material holder
140
may be sized to extend across the entire width of the packaging material
112
. Packaging material holder
140
may be made of any suitable material, such as metal or plastic, and may formed in any suitable shape, such as a bar, a square, a rectangle or a circle. It is preferable, however, that packaging material holder
140
be relatively small in size in order to facilitate moving packaging material holder
140
out from between load
124
and packaging material
112
. According to some other aspects of the invention, holders with opposed surfaces, such as traditional clamps, may be used.
In a preferred embodiment, as shown in
FIG. 15
, packaging material holder
140
may include a vacuum surface
142
for holding and releasing the leading end
30
of packaging material
112
. Vacuum surface
142
may include suction holes
148
(as shown in FIG.
21
), or vacuum surface
142
may include at least one suction or vacuum cup
144
. Vacuum surface
142
is preferably curved in shape to accommodate vacuum cup
144
. Vacuum cup
144
includes a raised lip area
146
for contacting the packaging material
112
as well as a concave or cup-shaped body portion
147
which sits within vacuum surface
142
.
Packaging material holder
140
includes an automatic valving to vacuum and pressure source
138
which is connected to the packaging material holder
140
for providing a vacuum through surface
142
and/or vacuum cups
144
to adhere the packaging material
112
to the packaging material holder
140
, and for stopping the application of a vacuum, or supplying a positive flow of air through vacuum surface
142
to release and blow the packaging material away from the packaging material holder
140
. Automatic valving to vacuum and pressure source
138
is controlled by a controller
26
which includes a microprocessor or other control circuitry which provides timing functions in a manner conventional with stretch wrapping machines.
According to the present invention, a support arm for moving the packaging material holder is provided. As embodied herein and as shown in
FIGS. 1-7
, support arm
150
supports packaging material holder
140
. As shown in
FIG. 1
, support arm
150
includes a metal tube. However, the arm can include other structures which support and move the packaging material holder
140
, such as a bar, a frame, a wire structure, or a truss. Additionally, support arm
150
may be made from any suitable material strong enough to support and move packaging material holder
140
, such as wood or other fibrous materials, plastics, metals, or composites of any of these materials.
Support arm
150
is moveable between a position distant from the sides of the load
124
and near the packaging material dispenser
102
and a position near a side of the load
124
to be wrapped. In a preferred embodiment, packaging material holder
140
is moveable on support arm
150
between a position distant from the load and adjacent the packaging material dispenser (hereinafter referred to as the distant position) and a position touching or close to a side of the load (hereinafter referred to as the near position). With respect to an axis of rotation for wrapping the load, the distant position is a radially outward position distant from the load and the near position is a radially inward position near a side of the load. According to one aspect of the present invention, the near and distant positions may be defined with respect to a circle circumscribed about the corners of a load
124
to be wrapped. The interior area of the circle is the area into which packaging material holder
140
and support arm
150
pass to reach the near position. In contrast, when packaging material holder
140
and support arm
150
are outside this circle, they are in the distant position. Support arm
150
may be rotatable between these positions, as shown in
FIGS. 1-7
.
Support arm
150
is moveable above a load support surface
130
. As embodied herein, load support surface
130
is the surface which supports load
124
during the wrapping process. As shown in
FIGS. 1 and 2
, the load support surface is the portion of conveyor
118
within the wrapping area upon which the load rests during wrapping. Alternatively, load support surface
130
may be the floor, a portion of a turntable, or any other surface upon which the load rests on, as opposed to below that surface, during wrapping.
Support arm
150
is moveable above the load support surface
130
between the distant position and the near position. Support arm
150
may be moveable in a horizonal plane above load support surface
130
or support arm
150
may slide on top of load support surface between the distant and near positions. Movement of support arm
150
between the distant position and the near position may be controlled by an air cylinder actuated by controller
26
. In a preferred embodiment, only the motion of support arm
150
moving from the near position to the distant position is actuated by an air cylinder, and the motion of support arm
150
from the distant position to the near position is driven solely by the force exerted on packaging material holder
140
by packaging material
112
as the wrapping cycle begins.
As shown in
FIGS. 1-7
and
15
, a first end of support arm
150
may be supported by a support frame
152
placed adjacent to a load support surface during wrapping. As seen in
FIGS. 1-7
and
15
, support arm
150
may be cantilevered to be positionable and moveable above the load support surface, in contrast to resting on the load support surface. According to this aspect of the invention, support arm
150
is not configured to be positionable under or moveable upward through the load support surface.
