US2597007A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Common control circuit for operating switches rearward to calling line
Assignee: International Standard Electric Corp
•
Filing: 1947-10-08
•
Granted: 1952-05-20
•
Expires: 1967-10-08
Abstract
No abstract record available.
Inventors
- 👤 Jakob Kruithof
- 👤 Ladislas Kozma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:07
CPC Classifications
H; H04; H04Q; H04Q1/00; H04Q1/18; H04Q3/00
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1714718A
Cited
US1767861A
Cited
US1857833A
Cited
US1851482A
Cited
US1829774A
Cited
US1845604A
Cited
US1903019A
Cited
US1984060A
Cited
US2081027A
Cited
US2169302A
Cited
US2201651A
Cited
US2424585A
Cited
US2444065A
Cited
US2452578A
Cited
US2454809A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-05-20 | 1955-11-19 | 1956-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-05-20 | 1959-11-19 | 1960-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-05-20 | 1963-11-19 | 1964-05-20 | $7700.00 | Window Closed / Lapsed |