US3538728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for producing flexible metal ducts
Assignee: Johns Manville Corp
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Filing: 1967-05-15
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Granted: 1970-11-10
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Expires: 1987-05-15
Abstract
No abstract record available.
Inventors
- 👤 John Massey Tribey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:03
CPC Classifications
B; B21; B21D; B21D15/00; B21D15/04; B21C; B21C37/00; B21C37/06; B21C37/12; B21C37/124; B21C37/15; B21C37/156; B21C37/157; F; F16; F16L; F16L11/00; F16L11/14; F16L11/15; F16L11/16
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
DE1071638B
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US1457193A
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US1596215A
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US1938318A
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US2305587A
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GB694478A
Cited
US2999525A
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US3132616A
Cited
US3183695A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-11-09 | 1974-05-11 | 1974-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-11-09 | 1978-05-11 | 1978-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-11-09 | 1982-05-11 | 1982-11-10 | $7700.00 | Window Closed / Lapsed |