Patent US4945330A successfully refreshed from Google Patents.
US4945330A
Expired / Lapsed
US
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Actuator
Assignee: Mitsubishi Chemical Corp
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Filing: 1989-03-27
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Granted: 1990-07-31
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Expires: 2009-03-27
Abstract
Abstract An actuator is disclosed, in which an movable armature and a permanent magnet mounted on a stationary yoke are disposed to face each other with a small gap. The armature has at least one pair of protruding poles which are movable along a predetermined path. The permanent magnet comprises plural pairs of juxtaposed magnetic pieces whose polarities are opposite to each other. The plural pairs of magnetic pieces are arranged in juxtaposition with each other at positions adjacent to the path of the corresponding protruding pole so that adjacent two magnetic pieces of adjacent two pairs have the same polarity with each other. The permanent magnet generates such a magnetic pattern that the amount thereof gradually decreases from both ends of the path of each protruding pole towards the boundary of the magnet pieces of the corresponding pair to avoid the influences due to the reluctance torque and the drive torque.
Inventors
- 👤 Yoji Arita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:25
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/06; H01F7/08; H01F7/02; H01F7/0205; H01F7/021; H01F7/14
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
175 words
An actuator comprising: an armature having at least one pair of protruding poles and movable so that each of said protruding poles is movable along a predetermined path; a coil disposed to surround each of said protruding poles and adapted for energizing same such that said protruding poles are energized in opposite polarities to each other; a stationary yoke extending in the direction parallel to said path; and a permanent magnet composed of plural pairs of juxtaposed magnetic pieces whose magnetic polarities are opposite to each other, said plural pairs of magnetic pieces corresponding in number to the number of said protruding poles and mounted on said yoke in juxtaposition with each other at positions adjacent to the path of the corresponding protruding pole, adjacent two magnetic pieces of adjacent pairs having the same polarity with each other, and said permanent magnet generating such a magnetic flux pattern that the amount thereof gradually decreases from both ends of the path of each protruding pole towards the boundary of the magnetic pieces of the corresponding pair.
Claim 2
Dependent Claim
175 words
An actuator comprising: an armature having at least one pair of protruding poles and movable so that each of said protruding poles is movable along a predetermined path; a coil disposed to surround each of said protruding poles and adapted for energizing same such that said protruding poles are energized in opposite polarities to each other; a stationary yoke extending in the direction parallel to said path; and a permanent magnet composed of plural pairs of juxtaposed magnetic pieces whose magnetic polarities are opposite to each other, said plural pairs of magnetic pieces corresponding in number to the number of said protruding poles and mounted on said yoke in juxtaposition with each other at positions adjacent to the path of the corresponding protruding pole, adjacent two magnetic pieces of adjacent pairs having the same polarity with each other, and said permanent magnet generating such a magnetic flux pattern that the amount thereof gradually decreases from both ends of the path of each protruding pole towards the boundary of the magnetic pieces of the corresponding pair.
Claim 3
Dependent Claim
70 words
The actuator as claimed in claim 1, wherein each magnetic pole of the magnetic pieces is magnetized uniformly, the total thickness of the permanent magnet and the yoke is uniform throughout their lengths, and the permanent magnet is formed in a shape such that the thickness thereof gradually decreases from both ends of the path of each protruding pole towards the boundary of the magnetic pieces of the corresponding pair.
Claim 4
Dependent Claim
56 words
The actuator as claimed in claim 1, wherein each magnetic pole of the magnetic pieces is magnetized uniformly, and the permanent magnet is formed in a shape such that the vertical length thereof, gradually decreases from both ends of the path of each protruding pole towards the boundary of the magnetic pieces of the corresponding pair.
Claim 5
Dependent Claim
65 words
The actuator as claimed in claim 1, wherein each magnetic pole of the magnetic pieces is magnetized uniformly, the thickness of the yoke is uniform throughout its length, and the permanent magnet is formed in a shape such that the thickness thereof gradually decreases from both ends of the path of each protruding pole towards the boundary of the magnetic pieces of the corresponding pair.
Claim 6
Dependent Claim
63 words
The actuator as claimed in claim 1, wherein both of the permanent magnet and the yoke are uniform in thickness throughout their lengths respectively, and each of the magnet pieces is magnetized so that the magnitude of the magnetization thereof gradually decreases from both ends of the path of each protruding pole towards the boundary of the magnetic pieces of the corresponding pair.
Claim 7
Dependent Claim
83 words
The actuator as claimed in claim 1, wherein both of the permanent magnet and the yoke are uniform in thickness throughout their lengths respectively, each of the magnet pieces is composed of a main magnet piece and an auxiliary magnet piece of opposite polarity, and the auxiliary magnet piece is formed in a shape such that the vertical length thereof gradually increases from both ends of the path of each protruding pole towards the boundary of the magnetic pieces of the corresponding pair.
Claim 8
Dependent Claim
59 words
The actuator as claimed in claim 1, wherein both of the permanent magnet and the yoke are uniform in thickness throughout their lengths respectively, and each of the magnet pieces is magnetized so that the magnetization thereof has a component in the direction parallel to the path, in addition to a component in the direction perpendicular to the path.
Claim 9
Dependent Claim
33 words
The actuator as claimed in claim 1, wherein the armature is rotatably disposed and the permanent magnet and the yoke are arranged in a circular arc about the rotational axis of the armature.
Claim 10
Dependent Claim
30 words
The actuator as claimed in claim 1, wherein the armature is disposed movable along a linear direction and the permanent magnet and the Yoke are arranged in a linear manner.
Claim 11
Dependent Claim
29 words
The actuator as claimed in claim 1, wherein the coil is wound around each protruding pole with a space therebetween to permit the protruding pole to move independently therefrom.
Claim 12
Dependent Claim
21 words
The actuator as claimed in claim 1, wherein the coil is directly wound around each protruding pole for the movement therewith.
Claim 13
Dependent Claim
19 words
The actuator as claimed claim 1, wherein the coil is wound around a part of the yoke-permanent magnet assembly.
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) | 1993-07-30 | 1994-01-29 | 1994-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-30 | 1998-01-29 | 1998-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-30 | 2002-01-29 | 2002-07-31 | $7700.00 | Window Closed / Lapsed |