Patent US2090017A successfully refreshed from Google Patents.
US3547721A
Expired / Lapsed
US
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Process of making a diffusion unit
Assignee: Dietzsch Hans Joachim GmbH
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Filing: 1967-08-28
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Granted: 1970-12-15
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Expires: 1987-08-28
Abstract
No abstract record available.
Inventors
- 👤 Hans-Joachim Dietzsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:47
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/08
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1631071A
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US1876229A
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US1713679A
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US2285502A
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US2485798A
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US2976576A
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US2972349A
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US3228877A
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US3198865A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-12-14 | 1974-06-15 | 1974-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-12-14 | 1978-06-15 | 1978-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-12-14 | 1982-06-15 | 1982-12-15 | $7700.00 | Window Closed / Lapsed |