Patent US2939835A successfully refreshed from Google Patents.
Patent US2563520A successfully refreshed from Google Patents.
US2563520A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Powdered iron core
Assignee: —
•
Filing: —
•
Granted: 1951-08-07
•
Expires: 1968-08-07
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:09
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
40 words
A MAGNETIC SUBSTANCE CONSISTING OF FINE SPHERICAL PARTICLES OF CARBONYL IRON, AN INSULATING AND RUST-RESISTING COATING OF LEAD CHROMATE ON SAID PARTICLES, AND A BINDER OF A POLYMERIZED PHENOL FORMALDEHYDE RESINOUS CONDENSATION PRODUCT HOLDING SAID PARTICLES IN A SOLID MASS.
Claim 2
Dependent Claim
40 words
A MAGNETIC SUBSTANCE CONSISTING OF FINE SPHERICAL PARTICLES OF CARBONYL IRON, AN INSULATING AND RUST-RESISTING COATING OF LEAD CHROMATE ON SAID PARTICLES, AND A BINDER OF A POLYMERIZED PHENOL FORMALDEHYDE RESINOUS CONDENSATION PRODUCT HOLDING SAID PARTICLES IN A SOLID MASS.
References Cited (Backward Citations)
US1669644A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-08-06 | 1955-02-05 | 1955-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-08-06 | 1959-02-05 | 1959-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-08-06 | 1963-02-05 | 1963-08-07 | $7700.00 | Window Closed / Lapsed |