Method and apparatus for stretch wrapping a load

Information

  • Patent Grant
  • 6269610
  • Patent Number
    6,269,610
  • Date Filed
    Thursday, August 20, 1998
    26 years ago
  • Date Issued
    Tuesday, August 7, 2001
    23 years ago
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)
Number Name Date Kind
4216654 Kaufman Aug 1980
4300326 Stackhouse Nov 1981
4432185 Geisinger Feb 1984
4563863 Humphrey Jan 1986
4619102 Geisinger Oct 1986
4765120 Phillips Aug 1988
4845920 Lancaster Jul 1989
4972656 Haugstad Nov 1990
4995224 Yourgalite et al. Feb 1991
5005335 Yourgalite et al. Apr 1991
5168691 Errani Dec 1992
5564258 Jones, Sr. et al. Oct 1996
5765344 Mandeville et al. Jun 1998
5941049 Lancaster et al. Aug 1999
Foreign Referenced Citations (5)
Number Date Country
0430902 A1 Jun 1991 EP
0 517 502 A1 Jun 1992 EP
0 671 324 Sep 1995 EP
2014107 Aug 1979 GB
2216489 Oct 1989 GB