US3852937A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shrink-wrapping method and apparatus
Assignee: AUBURN ENG Inc
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Filing: 1968-08-06
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Granted: 1974-12-10
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Expires: 1988-08-06
Abstract
Abstract There is disclosed a method of and apparatus for applying a tubular sheet of shrinkable polyethylene film to a load of articles or packages arranged on a pallet or other base by feeding a continuous flattened tubular sheet of film down around the load, and cutting it off. If the top of the package is closed, the sheet is transversely heat-sealed at a proper distance back of the leading edge of the strip, but if the package has an open top, the upper end of the tubular sheet is crimped in or gathered at the corners to keep the sheet from dropping down beyond the top of the load after it has been cut. The tubular sheet is opened out and pulled down around the load by suction belts.
Inventors
- 👤 M Bitsura
- 👤 R Brevko
- 👤 M Palmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:26
CPC Classifications
B; B65; B65B; B65B9/00; B65B9/10; B65B9/13; B65B9/135
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
266 words
The steps in the method of shrink-wrapping a polyethylene film about a bulky load on a supporting base wherein the polyethylene is a roll of tubular film flattened down upon itself, which comprises: a. mechanically feeding the flattened tubular sheet from the supply roll downward toward and about a load to be wrapped positioned beneath it; b. engaging the two opposed surfaces of the leading end of the flattened tubular sheet at a level above the load to be wrapped and below the level at which the mechanical feeding of the film occurs and opening it horizontally into a four-sided configuration by oppositely moving sheet-gripping means, mechanically feeding the flattened tubular sheet from the supply roll downwardly toward the load while the open end of the tube is so engaged and guiding it downwardly arounD the load whereby the gripping means is required to apply only sufficient tension to hold the film open and guide it downwardly around the load, c. terminating the downward feed of the sheet when the leading edge of the sheet is below the supporting base of the load, d. severing the flattened tubular sheet after the leading edge has progressed downwardly a predetermined distance back from the leading edge determined by the height of the load and at such a place so that when the leading edge is below the supporting base the severed edge will be at a level above the top of the load, and e. thereafter moving the load about which the film has been so placed through a heated environment to shrink the film about the load.
Claim 2
Dependent Claim
266 words
The steps in the method of shrink-wrapping a polyethylene film about a bulky load on a supporting base wherein the polyethylene is a roll of tubular film flattened down upon itself, which comprises: a. mechanically feeding the flattened tubular sheet from the supply roll downward toward and about a load to be wrapped positioned beneath it; b. engaging the two opposed surfaces of the leading end of the flattened tubular sheet at a level above the load to be wrapped and below the level at which the mechanical feeding of the film occurs and opening it horizontally into a four-sided configuration by oppositely moving sheet-gripping means, mechanically feeding the flattened tubular sheet from the supply roll downwardly toward the load while the open end of the tube is so engaged and guiding it downwardly arounD the load whereby the gripping means is required to apply only sufficient tension to hold the film open and guide it downwardly around the load, c. terminating the downward feed of the sheet when the leading edge of the sheet is below the supporting base of the load, d. severing the flattened tubular sheet after the leading edge has progressed downwardly a predetermined distance back from the leading edge determined by the height of the load and at such a place so that when the leading edge is below the supporting base the severed edge will be at a level above the top of the load, and e. thereafter moving the load about which the film has been so placed through a heated environment to shrink the film about the load.
Claim 3
Dependent Claim
87 words
The method defined in claim 1 in which the layers of flattened tubular sheet are sealed together across the width of the sheet at a predetermined interval depending on the height of the load back of the leading edge and the severing of the strip is just above the transverse seal whereby the seam so formed will ultimately be positioned across the top of the load and the leading edge of the next length of the sheet may be opened out for a succeeding cycle of operation.
Claim 4
Dependent Claim
49 words
The method defined in claim 1 in which the periphery of the tubular sheet when opened is greater than the periphery of the load and the sides of the sheet are held substantially free of contact with the load as the sheet material is moved down around the load.
Claim 5
Dependent Claim
66 words
The method defined in claim 1 in which the two opposed areas of the tubular sheet that are first opened out horizontal are maintained in parallel planes spaced from the sides of the load as the sheet is moved downward while the areas of the sheet between said two areas are free of any supporting surface and are held in tension by the two supported areas.
