US3974000A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semi-hard magnetic materials
Assignee: Fujitsu Ltd
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Filing: 1974-10-04
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Granted: 1976-08-10
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Expires: 1994-10-04
Abstract
Abstract A semi-hard magnetic alloy is disclosed consisting essentially of 15 to 30% of Ni, 35 to 52% of Fe, 1 to 5% of Nb and the balance cobalt. This alloy possesses a coercive force (Hc) of 10 to 50 Oe, a magnetic flux density (B100) of 10 to 17.5 KG., a squareness ratio (Br/B100) of not less than 0.70 and a fullness ratio of not less than approximately 0.70. The alloy material is also characterized by a good plastic workability.
Inventors
- 👤 Zenzo Henmi
- 👤 Tatsuji Sasaki
- 👤 Masanori Okada
- 👤 Makoto Kassai
- 👤 Yuichi Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:31
CPC Classifications
C; C22; C22F; C22F1/00; C22F1/10; C22C; C22C19/00; C22C38/00; C22C38/10; C22C38/105
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
81 words
A worked and heat-treated semi-hard magnetic alloy consisting essentially of 15 to 30% by weight of nickel, 35 to 52% by weight of iron, 1 to 5% by weight of niobium and the balance cobalt, and having a coercive force of 10 to 50 Oe, a magnetic flux density at a magnetic field of 100 Oe, of 10 to 17.5 kilo-gauss, a squareness ratio of not lower than approximately 0.70 and also having a fullness factor not lower than approximately 0.70.
Claim 2
Dependent Claim
81 words
A worked and heat-treated semi-hard magnetic alloy consisting essentially of 15 to 30% by weight of nickel, 35 to 52% by weight of iron, 1 to 5% by weight of niobium and the balance cobalt, and having a coercive force of 10 to 50 Oe, a magnetic flux density at a magnetic field of 100 Oe, of 10 to 17.5 kilo-gauss, a squareness ratio of not lower than approximately 0.70 and also having a fullness factor not lower than approximately 0.70.
Claim 3
Dependent Claim
47 words
A semi-hard magnetic alloy according to claim 1, consisting essentially of 20 to 26% by weight of nickel, 37 to 52% by weight of iron, 2 to 4% by weight of niobium and the balance cobalt, and having a squareness ratio of not lower than approximately 0.80.
Claim 4
Dependent Claim
18 words
A semi-hard magnetic alloy according to claim 2, wherein the squareness ratio is not lower than approximately 0.95.
References Cited (Backward Citations)
US1792483A
Cited
US3390443A
Cited
US3615910A
Cited
US3686042A
Cited
US3647424A
Cited
US3743550A
Cited
US3698055A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-10 | 1980-02-09 | 1980-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-10 | 1984-02-09 | 1984-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-10 | 1988-02-09 | 1988-08-10 | $7700.00 | Window Closed / Lapsed |