US3587137A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plastic pipe making apparatus
Assignee: Druid Plastics Inc
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Filing: 1967-08-21
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Granted: 1971-06-28
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Expires: 1987-08-21
Abstract
Abstract PLASTIC DUCT OR TUBING IS FABRICATED IN A ROTATIONAL MOLD BY HEATING THE MOLD CONTAINING PLASTIC POWDER OR GRANULES AND ROTATING THE MOLD AT SPEEDS LOWE THAN THAT AT WHICH CENTRIFUGAL FORCES BECOME APPRECIABLE.
Inventors
- 👤 William Griff Baldridge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:23
CPC Classifications
B; B29; B29C; B29C35/00; B29C35/02; B29C35/04; B29C41/00; B29C41/02; B29C41/04; B29C41/042; B29C41/34; B29C41/46; B29C35/045
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-27 | 1974-12-27 | 1975-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-27 | 1978-12-27 | 1979-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-27 | 1982-12-27 | 1983-06-28 | $7700.00 | Window Closed / Lapsed |