Patent US4685530A successfully refreshed from Google Patents.
Patent US3504221A successfully refreshed from Google Patents.
US3504221A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adjustable spark gap structure with preionizing means
Assignee: Westinghouse Electric Corp
•
Filing: 1969-04-01
•
Granted: 1970-03-31
•
Expires: 1989-04-01
Abstract
No abstract record available.
Inventors
- 👤 Joseph C Osterhout
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:18
CPC Classifications
H; H01; H01T; H01T4/00; H01T4/16
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-03-30 | 1973-09-29 | 1974-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-03-30 | 1977-09-29 | 1978-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-03-30 | 1981-09-29 | 1982-03-31 | $7700.00 | Window Closed / Lapsed |