US4658228A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Confinement of longitudinal, axially symmetric, magnetic fields to annular regions with permanent magnets
Assignee: United States Department of the Army
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Filing: 1986-05-01
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Granted: 1987-04-14
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Expires: 2006-05-01
Abstract
Abstract A magnetic device of permanent magnet materials for the control of linearlyxtending annular cross-sectioned magnetic fields formed of two concentrically nesting magnetic tubular elements defining an annular space therebetween, and inner and outer cladding magnets radially disposed around the outer of said tubular elements and interiorly of the inner of said tubular elements, the cladding magnets being thicker at the end extremities and diminishing in thickness towards and to the plane of zero magnetic potential at or near the center line of the device measured along its longitudinal axis.
Inventors
- 👤 Herbert A. Leupold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:21
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/02; H01F7/0273; H01F7/0278
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
121 words
A magnetic device for the production and substantially flux leakage free control and maintenance of a longitudinally extending annular cross-section magnetic field, comprising, in combination: an inner and outer cylindrical permanent magnet pair concentrically disposed and extending longitudinally to define an annular space therebetween; a first array of cladding magnets disposed exteriorly of said permanent magnet pair, extending longitudinally concentrically therewith and tapering in diminishing thickness from their ends towards and to a plane of zero magnetic potential transversely through the device; and a second array of cladding magnets arranged interiorly of said permanent magnet pair, extending longitudinally concentrically therethrough and tapering in diminishing thickness from their ends towards and to a plane of zero magnetic potential transversely through the device.
Claim 2
Dependent Claim
121 words
A magnetic device for the production and substantially flux leakage free control and maintenance of a longitudinally extending annular cross-section magnetic field, comprising, in combination: an inner and outer cylindrical permanent magnet pair concentrically disposed and extending longitudinally to define an annular space therebetween; a first array of cladding magnets disposed exteriorly of said permanent magnet pair, extending longitudinally concentrically therewith and tapering in diminishing thickness from their ends towards and to a plane of zero magnetic potential transversely through the device; and a second array of cladding magnets arranged interiorly of said permanent magnet pair, extending longitudinally concentrically therethrough and tapering in diminishing thickness from their ends towards and to a plane of zero magnetic potential transversely through the device.
Claim 3
Dependent Claim
24 words
Apparatus according to claim 1 wherein the respective flux orientations of said permanent magnet pair and the said arrays of cladding magnets are transverse.
Claim 4
Dependent Claim
24 words
Apparatus according to claim 1 wherein the permanent magnet pair and the first and second cladding magnets are characterized by having square hysterises characteristics.
Claim 5
Dependent Claim
45 words
Apparatus according to claim 1 wherein flux in the permanent magnet pair is oriented in axial longitudinally parallel alignment with said magnetic field, and flux in said first and said second arrays of cladding magnets is oriented radially transverse to the permanent magnet pair flux.
Claim 6
Dependent Claim
25 words
Apparatus according to claim 1 in combination with iron pole pieces and bucking magnets operably disposed at each of the longitudinal ends of said device.
References Cited (Backward Citations)
US3182234A
Cited
US3205415A
Cited
US3237059A
Cited
US3227931A
Cited
US4580120A
Cited
US4578663A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-04-13 | 1990-10-13 | 1991-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-13 | 1994-10-13 | 1995-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-13 | 1998-10-13 | 1999-04-14 | $7700.00 | Window Closed / Lapsed |