US4701736A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnet assembly having a plurality of nested coaxial coils
Assignee: Oxford Instruments Superconductivity Ltd
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Filing: 1985-02-01
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Granted: 1987-10-20
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Expires: 2005-02-01
Abstract
Abstract A magnet assembly, particularly for use in NMR imaging apparatus, comprises a plurality of nested, coaxial coils (2-5). The radius and number of turns of the coils (2-5) are such that when working currents flow through the coils substantially uniform magnetic field is generated in a homogeneous region (16).
Inventors
- 👤 Ian L. McDougall
- 👤 John M. Bird
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:45
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/38; G01R33/3806; G01R33/381; G01R33/3815; G01R33/387; G01R33/3875
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
67 words
A magnet assembly comprising a plurality of nested, coaxial coils each having a plurality of turns defining radii, whereby working currents are adapted to flow in opposite directions through at least two of said coils, said plurality of turns of said coils and said radii being adapted such that when working currents flow through said coils a substantially uniform magnetic field is generated in a homogeneous region.
Claim 2
Dependent Claim
67 words
A magnet assembly comprising a plurality of nested, coaxial coils each having a plurality of turns defining radii, whereby working currents are adapted to flow in opposite directions through at least two of said coils, said plurality of turns of said coils and said radii being adapted such that when working currents flow through said coils a substantially uniform magnetic field is generated in a homogeneous region.
Claim 3
Dependent Claim
20 words
An assembly according to claim 1, wherein a radially outermost coil defines a volume within each another coil is positioned.
Claim 4
Dependent Claim
21 words
An assembly according to claim 1, wherein the number of turns of said coils generally increases in the radially outward direction.
Claim 5
Dependent Claim
41 words
An assembly according to claim 1, said assembly defining a plane normal to said axis of said coils and passing through a mid point of said axis wherein at least one pair of said coils are positioned symmetrically about said plane.
Claim 6
Dependent Claim
36 words
An assembly according to claim 1, wherein each coil defines respective inner and outer radii and a mean radius, said inner and outer radii of each coil being close to said means radius of said coil.
Claim 7
Dependent Claim
11 words
NMR imaging apparatus including a magnet assembly according to claim 1.
Claim 8
Independent Claim
79 words
A method of operating a magnet assembly comprising a plurality of nested, coaxial coils each having a plurality of turns defining radii, the method comprising supplying electrical currents to said coils, said electrical currents flowing in opposite directions through at least two of said coils whereby the magnitude of said current in each said coil and the number of said turns and their radii is adapted such that a substantially uniform magnetic field is generated in a homogeneous region.
Claim 9
Independent Claim
79 words
A method of operating a magnet assembly comprising a plurality of nested, coaxial coils each having a plurality of turns defining radii, the method comprising supplying electrical currents to said coils, said electrical currents flowing in opposite directions through at least two of said coils whereby the magnitude of said current in each said coil and the number of said turns and their radii is adapted such that a substantially uniform magnetic field is generated in a homogeneous region.
Claim 10
Dependent Claim
21 words
A method according to claim 7, wherein the direction of flow of said current is opposite in adjacent, radially spaced coils.
Claim 11
Dependent Claim
18 words
A method according to claim 7, wherein said homogeneous region projects at least partially from said magnet assembly.
Claim 12
Dependent Claim
18 words
A method according to claim 8, wherein said homogeneous region projects at least partially from said magnet assembly.
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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) | 1990-10-19 | 1991-04-20 | 1991-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-19 | 1995-04-20 | 1995-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-19 | 1999-04-20 | 1999-10-20 | $7700.00 | Window Closed / Lapsed |