US2821955A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ultrasonic transmitter
Assignee: Zenith Electronics LLC
•
Filing: 1957-03-11
•
Granted: 1958-02-04
•
Expires: 1977-03-11
Abstract
No abstract record available.
Inventors
- 👤 Robert C Ehlers
- 👤 Clarence W Wandrey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:33
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/004; Y; Y10; Y10S; Y10S116/00; Y10S116/30
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1994560A
Cited
US2728902A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-02-03 | 1961-08-05 | 1962-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-02-03 | 1965-08-05 | 1966-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-02-03 | 1969-08-05 | 1970-02-04 | $7700.00 | Window Closed / Lapsed |