Patent US4329673A successfully refreshed from Google Patents.
US4329673A
Expired / Lapsed
US
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Switchable permanent magnet holding device
Assignee: Kanetsu Kogyo KK
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Filing: 1980-07-25
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Granted: 1982-05-11
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Expires: 2000-07-25
Abstract
Abstract A switchable permanent magnet holding device in which a permanent magnet rotatably disposed within a bore in a magnetic circuit block is rotated, so that the magnetism acting surfaces of the magnetic circuit block are brought into an exciting state for retaining a magnetic substance thereon and into a non-exciting state for releasing the magnetic substance therefrom. The permanent magnet is pressed against a stopper for impeding rotation thereof, due to a gyromagnetic force acting across the permanent magnet and the magnetic circuit block when the permanent magnet is rotated to a position in which the magnetism acting surfaces of the block become exciting.
Inventors
- 👤 Mamoru Uchikune
- 👤 Kiyoshi Yanagisawa
- 👤 Mutsukazu Tagami
- 👤 Taketo Shimizu
- 👤 Kunio Horiuchi
- 👤 Hiroo Sakaguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:55
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/02; H01F7/04
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
186 words
A switchable permanent magnet holding device comprising; a magnetic circuit block consisting of a pair of magnetic pole members respectively having a magnetism acting surface, and a non-magnetic plate disposed between said pair of magnetic pole members, said magnetic circuit block being provided with a bore having a circular cross section and running in parallel to the non-magnetic plate; a permanent magnet disposed in said bore rotatably about the central axis of said bore and adapted to be switched between a position in which said magnetism acting surfaces of said block become non-exciting and a position in which said magnetism acting surfaces thereof become exciting; and, a stopper for impeding rotation of the permanent magnet, said stopper being adapted to engage said permanent magnet rotated to a position over a predetermined angle of rotation at which said magnetism acting surfaces of said block become exciting and said magnetic circuit block is maintained in a state of magnetic equilibrium, when said permanent magnet is turned in one direction, in order to switch the non-excited state of the magnetism acting surface of said block to the exciting state.
Claim 2
Dependent Claim
186 words
A switchable permanent magnet holding device comprising; a magnetic circuit block consisting of a pair of magnetic pole members respectively having a magnetism acting surface, and a non-magnetic plate disposed between said pair of magnetic pole members, said magnetic circuit block being provided with a bore having a circular cross section and running in parallel to the non-magnetic plate; a permanent magnet disposed in said bore rotatably about the central axis of said bore and adapted to be switched between a position in which said magnetism acting surfaces of said block become non-exciting and a position in which said magnetism acting surfaces thereof become exciting; and, a stopper for impeding rotation of the permanent magnet, said stopper being adapted to engage said permanent magnet rotated to a position over a predetermined angle of rotation at which said magnetism acting surfaces of said block become exciting and said magnetic circuit block is maintained in a state of magnetic equilibrium, when said permanent magnet is turned in one direction, in order to switch the non-excited state of the magnetism acting surface of said block to the exciting state.
Claim 3
Dependent Claim
26 words
A permanent magnet holding device as defined in claim 1, wherein said permanent magnet is a columnar shaped permanent magnet magnetized in the diametrical direction thereof.
Claim 4
Dependent Claim
49 words
A permanent magnet holding device as defined in claim 2, wherein rotation of said permanent magnet is stopped by a stopper at a position in which the direction of magnetization of the permanent magnet is deviated at an angle over 90° from a position parallel to the non-magnetic plates.
Claim 5
Dependent Claim
56 words
A permanent magnet holding device as defined in claim 3, wherein said permanent magnet has at one end face thereof a diametrically extending ridge on which an operation knob is to be fitted, and said stopper is a projection extending from the peripheral surface of said bore and engageable with said ridge of the permanent magnet.
Claim 6
Dependent Claim
36 words
A permanent magnet holding device as defined in claim 4, wherein said projection is a tip of a pin inserted into a through-hole provided in one of said magnetic pole members to open to said bore.
References Cited (Backward Citations)
US2972485A
Cited
US4055824A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-05-10 | 1985-11-09 | 1986-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-10 | 1989-11-09 | 1990-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-10 | 1993-11-09 | 1994-05-11 | $7700.00 | Window Closed / Lapsed |