Patent US3947170A successfully refreshed from Google Patents.
US3947170A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary film blowhead for making tubular films of thermoplastic material
Assignee: Windmoeller and Hoelscher KG
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Filing: 1975-04-03
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Granted: 1976-03-30
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Expires: 1995-04-03
Abstract
Abstract A rotary blowhead for making tubular plastics film and comprising interior and exterior air cooling means is adapted to be centrally fed with plastics material from a stationary extruder and is connected to stationary air fans by means of segmented air distributing means.
Inventors
- 👤 Werner Zimmermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:18
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/88; B29C48/911; B29C48/9115; B29C48/912; B29C48/03; B29C48/09; B29C48/10; B29C48/30; B29C48/32; B29C48/33
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
84 words
A rotary film blowhead fed centrally with thermoplastic material for making tubular film, comprising film cooling means with interior and exterior cooling rings and air supply connectors, said blowhead being rotatably connected to a stationary extruder, characterised in that the individual co-rotating air supply connectors are connected to the stationary blowers (16, 21) by segmented relatively rotatable air distributing rings (19, 19', 19", 19'") which are sealed by sealing elements (23) and of which the portion connected to the blowers (16, 21) is stationary.
Claim 2
Dependent Claim
84 words
A rotary film blowhead fed centrally with thermoplastic material for making tubular film, comprising film cooling means with interior and exterior cooling rings and air supply connectors, said blowhead being rotatably connected to a stationary extruder, characterised in that the individual co-rotating air supply connectors are connected to the stationary blowers (16, 21) by segmented relatively rotatable air distributing rings (19, 19', 19", 19'") which are sealed by sealing elements (23) and of which the portion connected to the blowers (16, 21) is stationary.
Claim 3
Dependent Claim
18 words
A blowhead according to claim 1, characterised in that the exterior cooling ring (15) rotates with the blowhead.
Claim 4
Dependent Claim
56 words
Apparatus according to claim 1, characterised in that concentric relatively rotatable air chamber rings are mounted at the level of the rotary apparatus for the film blowhead, through which the cooling air supply to the outer ring, the cooling air supply to the interior cooling apparatus as well as the withdrawal of heated air takes place.
Claim 5
Dependent Claim
29 words
A blowhead according to claim 1, characterised in that the rotary portion of the film blowhead with cooling means is oscillatingly rotatable by means of a geared motor (10).
Claim 6
Dependent Claim
33 words
A blowhead according to claim 1, characterised in that a mixing tool (3") for evening out the temperatures in the stream of supplied molten material is mounted beyond the rotary sealing means (3').
Claim 7
Dependent Claim
44 words
A blowhead according to claim 1, characterised in that the current supply for the rotating parts takes place in known manner through slip rings (11) and the regulators for the heating zones are mounted on the rotating part of the air distributing chambers (19).
Claim 8
Dependent Claim
32 words
A blowhead according to claim 1, characterised in that the throttle flats (17, 22) necessary for controlling the degree of inflation are mounted on the stationary parts of the air supply means.
References Cited (Backward Citations)
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Cited
US3176347A
Cited
US3445891A
Cited
US3450806A
Cited
US3663133A
Cited
US3709290A
Cited
US3762853A
Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |