Patent US1942072A successfully refreshed from Google Patents.
US1942072A
Expired / Lapsed
US
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Gas purification
Assignee: Koppers Co of Delaware
•
Filing: 1928-09-03
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Granted: 1934-01-02
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Expires: 1948-09-03
Abstract
No abstract record available.
Inventors
- 👤 Jr Frederick W Sperr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:01
CPC Classifications
C; C10; C10K; C10K1/00; C10K1/08; C10K1/085; Y; Y10; Y10S; Y10S261/00; Y10S261/34
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) | 1937-01-01 | 1937-07-03 | 1938-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1941-01-01 | 1941-07-03 | 1942-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1945-01-01 | 1945-07-03 | 1946-01-02 | $7700.00 | Window Closed / Lapsed |