Package making – Methods – Enclosing contents within progressively formed web means
Reexamination Certificate
1999-01-25
2001-03-06
Gerrity, Stephen F. (Department: 3721)
Package making
Methods
Enclosing contents within progressively formed web means
C053S553000
Reexamination Certificate
active
06195966
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to apparatus for forming plastic pouches, air cushions, and plastic envelopes.
BACKGROUND OF THE INVENTION
When packing fragile objects in boxes for shipping or storage, it is often desirable to surround the objects with protective elements which absorb shocks and insulate the objects to prevent damage. Today the most commonly used materials are shaped styrofoam, styrofoam peanuts, shredded paper, urethane foam as used in foam-in-place systems, foam chips, corrugated inserts, or similar items which are light in weight yet absorb shocks. When packing other objects, it is common to add such materials between a container and its contents for void filling. The disadvantage of such items is that they are large in volume, so require a large storage space before use, many of them are environmentally unfriendly, and some are difficult to dispose of. Small items, such as peanuts, tend to sink to the bottom of a box, thereby leaving upper portions of the object packed therein uncovered and unprotected.
Instead of such materials, it has been suggested to use air cushions, also known as air pillows and air bags, for protecting fragile objects and for void filling. These are small plastic bags which are stored in roll form and inflated in the factory as needed. Thus, they require little storage space. However, conventional air cushion machines are complicated and expensive.
One example of a conventional machine for making air cushions operates using a compressor to provide pressurized air to inflate the cushions. Plastic sheaths sealed on both side edges are provided on a roll. The plastic is advanced between two rollers which grip the plastic between them and advance the plastic sheath as they rotate. When they stop rotating, typically by means of a sensor reading a coded symbol printed on the plastic, the sheath is held still. The sleeve is punctured and filled with air, and then the plastic is sealed at both ends, hopefully sealing the puncture at the same time.
Other known devices include a microprocessor for controlling the filling and sealing of the air cushions. These utilize a computerized system to measure the length of the cushion and send a signal to stop advancing the plastic sheath.
These devices are costly, and require precision in the operation of the sensor for stopping the advance of the plastic, as well as accuracy in sealing the cushions. Furthermore, changing the length of the cushions requires printing new rolls of plastic with the symbols for the end of the cushion located a different distance apart.
Accordingly, there is a long felt need for a relatively inexpensive device for making air cushions, and it would be very desirable to have such a device which is simple to manufacture and operate and wherein the length of the cushions can be changed easily without replacing the plastic roll.
Similarly, magazines and articles of mail, as well as powders, grains, granular material, beads, and other small particles and components, are now being packaged in plastic envelopes. The conventional packaging machines generally include a compressed air source, and a plurality of pistons and pneumatic elements, resulting in an expensive and complex device.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a device for forming plastic pouches including a source of at least two substantially superposed layers of plastic sheet, a pair of rollers for selectively advancing the layers of plastic sheet, a plastic filling element, and heat welding means for sealing open sides of the pouches, wherein portions of a longitudinal half of each of the rollers have a larger radius than the remainder of the roller whereby, when the larger radius portions of the rollers engage one another, they advance the plastic held between them, and when the smaller radius portions of the rollers are in registration with one another, they do not engage the plastic between them, so the plastic does not advance and can be heat sealed.
According to a preferred embodiment, the source of layers includes a roll of folded plastic sheet.
Further according to a preferred embodiment of the invention, the device includes a release mechanism for easy removal and replacement of one roller.
According to another embodiment of the invention, the heat sealing means are arranged to seal a plurality of adjacent bags simultaneously.
According to yet another preferred embodiment of the invention, the plastic filling element includes a blower or other source of air providing air between the layers of plastic to form air cushions.
According to a further embodiment of the invention, the plastic filling element includes a funnel or other source of filler material arranged to provide a quantity of the filler material between two plastic layers to form filled pouches.
Further according to the present invention, there is provided a method for forming plastic pouches including providing at least two substantially superposed layers of plastic sheet, rotating a pair of rollers, portions of one longitudinal half of each roller having a larger radius than the remainder of the roller, feeding the layers of plastic sheet between the rollers such that, when portions of the larger radius halves of the rollers overlap, they engage and advance the plastic sheet held between them, and when the larger radius portions of the rollers are not in registration, they do not engage plastic sheet, inserting material to be enclosed between two layers of plastic sheet, and heat sealing the open sides of the plastic sheets about the filler material so as to form a sealed pouch.
REFERENCES:
patent: 3596428 (1971-08-01), Young et al.
patent: 3735551 (1973-05-01), Pratt
patent: 5345750 (1994-09-01), Gries et al.
patent: 5454208 (1995-10-01), Kawano
patent: 5459980 (1995-10-01), Kenney et al.
patent: 5740661 (1998-04-01), Yamaguchi et al.
German Abstract of DE 37 05 167 “Multi-Chamber Inflatable Bag,” along with equivalent English Derwent Abstract of WO 88/06131.
German Abstract of DE 25 56 968 “Thermoplastic Film Bags Manufacturing System,” along with corresponding English Derwent Abstract.
German Abstract of DE 32 14 716 “Plastics Film Bag Machine for Shop Counters,” along with corresponding English Derwent Abstract.
German Abstract of DE 36 13 117 “Automatic Envelope Folding Machine,” along with corresponding English Derwent Abstract.
Matarasso Hasdi
Shomron Ari
Gerrity Stephen F.
Marshall O'Toole Gerstein Murray & Borun
Nova-Tek Technologies, Ltd.
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