US3581384A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing seamless metal tubes
Assignee: Vodafone GmbH
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Filing: 1968-06-25
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Granted: 1971-06-01
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Expires: 1988-06-25
Abstract
Abstract SEAMLESS TUBES ARE PRODUCED, FROM HOLLOW BLANKS OBTAINED BY CONTINUOUSLY CASTING, AND THE BLANKS HAVE A RATIO OF OUTER TO INNER DIAMETER OF ABOUT 2:1 TO ABOUT 5:1 AND A WALL THICKNESS OF AT LEAST 150 MM. AND AN INNER DIAMETER OF AT LEAST 80 MM., BY STRETCH ROLLING THE BLANKS, HEATING THEM AND FURTHER ROLLING THEM. A ROLLING MACHINE INCLUDES A THREE-RTOLL DIAGONAL ROLLING MILL, AND EACH ROLL HAS A SHOULDER CALIBRATION, AND A HOLLOW NOZZLE CARRYING MANDREL ROD THAT IS CAPABLE OF RECEIVING AND SPRAYING A PRESSURE WATER.
Inventors
- 👤 Ulrich Petersen
- 👤 Friedrich-Hans Grandin
- 👤 Jose Severin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:41
CPC Classifications
B; B21; B21C; B21C1/00; B21C1/16; B21C1/22; B21B; B21B19/00; B21B19/12; B21B19/14; B21B23/00; B21C37/00; B21C37/06; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4998; Y10T29/49988; Y10T29/49991
Claims Analysis
Total Claims: 0
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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) | 1974-05-31 | 1974-11-30 | 1975-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-31 | 1978-11-30 | 1979-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-31 | 1982-11-30 | 1983-06-01 | $7700.00 | Window Closed / Lapsed |