Vertical form, fill and seal packaging machine for making recloseable product filled bags

• US 5,400,565 A
• Filed: 06/14/1993
• Issued: 03/28/1995
• Est. Priority Date: 06/29/1992
• Status: Expired due to Term

• Current Assignee: Pacmac Incorporated
• Original Assignee: Pacmac Incorporated
• Inventors: Terminella, Emanuele, Terminella, Joseph, Terminella, Frank
• Primary Examiner(s): Larson, Lowell A.
• Application Number:
  US08/076,018
• Time in Patent Office: 652 Days
• Field of Search: 53/133.4, 53/139.2, 53/373.6, 53/551, 53/552, 53/554, 53/51, 53/64, 53/66
• US Class Current: 53/133.4
• CPC Class Codes: B65B 41/16 by rollers
• CPC Class Codes: B65B 61/188 by applying or incorporating profile-strips, e.g. for reclosable bags
• CPC Class Codes: B65B 9/20 the webs being formed into tubes in situ around the filling nozzles
• CPC Class Codes: B65B 9/2028 Rollers or belts
• CPC Class Codes: B65B 9/2042 Means for altering the cross-section of the tube filling opening prior to transversal sealing, e.g. tube spreading devices subdividing filled tubes to form two or more packages by sealing involving displacement of contents B65B9/12
• CPC Class Codes: B65B 9/213 the web having intermittent motion B65B9/22 takes precedence

Abstract

A vertical form, fill and seal packing machine and method for making recloseable bags having a safety seal exterior to a recloseable seal. The machine produces durable, substantially air-tight bags at high speed and provides for the production of different size bags and different amounts of product in the bags. The machine includes a film drive and pinch roll pair, a pair of film pull belts, and a pair of zipper drive rollers for pulling the plastic film and zipper strip through the machine. The production of different size bags is facilitated by having the film drive roll, pull belts, and zipper drive rollers simultaneously driven in bag length increments by a common drive source. Also, to accommodate the production of different size bags, the machine includes a vertically adjustable mark sensor. Further, the machine and method of the present invention insures reliable seals along the edges of each product filled bag by having the zipper drive rollers and a bag grabber mechanism stretch the bag material prior to cross-sealing and severing the bag material.

Claims

1. A vertical, form, fill, and seal apparatus of the type that operates in conjunction with a product supply apparatus providing product in discrete quantities and that forms a continuous, heat sealable plastic film and zipper strip into separate product filled, recloseable, sealed bags comprising:

a first controlled release festooner arrangement for storing and supplying a continuous plastic film,

a second controlled release festooner arrangement for storing and supplying a continuous, plastic, zippered cap strip,

a generally vertical fill tube assembly including a vertical fill tube downstream of the first festooner arrangement for the continuous film and around which the continuous film is formed and wrapped,

feeding means including a film drive roll upstream of the vertical fill tube, a pair of endless pull belts adjacent the vertical fill tube, a pair of zipper drive rollers located downstream of the vertical fill tube and a common drive source for the drive roll, pull belts and drive rollers for feeding the zippered cap strip and plastic film along the length of the vertical fill tube in bag length increments with edges of the plastic film in overlapping relationship with edges of the zippered cap strip,

vertical sealing means for sealing the edges of the plastic film to the edges of the zippered cap strip to form a length of flexible, plastic tube,

a pinch seal assembly downstream of the vertical fill tube for forming first and second horizontal seals across the flexible plastic tube and for severing the plastic tube, the first horizontal seal defining the downstream edge of a bag about to be filled with product and the second horizontal seal defining the upstream edge of a bag which has already received product, and

a bag grabber mechanism having opposing air cylinder units for gripping and horizontally elongating the flexible, plastic tube transverse to its length prior to formation of said first horizontal seal, for sequentially supporting the upstream edge of each product filled bag during formation of the second horizontal seal and for sequentially releasing each completed, recloseable, product filled, sealed bag following formation of the second horizontal seal and severing of the bag from the flexible tube,

wherein said zipper drive rollers and said bag grabber mechanism are mounted on a common reciprocating element so that said zipper drive rollers and said bag grabber mechanism are moved in unison transverse to the vertical fill tube between a first position in which the zipper drive rollers and bag grabber mechanism are vertically aligned along a vertical axis parallel to the vertical fill tube and a second position in which the zipper drive roller and bag grabber mechanism are spaced further from the vertical fill tube and wherein the zipper drive rollers and bag grabber mechanism are moved from the first position to the second position prior to and during formation of said horizontal seals and from the second position back to the first position following severing and horizontal sealing of the product filled bag and prior to incremental movement of the plastic film and zippered cap strip along the vertical fill tube.

