US4121952A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hard magnetic materials
Assignee: Panasonic Holdings Corp
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Filing: 1977-10-07
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Granted: 1978-10-24
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Expires: 1997-10-07
Abstract
Abstract Fine-grained sintered magnetic material having the composition expressed by SmMz where M is essentially cobalt or a combination of cobalt, iron and copper, exhibits a large coercive force critically when the z-value is in the vicinity of 8. As small amount of zinc can be added to the raw material to aid in the sintering of the material.
Inventors
- 👤 Harufumi Senn
- 👤 Yoshio Tawara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:56
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/047; H01F1/053; H01F1/055; H01F1/0555; H01F1/0557; C; C22; C22C; C22C19/00; C22C19/07
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
69 words
A sintered magnetic material consisting essentially of samarium, cobalt, iron and copper, said composition being expressed by the formula Sm(Co 1-x-y Fe x Cu y ) z , in which x is 0.01 to 0.15, y is 0.05 to 0.15 and z is 7.8 to 8.2, said sintered material having an average grain size less than 10 microns and exhibiting a coercive force of at least about 10,600 Oe.
Claim 2
Dependent Claim
69 words
A sintered magnetic material consisting essentially of samarium, cobalt, iron and copper, said composition being expressed by the formula Sm(Co 1-x-y Fe x Cu y ) z , in which x is 0.01 to 0.15, y is 0.05 to 0.15 and z is 7.8 to 8.2, said sintered material having an average grain size less than 10 microns and exhibiting a coercive force of at least about 10,600 Oe.
References Cited (Backward Citations)
US3947295A
Cited
US3982971A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-10-23 | 1982-04-24 | 1982-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-23 | 1986-04-24 | 1986-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-23 | 1990-04-24 | 1990-10-24 | $7700.00 | Window Closed / Lapsed |