Patent US2870435A successfully refreshed from Google Patents.
US2870435A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Calling system
Assignee: Individual
•
Filing: 1955-05-23
•
Granted: 1959-01-20
•
Expires: 1975-05-23
Abstract
No abstract record available.
Inventors
- 👤 Graaf Nicolaas Robert De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:07
CPC Classifications
H; H04; H04B; H04B5/00; H04M; H04M3/00; H04M3/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US887357A
Cited
US968224A
Cited
US1465932A
Cited
US2138894A
Cited
US2198901A
Cited
US2395132A
Cited
US2357925A
Cited
US2494451A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-01-19 | 1962-07-21 | 1963-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-01-19 | 1966-07-21 | 1967-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-01-19 | 1970-07-21 | 1971-01-20 | $7700.00 | Window Closed / Lapsed |