US2966700A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of thermoplastic seamless tubing
Assignee: DuPont Canada Inc
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Filing: 1958-08-27
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Granted: 1961-01-03
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Expires: 1978-08-27
Abstract
No abstract record available.
Inventors
- 👤 Dyer Gerald Benjamin
- 👤 Heinstein Warner Paul
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:07
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/88; B29C48/90; B29C48/908; B29C48/03; B29C48/09; B29C48/10; B29C48/89; B29C48/901; B29C48/902; B29C48/911; B29C48/9115; B29C48/912; B29C48/001; B29C48/0018; B29C48/0019
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
204 words
IN A METHOD OF PRODUCING A THERMOPLASTIC SEAMLESS TUBING, THE STEPS WHICH COMPRISE CONTINUOUSLY DRY EXTRUDING THE MOLTEN THERMOPLASTIC MATERIAL IN THE FORM OF A SEAMLESS TUBING, CONTINUOUSLY WITHDRAWING THE TUBING FROM THE POINT OF EXTRUSION, FLATTENING THE TUBING AT A POINT SPACED FROM THE POINT OF EXTRUSION, MAINTAINING A SUBSTANTIALLY CONSTANT CONTINUOUS BUBBLE OF A GASEOUS MEDIUM IN THE SECTION OF TUBING EXTENDING FROM THE POINT OF EXTRUSION TO THE POINT OF FLATTENING, THE GASEOUS MEDIUM IN THE BUBBLE BEING UNDER A DIFFERENTIAL PRESSURE SUCH THAT THE PRESSURE IN THE ZONE NEAREST THE POINT OF EXTRUSION IS SUFFICIENT TO EXPAND THE TUBING WHILE IN THE PLASTIC FORMATIVE STATE TO THE DESIRED DIAMETER AT A POINT BEYOND THE POINT OF EXTRUSION WHILE THE PRESSURE IN THE ZONE BEYOND THE POINT OF EXPANSION IS SUFFICIENT TO KEEP THE TUBING EXPANDED BUT INSUFFICIENT TO CAUSE FURTHER EXPANSION, AND COOLING SAID TUBING BETWEEN THE POINT OF EXTRUSION AND THE POINT OF EXPANSION TO THE FINAL DESIRED DIAMETER, THE TEMPERATURE OF EXTRUSION OF THE TUBING, THE RATE OF WITHDRAWING THE TUBING, THE DEGREE OF EXPANSION OF THE TUBING AND THE DEGREE OF COOLING THE TUBING ALL BEING CORRELATED IN ACCORDANCE WITH PREDETERMINED DESIRED PHYSICAL CHARACTERISTICS OF THE TUBING.
Claim 2
Dependent Claim
204 words
IN A METHOD OF PRODUCING A THERMOPLASTIC SEAMLESS TUBING, THE STEPS WHICH COMPRISE CONTINUOUSLY DRY EXTRUDING THE MOLTEN THERMOPLASTIC MATERIAL IN THE FORM OF A SEAMLESS TUBING, CONTINUOUSLY WITHDRAWING THE TUBING FROM THE POINT OF EXTRUSION, FLATTENING THE TUBING AT A POINT SPACED FROM THE POINT OF EXTRUSION, MAINTAINING A SUBSTANTIALLY CONSTANT CONTINUOUS BUBBLE OF A GASEOUS MEDIUM IN THE SECTION OF TUBING EXTENDING FROM THE POINT OF EXTRUSION TO THE POINT OF FLATTENING, THE GASEOUS MEDIUM IN THE BUBBLE BEING UNDER A DIFFERENTIAL PRESSURE SUCH THAT THE PRESSURE IN THE ZONE NEAREST THE POINT OF EXTRUSION IS SUFFICIENT TO EXPAND THE TUBING WHILE IN THE PLASTIC FORMATIVE STATE TO THE DESIRED DIAMETER AT A POINT BEYOND THE POINT OF EXTRUSION WHILE THE PRESSURE IN THE ZONE BEYOND THE POINT OF EXPANSION IS SUFFICIENT TO KEEP THE TUBING EXPANDED BUT INSUFFICIENT TO CAUSE FURTHER EXPANSION, AND COOLING SAID TUBING BETWEEN THE POINT OF EXTRUSION AND THE POINT OF EXPANSION TO THE FINAL DESIRED DIAMETER, THE TEMPERATURE OF EXTRUSION OF THE TUBING, THE RATE OF WITHDRAWING THE TUBING, THE DEGREE OF EXPANSION OF THE TUBING AND THE DEGREE OF COOLING THE TUBING ALL BEING CORRELATED IN ACCORDANCE WITH PREDETERMINED DESIRED PHYSICAL CHARACTERISTICS OF THE TUBING.
Claim 3
Independent Claim
52 words
AN APPARATUS COMPRISING IN COMBINATION, AN ANNULAR EXTRUSION DIE, MEANS FOR EXTRUDING A MOLTEN THERMOPLASTIC MATERIAL THROUGH SAID DIE IN THE FORM OF CONTINUOUS SEAMLESS TUBING, MEANS FOR ADMITTING A GASEOUS MEDIUM INTO SAID TUBING IN PROXIMITY TO SAID DIE, AND MEANS FOR CAUSING A BACK PRESSURE IN SAID TUBING IN THE
Claim 4
Independent Claim
52 words
AN APPARATUS COMPRISING IN COMBINATION, AN ANNULAR EXTRUSION DIE, MEANS FOR EXTRUDING A MOLTEN THERMOPLASTIC MATERIAL THROUGH SAID DIE IN THE FORM OF CONTINUOUS SEAMLESS TUBING, MEANS FOR ADMITTING A GASEOUS MEDIUM INTO SAID TUBING IN PROXIMITY TO SAID DIE, AND MEANS FOR CAUSING A BACK PRESSURE IN SAID TUBING IN THE
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) | 1964-01-03 | 1964-07-04 | 1965-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-01-03 | 1968-07-04 | 1969-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-01-03 | 1972-07-04 | 1973-01-03 | $7700.00 | Window Closed / Lapsed |