Extruder mixing screw
Abstract
Abstract A SINGLE STAGE EXTRUDER SCREW WHEREIN, IN ADDITION TO HAVING A CONTINUOUS HELICAL FLIGHT FOR ADVANCING THERMOPLASTIC MATERIAL, SUCH AS FOOD GRADE PVC, THERE IS PROVIDED RADIAL MIXING PINS ARRANGED IN NINE CIRCUMFERENTIAL ROWS WHICH ARE AXIALLY SPACED ALONG THE SCREW FOR MIXING THE ADVANCING THERMOPLASTIC MATERIAL. SEVEN OF THE NINE ROWS ARE INCOMPLETE CIRCUMFERENTIAL ROWS OF RADIAL PINS, THE ROWS BEING INTERRUPTED BY THE HELICAL FIGHT AND ALIGNED TO DIAGONALLY BISECT A PORTION OF A HELICAL CHANNEL DEFINED BY THE ADJACENT TURNS OF THE HELICAL FLIGHT ON EITHER SIDE OF THE LOCATION AT WHICH EACH ROW IS INTERRUPTED BY THE HELICAL FLIGHT. FURTHER, ONE COMPLETE FLIGHT TURN IS CUT BACK ON THE EXTRUDING END OF THE SCREW THEREBY LEAVING A FLIGHTLESS ROOT PORTION AT THIS END OF THE SCREW. FINALLY, THE REMAINING TWO OF THE NINE ROWS ARE CIRCUMFERENTIALLY ARRANGED ABOUT THIS END OF THE SCREW AT THE FLIGHTLESS ROOT PORTION AND ARE COMPLETE ROWS OF RADIAL MIXING PINS.
Inventors
- 👤 Roland Norbert Wendricks
Bibliographic Details
Claims Analysis
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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) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |