US2528026A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High-frequency siren
Assignee: Pennsylvania Research Corp
•
Filing: 1948-08-18
•
Granted: 1950-10-31
•
Expires: 1968-08-18
Abstract
No abstract record available.
Inventors
- 👤 Clayton H Allen
- 👤 Rudnick Isadore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:53
CPC Classifications
G; G10; G10K; G10K7/00; G10K7/02; G10K7/04
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) | 1953-10-30 | 1954-05-01 | 1954-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-10-30 | 1958-05-01 | 1958-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-10-30 | 1962-05-01 | 1962-10-31 | $7700.00 | Window Closed / Lapsed |