US2547035A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric signaling system
Assignee: International Standard Electric Corp
•
Filing: 1947-01-02
•
Granted: 1951-04-03
•
Expires: 1967-01-02
Abstract
No abstract record available.
Inventors
- 👤 Mcwhirter Eric Maleolm Swift
- 👤 Dunn Roland Harris
- 👤 Lennox Peter William
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:10
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/12; H03M1/14; H03M1/142
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1602882A
Cited
GB266798A
Cited
US1778827A
Cited
US2110015A
Cited
US2207744A
Cited
US2237713A
Cited
US2217477A
Cited
US2241743A
Cited
US2432826A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-04-02 | 1954-10-02 | 1955-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-04-02 | 1958-10-02 | 1959-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-04-02 | 1962-10-02 | 1963-04-03 | $7700.00 | Window Closed / Lapsed |