US4785210A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear motor
Assignee: Sony Corp
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Filing: 1987-05-18
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Granted: 1988-11-15
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Expires: 2007-05-18
Abstract
Abstract The present invention is concerned with a linear motor adapted to produce a thrust in a linear direction, wherein the magnetic fluxes produced by coils of a stationary part are passed through a closed magnetic circuit including a gap of a movable part for lowering the power consumption and the manufacture costs while also reducing the size and weight of the motor.
Inventors
- 👤 Shigehisa Maruyama
- 👤 Hideo Niikura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:45
CPC Classifications
H; H02; H02K; H02K41/00; H02K41/02; H02K41/03; H02K41/031; H02K41/033; G; G03; G03B; G03B3/00; G03B3/10; H01; H01F; H01F7/00; H01F7/06; H01F7/08; H01F7/16; H01F7/1607; H01F7/1615; H04; H04N; H04N23/00; H04N23/60; H04N23/67; H01F7/121; H01F7/122
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
81 words
A linear motor, comprising: first yoke means including a pair of magnetic yokes having a gap separating a first of said yokes from a second of said yokes; second yoke means slidably coupled to said first yoke means; permanent magnet means for generating magnetic fluxes passing through said first and second yoke means; and coil means secured to said second yoke means for generating control magnetic fluxes for determining the relative position of said first yoke means and second yoke means.
Claim 2
Dependent Claim
81 words
A linear motor, comprising: first yoke means including a pair of magnetic yokes having a gap separating a first of said yokes from a second of said yokes; second yoke means slidably coupled to said first yoke means; permanent magnet means for generating magnetic fluxes passing through said first and second yoke means; and coil means secured to said second yoke means for generating control magnetic fluxes for determining the relative position of said first yoke means and second yoke means.
Claim 3
Dependent Claim
84 words
A linear motor according to claim 1, wherein said second yoke means has a first leg portion slidably coupled to one of said yokes of said first yoke means, a second leg portion of said second yoke means slidably coupled to the other yoke of said first yoke means, and a connecting portion extending between said first and second leg portions, said permanent magnet means and said coil means being positioned within a space defined by said first yoke means and second yoke means.
Claim 4
Dependent Claim
39 words
A linear motor according to claim 2, wherein said coil means includes a first coil and a second coil connected in series with said first coil, and said permanent magnet means being positioned between said first and second coils.
Claim 5
Dependent Claim
24 words
A linear motor according to claim 3, wherein said permanent magnet means is positioned in opposition to said gap of said first yoke means.
Claim 6
Dependent Claim
39 words
A linear motor according to claim 1, wherein said yokes of said first yoke means have cylindrical forms and said yokes of said second yoke means also have cylindrical forms so as to conform to a concentric linear motor.
Claim 7
Dependent Claim
23 words
A linear motor as claimed in claim 5, wherein said concentric linear motor is adapted to move a lens system of a camera.
Claim 8
Dependent Claim
50 words
A linear motor as claimed in claim 6, wherein said first yoke is concentrically disposed within said second yoke, said first yoke being fixedly mounted to lens elements of said lens system so that sliding movement of said first yoke relative to said second yoke effects focusing of said camera.
Claim 9
Dependent Claim
54 words
A linear motor as claimed in claim 2, wherein said first leg portion is a first bobbin having a first coil, said second leg portion is a second bobbin having a second coil, and said permanent magnet means includes a permanent magnet mounted in said second yoke means between said first and second bobbins.
Claim 10
Dependent Claim
23 words
A linear motor as claimed in claim 5, wherein said permanent magnet means includes an annular permanent magnet magnetized in a radial direction.
Claim 11
Dependent Claim
55 words
A linear motor as claimed in claim 3, further comprising: a closed loop focusing control having: an image receiving element, a focusing detection element connected to said image receiving element, and linear motor control circuit connected to said focusing detection element, said linear motor control circuit connected to said first and second series connected coils.
Claim 12
Dependent Claim
124 words
A linear motor according to claim 1, wherein said second yoke means has: a first leg portion slidably coupled to one of said yokes of said first yoke means; a second leg portion of said second yoke means slidably coupled to the other yoke of said first yoke means; and a connecting portion of said second yoke means extending between said first and second leg portions, said permanent magnet means and said coil means being positioned between said first leg portion and said second leg portion and in a space defined between said connecting portion and said first yoke means to form a magnetic circuit through said first and second leg portions, said connecting portion, and said first yoke means and across said gap.
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) | 1991-11-15 | 1992-05-16 | 1992-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-15 | 1996-05-16 | 1996-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-15 | 2000-05-16 | 2000-11-15 | $7700.00 | Window Closed / Lapsed |