2. Apparatus as recited in claim 1 further comprising guiding means for guiding the zippered cap strip down along the vertical fill tube including a pair of grooved idler rollers mounted adjacent the vertical fill tube near its upper end, a grooved guide bar extending along a portion of the length of the vertical fill tube, and the zipper drive rollers mounted downstream of the vertical fill tube.

3. Apparatus as recited in claim 1 wherein said bag grabber mechanism, said zipper drive rollers and an oppositely disposed rod extending downwardly from said vertical fill tube comprise a plastic tube tensioning means.

4. Apparatus as recited in claim 1 wherein each of the pull belts is mounted adjacent one side of the vertical fill tube and spring biased against the plastic film wrapped around the fill tube.

5. Apparatus as recited in claim 1 wherein the common drive source comprises an electric servomotor having a drive output connected to a transmission having a first transmission output providing drive to the zipper drive rollers and the film pull belts, and a second transmission output providing drive to the film drive roll.

6. The apparatus as recited in claim 5 wherein the first transmission output is operatively connected to the film pull belts by a drive train including a horizontally compact vertically arranged belt transmission including a plurality of drive and idler sprockets, at least one toothed drive belt and respective shafts including expanding universal joints to accommodate movement of said pull belts toward and away from said fill tube.

7. Apparatus as recited in claim 5 wherein the first transmission output provides drive to the zipper drive rollers by being operatively connected to a hexagonal shaft extending transverse to and spaced from the fill tube, and wherein a first drive belt pulley having a hexagonal central opening is mounted for sliding movement along at least a portion of the hexagonal shaft, a first drive belt passes over the first pulley and a second pulley operatively connected to one of the zipper drive rollers.

8. Apparatus as recited in claim 7 wherein each of the zipper drive rollers has a set of gear teeth at one end thereof, the gear teeth of each zipper drive roller intermeshing with one another to cause the drive rollers to rotate in opposite directions.

9. Apparatus as recited In claim 4 wherein each of said pull belts is supported by a cantilevered leaf spring arrangement which allows said belts to be moved away from said vertical fill tube to accommodate cleaning and maintenance of said fill tube.

10. Apparatus as recited in claim 9 wherein said cantilevered leaf spring arrangement includes a vertical bracket supporting a pull belt drive roller and a plurality of pull belt idler rollers, a slide block and a plurality of leaf springs connecting said vertical bracket to said slide block.

11. Apparatus as recited in claim 1 wherein said zipper drive rollers are located upstream of said pinch seal assembly and said bag grabber mechanism is located downstream of said pinch seal assembly.

12. A vertical, form, fill, and seal apparatus of the type that operates in conjunction with a product supply apparatus providing product in discrete quantities and that forms a continuous, heat sealable plastic film into separate product-filled sealed bags comprising:

first controlled release means for storing and supplying a continuous plastic film,

second controlled release means for storing and supplying a continuous, plastic, cap strip,

a generally vertical fill tube assembly including a vertical fill tube downstream of said first controlled release means for the plastic film,

feeding means including a plastic film drive roll upstream of said fill tube, a pair of pull belts adjacent said fill tube, and a pair of cap strip drive rollers downstream of said fill tube for feeding the cap strip and plastic film along the length of said vertical fill tube in bag length increments with edges of the continuous film in overlapping relationship with edges of the cap strip,

vertical sealing means for sealing the edges of the plastic film to the edges of the cap strip to form a length of flexible, plastic tube,

each of said pair of pull belts being mounted on a respective side of the vertical fill tube and biased against the plastic film and said vertical fill tube,

horizontal sealing and severing means downstream of said vertical fill tube for severing the plastic tube and forming horizontal seals across the plastic tube, and

tensioning means for horizontally elongating the plastic tube transverse to its length prior to severing and formation of said horizontal seals.

13. Apparatus as recited in claim 12 further comprising common drive means for simultaneously driving said plastic film drive roll, said pull belts and said cap strip drive rollers at proportional speeds.

14. Apparatus as recited in claim 13 wherein said tensioning means includes said cap strip drive rollers and an opposing rod extending downwardly from said vertical fill tube.

15. Apparatus as recited in claim 14 wherein said tensioning means further includes bag grabber means comprising a pair of opposing air cylinder units located downstream of said vertical fill tube for selectively clamping said cap strip therebetween.

16. Apparatus as recited in claim 15 wherein the bag grabber means and said cap strip drive rollers are mounted on a common support for reciprocation transverse to said vertical fill tube.

