Information
-
Patent Grant
-
6269610
-
Patent Number
6,269,610
-
Date Filed
Thursday, August 20, 199826 years ago
-
Date Issued
Tuesday, August 7, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Finnegan, Henderson, Farabow, Garrett & Dunner, L.L.P.
-
CPC
-
US Classifications
Field of Search
US
- 053 587
- 053 556
- 053 588
- 053 211
- 053 399
- 053 441
-
International Classifications
-
Abstract
A leading end of packaging material is grasped in a packaging material holder while a load is wrapped. 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 holder may be positioned on the rotating surface of a turntable but isolated from any electrical or fluid power source of a rotatable surface of the turntable. During the wrapping cycle, the packaging material holder moves downstream along the turntable, automatically releasing the leading end of the packaging material and automatically grasping a trailing end of the packaging material. The packaging material is weakened and then severed between the packaging material holder and the load. The packaging material holder is mounted to permit it to move upstream due to force exerted by the packaging material held in the holder.
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 securing a leading end of the packaging material to the load or a turntable clamp, dispensing the packaging material by providing relative rotation between the load and a packaging material dispenser to cause the load to be enveloped by the packaging material, and severing the packaging material between the load and a packaging material dispenser. The relative rotation between the load and the dispenser can be provided either by rotating the load on a turntable, or by rotating the dispenser around a stationary load. Stretch wrapping usually employs a web of stretch film as the packaging material, and the machinery can be either automatic or semi-automatic.
Semi-automatic stretch wrapping machinery requires the operator to attach a leading end of the packaging material to the load for each load to be wrapped. 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 by 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 reaction to force needed to pull 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 are significantly more expensive than semi-automatic machines. The automatic machines typically use film clamps that grip the film web between two opposed surfaces, use electrical or pneumatic actuators to open and close the clamps, typically supply electrical or pneumatic power to the actuators on a turntable through the journal of the turntable, and use hot wires or other expensive cutting devices are used to cut the film. 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.
In light of the cost of such automatic machines, there is a need for a method and apparatus for wrapping a load with packaging material that operates as effectively as those previously developed to allow automatic release and clamping of portions of the packaging material 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 over and obviates several problems associated with 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 concerns an apparatus for wrapping a load with packaging material, including a dispenser for dispensing packaging material, a rotatable turntable for providing relative rotation between the dispenser and the load to wrap packaging material around the load, and a packaging material holder mounted on the turntable and isolated from any electrical or fluid power source by the rotatable turntable for automatically grasping and releasing portions of the packaging material.
According to another aspect of the present invention, the invention concerns an apparatus for wrapping 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 for holding and releasing the packaging material, the packaging material holder being mounted to move upstream with the packaging material in response to force exerted on the packaging material by the packaging material holder to permit the packaging material to sever at a weakened portion between the packaging material holder and the load.
According to a further aspect of the present invention, there is provided a method of wrapping a load with packaging material, including grasping a leading end of packaging material with a packaging material holder mounted on a rotatable turntable and isolated from any electrical or fluid power source by the rotatable turntable, dispensing packaging material from a packaging material dispenser and rotating the turntable to wrap packaging material around the sides of the load, automatically releasing the leading end of the packaging material from the packaging material holder, and automatically grasping a trailing end of the packaging material with the packaging material holder at a point upstream of the leading end.
According to another aspect of the present invention, a method of wrapping a load with packaging material is provided including 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, holding a portion of the packaging material in a packaging material holder, weakening the packaging material between the load and the packaging material dispenser, and severing the packaging material at the weakened portion by tensioning the packaging material between the packaging material dispenser and the load while permitting the packaging material holder to move upstream with the packaging material toward the dispenser.
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. 1A
is a perspective view of the load wrapping apparatus of the present invention;
FIG. 1B
is a top view of the load wrapping apparatus of
FIG. 1A
;
FIG. 2
is an enlarged fragmentary perspective view of apparatus shown in
FIG. 1
;
FIG. 3A
is a perspective view of the packaging material holder of the present invention;
FIG. 3B
is a perspective view of the packaging material holder of
FIG. 3A
mounted on a turntable;
FIG. 4A
is a perspective view showing the packaging material holder of
FIG. 3
from an opposite side;
FIG. 4B
is a perspective view of the packaging material holder of
FIG. 4A
mounted on a turntable; and
FIGS. 5-11
are schematics showing movement of the packaging material holder during the wrapping process of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following text and accompanying drawings illustrate examples of the present preferred embodiments of the present invention.
According to the invention, an apparatus is provided for wrapping a load with packaging material. As embodied herein and shown in
FIGS. 1 and 2
, an apparatus for wrapping a load with packaging material is generally designated by the reference numeral
100
and includes a packaging material dispenser, means for providing relative rotation between a load and the dispenser, and a packaging material holder.
As shown in
FIG. 1
, a dispenser
102
is provided for dispensing packaging material. Packaging material dispenser
102
dispenses a sheet of packaging material
116
in a web form. Packaging material dispenser
102
includes a roll carriage
109
that supports a roll of packaging material
108
. Roll carriage
109
of dispenser
102
is mounted on and vertically moveable on a mast
104
, shown in
FIG. 1
, to dispense packaging material
116
spirally about load
124
as rotation is provided between load
124
and dispenser
102
. Roll carriage
109
, as embodied herein and shown in
FIG. 1
, includes a support for packaging material roll
108
and means for moving on mast
104
. Alternatively, roll carriage
109
may include a container for holding packaging material roll
108
, and a slit for dispensing packaging material
116
from packaging material roll
108
.
In a preferred embodiment, stretch wrap packaging material is used. In the stretch wrapping art, stretch wrap packaging material is known to have a high yield coefficient to allow the material a large amount of stretch during wrapping. Various other packaging materials, generally not considered to be stretch wrap materials, such as netting, strapping, banding, and tape, can be used as well. Dispenser
102
may also include a variety of rollers, optionally including prestretch rollers for stretching the packaging material longitudinally and/or transversely, to position, dispense, and stretch the packaging material as packaging material
116
is being dispensed from the roll of packaging material.
As shown in
FIGS. 1 and 2
, apparatus
100
includes means for providing relative rotation between the dispenser and the load to wrap packaging material around the load. As embodied herein, the means for providing relative rotation include a conventional turntable assembly
120
. Turntable assembly
120
has a rotatable turntable
122
. Turntable assembly
120
may be positioned proximate a conveyor to receive a load
124
to be wrapped from a load building area. Load
124
is rotated by rotatable turntable
122
of turntable assembly
120
to provide relative motion between dispenser
102
and load
124
.
Although not shown here, turntable assembly
120
may include an upper conveying surface with a plurality of powered rollers. As an alternative to the turntable embodiment, relative rotation may be accomplished by rotating dispenser
102
around a stationary load.
According to the present invention, a packaging material holder for automatically releasing and grasping portions of the packaging material is provided. As embodied herein and shown in
FIGS. 1-4
, the packaging material holder includes packaging material holder
110
, mounted on rotatable turntable
122
of turntable assembly
120
. Packaging material holder
110
includes a clamp for grasping, holding, and releasing packaging material
116
, and a mechanical movement for actuating the clamp. A roper for forming a rope of the packaging material, and a packaging material weakener for weakening the packaging material prior to severing are provided as well in this embodiment.
The clamp for holding and releasing packaging material
116
, as shown in
FIGS. 1-4
, preferably includes opposed surfaces for grasping the packaging material
116
, such as jaws
112
,
114
. Jaws
112
,
114
may be made of any suitable material, such as metal or plastic, and in any suitable shape which will allow the jaws to grasp and hold the packaging material without severing it. Jaws
112
,
114
are preferably mounted on a rail mounted on the turntable to allow jaws
112
,
114
to translate relative to the turntable. Other alternative embodiments of the packaging material holder may include other arrangements such as a single unopposed packaging material engaging surface, such as a sticky or tacky surface for holding the packaging material, or in some instances, a vacuum surface.
As shown in
FIGS. 3 and 4
, the mechanical movement is mounted on the rotatable turntable and includes a floating cam in the form of a ramp
150
attached to rotatable turntable
122
for supporting the packaging material holder
110
on the turntable assembly
120
. The upper surface of ramp
150
forms a downstream pathway
152
at a first height, and the lower surface of ramp
150
from an upstream pathway
154
at a second, lower height. “Upstream” and “downstream,” as used herein, are intended to define the direction of movement relative to the flow of packaging material from the dispenser
102
. Thus, since the packaging material flows from the dispenser, movement toward the dispenser and against the flow of packaging material from the dispenser is defined as “upstream” and movement away from the dispenser and with the flow of packaging material from the dispenser is defined as “downstream.” As used herein, the leading end
30
of packaging material
116
is downstream of the trailing end
32
of packaging material
116
.
As embodied herein, the mechanical movement also includes a cam follower
158
, which allows jaws
112
,
114
to travel on the paths
152
,
154
of ramp
150
. As shown in
FIG. 5
, the cam follower
158
sits at an upstream end of ramp
150
when holding the packaging material during wrapping. Upon actuation of packaging material holder
110
, cam follower
158
moves to the top of the upstream end of ramp
150
and then travels along downstream path
152
. Movement of cam follower
158
up onto the upper surface of ramp
150
automatically causes jaws
112
,
114
of packaging material holder
110
to open. Jaws
112
,
114
remain open as long as cam follower
158
is moving along the downstream path
152
of ramp
150
. Once cam follower
158
reaches the end of downstream path
152
of ramp
150
, cam follower
158
rolls off of the end of ramp
150
. Cam follower
158
rolling off the end of ramp
150
automatically causes jaws
112
,
114
to close. As used herein, the term “automatically” is intended to mean that manual assistance is normally not required.
As embodied herein, the mechanical movement includes a cog mechanism
132
that rotates with packaging material holder
110
as turntable
122
rotates. Cog mechanism
132
consists of an engaging element
134
and a chain element
136
. Chain element
136
forms a complete loop, connected at each of its ends to engaging element
134
. Chain element
136
engages gears placed along the length of packaging material holder
110
, and is moveable along the length of packaging material holder
110
.
As embodied herein, an actuator for the mechanical movement is provided. Preferably, the actuator is positioned apart from rotatable turntable
122
and the mechanical movement, so that the actuator does not rotate with rotatable turntable
122
. As shown, the actuator includes a pin
130
. Engaging element
134
engages and is driven by pin
130
attached to the non-rotating portion of turntable assembly
120
. Pin
130
is moveable between a non-upright position and an upright position, and pin
130
is may be actuated to move to the upright position by a controller. In the upright position, pin
130
engages engaging element
134
of cog
132
as cog
132
rotates with rotatable turntable
122
, driving cog
132
in a direction opposite to that of the rotation. As cog
132
is driven along the length of ramp
150
of packaging material holder
110
, jaws
112
,
114
of packaging material holder
110
moves along the length of ramp
150
in the opposite direction, driven along the downstream path
152
.
Cog element
132
also includes a release element
138
attached to rotatable surface
122
of turntable
120
. Preferable, release element
138
is positioned at the upstream end of packaging material holder
110
. Release element
138
is positioned to knock down or disengage pin
130
from cog
132
once cog
132
has moved from the downstream end of packaging material holder
110
to the upstream end of packaging material holder
110
. As the length of packaging material holder
110
defines the full range of movement for cog
132
, it is necessary to have a release once cog
132
has reached the end of its range of motion. Release element
138
serves this purpose.
Jaws
112
,
114
of packaging material holder
110
moves along upstream path
154
after it has reached the end of downstream path
152
. Cam follower
158
is pulled along upstream path
154
by the force exerted upon packaging material
116
held in jaws
112
,
114
by the roll of packaging material in dispenser
102
. As shown in
FIGS. 3 and 4
, downstream path
152
is positioned above upstream path
154
, such that packaging material holder
110
travels at a first level downstream, and at a second, lower level upstream.
As discussed above, packaging material holder
110
is mounted on the top surface of rotatable turntable
122
, and jaws
112
,
114
of packaging material holder
110
are actuated to automatically open and close at predetermined points along the length of ramp
150
of packaging material holder
110
. As embodied herein, packaging material holder
110
is isolated from any electrical or fluid source of power by the turntable, in contrast to conventional devices in which the packaging material holder is connected to an electrical or fluid source of power by the turntable such as by a power connection through the journal of the turntable to the packaging material holder. This means that the packaging material holder also does not receive any electrical or fluid power from brushes, or the like, around a circumference of the turntable. The rotatable turntable
122
therefore does not carry electrical or fluid power sources with it during rotation and acts as a barrier between the packaging material holder and any electrical or fluid source of power.
