US2487781A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signaling system
Assignee: AT&T Inc
•
Filing: 1947-04-25
•
Granted: 1949-11-15
•
Expires: 1967-04-25
Abstract
No abstract record available.
Inventors
- 👤 Henry M Bascom
- 👤 Robert F Massonneau
- 👤 Jr Bernard Ostendorf
- 👤 Wilton T Rea
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:08
CPC Classifications
H; H03; H03K; H03K23/00; H03K23/82
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2272070A
Cited
US2308778A
Cited
US2401657A
Cited
US2373134A
Cited
GB567863A
Cited
US2422583A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1952-11-14 | 1953-05-16 | 1953-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-11-14 | 1957-05-16 | 1957-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-11-14 | 1961-05-16 | 1961-11-15 | $7700.00 | Window Closed / Lapsed |