A second end of support arm
150
is connected to and supports packaging material holder
140
. As shown in
FIG. 4
, support arm
150
may be flexibly connected to packaging material holder
140
. Alternatively, support arm
150
may be rigidly connected to packaging material holder
140
. As shown in
FIG. 1
, support arm
150
may support packaging material holder
140
in an upright position above support arm
150
such that packaging material holder
140
holds the packaging material above the support arm
150
. Support arm
150
and packaging material holder
140
are thus arranged such that packaging material holder
140
holds the packaging material
112
away from support arm
150
so that support arm
150
does not engage the packaging material or interfere with the wrapping process.
Support arm
150
may include a shoulder
154
, as shown in
FIG. 1
, for allowing support arm
150
to rotate about its principal axis. If packaging material holder
140
is rigidly connected to support arm
150
, it may rotate together with support arm
150
as it rotates about its principal axis. Alternatively, support arm
150
may not be rotatable about its principal axis, and packaging material holder
140
and support arm
150
may rotate together about an axis generally perpendicular to the principal axis of support arm
150
, resulting in a general “shoehorn” type of motion. In this case, a “shoehorn” motion means a generally curved upward and outward (i.e., away from the load) motion.
Alternatively, packaging material holder
140
may be connected to support arm
150
by a wrist portion
160
. Wrist portion
160
may include a rod
162
of smaller diameter than support arm
150
which fits within support arm
150
and is attached to packaging material holder
140
to provide rotation of packaging material holder
140
relative to support arm
150
(see FIG.
15
). Alternatively, wrist portion
160
may be flexible and include a spring located between and attached to support arm
150
and packaging material holder
140
to allow packaging material holder
140
to rotate relative to support arm
150
. Rotation of wrist portion
160
may be actuated by an air cylinder or piston, or rotation may be driven by unpowered force such as movement of support arm
150
by pulling away from packaging material holder
140
. Wrist portion
160
may include any suitable device for providing articulation between support arm
150
and packaging material holder
140
such as a hinge, a ball, or a ball and socket combination. Wrist portion
160
may be made from any material which provides the necessary strength and flexibility to allow articulation between support arm
150
and packaging material holder
140
while facilitating the support of packaging material holder
140
on support arm
150
. Examples of suitable materials are metals, plastics, rubbers, and other polymers.
According to the present invention, a dispenser is provided for dispensing packaging material. As shown in
FIG. 2
, packaging material dispenser
102
dispenses a sheet of packaging material
112
in a web form. Packaging material dispenser
102
includes a roll of packaging material contained within a roll carriage
108
and may also include a variety of rollers
110
, optionally including prestretch rollers for stretching the packaging material longitudinally and/or transversely, to position, dispense, and stretch the packaging material as packaging material
112
is being dispensed from the roll of packaging material. Roll carriage
108
of dispenser
102
is vertically moveable on arm
104
to dispense packaging material
112
spirally about load
124
as arm
104
rotates about load
124
. In a preferred embodiment, stretch wrap packaging material is used, however, various other packaging materials such as netting, strapping, banding, or tape can be used as well.
According to the present invention, the apparatus includes means for providing relative rotation between the dispenser and the load to wrap packaging material around the load. As shown in
FIGS. 1 and 2
, the means for providing relative rotation between the dispenser and the load may include an arrangement in which film dispenser
102
revolves around load
124
, so that the dispenser may be carried by a ring or arm or other arrangement. As embodied in
FIGS. 1 and 2
, the means for providing the relative rotation includes a L-shaped arm
104
for supporting and rotating roll carriage
108
of film dispenser
102
in a circle about a vertical axis
128
and about load
124
sifting on a load support surface
130
. L-shaped arm
104
is rotated by a motor driven bearing
134
which drives L-shaped arm
104
and dispenser
102
around a load
124
. Load support surface
130
is preferably a portion of the surface of conveyor
118
but may include other suitable surfaces such as the floor or a portion of a turntable surface. The relative rotation may occur about a vertical axis as shown for pallet loads, or may occur around a horizontal axis for bundling operations.
