US2197029A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Line amplifier for telephony purposes
Assignee: International Standard Electric Corp
•
Filing: 1934-11-22
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Granted: 1940-04-16
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Expires: 1954-11-22
Abstract
No abstract record available.
Inventors
- 👤 Bast Gerardus Henricus
- 👤 Stieltjes Frederik Hendrik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:54
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/20; H03F3/22; H04; H04B; H04B1/00; H04B1/38; H04B1/40; H04B1/54; H04B1/58; H04B3/00; H04B3/02; H04B3/03
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1943-04-16 | 1943-10-16 | 1944-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-04-16 | 1947-10-16 | 1948-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-04-16 | 1951-10-16 | 1952-04-16 | $7700.00 | Window Closed / Lapsed |