This enables the present invention to take advantage of the changing of the angle of the packaging material relative to the load as the turntable rotates. The rotation of the turntable is harnessed to linearly move the packaging material holder along the turntable surface. During the last rotation of the turntable, as the angle becomes smaller and the packaging material approaches the side of the load, the packaging material holder is driven by the rotation of the turntable into a position to engage the trailing end of the packaging material.
In a preferred embodiment, as shown in
FIG. 2
, the movement of the turntable is utilized to move jaws
112
,
114
, opening and closing jaws
112
,
114
to automatically release and grasp, respectively, packaging material
116
. As discussed above, cog element
132
cooperates with pin
130
to move jaws
112
,
114
relative to rotatable turntable
122
and thereby open and close jaws
112
,
114
. Pin
130
can be actuated to move from the non-upright position to the upright position at a predetermined point in the wrapping cycle by the controller. Preferably, pin
130
is actuated during the last rotation in the wrapping cycle, and most preferably during the last quarter turn of the wrapping cycle, to engage cog
132
. Because cog
132
moves with rotatable surface
122
of turntable
120
, the rotation of the turntable can be used to move cog
132
. Cog
132
is moveably connected to jaws
112
,
114
such that, if cog
132
moves to the left, jaws
112
,
114
will move to the right. Alternatively, if cog
132
is moved to the right, jaws
112
,
114
will move to the left. Thus, it is the rotation of the turntable, rather than an electrical or fluid power source carried by the rotating turntable, that is used to move and thereby automatically open and close jaws
112
,
114
.
Other mechanical movements including various combinations of mechanical or electrical devices may be used to cause movement and opening and closing of jaws
112
,
114
. Alternatively, turntable
122
may not rotate while the packaging material is automatically released and grasped by the packaging material holder. In such a situation, packaging material holder
110
could be powered by a separate power source such as a motor placed on the floor or near the turntable.
According to one aspect of the invention, a roper may be provided for forming a rope of packaging material. As discussed herein, “roping” packaging material means rolling or twisting or collapsing a portion of the web of packaging material
116
to shape it into a rope-like form. In order to withstand a starting force during wrapping, at least 20% of the web of packaging material
116
should be held by the packaging material holder. For example, a web of packaging material twenty (20) inches high may have a five (5) or six (6) inch portion formed into a rope. This allows the jaws
112
,
114
to engage a rope
118
and a portion of the web of packaging material
116
, rather than holding only a small portion of the packaging material
116
between the opposing surfaces. As seen in
FIGS. 1 and 2
, jaws
112
,
114
can grasp a substantial cross section of the web of packaging material
116
when it has been roped. This gives the lower portion of the web of packaging material
116
between jaws
112
,
114
and dispenser
102
the triangular shape seen in
FIGS. 1 and 2
. As embodied herein and shown in
FIG. 4
, the roper includes scooping element
140
, which is attached to and moveable with jaws
112
,
114
of packaging material holder
110
. As jaws
112
,
114
and scooping element to
140
move along downstream path
152
, they move from a flat position to an upright position. As scooping element
140
changes position, it captures the web of packaging material
116
and rolls the packaging material
116
into a rope
118
as it moves into the full upright position.
Although the present invention, as embodied herein, uses a scoop for roping, it is possible to use a wheel to roll the lower edge of the packaging material upward to form a rope of packaging material or to use a combination of a scoop and a wheel. Alternatively, other means such as a ramp may be used to gather the packaging material together to form a rope.
A positioner may be provided for passing the packaging material over the packaging material holder during wrapping. As embodied herein and shown in
FIGS. 3 and 4
, the positioner for passing the packaging material over packaging material holder includes wheel
141
. Wheel
141
rolls a lower edge of packaging material
116
as it passes over wheel
141
, lifting it above packaging material holder
110
. Thus it causes packaging material
116
to pass above packaging material holder
110
, avoiding the tenting effect of holders in the prior art.
As embodied herein and shown in
FIG. 3
, a packaging material weakener is provided for weakening the packaging material
116
between the load
124
and the dispenser
102
. The packaging material holder
110
preferably includes a cutter
142
. Cutter
142
may include an opposed cutting element, such as scissors, or a single cutting element such as a razor blade. Cutter
142
is connected to an actuation lever
144
which moves with jaws
112
,
114
. Actuation lever
144
is moveable between a free position and a contact position. As jaws
112
,
114
move along downstream path
152
, jaws
112
,
114
open, automatically releasing packaging material
116
, scooping element
140
moves upward to scoop the lower edge of the web of packaging material
116
into a rope
118
, and actuator lever
144
moves from the free position to the contact position. When actuation lever
144
is in the contact position, cutter
142
is activated to weaken packaging material
116
by cutting at least a portion of the web of packaging material
116
, including the rope
118
of packaging material
116
.
According to one aspect of the present invention, the apparatus may include means for securing a trailing end of packaging material to the load. As embodied herein, the means for securing includes a film wipedown mechanism for wiping a film tail onto the load after the packaging material has been cut. As shown in
FIG. 1
, the film wipedown mechanism
180
includes wipe loops
182
and a wipe arm
184
. This allows a film tail to be wiped onto load
124
as the packaging material
116
is cut.
Other cutters and wipedown arrangements may also be used.
A method for wrapping a load according to the present invention is shown in
FIGS. 5-11
. As shown in FIG.
5
and according to a preferred embodiment of the present invention, a load
124
is conveyed by a conveyor
118
to a turntable assembly
120
in the wrapping station and load
124
is positioned on top of rotatable turntable
122
of turntable assembly
120
. Jaws
112
,
114
of packaging material holder
110
hold a leading end portion
30
of a roped sheet of packaging material
116
, preferably stretch wrap packaging material. Cog
132
is positioned at a downstream end of packaging material holder
110
, and jaws
112
,
114
are positioned at the upstream end of packaging material holder
110
, and cam follower
158
is positioned to the upstream side of ramp
150
(FIG.
5
).
Rotatable turntable
122
begins to rotate and packaging material
116
is dispensed from dispenser
102
about load
124
. As packaging material
116
passes over packaging material holder
110
, wheel
41
engages the lower edge of the packaging material, ensuring that the packaging material passes over packaging material holder
110
and does not become caught on it. This avoids a “tenting” effect and allows tight wrapping of the load. Load
124
is spirally wrapped with packaging material
116
as dispenser
102
moves vertically along mast
104
as the relative rotation is provided.
As the load is wrapped and rotatable turntable
122
enters the last rotation of the wrapping cycle, see
FIG. 6
, a pin
130
attached to a non-rotating portion of turntable assembly
120
is actuated by the controller, moving from a non-upright position to an upright position. As the turntable
122
rotates, pin
130
engages engaging element
134
of cog
132
, located on top of rotatable turntable
122
of turntable assembly
120
. Pin
130
causes cog
132
to move upstream (in a direction opposite to that of the rotation) along the top surface of rotatable turntable
122
of turntable assembly
120
as rotation continues.
As cog
132
moves, the movement causes cam follower
158
to move up onto the top of ramp
150
, to the start of downstream path
152
. When cam follower
158
moves to the top of ramp
150
, jaws
112
,
114
open, automatically releasing leading end portion
30
of packaging material
116
(see FIG.
7
). Additionally, dispenser
102
is shut off to tension the film between load
124
and dispenser
102
.
As cog
132
moves, it drives jaws
112
,
114
downstream along a downstream path
152
of ramp
150
. Concurrently, scooping element
140
begins to move from a retracted position to an upright position, scooping a trailing end
32
of packaging material
116
into a rope
118
. As jaws
112
,
114
continue to move downstream, they remain open, receiving trailing end
32
of packaging material
116
formed into rope
118
as scooping element
140
reaches its full upright position (see FIG.
8
). As cog
132
reaches the upstream end of packaging material holder
110
, cam follower
158
reaches the end of path
152
and rolls off the end of ramp
150
, causing jaws
112
,
114
to automatically clamp shut on and grasp trailing end
32
of roped packaging material
116
.
As scooping element
140
is moving from the retracted position to the full upright position (see FIG.
9
), actuation lever
144
moves from the free position to the contact position, activating cutter
142
to weaken packaging material
116
between jaws
112
,
114
and load
124
after jaws
112
,
114
have automatically grasped the trailing end
32
of packaging material
116
. At the same time, pin
130
encounters release element
138
at the upstream end of packaging material holder
110
, which knocks pin
130
into its non-upright position, causing it to disengage from cog
132
.