According to one aspect of the present invention, the apparatus may include means for severing the packaging material between the load and the packaging material holder while holding the packaging material with the packaging material holder. As shown in
FIGS. 5B
,
6
B, and
7
B, the means for severing includes a cutting mechanism
170
, which may include a hot wire or knife, which acts to heat and sever the film by heating when pulsed with electricity as directed by controller
26
. The severing means may be mounted on mast
106
, on film dispenser
102
, or in any other suitable location.
According to one aspect of the present invention, the apparatus may include a film wipedown mechanism for wiping a film tail onto the load after the packaging material has been cut. As embodied herein and shown in
FIGS. 5B
,
6
B, and
7
B, the film wipedown mechanism
180
includes wipe loops
182
and a wipe arm
184
. In a preferred embodiment, cutting mechanism
170
is mounted on wipe arm
184
to allow the film tail
190
to be wiped onto load
124
as the packaging material
112
is cut.
According to another embodiment of the present invention shown in
FIGS. 8-14
, in which similar numerals designate similar components, an apparatus for wrapping a load with packaging material includes stretch wrapping apparatus
200
. As shown in
FIGS. 8-14
, packaging material dispenser
202
is mounted on a stationary mast
206
upon which roll carriage
208
containing a roll of packaging material can be vertically positioned to dispense packaging material
212
from dispenser
202
to wrap load
224
as it rotates. Again, roll carriage
208
may include a frame, a film roll support, and a variety of rollers
210
, optionally including prestretch rollers, to position, dispense, and stretch the packaging material as packaging material
212
is being dispensed from a roll of packaging material.
In this second embodiment of the present invention, the means for providing relative rotation include a motor driven turntable
220
mounted on base
222
to rotate load
224
about a vertical axis
228
. The turntable
220
includes a load support surface
230
upon which the load is supported as it is wrapped and preferably includes conveying means
232
for conveying load
224
into and out of the wrapping area.
The packaging material holder
240
is similar to packaging material holder
140
as described with respect to
FIGS. 1-7
and
15
. Support arm
250
also may be similar to support arm
150
as described with respect to
FIGS. 1-7
and
15
. Alternatively, and as embodied in
FIG. 8
, a first end of support arm
250
may be located on turntable
220
, to one side of load support surface
230
. Support arm
250
supports packaging material dispenser
240
in the manner discussed above, and support arm
250
and packaging material holder
240
may be moveable together or relative to one another as discussed above with respect to
FIGS. 1-7
and
15
.
The packaging material wipedown mechanism
280
and means for severing the packaging material
270
are similar to packaging material wipedown mechanism
180
and severing means
170
as described with respect to
FIGS. 1-7
above. Alternatively, wipedown mechanism
280
may be mounted on the floor, or on mast
206
.
According to a third embodiment of the present invention shown in
FIGS. 16-20
, in which similar numerals designate similar components, an apparatus for wrapping a load with packaging material includes stretch wrapping apparatus
300
. As shown in
FIGS. 16-20
, the dispenser
302
for dispensing packaging material is similar to dispenser
102
as described with respect to
FIGS. 1-7
and the means for providing relative rotation between the dispenser
302
and the load
324
to wrap packaging material
312
around the load
324
is similar to the means for providing relative rotation between dispenser
102
and load
124
as discussed with respect to the first embodiment of the invention.
The packaging material holder
340
is similar to packaging material holder
140
as described with respect to
FIGS. 1-7
and
15
. Support arm
350
also may be similar to support arm
150
as described with respect to
FIGS. 1-7
and
15
. Alternatively, and as embodied in
FIGS. 16-20
, a first end of support arm
350
may be attached to mast
306
or dispenser
302
and support arm
350
may extend linearly between the radially inward and outward positions. As shown in FIG.
17
and embodied herein, support arm
350
may include an extensible support arm portion
352
which may fit into and be extensible from support arm
350
over load support surface
330
to move packaging material holder
340
between the radially outward position and the radially inward position.
Alternatively, extensible support arm portion
352
may move between the radially outward position and radially inward position in a variety of ways. For example, extensible support arm portion
352
may slide upon the top or bottom surface of support arm
350
, slide within a groove in the top or bottom surface of support arm
350
, fold into and out from a portion of support arm
350
, or rotate to and from a portion of support arm
350
. Extensible support arm portion
352
may be made of any material suitable for supporting and moving packaging material holder
340
to and from the load. Examples of such materials include plastics, metals, and other composite materials.