Claim 6
Dependent Claim
77 words
The method defined in claim 1 in which the flattened tubular sheet has infolded gussets along each edge between two sheet areas of equal width and only said two sheet areas are the areas which are engaged by the oppositely-moving sheet-gripping means and first opened out in a horizontal direction and then moved down vertically to form two opposed sides of the four-sided configuration and the infolded gussets are opened out to form the other two sides.
Claim 7
Dependent Claim
81 words
The method defined in claim 1 wherein the upper portion of the sheet that extends above the top of the load is gathered in at intervals around the sheet and the gathers sealed together to prevent them from reopening whereby the gathers constrict the perimeter of the sheet at the top of the load and hold the sheet which surrounds the load from dropping below a predetermined position relative to the load until the sheet has been heatshrunk about the load.
Claim 8
Dependent Claim
99 words
The method of shrink-wrapping as defined in claim 1 wherein a layer of polyethylene film is first placed over the supporting base with its edges extending beyond the base, then placing the load on the base over said layer of film, lifting the extending edges of said film layer up around the base of the load and confining them at least temporarily against the load, after which the tubular sheet is passed down over the load, whereby when the tubular sheet heat-shrinks, the lower portion of the sheet will contact and fuse to the upturned edges of said layer.
Claim 9
Dependent Claim
136 words
The method of shrink-wrapping as defined in claim 1 in which the sheeted tubular film is gusseted to provide two outer flat layers that form two sides of the four-sided configuration when the strip is folded out and two opposed inturned gussets that form the other two sides wherein all of the several layers of said film are fused together to form a transverse seam in advance of the line on which the sheet is severed, and the downward travel of the film is stopped with the severed top end of the tubular film terminating in said transverse seam, whereby the seam prevents the full opening of the film in its final downward movement whereby the sleeve at opposite ends of the transverse seam is pulled in toward the center of the load along diagonal lines.
Claim 10
Dependent Claim
111 words
The method of shrink-wrapping as defined in claim 1 in which the sheeted tubular film is gusseted to provide two outer flat layers that form two sides of the four-sided configuration when the strip is folded out and two opposed inturned gussets that form the other two sides comprising the further steps of partially spreading the folds of the gussets in advance of the sheet being severed and heat-sealing the corners only of the sheet to form gathers at intervals along the length of the sheet to restrict the perimeter of the sheet where such gathers are formed, and severing the sheet just above the level of the gathers so formed.
Claim 11
Dependent Claim
175 words
Bulk shrink film packaging apparatus comprising: a. a frame having means therein for supporting a load to be wrapped, b. means on the frame for supporting a roll of flat tubular wrapping sheet, c. means arranged to feed wrapping material from said roll downwardly from the top of said frame toward a load positioned on the load-supporting means to be wrapped, d. tube-gripping and holding means movable in opposite directions from the plane of the descending flat tubular sheet and positioned at a level above the load to be wrapped and below the sheet feeding means, said tube-gripping means being arranged to engage opposite sides of the flat tubular sheet as it is fed downwardly and spread them apart to form the sheet into a four-sided configuration and then hold it in said configuration and guide it downwardly around the load as the sheet-feeding means continues to feed the sheet downwardly, and e. means positioned at a level below the sheet-feeding means and above the tube-gripping and holding means for severing the flattened tubular sheet.
Claim 12
Dependent Claim
175 words
Bulk shrink film packaging apparatus comprising: a. a frame having means therein for supporting a load to be wrapped, b. means on the frame for supporting a roll of flat tubular wrapping sheet, c. means arranged to feed wrapping material from said roll downwardly from the top of said frame toward a load positioned on the load-supporting means to be wrapped, d. tube-gripping and holding means movable in opposite directions from the plane of the descending flat tubular sheet and positioned at a level above the load to be wrapped and below the sheet feeding means, said tube-gripping means being arranged to engage opposite sides of the flat tubular sheet as it is fed downwardly and spread them apart to form the sheet into a four-sided configuration and then hold it in said configuration and guide it downwardly around the load as the sheet-feeding means continues to feed the sheet downwardly, and e. means positioned at a level below the sheet-feeding means and above the tube-gripping and holding means for severing the flattened tubular sheet.
Claim 13
Dependent Claim
92 words
Bulk shrinkfilm packaging apparatus as defined in claim 10 wherein said tube gripping and holding means comprises two upper vacuum belt units having inner ends closely spaced from each other with the under reaches of each endless belt being movable in opposite directions over a suction surface together with a vertical vacuum belt unit adjacent the outer end of each of said upper belt units, each vertical vacuum belt unit having a downwardly-moving flight confronting the other at opposite sides of the load, each such downwardly-moving flight moving over a suction surface.