Once jaws
112
,
114
have reached the downstream end of packaging material holder
110
, they grasp and hold trailing end
32
of packaging material
116
. Packaging material
116
extends between dispenser
102
, jaws
112
,
114
, and load
124
. The tension in packaging material
116
between dispenser
102
and jaws
112
,
114
causes jaws
112
,
114
to move upstream toward the dispenser (see FIG.
10
). Jaws
112
,
114
move upstream as cam follower
158
travels along upstream path
154
of ramp
150
in response to the force exerted by the packaging material. Because cam follower
158
can travel underneath the floating cam (ramp
150
) as it returns upstream, instead of traveling on top of ramp
150
, jaws
112
,
114
remain shut as they travel upstream. As jaws
112
,
114
holding trailing end
32
of packaging material
116
move upstream, packaging material
116
is tensioned between jaws
112
,
114
and load
124
. Because of the relative movement of the packaging material holder, packaging material
116
then breaks at the weakened portion between load
124
and jaws
112
,
114
, rather than between the packaging material holder and the dispenser. This provides a true automatic operation by maintaining the packaging material to be held in the packaging material holder before, during and after severing.
Other arrangements for permitting the packaging material holder to move upstream with the packaging material toward the dispenser may also be provided.
Although the arrangement illustrated in the drawings weakens and then breaks the packaging material between the load and the jaws, it is in the scope of the one aspect of the invention to weaken the film somewhere between the dispenser and the load, and then break the film between the jaws and the load. Additionally, it is possible to simply sever the packaging material, as opposed to weakening and then breaking the packaging material.
All of the functions can be controlled with a conventional microprocessor, electromechanical controller, or other controller devices which are conventionally used with the stretch wrapping apparatus.
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 existing rotary stretch wrapping apparatus to be retrofit to become fully automated. By using the rotation of the turntable to facilitate the releasing, grasping, and cutting of the packaging material, the need to supply power through the rotatable turntable of the turntable assembly to the packaging material holder and the need for expensive timing circuits is eliminated.
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. A method of automatically wrapping a load with packaging material, comprising:automatically 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; automatically holding a portion of the packaging material in a packaging material holder; automatically weakening the packaging material between the load and the packaging material dispenser; and automatically severing the packaging material at the weakened portion by tensioning the packaging material between the packaging material dispenser and the load while permitting the packaging material holder to move upstream with the packaging material toward the dispenser.
- 2. The method of claim 1, wherein providing relative rotation includes rotating a turntable having the packaging material holder mounted on it.
- 3. The method of claim 1, wherein the packaging material holder is mounted on a turntable and is mechanically repositioned downstream prior to the weakening due to the rotation of the turntable.
- 4. The method of claim 1, wherein the packaging material holder is mounted on a turntable and jaws of the packaging material holder are automatically opened and closed by a power source isolated by the rotatable turntable.
- 5. The method of claim 1, wherein the packaging material is roped into the packaging material holder prior to weakening.
- 6. The method of claim 1, including roping the packaging material into the packaging material holder and weakening the packaging material by cutting a portion of the roped packaging material.
- 7. The method of claim 1, wherein the automatically weakening includes cutting a portion of the wrapped packaging material with an opposed cutting element.
- 8. The method of claim 1, including moving the packaging material holder downstream prior to weakening the packaging material.
- 9. The method of claim 1, including moving the packaging material holder downstream prior to weakening the packaging material, and moving the packaging material holder upstream subsequent to weakening the packaging material.
- 10. The method of claim 1, including weakening the packaging material between the packaging material holder and the dispenser, and severing the packaging material between the packaging material holder and the load.
- 11. The method of claim 1, wherein the weakening and severing occur between the load and the packaging material holder.
- 12. The method of claim 1, wherein the weakening is prior to the holding.
- 13. The method of claim 1, wherein the holding is prior to the weakening.
- 14. The method of claim 1, including automatically releasing the leading end of the packaging material from the packaging material holder prior to weakening.
- 15. The method of claim 1, wherein the packaging material holder moves downstream to automatically release and grasp the packaging material, and the packaging material holder moves upstream to sever the packaging material.
- 16. The method of claim 1, wherein the packaging material holder is mounted on a cam follower and rides downstream on a ramp formed by a top portion of a cam at a first height to automatically release and grasp the packaging material, and the packaging material holder rides upstream along a lower portion of the cam at a lower height to provide tension on the weakened portion of the packaging material to sever the packaging material between the load and the packaging material holder.
