Patent US1975164A successfully refreshed from Google Patents.
US1975164A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Grid-controlled mercury arc tube
Assignee: Westinghouse Electric Corp
•
Filing: 1933-05-27
•
Granted: 1934-10-02
•
Expires: 1953-05-27
Abstract
No abstract record available.
Inventors
- 👤 Leon R Ludwig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:08
CPC Classifications
H; H01; H01J; H01J13/00; H01J13/02; H01J13/34; H01J13/48; H01J2893/00; H01J2893/0072; H01J2893/0073; H01J2893/0074; H01J2893/0087
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1937-10-01 | 1938-04-02 | 1938-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1941-10-01 | 1942-04-02 | 1942-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1945-10-01 | 1946-04-02 | 1946-10-02 | $7700.00 | Window Closed / Lapsed |