17. The apparatus as recited in claim 13 wherein said common drive means includes a single electric servomotor and respective drive trains for driving at least said pull belts and drive rollers.

18. The apparatus as recited in claim 17 wherein said drive train for said pull belts includes a horizontally compact vertically arranged belt transmission.

19. A vertical, form, fill, and seal apparatus of the type that operates in conjunction with a product supply apparatus providing product in discrete quantities and that forms a continuous, heat sealable plastic film and zippered cap strip into separate product filled, recloseable, sealed bags comprising:

means for storing and supplying the continuous plastic film,

means for storing and supplying the continuous, plastic, zippered cap strip,

a generally vertical fill tube assembly including a vertical fill tube downstream of the means for storing and supplying the continuous film and around which the continuous film is formed and wrapped,

feeding means including a film drive roll upstream of said vertical fill tube, a pair of film pull belts adjacent said vertical fill tube, and a pair of zipper drive rollers downstream of said pull belts for feeding the continuous zippered cap strip and plastic film along the length of the vertical fill tube in bag length increments with edges of the continuous film in overlapping relationship with edges of the zippered cap strip,

vertical sealing means for sealing the edges of the continuous film to the edges of the continuous zippered cap strip to form a flexible, plastic tube,

horizontal sealing and severing means downstream of the vertical fill tube for forming horizontal seals across the flexible plastic tube and for severing the plastic tube,

tensioning means including said zipper drive rollers for horizontally elongating the flexible, plastic tube transverse to its length prior to formation of said horizontal seals, and

bag support means for sequentially supporting each product filled bag during formation of said horizontal seals and releasing each completed, recloseable, product filled, sealed bag following severing of the bag from the flexible tube.

20. The apparatus as recited in claim 19 wherein the feeding means for the plastic zippered cap strip includes a pair of grooved idler rollers mounted adjacent the vertical fill tube near its upper end, a grooved guide bar extending along a portion of the length of the vertical fill tube, and a grooved guide element mounted adjacent said zipper drive rollers.

21. The apparatus as recited in claim 20 wherein said grooved guide element and said zipper drive rollers are mounted for reciprocation between first and second positions in a plane transverse to the vertical fill tube wherein, in the first position, the grooved idler rollers, grooved guide bar, grooved guide element and zipper drive rollers are vertically aligned along a common vertical axis parallel to the vertical fill tube and in the second position, the grooved guide element and zipper drive rollers are spaced further from the vertical fill tube and out of vertical alignment with the grooved idler rollers and grooved guide bar, and wherein the grooved guide element and zipper drive rollers are moved from the first to the second position prior to and during formation of said horizontal seals and from the second position back to the first position following horizontal sealing and severing of the product filled bag and prior to incremental movement of the plastic film and zippered cap strip along the vertical fill tube.

22. The apparatus as recited in claim 19 wherein said tensioning means comprises said zipper drive rollers and an oppositely disposed rod extending downwardly from said vertical fill tube.

23. The apparatus as recited in claim 19 wherein one of the pair of film pull belts is mounted on each side of the vertical fill tube and spring biased against the plastic film wrapped around the fill tube.

24. The apparatus as recited in claim 19 wherein the film drive roll, the film pull belts, and the zipper drive rollers are driven by a common drive means.

25. The apparatus as recited in claim 24 wherein the common drive means comprises an electric servomotor having a drive output connected to a transmission having a first transmission output providing drive to the zipper drive rollers and the film pull belts, and a second transmission output providing drive to the film drive roll.

26. The apparatus as recited in claim 25 wherein the first transmission output provides drive to the zipper drive rollers by being operatively connected to a non-cylindrical shaft extending transverse to and spaced from the fill tube, and wherein a first drive belt pulley having a non-cylindrical central opening is mounted for sliding movement along at least a portion of the shaft, and a first drive belt passes over the first pulley and a second pulley operatively connected to at least one of the zipper drive rollers.

27. The apparatus as recited in claim 26 wherein each of the zipper drive rollers has a set of gear teeth at one end thereof, the gear teeth of each zipper drive roller intermeshing with one another to cause the drive rollers to rotate in opposite directions.

28. The apparatus as recited in claim 25 wherein said first transmission output is operatively connected to said film pull belts by a horizontally compact vertically arranged belt transmission and respective drive shafts having expanding universal joints.

29. A vertical, form, fill, and seal apparatus of the type that operates in conjunction with a product supply apparatus providing product in discrete quantities and that forms a continuous, heat sealable plastic film into separate product-filled sealed bags comprising:

means for storing and supplying the continuous plastic film,

means for storing and supplying a continuous, plastic, cap strip,

a generally vertical tube assembly downstream of said means for storing and supplying the continuous plastic film, said tube assembly including a vertical fill tube and means for forming said film around said fill tube,

feeding means including a film drive roll upstream of the fill tube, a pair of film pull belts, and a pair of cap strip drive rollers downstream of said pull belts for feeding the cap strip and plastic film along the length of said fill tube in bag length increments with edges of the continuous film in overlapping relationship with edges of the cap strip, each belt of said pair of film pull belts being mounted on a respective opposing side of the vertical fill tube and biased against the plastic film and said fill tube,

vertical sealing means adjacent said fill tube for sealing the edges of the continuous film to the edges of the cap strip to form a flexible, plastic tube,

horizontal sealing and severing means downstream of said fill tube for forming horizontal seals across the flexible plastic tube and for severing the plastic tube, and

tensioning means including said cap strip drive rollers for horizontally elongating the flexible, plastic tube transverse to its length prior to formation of said horizontal seals.

30. The apparatus as recited in claim 29 further comprising common drive means for positively and simultaneously driving said film drive roll, said film pull belts, and said cap strip drive rollers at proportional speeds.

31. The apparatus as recited in claim 30 wherein said tensioning means further includes a rod extending downwardly from said vertical fill tube assembly opposite said cap strip drive rollers.

32. In a vertical form, fill and seal apparatus including a vertical fill tube and horizontal sealing means and of the type that forms a continuous, heat sealable plastic film and a continuous plastic zippered cap strip into a flexible tube and then into separate, recloseable, sealed bags, the improvement comprising:

at least one pair of zipper drive rollers located downstream of the vertical fill tube and upstream of the horizontal sealing means to grip the zippered cap strip therebetween and mounted for reciprocation between a first position whereat the zippered cap strip is aligned vertically and parallel to the vertical fill tube to facilitate alignment of the zippered cap strip and plastic film and a second position spaced outwardly from the fill tube sufficiently to tension the flexible tube to remove wrinkles therein prior to formation of horizontal seals, and said zipper drive rollers being intermittently driven so as draw the zippered cap strip and plastic film through said apparatus in bag length increments.

33. In a vertical form, fill and seal apparatus including a vertical fill tube and of the type that forms a continuous, heat sealable plastic film and a continuous plastic cap strip into a flexible tube and then into separate, sealed bags, the improvement comprising:

at least one pair of cap strip drive rollers located downstream of the vertical fill tube to grip the cap strip therebetween and mounted for reciprocation between a first position whereat the cap strip is aligned vertically and parallel to the vertical fill tube to facilitate alignment of the cap strip and plastic film and a second position spaced outwardly from the fill tube sufficiently to tension the flexible tube to remove wrinkles therein prior to formation of horizontal seals, said cap strip drive rollers being selectively rotatably driven so as draw the cap strip and plastic film through said apparatus in bag length increments.

34. A vertical, form, fill, and seal apparatus of the type that operates in conjunction with a product supply apparatus providing product in discrete quantities and that forms a continuous, heat sealable plastic film into separate product filled, sealed bags comprising:

means for storing and supplying the continuous plastic film,

a generally vertical fill tube assembly including a vertical fill tube downstream of the means for storing and supplying the continuous film and around which the continuous film is formed and wrapped,

feeding means including a film drive roll upstream of said vertical fill tube, a pair of film pull belts adjacent said vertical fill tube, and a pair of drive rollers downstream of said vertical fill tube for feeding the continuous plastic film along the length of the vertical fill tube in bag length increments,

vertical sealing means for sealing the edges of the continuous film to form a flexible, plastic tube,

horizontal sealing and severing means downstream of the vertical fill tube for forming horizontal seals across the flexible plastic tube and for severing the plastic tube,

tensioning means including said drive rollers for horizontally elongating the flexible, plastic tube transverse to its length prior to formation of said horizontal seals, and

bag support means for sequentially supporting each product filled bag during formation of said horizontal seals and releasing each completed, product filled, sealed bag following severing of the bag from the flexible tube.

35. In a vertical form, fill and seal apparatus including a vertical fill tube and of the type that forms a continuous, heat sealable plastic film into a flexible tube and then into separate, sealed bags, the improvement comprising:

at least one pair of drive rollers located downstream of the vertical fill tube to grip the plastic film therebetween and mounted for controllable reciprocation to tension the flexible tube to remove wrinkles therein prior to formation of horizontal seals, said drive rollers being controllably rotatably driven so as draw the flexible tube through said apparatus in bag length increments.