- 17. An apparatus for wrapping 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 for automatically holding and releasing the packaging material, the packaging material holder being mounted to move upstream with the packaging material in response to force exerted on the packaging material by the packaging material holder to permit the packaging material to sever at a weakened portion between the packaging material holder and the load.
- 18. The apparatus of claim 17, including a packaging material weakener.
- 19. The apparatus of claim 17, wherein the packaging material holder severs the weakened packaging material as the packaging material holder moves upstream.
- 20. The apparatus of claim 17, wherein the means for providing relative rotation is a turntable and the packaging material holder is mounted on the turntable.
- 21. The apparatus of claim 17, wherein the packaging material holder is mounted on a rotatable turntable and the packaging material holder is isolated from any source of electrical or fluid power by the rotatable turntable.
- 22. The apparatus of claim 17, including means for roping the packaging material into the packaging material holder.
- 23. The apparatus of claim 17, wherein the packaging material holder is moveable downstream and including a packaging material weakener, wherein the packaging material weakener is actuated as the packaging material holder is moved downstream.
- 24. The apparatus of claim 17, wherein the packaging material holder includes jaws for grasping and holding the packaging material.
- 25. The apparatus of claim 17, including means for moving the packaging material holder downstream to automatically release a leading end of the packaging material from the packaging material holder.
- 26. The apparatus of claim 17, including means for moving the packaging material holder downstream to automatically release a leading end of the packaging material from the packaging material holder, wherein the means for moving is isolated from a power source causing the relative rotation.
- 27. The apparatus of claim 17, including means for moving the packaging material holder downstream to automatically grasp a trailing end of the packaging material from the packaging material holder.
- 28. The apparatus of claim 17, including means for moving the packaging material holder downstream to automatically grasp a trailing end of the packaging material from the packaging material holder, wherein the means for moving is isolated from a power source causing the relative rotation.
- 29. The apparatus of claim 17, further including means for moving the packaging material holder downstream to automatically release a leading end of the packaging material from the packaging material holder and to automatically grasp a trailing end of the packaging material from the packaging material holder.
- 30. The apparatus of claim 17, including a packaging material weakener, wherein the packaging material weakener includes an opposed cutting element.
- 31. The apparatus of claim 17, further including means for securing a trailing end of packaging material to the load.
- 32. An apparatus for wrapping a load with packaging material, comprising:a dispenser for dispensing packaging material; a rotatable turntable for providing relative rotation between the dispenser and the load to wrap packaging material around the load; and a packaging material holder mounted on the rotatable turntable and isolated from any electrical or fluid power source by the rotatable turntable for automatically grasping and releasing portions of the packaging material, the packaging material holder being mounted to translate along a path on the turntable to permit the packaging material to pull the packaging material holder in an upstream direction on the path.
- 33. An apparatus for wrapping a load with packaging material, comprising:a dispenser for dispensing packaging material; a rotatable turntable for providing relative rotation between the dispenser and the load to wrap packaging material around the load; a packaging material holder mounted on the rotatable turntable and isolated from any electrical or fluid power source by the rotatable turntable for automatically grasping and releasing portions of the packaging material; and a floating cam mounted on the turntable for moving the packaging material holder and a cam follower mounted to the packaging material holder, wherein the cam includes a downstream ramp at a first height and an upstream ramp at a second lower height.
- 34. A method of wrapping a load with packaging material, comprising:grasping a leading end of packaging material with a packaging material holder mounted on a rotatable turntable and isolated from any electrical or fluid power source by the rotatable turntable; dispensing packaging material from a packaging material dispenser and rotating the turntable to wrap packaging material around the sides of the load; engaging and actuating the packaging material holder with an actuator stationed apart from the rotatable turntable; automatically releasing the leading end of the packaging material from the packaging material holder; and automatically grasping a trailing end of the packaging material with the packaging material holder at a point upstream of the leading end.
- 35. The method of claim 34, wherein the automatically grasping includes grasping the packaging material with jaws and the automatically releasing includes releasing the packaging material from the jaws.
- 36. The method of claim 34 including an actuator stationed apart from the rotatable turntable, and wherein the packaging material holder includes a mechanical movement engageable by the actuator to actuate the packaging material holder.
- 37. The method of claim 34, wherein the automatically releasing includes using movement of the turntable to release the packaging material from the packaging material holder.
