US2542638A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency responsive apparatus
Assignee: General Electric Co
•
Filing: 1949-03-29
•
Granted: 1951-02-20
•
Expires: 1969-03-29
Abstract
No abstract record available.
Inventors
- 👤 Philip F Desch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:06
CPC Classifications
H; H02; H02J; H02J3/00; H02J3/04; H02J3/08
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-02-19 | 1954-08-21 | 1955-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-02-19 | 1958-08-21 | 1959-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-02-19 | 1962-08-21 | 1963-02-20 | $7700.00 | Window Closed / Lapsed |