US3538417A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bridge type frequency converter
Assignee: US Philips Corp
•
Filing: 1968-03-05
•
Granted: 1970-11-03
•
Expires: 1988-03-05
Abstract
No abstract record available.
Inventors
- 👤 Engbert Bernard Gerard Nijhof
- 👤 Wilhelmus Bernardus Rosink
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 18:33
CPC Classifications
H; H02; H02M; H02M5/00; H02M5/02; H02M5/04; H02M5/22; H02M5/25; H02M5/27; H02M5/271
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3302093A
Cited
US3213347A
Cited
US3360710A
Cited
US3406326A
Cited
US3435321A
Cited
US3431483A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-11-02 | 1974-05-04 | 1974-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-11-02 | 1978-05-04 | 1978-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-11-02 | 1982-05-04 | 1982-11-03 | $7700.00 | Window Closed / Lapsed |