US4413895A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnetic actuator having a compliant armature
Assignee: Eastman Kodak Co
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Filing: 1982-05-17
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Granted: 1983-11-08
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Expires: 2002-05-17
Abstract
Abstract An electromagnetic actuator of the type having an armature positioned for movement in a magnetic gap is characterized by the armature being sufficiently compliant so as to allow the armature to contact the sides of the gap, and easily conform to the shape of the gap. The magnetic gap is substantially coextensive with the armature, for providing mechanical support to the armature. In one embodiment of the invention, the compliant armature is employed in a reciprocating actuator for a photographic shutter/aperture. In another embodiment, the invention is employed in a rotary DC motor of the pancake type. In a still further embodiment, the invention is employed in a rotary DC motor of the cup or basket type.
Inventors
- 👤 James K. Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:08
CPC Classifications
G; G03; G03B; G03B9/00; G03B9/02; G03B7/00; G03B7/08; G03B7/081; G03B7/085
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
80 words
An electromagnetic actuator of the type having means for forming a substantially planar magnetic gap and a flat armature positioned for movement in the magnetic gap, said actuator being characterized in that a portion of said armature is sufficiently compliant to contact and generally conform to the shape of said gap, and in that portions of said gap are substantially coextensive with said armature, for supporting said armature in a direction generally perpendicular to the path of said armature movement.
Claim 2
Dependent Claim
80 words
An electromagnetic actuator of the type having means for forming a substantially planar magnetic gap and a flat armature positioned for movement in the magnetic gap, said actuator being characterized in that a portion of said armature is sufficiently compliant to contact and generally conform to the shape of said gap, and in that portions of said gap are substantially coextensive with said armature, for supporting said armature in a direction generally perpendicular to the path of said armature movement.
Claim 3
Dependent Claim
36 words
The invention claimed in claim 1 wherein said electromagnetic actuator is a rotary motor and said armature is a rotor having a central axle supporting a central portion of said armature for movement in said gap.
Claim 4
Dependent Claim
38 words
The invention claimed in claim 2 wherein said actuator further comprises means for admitting air near said axle between said armature and said gap forming means, whereby said armature flies in said gap when said motor is running.
Claim 5
Dependent Claim
26 words
The invention claimed in claim 1 wherein said electromagnetic actuator is a recriprocating type actuator and said armature is mounted for reciprocating movement in said gap.
Claim 6
Dependent Claim
23 words
The invention claimed in claim 1 further characterized by friction reducing means disposed between said compliant armature and said magnetic gap forming means.
Claim 7
Dependent Claim
26 words
The invention claimed in claim 5 wherein said friction reducing means comprises a coating of polytetrafluoroethylene plastic on the sides of said magnetic gap forming means.
Claim 8
Dependent Claim
20 words
The invention claimed in claim 5 wherein said friction reducing means comprises a coating of polytetrafluoroethylene plastic on said armature.
Claim 9
Dependent Claim
31 words
The invention claimed in claim 5 wherein said friction reducing means comprises thin sheets of polytetrafluoroethylene plastic disposed between said compliant armature and the sides of said magnetic gap forming means.
Claim 10
Dependent Claim
107 words
In combination with a photographic camera, an electromagnetic actuator comprising: a mild steel plate; a flat magnet having a first portion magnetized in a first direction generally perpendicular to the plane of said magnet, and a second portion magnetized in a generally opposite direction; means for mounting said magnet over said plate to form a magnetic gap; an armature mounted for movement in said gap, said armature comprising a planar conductor coil on a sheet of insulating material, and being sufficiently compliant to contact the sides of said gap, said magnet and said plate providing support for said armature in a direction generally perpendicular to its plane.
Claim 11
Dependent Claim
107 words
In combination with a photographic camera, an electromagnetic actuator comprising: a mild steel plate; a flat magnet having a first portion magnetized in a first direction generally perpendicular to the plane of said magnet, and a second portion magnetized in a generally opposite direction; means for mounting said magnet over said plate to form a magnetic gap; an armature mounted for movement in said gap, said armature comprising a planar conductor coil on a sheet of insulating material, and being sufficiently compliant to contact the sides of said gap, said magnet and said plate providing support for said armature in a direction generally perpendicular to its plane.
Claim 12
Dependent Claim
19 words
The invention claimed in claim 9 wherein said armature comprises a photofabricated conductor on a sheet of insulating material.
Claim 13
Dependent Claim
20 words
The invention claimed in claim 10 wherein said insulating material is polyethylene terephthalate film between 1 to 3 mils thick.
Claim 14
Dependent Claim
23 words
The invention claimed in claim 9 further comprising friction reducing and electrically insulating means between said armature and the sides of said gap.
Claim 15
Dependent Claim
30 words
The invention claimed in claim 9 wherein said actuator is a reciprocatory actuator and said compliant armature is mounted for reciprocating movement in said gap for driving a shutter blade.
Claim 16
Dependent Claim
19 words
The invention claimed in claim 13 wherein an extension of said sheet of insulating material defines a shutter blade.
Claim 17
Dependent Claim
33 words
The invention claimed in claim 14 wherein said insulating material is polyethylene terephthalate film between 1 to 3 mils thick, loaded with one micron size particles of carbon to render the film opaque.
Claim 18
Dependent Claim
21 words
The invention claimed in claim 9, wherein said actuator is a rotary DC motor and said compliant armature is a rotor.
Claim 19
Dependent Claim
22 words
The invention claimed in claim 16 wherein the commutator of said DC motor is formed by photofabrication techniques on said compliant armature.
Claim 20
Dependent Claim
67 words
An electromagnetic actuator of the type having an armature positioned for movement between means defining a magnetic gap, characterized by said armature being sufficiently compliant so as to contact the gap defining means and easily conform to the shape of said gap, said gap defining means being substantially coextensive with said armature for providing mechanical support to said armature and substantially influencing the shape of said armature.
Claim 21
Dependent Claim
67 words
An electromagnetic actuator of the type having an armature positioned for movement between means defining a magnetic gap, characterized by said armature being sufficiently compliant so as to contact the gap defining means and easily conform to the shape of said gap, said gap defining means being substantially coextensive with said armature for providing mechanical support to said armature and substantially influencing the shape of said armature.
Claim 22
Dependent Claim
16 words
The invention claimed in claim 18, wherein said armature includes flexible conductor means defining a coil.
Claim 23
Dependent Claim
28 words
The invention claimed in claim 18, wherein said armature comprises a sheet of flexible insulating material and a flexible conductor defining a coil carried by said flexible sheet.
Claim 24
Dependent Claim
20 words
The invention claimed in claim 20, wherein said flexible conductor is formed on said insulating sheet material by photofabrication techniques.
Claim 25
Dependent Claim
66 words
An electromagnetic actuator of the type having means for defining a magnetic gap, and conductor means positioned in said gap, said gap defining means and said conductor means being moveable relative to one another, characterized by said conductor means being sufficiently compliant so as to conform to the shape of said gap, whereby frictional forces between said gap defining means and said conductor means are limited.
Claim 26
Dependent Claim
66 words
An electromagnetic actuator of the type having means for defining a magnetic gap, and conductor means positioned in said gap, said gap defining means and said conductor means being moveable relative to one another, characterized by said conductor means being sufficiently compliant so as to conform to the shape of said gap, whereby frictional forces between said gap defining means and said conductor means are limited.
Claim 27
Dependent Claim
28 words
The invention claimed in claim 22, wherein said conductor means comprises a flexible sheet of electrically insulating material, and a flexible conductor pattern carried by said insulating sheet.
Claim 28
Dependent Claim
19 words
The invention claimed in claim 23, wherein said conductor pattern is formed on said flexible sheet by photofabrication techniques.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-11-07 | 1987-05-09 | 1987-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-07 | 1991-05-09 | 1991-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-07 | 1995-05-09 | 1995-11-08 | $7700.00 | Window Closed / Lapsed |