Extensible support arm portion
352
may be rotatable relative to support arm
350
about its principal axis. If packaging material holder
340
is rigidly connected to extensible support arm portion
352
, it may rotate together with extensible support arm portion
352
relative to support arm
350
. Alternatively, extensible support arm portion
352
may not be rotatable about its principal axis, and packaging material holder
340
, support arm
350
, and extensible support arm portion
352
may rotate together about an axis generally perpendicular to the principal axis of support arm
350
, resulting in a general “shoehorn” type of motion as heretofore described.
Alternatively, packaging material holder
340
may be connected to extensible support arm portion
352
by a flexible wrist portion
360
. In this embodiment, wrist
360
is located between extensible support arm portion
352
and packaging material holder
340
. Wrist
360
may be similar to wrist
160
as described with respect to
FIGS. 1-7
and
15
. Wrist portion
360
may include a rod
362
of smaller diameter than support arm
350
attached to extensible support arm portion
352
and attached to packaging material holder
340
to provide rotation of packaging material holder
340
relative to support arm
350
and extensible support arm portion
352
(see FIG.
17
). Wrist portion
360
may include a spring located between and attached to extensible support arm portion
352
and packaging material holder
340
to allow packaging material holder
340
to rotate relative to support arm
350
and extensible support arm portion
352
. Rotation of wrist portion
360
may be actuated by an air cylinder or piston, or rotation may be driven by unpowered force such as movement of extensible support arm portion
352
by pulling away from packaging material holder
340
.
The packaging material wipedown mechanism
380
and means for severing the packaging material
370
are similar to packaging material wipedown mechanism
180
and severing means
170
as described with respect to
FIGS. 1-7
above.
According to a fourth embodiment of the invention shown in
FIGS. 21 and 22
, in which similar numerals designate similar components, an apparatus for wrapping a load with packaging material includes stretch wrapping apparatus
400
. According to this embodiment of the present invention, a dispenser for dispensing packaging material and means for providing relative rotation between the dispenser and the load to wrap packaging material around the load are provided. As shown in
FIGS. 21 and 22
, the dispenser
402
includes a roll of packaging material
403
mounted on a ring
415
which is supported by a vertically moveable frame
425
. The roll of packaging material
403
rotates about a vertical axis
428
as the frame
425
moves up and down to spirally wrap packaging material
412
about the load
424
. Load
424
can be manually placed in the wrapping area or conveyed into the wrapping area by conveyor
418
. Packaging material holder
440
is mounted on frame
425
, and is moveable above conveyor
418
, which serves as a load support surface
430
in the wrapping area, between a radially outward position distant from a side of the load to a radially inward position near a side of the load.
Packaging material holder
440
is similar to packaging material holder
140
as described with respect to
FIGS. 1-7
and
15
. Alternatively, in this embodiment, packaging material holder
440
may be mounted on support arm
450
such that packaging material holder
440
holds the packaging material below support arm
450
and out of the way of rotating wrapping ring
415
during the wrapping process. Support arm
450
also may be similar to support arm
150
as described with respect to
FIGS. 1-7
and
15
. Alternatively, support arm
450
may be mounted on vertical frame
425
as shown in FIG.
21
.
The fourth embodiment of the present invention may also include a packaging material wipedown mechanism and means for severing the packaging material similar to packaging material wipedown mechanism
180
and severing means
170
as described with respect to
FIGS. 1-7
above.
A method for wrapping a load according to the present invention is shown in
FIGS. 1-7
. As shown and according to a preferred embodiment of the present invention, a load
124
is conveyed by a conveyor
118
to a load support surface
130
in the wrapping station. A leading end portion
30
of a sheet of packaging material
112
, preferably stretch wrap packaging material, is engaged by the vacuum cups
144
on unopposed surface
142
of the packaging material holder
140
. Motor driven rotating L-shaped arm
104
begins to rotate film dispenser
102
in a circle about a vertical axis
128
and about load
124
sitting on load support surface
130
. As arm
104
and dispenser
102
rotate about axis
28
, the force exerted upon packaging material holder
140
by leading end portion
30
of packaging material
112
causes packaging material
112
and packaging material holder
140
on supporting arm
150
to move above the load support surface
130
(the portion of conveyor
118
in the wrapping area) from a radially outward position distant from the sides of the load to a radially inward position near the sides of the load as shown in FIG.
