Patent US1774841A successfully refreshed from Google Patents.
Patent US623189A successfully refreshed from Google Patents.
Patent US2857516A successfully refreshed from Google Patents.
US2857516A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic commutation circuit
Assignee: Unisys Corp
•
Filing: 1955-10-21
•
Granted: 1958-10-21
•
Expires: 1975-10-21
Abstract
No abstract record available.
Inventors
- 👤 Perlmutter Norman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:10
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/04; H03K3/05; H03K3/06; H03K3/12
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US2478683A
Cited
US2524953A
Cited
US2602896A
Cited
US2556935A
Cited
US2647208A
Cited
US2644887A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-10-20 | 1962-04-21 | 1962-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-10-20 | 1966-04-21 | 1966-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-10-20 | 1970-04-21 | 1970-10-21 | $7700.00 | Window Closed / Lapsed |