Patent US501450A successfully refreshed from Google Patents.
US3239883A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screw for extruders
Assignee: Individual
•
Filing: 1963-10-16
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Granted: 1966-03-15
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Expires: 1983-10-16
Abstract
No abstract record available.
Inventors
- 👤 Ferrari Giuseppe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:07
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/50; B29C48/505; B29C48/62; B29C48/03
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
177 words
AN EXTRUSION SCREW FOR EXTRUDING RUBBER AND PLASTIC MATERIAL THROUGH AN EXTRUSION DIE, SAID SCREW HAVING A REAR END AND A FREE FRONT END AND BEING DIVIDED IN AT LEAST TWO ZONES, ONE EXTENDING FROM THE REAR END TO AN INTERMEDIATE SECTION BETWEEN SAID ENDS AND THE OTHER FROM THE INTERMEDIATE SECTION TO SAID FRONT END, EACH ZONE INCLUDING A FRUSTO-CONICAL HAVING A SMALL DIAMETER CLOSER TO SAID REAR END AND A LARGER DIAMETER CLOSER TO SAID FRONT END, THE RATIO OF THE LARGER DIAMETER TO THE SMALLER DIAMETER OF THE ZONE BETWEEN SAID REAR END AND SAID INTERMEDIATE SECTION BEING GREATER THAN THE RATIO OF THE LARGER DIAMETER TO THE SMALLER DIAMETER OF THE OTHER SECTION; A THREAD OF UNIFORM PITCH AND UNIFORM OUTER DIAMETER EXTENDING IN A CONTINUOUS SPIRAL ABOUT THE CORES OF SAID TWO ZONES; AND AT LEAST ONE PERFORATED BAFFLE EXTENDING IN AXIAL DIRECTION BETWEEN TWO SUCCESSIVE TURNS OF SAID THREAD AND RADIALLY FROM THE OUTER SURFACE OF THE CORRESPONDING CORE, SAID BAFFLE HAVING AN OUTER DIAMETER EQUAL TO THAT OF SAID THREAD.
Claim 2
Dependent Claim
177 words
AN EXTRUSION SCREW FOR EXTRUDING RUBBER AND PLASTIC MATERIAL THROUGH AN EXTRUSION DIE, SAID SCREW HAVING A REAR END AND A FREE FRONT END AND BEING DIVIDED IN AT LEAST TWO ZONES, ONE EXTENDING FROM THE REAR END TO AN INTERMEDIATE SECTION BETWEEN SAID ENDS AND THE OTHER FROM THE INTERMEDIATE SECTION TO SAID FRONT END, EACH ZONE INCLUDING A FRUSTO-CONICAL HAVING A SMALL DIAMETER CLOSER TO SAID REAR END AND A LARGER DIAMETER CLOSER TO SAID FRONT END, THE RATIO OF THE LARGER DIAMETER TO THE SMALLER DIAMETER OF THE ZONE BETWEEN SAID REAR END AND SAID INTERMEDIATE SECTION BEING GREATER THAN THE RATIO OF THE LARGER DIAMETER TO THE SMALLER DIAMETER OF THE OTHER SECTION; A THREAD OF UNIFORM PITCH AND UNIFORM OUTER DIAMETER EXTENDING IN A CONTINUOUS SPIRAL ABOUT THE CORES OF SAID TWO ZONES; AND AT LEAST ONE PERFORATED BAFFLE EXTENDING IN AXIAL DIRECTION BETWEEN TWO SUCCESSIVE TURNS OF SAID THREAD AND RADIALLY FROM THE OUTER SURFACE OF THE CORRESPONDING CORE, SAID BAFFLE HAVING AN OUTER DIAMETER EQUAL TO THAT OF SAID THREAD.
References Cited (Backward Citations)
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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) | 1969-03-14 | 1969-09-13 | 1970-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-03-14 | 1973-09-13 | 1974-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-03-14 | 1977-09-13 | 1978-03-15 | $7700.00 | Window Closed / Lapsed |