Patent US4243899A successfully refreshed from Google Patents.
US4243899A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear motor with ring magnet and non-magnetizable end caps
Assignee: Singer Co
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Filing: 1979-03-08
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Granted: 1981-01-06
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Expires: 1999-03-08
Abstract
Abstract A linear motor is provided with a coil, a plunger selectively positionable thereby, a permanent magnet concentric with the coil and plunger having oppositely polarized magnetic poles on outer and inner surfaces creating a magnetic circuit extending through the plunger, end caps of non-magnetizable material in line with the plunger, and an output shaft of non-magnetizable material extending through an end cap.
Inventors
- 👤 Wolfgang Jaffe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 02:50
CPC Classifications
H; H02; H02K; H02K41/00; H02K41/02; H02K41/03; H02K41/031; H02K41/033; H01; H01F; H01F7/00; H01F7/06; H01F7/08; H01F7/16; H01F7/1607; H01F7/1615; H01F7/121; H01F7/122; H02K2207/00; H02K2207/03
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
145 words
A linear motor comprising a casing of ferromagnetic material, a coil within said casing, a plunger which is wholly in a passageway in the coil and which is movable by the coil in opposite directions to selected positions in the passageway, a permanent magnet in the casing concentric with the coil and plunger, and having oppositely polarized magnetic poles on outer and inner surfaces, fixed end caps of non-magnetizable material which seal ends of the longitudinal passagway wherein the plunger is wholly located and provide an in-line face to face relationship between the ends of the plungers and the end caps extending from the plunger in the directions of movement thereof by the coil only to the non-magnetizable material of the end caps; and an output shaft of non-magnetizable material attached to the plunger and extending from the plunger to and through an end cap.
Claim 2
Dependent Claim
145 words
A linear motor comprising a casing of ferromagnetic material, a coil within said casing, a plunger which is wholly in a passageway in the coil and which is movable by the coil in opposite directions to selected positions in the passageway, a permanent magnet in the casing concentric with the coil and plunger, and having oppositely polarized magnetic poles on outer and inner surfaces, fixed end caps of non-magnetizable material which seal ends of the longitudinal passagway wherein the plunger is wholly located and provide an in-line face to face relationship between the ends of the plungers and the end caps extending from the plunger in the directions of movement thereof by the coil only to the non-magnetizable material of the end caps; and an output shaft of non-magnetizable material attached to the plunger and extending from the plunger to and through an end cap.
Claim 3
Dependent Claim
17 words
A linear motor as defined in claim 1 wherein the permanent magnet is located outside the coil.
Claim 4
Dependent Claim
17 words
A linear motor as defined in claim 1 wherein the permanent magnet is located inside the coil.
Claim 5
Dependent Claim
20 words
A linear motor as defined in claim 3 wherein the coil extends longitudinally in the casing beyond the permanent magnet.
Claim 6
Dependent Claim
42 words
A linear motor as defined in claim 1 wherein the said permanent magnet is located outside the coil, and a second permanent magnet is provided inside the coil, the second permanent magnet having oppositely polarized magnetic poles on outer and inner surfaces.
Claim 7
Dependent Claim
21 words
A linear motor as defined in claim 5 wherein the coil extends longitudinally in the casing beyond said second permanent magnet.
References Cited (Backward Citations)
US3241006A
Cited
US3740594A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-06 | 1984-07-07 | 1985-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-06 | 1988-07-07 | 1989-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-06 | 1992-07-07 | 1993-01-06 | $7700.00 | Window Closed / Lapsed |