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Patent US4902361A successfully refreshed from Google Patents.
US4902361A
Expired / Lapsed
US
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Bonded rare earth-iron magnets
Assignee: Magnequench International LLC
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Filing: 1986-02-10
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Granted: 1990-02-20
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Expires: 2006-02-10
Abstract
Abstract This invention relates to permanent bonded magnets of very finely crystalline, melt-spun, rare earth-iron alloys. The compacts are magnetically isotropic.
Inventors
- 👤 Robert W. Lee
- 👤 John J. Croat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:08
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/047; H01F1/053; H01F1/055; H01F1/057; H01F1/0571; H01F1/0575; H01F1/0578
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
65 words
A bonded, magnetically isotropic permanent magnet comprising a bonding agent interspersed with melt-spun, finely crystalline particles comprising, on an atomic percent basis, at least about 10 to about 40 percent of one or more rare earth elements taken from the group consisting of neodymium and praseodymium, at least about 0.5 to about 10 percent boron, and at least about 50 to about 90 percent iron.
Claim 2
Dependent Claim
65 words
A bonded, magnetically isotropic permanent magnet comprising a bonding agent interspersed with melt-spun, finely crystalline particles comprising, on an atomic percent basis, at least about 10 to about 40 percent of one or more rare earth elements taken from the group consisting of neodymium and praseodymium, at least about 0.5 to about 10 percent boron, and at least about 50 to about 90 percent iron.
Claim 3
Dependent Claim
63 words
A bonded, magnetically isotropic permanent magnet comprising a bonding agent interspersed with magnetically isotropic particles comprising, on an atomic percent basis, at least about 50 to about 90 percent iron, at least 10 to about 40 percent of one or more rare earth elements taken from the group consisting of neodymium and praseodymium, and at least about 0.5 to about 18 percent boron.
Claim 4
Dependent Claim
63 words
A bonded, magnetically isotropic permanent magnet comprising a bonding agent interspersed with magnetically isotropic particles comprising, on an atomic percent basis, at least about 50 to about 90 percent iron, at least 10 to about 40 percent of one or more rare earth elements taken from the group consisting of neodymium and praseodymium, and at least about 0.5 to about 18 percent boron.
Claim 5
Dependent Claim
89 words
A bonded, magnetically isotropic permanent magnet comprising a bonding agent and magnetically isotropic alloy particles comprising, on an atomic percent basis, up to about 40 percent of one or more rare earth elements where neodymium and/or praseodymium comprise at least about 10 percent of the total composition, up to about 90 percent of one or more transition metals taken from the group consisting of iron, nickel and cobalt including at least about 50 percent iron based on the total alloy composition, and from about 0.5 to 10 percent boron.
Claim 6
Dependent Claim
89 words
A bonded, magnetically isotropic permanent magnet comprising a bonding agent and magnetically isotropic alloy particles comprising, on an atomic percent basis, up to about 40 percent of one or more rare earth elements where neodymium and/or praseodymium comprise at least about 10 percent of the total composition, up to about 90 percent of one or more transition metals taken from the group consisting of iron, nickel and cobalt including at least about 50 percent iron based on the total alloy composition, and from about 0.5 to 10 percent boron.
Claim 7
Dependent Claim
76 words
A bonded, magnetically isotropic permanent magnet comprising a compact of an organic polymeric bonding agent and fractured melt-spun, magnetically isotropic alloy particles comprising, on an atomic percent basis, at least about 50 to 90 percent iron, at least about 10 to about 40 percent of one or more rare earth elements taken from the group consisting of neodymium and praseodymium, and at least about 0.5 to about 18 percent boron, the density of the alloy particles.
Claim 8
Dependent Claim
76 words
A bonded, magnetically isotropic permanent magnet comprising a compact of an organic polymeric bonding agent and fractured melt-spun, magnetically isotropic alloy particles comprising, on an atomic percent basis, at least about 50 to 90 percent iron, at least about 10 to about 40 percent of one or more rare earth elements taken from the group consisting of neodymium and praseodymium, and at least about 0.5 to about 18 percent boron, the density of the alloy particles.
Claim 9
Dependent Claim
130 words
A bonded permanent magnet comprising magnetically isotropic ribbon particles of a melt-spun alloy containing at least about 10 to about 40 atomic percent neodymium and/or praseodymium, at least about 0.5 to about 18 percent boron and at least about 50 to about 90 atomic percent iron, said particles being bonded together by means of an organic or inorganic bonding agent; and said particles having a substantially brick-like shape and being spatially oriented substantially parallel to each other within regions of the compact to achieve high compact densities and compact green strength; said magnet being equally susceptible to magnetization in any direction in an applied magnetic field such that at a compact density of 80 percent of said alloy the magnet has a magnetic remanence of at least about 6 kiloGauss.
Claim 10
Dependent Claim
130 words
A bonded permanent magnet comprising magnetically isotropic ribbon particles of a melt-spun alloy containing at least about 10 to about 40 atomic percent neodymium and/or praseodymium, at least about 0.5 to about 18 percent boron and at least about 50 to about 90 atomic percent iron, said particles being bonded together by means of an organic or inorganic bonding agent; and said particles having a substantially brick-like shape and being spatially oriented substantially parallel to each other within regions of the compact to achieve high compact densities and compact green strength; said magnet being equally susceptible to magnetization in any direction in an applied magnetic field such that at a compact density of 80 percent of said alloy the magnet has a magnetic remanence of at least about 6 kiloGauss.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-02-19 | 1993-08-21 | 1994-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-19 | 1997-08-21 | 1998-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-19 | 2001-08-21 | 2002-02-20 | $7700.00 | Window Closed / Lapsed |