- 38. The method of claim 34, wherein the packaging material holder includes jaws and the automatically releasing includes translating the jaws relative to the turntable to open the jaws to release the packaging material.
- 39. The method of claim 34, wherein the packaging material holder includes jaws and the automatically grasping includes translating the jaws relative to the turntable to close the jaws to grasp the packaging material.
- 40. The method of claim 34 including automatically severing the packaging material.
- 41. The method of claim 34, including automatically severing the packaging material and weakening the packaging material prior to severing it.
- 42. The method of claim 34, including automatically weakening the packaging material prior to severing the packaging material.
- 43. The method of claim 34, including automatically weakening the packaging material with an opposed blade.
- 44. The method of claim 34, including roping the packaging material prior to automatically grasping the packaging material.
- 45. The method of claim 34, including severing the packaging material and roping the packaging material prior to severing the roped packaging material.
- 46. The method of claim 34, including securing the trailing edge of the packaging material to the load after severing the packaging material.
- 47. The method of claim 34 including roping, weakening, and severing the packaging material.
- 48. An apparatus for wrapping a load with packaging material, comprising:a dispenser for dispensing packaging material; a rotatable turntable for providing relative rotation between the dispenser and the load to wrap packaging material around the load; a packaging material holder mounted on the rotatable turntable and isolated from any electrical or fluid power source by the rotatable turntable for automatically grasping and releasing portions of the packaging material; and an actuator, stationed apart from the rotatable turntable, for engaging and actuating the packaging material holder.
- 49. The apparatus of claim 48 including an actuator stationed apart from the rotatable turntable, and wherein the packaging material holder includes a mechanical movement engagable by the actuator to actuate the packaging material holder.
- 50. The apparatus of claim 48, wherein the packaging material holder is mounted to translate along a path on the turntable, and including a mechanical movement for moving the packaging material holder in a downstream direction on the path.
- 51. The apparatus of claim 48, wherein the packaging material holder is moveable upstream and downstream and includes a floating cam mounted on the turntable to keep the packaging material holder open when moving downstream and closed while moving upstream.
- 52. The apparatus of claim 48, including a weakener for weakening the packaging material.
- 53. The apparatus of claim 48, wherein the packaging material holder includes jaws for holding the packaging material.
- 54. The apparatus of claim 48, including means for forming a rope of packaging material and directing it into the open packaging material holder.
- 55. The apparatus of claim 48, including means for securing a trailing end of packaging material to the load.
- 56. A method of wrapping a load with packaging material, comprising:grasping a leading end of packaging material with a packaging material holder mounted on a rotatable turntable and isolated from any electrical or fluid power source by the rotatable turntable; dispensing packaging material from a packaging material dispenser and rotating the turntable to wrap packaging material around the sides of the load; translating the packaging material holder along a path on the rotatable turntable; automatically releasing the leading end of the packaging material from the packaging material holder; and automatically grasping a trailing end of the packaging material with the packaging material holder at a point upstream of the leading end.
- 57. An apparatus for wrapping a load with packaging material, comprising:a dispenser for dispensing packaging material; a rotatable turntable for providing relative rotation between the dispenser and the load to wrap packaging material around the load; and a packaging material holder mounted on and translatable along a path on the rotatable turntable and isolated from any electrical or fluid power source by the rotatable turntable for automatically grasping and releasing portions of the packaging material.
- 58. A method of wrapping a load with packaging material, comprising:grasping a leading end of packaging material with a packaging material holder mounted on a rotatable turntable and isolated from any electrical or fluid power source by the rotatable turntable; dispensing packaging material from a packaging material dispenser and rotating the turntable to wrap packaging material around the sides of the load; actuating the packaging material holder by rotating the turntable; automatically releasing the leading end of the packaging material from the packaging material holder; and automatically grasping a trailing end of the packaging material with the packaging material holder at a point upstream of the leading end.
- 59. An apparatus for wrapping a load with packaging material, comprising:a dispenser for dispensing packaging material; a rotatable turntable for providing relative rotation between the dispenser and the load to wrap packaging material around the load; and a packaging material holder mounted on the rotatable turntable and isolated from any electrical or fluid power source by the rotatable turntable for automatically grasping and releasing portions of the packaging material, wherein rotation of the turntable actuates the packaging material holder.
US Referenced Citations (14)
Foreign Referenced Citations (5)
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