Patent US6726691B2 successfully refreshed from Google Patents.
US2221983A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Layered magnetizable material and structure for electrical purposes
Assignee: Individual
•
Filing: 1938-02-25
•
Granted: 1940-11-19
•
Expires: 1958-02-25
Abstract
No abstract record available.
Inventors
- 👤 Emil E Mayer
- 👤 Schwarzkopf Paul
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:44
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/02; H01F41/0206; H01F41/0246; Y; Y10; Y10S; Y10S29/00; Y10S29/028; Y10S428/00; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49075; Y10T29/49076; Y10T29/49078; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12028; Y10T428/12049; Y10T428/12056; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/25; Y10T428/256
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) | 1943-11-19 | 1944-05-20 | 1944-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-11-19 | 1948-05-20 | 1948-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-11-19 | 1952-05-20 | 1952-11-19 | $7700.00 | Window Closed / Lapsed |