US3804572A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for making tubular plastics film by means of a blowhead
Assignee: Windmoeller and Hoelscher KG
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Filing: 1971-10-19
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Granted: 1974-04-16
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Expires: 1991-10-19
Abstract
Abstract In apparatus for making tubular plastics film by means of a blowhead which forms the film as a continuously moving tube, flattening means for the tube and take-off rollers for the flattened tube, the spacing between the blowhead and the take-off rollers is made constant but the spacing between the blowhead and the flattening means is adjustable.
Inventors
- 👤 H Upmeier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:42
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/03; B29C48/09; B29C48/10; B29C48/001; B29C48/0018; B29C48/0019; B29C48/25; B29C48/355
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
89 words
An apparatus for making tubular plastic film comprising a blowhead for forming a tube of plastic film, flattening means located downstream of said blowhead for flattening said tube, take-off rollers located downstream of said flattening means for withdrawing said flattened tube, a means for adjusting the distance between said blowhead and said flattening means such that the distance between said blowhead and said take-off rollers remains constant, and guide rollers for maintaining said flattened tube taut and preventing reinflation thereof located between said flattening means and said take-off rollers.
Claim 2
Independent Claim
89 words
An apparatus for making tubular plastic film comprising a blowhead for forming a tube of plastic film, flattening means located downstream of said blowhead for flattening said tube, take-off rollers located downstream of said flattening means for withdrawing said flattened tube, a means for adjusting the distance between said blowhead and said flattening means such that the distance between said blowhead and said take-off rollers remains constant, and guide rollers for maintaining said flattened tube taut and preventing reinflation thereof located between said flattening means and said take-off rollers.
Claim 3
Dependent Claim
39 words
The apparatus of claim 1 wherein said guide rollers are positioned to lead said flattened tube in a zig-zag path and means for adjusting the position of said guide rollers relative to said flattening means and said take-off rollers.
Claim 4
Dependent Claim
37 words
The apparatus of claim 1 and further comprising a pair of squeeze rollers positioned immediately downstream of said flattening means and mounted for movement therewith and spring biasing means for biasing said squeeze rollers toward one another.
Claim 5
Dependent Claim
30 words
The apparatus of claim 3 in which said squeeze rollers are mounted so that one of said squeeze rollers can be moved away from the other of said squeeze rollers.
Claim 6
Dependent Claim
13 words
The apparatus of claim 1 in which said flattening means comprise flattening plates.
Claim 7
Dependent Claim
39 words
The apparatus of claim 1 in which said means for adjusting the distance between said blowhead and said flattening means comprises guide rails and a slide moveable on said guide rails and on which said flattening means are mounted.
Claim 8
Dependent Claim
36 words
The apparatus of claim 2 in which said means for adjusting the position of said guide rollers relative to said flattening means and said take-off rollers comprises lazy tongs on which said guide rollers are mounted.
Claim 9
Dependent Claim
14 words
The apparatus of claim 1 and further comprising means rotatably mounting said take-off rollers.
References Cited (Backward Citations)
US2337927A
Cited
GB922084A
Cited
US3231651A
Cited
US3238564A
Cited
US3456044A
Cited
FR1553853A
Cited
US3687585A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-15 | 1977-10-15 | 1978-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-15 | 1981-10-15 | 1982-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-15 | 1985-10-15 | 1986-04-16 | $7700.00 | Window Closed / Lapsed |