US4033089A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Package wrapping method and apparatus
Assignee: Individual
•
Filing: 1976-07-21
•
Granted: 1977-07-05
•
Expires: 1996-07-21
Abstract
Abstract A method of automatically wrapping in plastic film a shallow tray filled with irregularly-shaped contents such as meat or vegetables is provided. No elevator for tray movement is required yet the method forms a lap seal on the bottom of the tray with any of the modern soft plastic films, including stretching and shrink films. The trays advance into a curtain of the plastic film arranged transversely to a tray feed track. A first air blower blows onto the film surface above the tray, billowing the film smoothly ahead of the tray to prevent folds from forming in the film and to keep moving air between the tray and the film during tray advance to avoid snagging therebetween. A lower edge of the film is captured between the tray bottom and tray support rollers. The film is draped over the top and back of the tray. A second fan blows air upwardly onto the under-tucked film to ensure proper placement thereof. A tucking device displaces the support rollers downwardly and tucks and forms a lap joint between the film ends beneath the stationary tray. End folders then tension and fold the tubed ends of the film upwardly to the sides of the tray and downwardly to the bottom of the tray prior to shrinking or final heat treatment of the film.
Inventors
- 👤 Henry Lowell Byland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:33
CPC Classifications
B; B65; B65B; B65B11/00; B65B11/06; B65B11/08; B65B11/10; B65B11/12
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
209 words
The method of automatically wrapping in a sheet of plastic film a tray filled with contents, comprising the sequential steps: (a) feeding said film between rollers driven in syncronization with tray travel and supporting said film at upper and lower edges thereof transversely to a path of advance of said tray; (b) preventing said film from wrinkling at its vertical edges and from prematurely catching upon said tray by directing a stream of air wider than said film onto said film from a side of advance of said tray; (c) advancing said tray horizontally into said film, and simultaneously releasing a bottom edge of said film to be drawn up and captured between a bottom of said tray and a support surface on which said tray is carried as the tray advances entirely past the initial position of said film; (d) lowering the top edge of said film down behind said tray to drape said contents of said tray with said film; and (e) inserting a tucker and undersealer device between said surface and said tray, simultaneously folding said top edge of said film beneath said tray and joining said film to itself in a lap joint, thereby forming a pair of tubes to each side of said tray.
Claim 2
Independent Claim
209 words
The method of automatically wrapping in a sheet of plastic film a tray filled with contents, comprising the sequential steps: (a) feeding said film between rollers driven in syncronization with tray travel and supporting said film at upper and lower edges thereof transversely to a path of advance of said tray; (b) preventing said film from wrinkling at its vertical edges and from prematurely catching upon said tray by directing a stream of air wider than said film onto said film from a side of advance of said tray; (c) advancing said tray horizontally into said film, and simultaneously releasing a bottom edge of said film to be drawn up and captured between a bottom of said tray and a support surface on which said tray is carried as the tray advances entirely past the initial position of said film; (d) lowering the top edge of said film down behind said tray to drape said contents of said tray with said film; and (e) inserting a tucker and undersealer device between said surface and said tray, simultaneously folding said top edge of said film beneath said tray and joining said film to itself in a lap joint, thereby forming a pair of tubes to each side of said tray.
Claim 3
Dependent Claim
47 words
A method as defined in claim 1, wherein between steps c and d a package fence is raised behind said tray to prevent backwards movements thereof as said top edge of said film is lowered and tightened, and said fence being lowered between steps d and e.
Claim 4
Dependent Claim
61 words
The method of claim 1, further comprising between steps d and e a step of directing a second stream of air onto the bottom of said tray and said bottom edge of said film and maintaining this stream during step e, to maintain said bottom edge against said tray during formation of the lap joint by the tucker and undersealer device.
Claim 5
Dependent Claim
74 words
The method of claim 1, further comprising the sequential steps following step e: (f) retracting said tucker and undersealer device; (g) advancing said tray horizontally to an end folding station; (h) tucking a lower portion of each film tube adjacent said tray upwardly against a corresponding one of said tray sides; (i) folding each of said film tubes downwardly past said tray sides; and (j) tucking said film tubes flat beneath said tray bottom.
Claim 6
Dependent Claim
18 words
The method of claim 4, wherein step i further includes stretching said film tightly over said tray contents.
Claim 7
Dependent Claim
29 words
The method of claim 4, further comprising after the step j the further step: (k) advancing said tray horizontally from said end folding station to a heated conveyor surface.
Claim 8
Dependent Claim
18 words
The method of claim 6, further comprising the step of advancing the tray horizontally through a shrink tunnel.
Claim 9
Independent Claim
250 words
A method of automatically wrapping in a plastic film a rectangular tray filled with irregular contents, comprising the sequential steps: (a) forming a curtain of a length of said plastic film across a path of advance of said tray by supporting said film at top and bottom edges thereof; (b) blowing a stream of air onto a side of said film in said advance direction; (c) advancing said tray into said curtain and onto a surface extending in the tray advance direction, continuing to feed film until enough film is fed to satisfy the package size and to trigger a cut off knife, and releasing the severed bottom edge of said curtain, thereby to engage a front edge of said tray and a bottom portion thereof above said surface with said film; (d) lowering said curtain across and down behind said tray; (e) tucking and sealing said film from behind said tray to the underside of said tray above said surface, forming a lap seal in said film to itself and a pair of film tubes on either side of said tray; (f) advancing said package along said surface to an end folding and tucking station; (g) folding a lower portion of said film tubes to the lower sides of said tray; (h) lowering and flattening said film tubes downwardly across the sides of said tray; and (i) i. tucking and sealing said flattened film tubes beneath and to the bottom of said tray above a retracted support surface thereof.
Claim 10
Independent Claim
250 words
A method of automatically wrapping in a plastic film a rectangular tray filled with irregular contents, comprising the sequential steps: (a) forming a curtain of a length of said plastic film across a path of advance of said tray by supporting said film at top and bottom edges thereof; (b) blowing a stream of air onto a side of said film in said advance direction; (c) advancing said tray into said curtain and onto a surface extending in the tray advance direction, continuing to feed film until enough film is fed to satisfy the package size and to trigger a cut off knife, and releasing the severed bottom edge of said curtain, thereby to engage a front edge of said tray and a bottom portion thereof above said surface with said film; (d) lowering said curtain across and down behind said tray; (e) tucking and sealing said film from behind said tray to the underside of said tray above said surface, forming a lap seal in said film to itself and a pair of film tubes on either side of said tray; (f) advancing said package along said surface to an end folding and tucking station; (g) folding a lower portion of said film tubes to the lower sides of said tray; (h) lowering and flattening said film tubes downwardly across the sides of said tray; and (i) i. tucking and sealing said flattened film tubes beneath and to the bottom of said tray above a retracted support surface thereof.
Claim 11
Dependent Claim
52 words
The method of claim 8, wherein the stream of air blown in steps b through d is sufficiently strong to prevent said film from wrinkling at its edges as said tray is advanced into said film and to form an air gap between said film and said tray as said tray advances.
Claim 12
Dependent Claim
33 words
The method of claim 8, wherein step e thereof is accomplished by retracting said surface downwardly as a tucking and sealing element is passed between said surface and the bottom of said tray.
Claim 13
Dependent Claim
44 words
The method of claim 10, further comprising simultaneously with step e directing a second stream of air against an underside of said tray and said bottom edge of said film thereagainst to maintain said film in flat contact with the underside of said tray.
Claim 14
Dependent Claim
207 words
A mechanism for automatically wrapping a tray in a sheet of plastic film comprising: first means for supporting said film at upper and lower edges thereof transversely to a path of advance of said tray; second means for preventing said film from wrinkling at its vertical edges and from prematurely catching upon said tray, said second means directing a stream of air wider than said film onto said film from a side of advance of said tray; third means for advancing said tray horizontally into said film; fourth means for simultaneously releasing a bottom edge of said film to be drawn up and captured between a bottom of said tray and a support surface on which said tray is carried as the tray advances entirely past the initial position of said film; fifth means for lowering the top edge of said film down behind said tray to drape said contents of said tray with said film; and sixth means for inserting a tucker and undersealer device between said surface and said tray and for simultaneously folding said top edge of said film beneath said tray and joining said film to itself in a lap joint, thereby forming a pair of tubes on each side of said tray.
Claim 15
Dependent Claim
207 words
A mechanism for automatically wrapping a tray in a sheet of plastic film comprising: first means for supporting said film at upper and lower edges thereof transversely to a path of advance of said tray; second means for preventing said film from wrinkling at its vertical edges and from prematurely catching upon said tray, said second means directing a stream of air wider than said film onto said film from a side of advance of said tray; third means for advancing said tray horizontally into said film; fourth means for simultaneously releasing a bottom edge of said film to be drawn up and captured between a bottom of said tray and a support surface on which said tray is carried as the tray advances entirely past the initial position of said film; fifth means for lowering the top edge of said film down behind said tray to drape said contents of said tray with said film; and sixth means for inserting a tucker and undersealer device between said surface and said tray and for simultaneously folding said top edge of said film beneath said tray and joining said film to itself in a lap joint, thereby forming a pair of tubes on each side of said tray.
References Cited (Backward Citations)
US3546836A
Cited
US3816969A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-07-04 | 1981-01-03 | 1981-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-04 | 1985-01-03 | 1985-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-04 | 1989-01-03 | 1989-07-05 | $7700.00 | Window Closed / Lapsed |