2
. In a preferred embodiment, the packaging material holder
140
will continue to move toward the sides of the load until it touches a side of the load, thus stopping the movement of the packaging material holder
140
.
As the packaging material holder reaches the near position, dispenser
102
and arm
104
continue to rotate about load
124
, dispensing and wrapping packaging material
112
about load
124
and packaging material holder
140
near the load (see FIG.
3
). After load
124
is wrapped and arm
104
and dispenser
102
have returned to a “home” position, overwrapped packaging material holder
140
releases the leading end
30
of packaging material and rotates relative to load
124
to move from between packaging material
112
and load
124
as shown in FIG.
4
. If packaging material holder
140
is employing a vacuum surface
142
, controller
26
stops the vacuum and supplies a positive flow of air to blow packaging material
112
away from vacuum surface
142
and vacuum cups
144
.
As shown in the embodiment in
FIG. 4
, packaging material holder
140
rotates on a flexible wrist portion
160
relative to support arm
150
, and by this rotation moves out from between the load
124
and packaging material
112
. If the flexible wrist portion includes a spring, movement of support arm
150
away from the wrapped load toward the distant position will generate a force sufficient to cause packaging material holder
140
to rotate relative to the load
124
and support arm
150
to move packaging material holder
140
from between load
124
and packaging material
112
.
Alternatively, if packaging material holder
140
is rigidly connected to support arm
150
, both packaging material holder
140
and support arm
150
may rotate together along the principal axis of support arm
150
on shoulder
154
to move packaging material holder
140
out from between the load
124
and packaging material
112
. In an alternative embodiment, where packaging material holder
140
is rigidly connected to support arm
150
, both packaging material holder
140
and support arm
150
may rotate together relative to the side of the load about an axis generally perpendicular to the principal axis of support arm
150
to slide packaging material holder
140
out from between the load
124
and packaging material
112
in a “shoehorn” type of motion.
After packaging material holder
140
moves from between load
124
and packaging material
112
, support arm
150
and packaging material holder
140
move away from the load to the distant position. At this point, controller
26
actuates packaging material cutter
170
and wipedown mechanism
180
. Packaging material cutter
170
and wipe-loops
182
of wipedown mechanism
180
extend and press packaging material
112
into packaging material holder
140
, at which time the vacuum cups
144
on vacuum surface
142
are actuated to engage packaging material
112
. The packaging material is severed by packaging material cutter
170
, the trailing end
190
of packaging material may be secured to the load and wiped down by the wipedown mechanism
180
, and the wrapped load is conveyed out of the wrapping area.
All of the functions can be controlled with a typical programmed microprocessor or other controller devices which are conventionally used with the stretch wrapping apparatus.
In the second embodiment of the present invention, as shown in
FIGS. 8-14
, a load is conveyed by a conveyor
218
to a turntable
220
having load support surface
230
in the wrapping station. A leading end portion
30
a
of a sheet of stretch wrap packaging material
212
is engaged by the vacuum cups
244
on unopposed surface
242
of the packaging material holder
240
. Turntable
220
begins to rotate load
224
of load units
226
sitting on load support surface
230
about a vertical axis
228
relative to film dispenser
202
. As turntable
220
rotates about axis
228
, the force exerted upon packaging material holder
240
by leading end portion
30
a
of packaging material
212
causes packaging material
212
and packaging material holder
240
on supporting arm
250
on the turntable
220
to move above the load support surface
230
from a radially outward position distant from the sides of the load to a radially inward position near the sides of the load as shown in FIG.
9
. In a preferred embodiment, the packaging material holder
240
will continue to move toward the sides of the load until it touches a side of the load, thus stopping the movement of the packaging material holder
240
. The remainder of the wrapping process is the same as discussed in the first embodiment shown in
FIGS. 1-7
.
Alternatively, as discussed in the third embodiment of the present invention and as shown in
FIGS. 16-20
, support arm
350
and packaging material holder
340
are moved between the distant position and the near position not by the force applied by the leading end
30
b
of the packaging material
312
, but are actuated by an air cylinder causing an extensible support arm portion
352
to extend from within support arm
350
toward the load with packaging material holder
340
. Extensible support arm portion
352
and packaging material holder
340
move linearly above the load support surface
330
towards the load
324
until packaging material holder
340
touches a side of the load and the wrapping begins.