Claim 14
Dependent Claim
67 words
Bulk shrinkage film packaging apparatus as defined in claim 11 wherein means is provided for holding a continuous roll of the flattened tubular sheet material and wherein a pair of pinch rolls is provided in the frame above the sheetsevering means for pulling the sheet material from the roll and feeding it vertically into the space between the confronting ends of the two upper vacuum belt units.
Claim 15
Dependent Claim
48 words
Bulk shrinkage film packaging apparatus as defined in claim 12 wherein means is provided for driving the pinch rolls at a peripheral speed slightly slower than the lineal speed of the belts whereby to tension the folded sheet between the pinch rolls and the upper suction belt units.
Claim 16
Dependent Claim
112 words
Bulk shrinkage film packaging apparatus as defined in claim 12 wherein means is provided in the path of travel of the tubular sheet between a roll of such sheet film on said roll-holding means and the pinch rolls for forming a transverse heat seal across the flattened tubular sheet at a distance back from the sheet-severing means such that the sheet being advanced by the pinch rolls will always be severed by the sheet-severing means just above a previously-formed transverse seal so that the sheet is severed in uniform lengths and the trailing end of the severed sheet section is sealed and the leading edge of the succeeding section may be opened.
Claim 17
Dependent Claim
143 words
Bulk shrinkage film packaging apparatus as defined in claim 12 in which the continuous roll of tubular sheet film is a flat gusseted sheet wherein: a. opposed gusset spreader and anvil elements are arranged between the roll-holding means and the severing means at each side of the sheet to spread the gusseted sheet, one being positioned to separate and firmly support the two corners of the sheet along one edge thereof and the other arranged to separate and support the two corners of the sheet at the other edge thereof, b. a heat-sealing element at each corner movable toward and away from the anvil element and the film supported thereon for confining the film against the anvil element and heat-sealing the corners of the film, and c. means for moving said heat-sealing elements into and out of heat-sealing engagement with the film corners.
Claim 18
Dependent Claim
53 words
Bulk shrinkage film packaging apparatus as defined in claim 10 for use with flattened tubular gusseted film in which a. means is provided in advance of said severing means for separately squeezing together and heat-sealing each of the four corners of the flattened tubular sheet only at predetermined spaced intervals along its length.
Claim 19
Dependent Claim
154 words
A corner sealing apparatus for separately squeezing together and heat-sealing each of the four corners of a flattened tubular gusseted sheet of plastic film at intervals along its length comprising a. means for intermittently advancing the tubular sheet from a roll to a severing device, b. means in the path of travel of the sheets at each side edge thereof engaged in the gussets for partially opening them and supporting the separated four corners thereof, c. heated tube-sealing elements positioned adjacent said tube opening and corner supporting means movable toward and away from the film and arranged when moved toward the film to squeeze only tube corners against the corner supporting means and heat-seal the corners only of the tube together, and d. means for moving said elements into and out of engagement with the corners of the film whereby said corners may be sealed at spaced intervals along the length of the sheet.
Claim 20
Dependent Claim
154 words
A corner sealing apparatus for separately squeezing together and heat-sealing each of the four corners of a flattened tubular gusseted sheet of plastic film at intervals along its length comprising a. means for intermittently advancing the tubular sheet from a roll to a severing device, b. means in the path of travel of the sheets at each side edge thereof engaged in the gussets for partially opening them and supporting the separated four corners thereof, c. heated tube-sealing elements positioned adjacent said tube opening and corner supporting means movable toward and away from the film and arranged when moved toward the film to squeeze only tube corners against the corner supporting means and heat-seal the corners only of the tube together, and d. means for moving said elements into and out of engagement with the corners of the film whereby said corners may be sealed at spaced intervals along the length of the sheet.
Claim 21
Dependent Claim
83 words
A corner sealing apparatus as defined in claim 17 wherein said means at each side edge thereof comprises a wedgeshaped element at each side of the sheet engaged between the folds of the gussets with its narrow end directed toward the roll and with a flat surface at its widest end on each side thereof, said heating elements being positioned to squeeze the corner folds of film against said flat surfaces to seal the folds where they are supported on said flat surfaces.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |