US2550819A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cordless key control testboard for telephone systems
Assignee: Automatic Electric Laboratories Inc
•
Filing: 1947-09-17
•
Granted: 1951-05-01
•
Expires: 1967-09-17
Abstract
No abstract record available.
Inventors
- 👤 Kessler Frank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:54
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/22; H04M3/26; H04M3/28
Claims Analysis
Total Claims: 0
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-04-30 | 1954-10-30 | 1955-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-04-30 | 1958-10-30 | 1959-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-04-30 | 1962-10-30 | 1963-05-01 | $7700.00 | Window Closed / Lapsed |