After load
324
is wrapped and arm
304
and dispenser
302
have returned to a “home” position, overwrapped packaging material holder
340
releases the leading end
30
b
of packaging material and rotates relative to load
324
to move from between packaging material
312
and load
324
as shown in
FIGS. 18 and 19
. If packaging material holder
340
is employing a vacuum surface
342
, controller
26
stops the vacuum and supplies a positive flow of air to blow packaging material
312
away from vacuum surface
342
and vacuum cups
344
.
As shown in the embodiment in
FIGS. 18 and 19
, packaging material holder
340
rotates on a flexible wrist portion
360
relative to extensible support arm portion
352
and support arm
350
, and by this rotation moves out from between the load
324
and packaging material
312
. If the flexible wrist portion includes a spring, movement of extensible support arm portion
352
away from the wrapped load toward the distant position will generate a force sufficient to cause packaging material holder
340
to rotate relative to the load
324
, extensible support arm portion
352
, and support arm
350
to move packaging material holder
340
from between load
324
and packaging material
312
.
Alternatively, if packaging material holder
340
is rigidly connected to extensible support arm portion
352
, both packaging material holder
340
and extensible support arm portion
352
may rotate together along the principal axis of extensible support arm portion
352
to move packaging material holder
340
out from between the load
324
and packaging material
312
. In an alternative embodiment, where packaging material holder
340
is rigidly connected to extensible support arm portion
352
and support arm
150
, packaging material holder
340
, extensible support arm portion
352
, and support arm
350
may rotate together relative to the side of the load about an axis generally perpendicular to the principal axis of support arm
350
to slide packaging material holder
340
out from between the load
324
and packaging material
312
in a “shoehorn” type of motion.
After packaging material holder
340
moves from between load
324
and packaging material
312
, extensible support arm portion
352
and packaging material holder
340
move away from the load to the distant position. The remainder of the wrapping process is the same as discussed for the embodiment depicted in
FIGS. 1-7
.
As depicted in the fourth embodiment, to begin the wrapping process, support arm
450
mounted on a vertically moveable frame
425
and supporting wrapping ring
415
and packaging material dispenser
402
is in a radially outward position distant from the load. Packaging material holder
440
engages a leading end
30
c
of packaging material
412
, and as wrapping ring
415
and dispenser
402
begin to rotate about load
424
, support arm
450
and packaging material holder
440
are pulled toward the side of load
424
by the force exerted on the leading end
30
c
of packaging material
412
by the rotation of the dispenser
402
. Due to the rotational force, support arm
450
and packaging material holder
440
move above the load support surface from a distant position toward the side of the load until the near position is reached. The remainder of the wrapping process is essentially as discussed above with reference to
FIGS. 1-7
.
The present invention as embodied herein and described above, allows fully automated wrapping of loads at a drastically reduced cost and in an extremely efficient manner. The simplicity of the apparatus and its function allows any existing rotary stretch wrapping apparatus to be retrofit to become fully automated. The present invention also overcomes the problems in the prior art, in particular, costly mechanical devices that require upkeep and repair, mechanical interference in load support and conveying means, and leaving a tail portion of the packaging material hanging free from the load.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover all modifications and variations of this invention that come within the scope of the appended claims and their equivalents.
Claims
- 1. An apparatus for wrapping the sides of a load with packaging material comprising:a load support surface for supporting the load during wrapping; a dispenser for dispensing packaging material; means for providing relative rotation between the dispenser and the load to wrap packaging material around the sides of the load; a packaging material holder for selectively holding and releasing a leading end of packaging material; and a support arm moveable above the load support surface for moving the packaging material holder between a radially outward position distant from the sides of the load and a radially inward position near the sides of the load, wherein the support arm and packaging material holder are moveable together about an axis generally perpendicular to the principal axis of the support arm to remove the packaging material holder from between the packaging material and the load.
- 2. An apparatus for wrapping the sides of a load with packaging material comprising:a load support surface for supporting the load during wrapping; a dispenser for dispensing packaging material; means for providing relative rotation between the dispenser and the load to wrap packaging material around the sides of the load; a packaging material holder for selectively holding and releasing a leading end of packaging material; and a support arm moveable above the load support surface for moving the packaging material holder between a radially outward position distant from the sides of the load and a radially inward position near the sides of the load, wherein the support arm includes a shoulder portion allowing the support arm and packaging material holder rotate together about the principal axis of the support arm to remove the packaging material holder from between the packaging material and the load.
- 3. An apparatus for wrapping the sides of a load with packaging material comprising:a load support surface for supporting the load during wrapping; a dispenser for dispensing packaging material; means for providing relative rotation between the dispenser and the load to wrap packaging material around the sides of the load; a packaging material holder for selectively holding and releasing a leading end of packaging material; and a support arm moveable above the load support surface for moving the packaging material holder between a radially outward position distant from the sides of the load and a radially inward position near the sides of the load, wherein the support arm is flexibly connected to the packaging material holder by a wrist portion and wherein the packaging material holder rotates about the wrist portion relative to the support arm to move from between the load and the packaging material.
- 4. An apparatus for wrapping the sides of a load with packaging material comprising:a dispenser for dispensing packaging material; means for providing relative rotation between the dispenser and the load to wrap packaging material around the load; and a packaging material holder with at least one vacuum cup for selectively holding and releasing a leading end of the packaging material, wherein the packaging material holder with the vacuum cup is connected to a support arm and the packaging material holder and support arm are moveable together about an axis generally perpendicular to the principal axis of the support arm to remove the packaging material holder from between the packaging material and the load.
- 5. An apparatus for wrapping the sides of a load with packaging material comprising:a dispenser for dispensing packaging material; means for providing relative rotation between the dispenser and the load to wrap packaging material around the load; and a packaging material holder with at least one vacuum cup for selectively holding and releasing a leading end of the packaging material, wherein the packaging material holder with the vacuum cup is connected to a support arm and the support arm includes a shoulder portion allowing the support arm and packaging material holder to rotate together about the principal axis of the support arm to remove the packaging material holder from between the packaging material and the load.
- 6. An apparatus for wrapping the sides of a load with packaging material comprising:a dispenser for dispensing packaging material; means for providing relative rotation between the dispenser and the load to wrap packaging material around the load; and a packaging material holder with at least one vacuum cup for selectively holding and releasing a leading end of the packaging material, wherein the packaging material holder having the vacuum cup is connected to a support arm by a flexible wrist portion and wherein the packaging material holder rotates about the wrist portion relative to the support arm to move from between the load and the packaging material.
- 7. An apparatus for wrapping a load with packaging material comprising:a load support surface for supporting the load during wrapping; a dispenser for dispensing packaging material; means for providing relative rotation between the dispenser and the load to wrap packaging material around the load; a packaging material holder for selectively engaging and releasing a leading end of the packaging material; and a support arm connected to the packaging material holder for holding the packaging material holder and leading end of the packaging material in a radially inward wrapping position near the sides of the load to wrap the packaging material about the sides of the load and the packaging material holder and for moving the packaging material holder away from the sides of the load to release the packaging material after wrapping, wherein the support arm is flexibly connected to the packaging material holder by a wrist portion, and wherein the packaging material holder rotates about the wrist portion relative to the support arm to move from between the sides of the load and the packaging material as the support arm moves the packaging material holder away from the sides of the load.
- 8. A method for wrapping sides of a load with packaging material comprising:positioning the load on a load support surface; holding a leading end of packaging material with a packaging material holder; moving a support arm connected to the packaging material holder with the packaging material toward a side of the load above the load support surface; dispensing packaging material from a packaging material dispenser and providing relative rotation between the dispenser and the load to wrap packaging material around the sides of the load and over the packaging material holder; rotating the packaging material holder and support arm about a principal axis of the support arm to remove the packaging material holder from between the side of the load and the packaging material; and releasing the packaging material from the packaging material holder and moving the support arm and packaging material holder away from the side of the load above the load support surface.
- 9. A method for wrapping sides of a load with packaging material comprising:positioning the load on a load support surface; holding a leading end of packaging material with a packaging material holder; moving a support arm connected to the packaging material holder with the packaging material toward a side of the load above the load support surface; dispensing packaging material from a packaging material dispenser and providing relative rotation between the dispenser and the load to wrap packaging material around the sides of the load and over the packaging material holder; rotating the packaging material holder and support arm about an axis generally perpendicular to the principal axis of the support arm to remove the packaging material holder from between the side of the load and the packaging material; and releasing the packaging material from the packaging material holder and moving the support arm and packaging material holder away from the side of the load above the load support surface.
- 10. A method for wrapping sides of a load with packaging material comprising:positioning the load on a load support surface; holding a leading end of packaging material with a packaging material holder; moving a support arm connected to the packaging material holder with the packaging material toward a side of the load above the load support surface; dispensing packaging material from a packaging material dispenser and providing relative rotation between the dispenser and the load to wrap packaging material around the sides of the load and over the packaging material holder; rotating the packaging material holder relative to the support arm on a flexible wrist between the packaging material holder and support arm to remove the packaging material holder from between the side of the load and the packaging material; and releasing the packaging material from the packaging material holder and moving the support arm and packaging material holder away from the side of the load above the load support surface.
- 11. A method for wrapping sides of a load with packaging material comprising:positioning the load on a load support surface; holding a leading end of packaging material with a packaging material holder; moving a support arm connected to the packaging material holder with the packaging material toward a side of the load above the load support surface; dispensing packaging material from a packaging material dispenser and providing relative rotation between the dispenser and the load to wrap packaging material around the sides of the load and over the packaging material holder; and releasing the packaging material from the packaging material holder and moving the support arm and packaging material holder away from the side of the load above the load support surface, wherein moving the support arm and packaging material holder away from the side of the load includes pulling on a flexible wrist portion between the packaging material holder and support arm, causing the packaging material holder to rotate about the wrist portion relative to the support arm to remove the packaging material holder from between the side of the load and the packaging material.
- 12. A method for wrapping sides of a load with packaging material comprising:positioning the load on a load support surface; holding a leading end of packaging material with an unopposed surface of a packaging material holder; moving the packaging material holder with a support arm between a radially outward position distant from the sides of the load and a radially inward position near a side of the load, wherein the moving the packaging material holder between a radially outward position and a radially inward position includes rotating a cantilevered support arm above the load support surface; dispensing packaging material from a packaging material dispenser and providing relative rotation between the dispenser and the load to wrap packaging material around the sides of the load and the packaging material holder; and releasing the packaging material from the packaging material holder, rotating the packaging material holder relative to the load, and moving the support arm away from the sides of the load.
- 13. An apparatus for retaining and positioning a free end of packaging material to a load to be wrapped with a rotary stretch wrapping apparatus, comprising:an unopposed packaging material holder moveable between a first position and a second position; a support arm for moving the packaging material holder between a position distant from the sides of the load to be wrapped and a position near the sides of the load to be wrapped, wherein the packaging material holder and support arm are rotatable together about an axis generally perpendicular to the principal axis of the support arm; and a support frame for the support arm and configured to be mounted on or adjacent to a load support surface of a rotary stretch wrapping apparatus.
- 14. An apparatus for retaining and positioning a free end of packaging material to a load to be wrapped with a rotary stretch wrapping apparatus, comprising:an unopposed packaging material holder moveable between a first position and a second position; a support arm for moving the packaging material holder between a position distant from the sides of the load to be wrapped and a position near the sides of the load to be wrapped, wherein the packaging material holder and support arm are rotatable together about the principal axis of the support arm; and a support frame for the support arm and configured to be mounted on or adjacent to a load support surface of a rotary stretch wrapping apparatus.
- 15. An apparatus for retaining and positioning a free end of packaging material to a load to be wrapped with a rotary stretch wrapping apparatus, comprising:an unopposed packaging material holder moveable between a first position and a second position; a support arm for moving the packaging material holder between a position distant from the sides of the load to be wrapped and a position near the sides of the load to be wrapped, wherein the packaging material holder is rotatable about a wrist portion relative to the support arm; and a support frame for the support arm and configured to be mounted on or adjacent to a load support surface of a rotary stretch wrapping apparatus.
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Foreign Referenced Citations (7)
Number |
Date |
Country |
3820048 A1 |
Dec 1989 |
DE |
0630813 A1 |
Jun 1994 |
EP |
2493802 |
Nov 1980 |
FR |
2014107 A |
Aug 1979 |
GB |
2216489 A |
Oct 1989 |
GB |
0430902 A1 |
Jun 1991 |
GB |
27 17 647 |
Nov 1978 |
NL |