US3709290A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cooling equipment for tubular plastics film made by a blowhead
Assignee: Windmoeller and Hoelscher KG
•
Filing: 1970-12-04
•
Granted: 1973-01-09
•
Expires: 1990-12-04
Abstract
Abstract Cooling equipment for tubular plastic film made by a blowhead, comprising an external air cooling ring for mounting between the blowhead and a position where the film has solidified, the air outlet from said external ring being directed onto the outside of the tubular film, a supply conduit and a withdrawal conduit, both extending axially through the blowhead, for the passage of internal cooling air, and an annular nozzle at the outlet of the supply conduit, the outlet of said nozzle being directed onto the interior surface of the film in such a way that the interior and exterior streams of cooling air impinge on the film at substantially the same level.
Inventors
- 👤 H Upmeier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:09
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/88; B29C48/885; B29C48/03; B29C48/09; B29C48/10; B29C48/89; B29C48/911; B29C48/9115; B29C48/912
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
141 words
A blowhead for making tubular plastic film comprising: means to cool said film, said cooling means comprising an external air cooling ring for mounting between the blowhead and a position where the film has solidified, said cooling ring having an annular discharge passage in its inner periphery being directed onto the outside of the tubular film; a supply conduit extending axially through the blowhead for supplying internal cooling air; a withdrawal conduit extending axially through the blowhead for withdrawing internal cooling air; and an internal annular nozzle at the outlet of the supply conduit, said internal annular nozzle having an annular discharge passage in its outer periphery, said discharge passage being directed onto the interior surface of the film in such a way that the interior and exterior streams of cooling air impinge on the film at substantially the same level.
Claim 2
Dependent Claim
141 words
A blowhead for making tubular plastic film comprising: means to cool said film, said cooling means comprising an external air cooling ring for mounting between the blowhead and a position where the film has solidified, said cooling ring having an annular discharge passage in its inner periphery being directed onto the outside of the tubular film; a supply conduit extending axially through the blowhead for supplying internal cooling air; a withdrawal conduit extending axially through the blowhead for withdrawing internal cooling air; and an internal annular nozzle at the outlet of the supply conduit, said internal annular nozzle having an annular discharge passage in its outer periphery, said discharge passage being directed onto the interior surface of the film in such a way that the interior and exterior streams of cooling air impinge on the film at substantially the same level.
Claim 3
Dependent Claim
24 words
Cooling equipment according to claim 1, wherein the outlet of said external ring and/or said annular nozzle are slightly inclined towards the blowhead nozzle.
Claim 4
Dependent Claim
45 words
Cooling equipment according to claim 1, wherein the widths of the outlets of the external ring and annular nozzle and the pressures in the supply and withdrawal conduits are designed so that the dynamic pressures of the interior and exterior air streams are substantially equal.
Claim 5
Dependent Claim
28 words
Cooling equipment according to claim 1, wherein the supply conduit is formed by an annular passage and the withdrawal conduit is a pipe extending through the annular passage.
Claim 6
Dependent Claim
29 words
Cooling equipment according to claim 4, wherein the external diameter of a guide ring for the internal cooling air is substantially equal to the diameter of the blowhead nozzle.
Claim 7
Dependent Claim
16 words
Cooling equipment according to claim 4, wherein the annular passage is lined with heat insulating layers.
References Cited (Backward Citations)
US3064905A
Cited
US3170011A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |