US4042898A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pole piece for use in magnet device and method for manufacturing same
Assignee: Hitachi Ltd
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Filing: 1975-03-10
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Granted: 1977-08-16
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Expires: 1995-03-10
Abstract
Abstract A pole piece for use in a magnet device and a method for manufacturing same, in which the structure of the pole piece for use in a magnet device used in an analyzing apparatus for analyzing such as nuclear magnetic resonance is varied in concentric fashion from the center towards the outer circumference of the pole piece. The pole piece is manufactured according to the die-forging, whereby the magnetic properties of the pole piece become hetrogenous in concentric fashion. The use of such a pole piece brings about a magnet device which is compact in size and which provides a strong and uniform magnetic field.
Inventors
- 👤 Sadami Tomita
- 👤 Akio Chiba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:27
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/02; H01F7/0273; H01F7/0278; H01F3/00; H01F41/00; H01F41/02; H01F41/0206; H01F41/0246
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
38 words
A pole piece for use in a magnet device, characterized in that the crystal structure of the surface of said pole piece is different depending on the center portion and the outer circumferential portion of said pole piece.
Claim 2
Dependent Claim
38 words
A pole piece for use in a magnet device, characterized in that the crystal structure of the surface of said pole piece is different depending on the center portion and the outer circumferential portion of said pole piece.
Claim 3
Dependent Claim
62 words
A pole piece for use in a magnet device, characterized in that the crystal structure of the surface of said pole piece is different depending on the center portion and the outer circumferential portion of said pole piece, wherein the outer circumferential portion of said pole piece has a fine crystal structure, while the center portion thereof has a rough crystal structure.
Claim 4
Dependent Claim
62 words
A pole piece for use in a magnet device, characterized in that the crystal structure of the surface of said pole piece is different depending on the center portion and the outer circumferential portion of said pole piece, wherein the outer circumferential portion of said pole piece has a fine crystal structure, while the center portion thereof has a rough crystal structure.
Claim 5
Dependent Claim
37 words
A pole piece for use in a magnet device as set forth in claim 2, wherein the ratio in the crystal grain size of said fine crystal structure to said rough crystal structure is 1 : 4.
Claim 6
Dependent Claim
35 words
A pole piece for use in a magnet device, characterized in that the crystal structure of the surface of said pole piece varies in an annular ring fashion from its center towards its outer circumference.
Claim 7
Dependent Claim
35 words
A pole piece for use in a magnet device, characterized in that the crystal structure of the surface of said pole piece varies in an annular ring fashion from its center towards its outer circumference.
Claim 8
Independent Claim
43 words
A method of manufacturing a pole piece for use in a magnet device, comprising the step of using die-forging, whereby a fine crystal structure is obtained by applying heavy plastic working, while a rough crystal structure is obtained due to light plastic working.
Claim 9
Independent Claim
43 words
A method of manufacturing a pole piece for use in a magnet device, comprising the step of using die-forging, whereby a fine crystal structure is obtained by applying heavy plastic working, while a rough crystal structure is obtained due to light plastic working.
Claim 10
Dependent Claim
36 words
A method of manufacturing a pole piece for use in a magnet device as set forth in claim 5, wherein the degree of plastic working is adjusted by utilizing the configuration of a lower punch die.
Claim 11
Dependent Claim
75 words
A method for manufacturing a pole piece for use in a magnet device as set forth in claim 5, wherein the portion of said pole piece, which has been subjected to heavy plastic working, is obtained by means of a concave portion of said lower punch die while the portions of said pole piece, which has been subjected to light plastic working, is obtained by means of a convex portion of said lower punch die.
Claim 12
Dependent Claim
98 words
A unitary pole piece for use in a magnet device, comprising at least two regions, a first of said at least two regions being substantially continuous along the circumferential direction of the pole piece, said first region having a crystal structure different in grain size from the crystal structure of a second of said at least two regions, wherein said first region has a fine grain size crystal structure and said second region has a rough grain size crystal structure, and wherein the magnetic permeability of said first region is substantially lower than that of said second region.
Claim 13
Dependent Claim
98 words
A unitary pole piece for use in a magnet device, comprising at least two regions, a first of said at least two regions being substantially continuous along the circumferential direction of the pole piece, said first region having a crystal structure different in grain size from the crystal structure of a second of said at least two regions, wherein said first region has a fine grain size crystal structure and said second region has a rough grain size crystal structure, and wherein the magnetic permeability of said first region is substantially lower than that of said second region.
Claim 14
Dependent Claim
38 words
A unitary pole piece as defined in claim 8, wherein said first region is positioned at the outer peripheral portion of the pole piece, and said second region is positioned in the central portion of the pole piece.
Claim 15
Dependent Claim
31 words
A unitary pole piece as defined in claim 9, wherein the ratio in the crystal grain size of said fine crystal structure to said rough crystal structure is 1 : 4.
Claim 16
Dependent Claim
31 words
A unitary pole piece as defined in claim 8, wherein said first region of the fine grain size crystal structure is formed by die-forging of a material for said pole piece.
Claim 17
Dependent Claim
38 words
A unitary pole piece as defined in claim 11, wherein said first region is positioned in the outer peripheral portion of the pole piece, and said second region is positioned in the central portion of the pole piece.
Claim 18
Dependent Claim
31 words
A unitary pole piece as defined in claim 12, wherein the ratio in the crystal grain size of said fine crystal structure to said rough crystal structure is 1 : 4.
Claim 19
Dependent Claim
67 words
A unitary pole piece as defined in claim 8, wherein a plurality of said regions are concentrically provided in the surface of the pole piece, each of said plurality of concentric regions having crystal structures of different grain sizes, wherein at least one of said plurality of regions has said fine grain structure and at least another of said plurality of regions has said rough grain structure.
Claim 20
Dependent Claim
30 words
A unitary pole piece as defined in claim 14, wherein three concentric regions of different grain sizes are provided with said three regions having alternate fine and rough grain sizes.
Claim 21
Dependent Claim
30 words
A unitary pole piece as defined in claim 14, wherein five concentric regions of different grain sizes are provided with said five regions having alternate fine and rough grain sizes.
Claim 22
Dependent Claim
21 words
A unitary pole piece as defined in claim 8, wherein said regions are provided in the surface of the pole piece.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-15 | 1981-02-14 | 1981-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-15 | 1985-02-14 | 1985-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-15 | 1989-02-14 | 1989-08-16 | $7700.00 | Window Closed / Lapsed |