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Patent US4205242A successfully refreshed from Google Patents.
US4205242A
Expired / Lapsed
US
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Electret bistable system
Assignee: Thales SA
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Filing: 1978-01-03
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Granted: 1980-05-27
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Expires: 1998-01-03
Abstract
Abstract The invention relates to electret bistable systems comprising two fixed electrodes forming a capacitor. A sheet of electret material is inserted for creating holding forces in two rest positions of a moving element located in the capacitor gap. In accordance with the invention, the electret sheet is separated from the corresponding fixed electrode by a layer of dielectric which can be an air gap. As a variant, the charge density of the electret sheet may be concentrated in islands for reducing the holding forces.
Inventors
- 👤 Francois Micheron
- 👤 Jean L. Bruneel
- 👤 Pierre Leclerc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:30
CPC Classifications
H; H01; H01H; H01H59/00; H02; H02N; H02N1/00; H02N1/002; H02N1/006; H01H2059/009
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
106 words
Electret bistable system comprising: a moving element inserted between two fixed electrodes forming a capacitor: at least one layer of electret material arranged within said capacitor for holding said moving element in either of two rest positions; and means positioned within said capacitor for lowering the electrostatic force holding said moving element near one of said two fixed electrodes, said force being created by said layer of electret material, said means comprising spacer means interposed between said moving element and said two fixed electrodes respectively in said two rest positions, said spacer means comprising solid dielectric layers deposited on the inner faces of said fixed electrodes.
Claim 2
Dependent Claim
106 words
Electret bistable system comprising: a moving element inserted between two fixed electrodes forming a capacitor: at least one layer of electret material arranged within said capacitor for holding said moving element in either of two rest positions; and means positioned within said capacitor for lowering the electrostatic force holding said moving element near one of said two fixed electrodes, said force being created by said layer of electret material, said means comprising spacer means interposed between said moving element and said two fixed electrodes respectively in said two rest positions, said spacer means comprising solid dielectric layers deposited on the inner faces of said fixed electrodes.
Claim 3
Dependent Claim
113 words
Electret bistable system comprising: a moving element inserted between two fixed electrodes forming a capacitor: at least one layer of electret material arranged within said capacitor for holding said moving element in either of two rest positions; and means positioned within said capacitor for lowering the electrostatic force holding said moving element near one of said two fixed electrodes, said force being created by said layer of electret material, said means comprising spacer means interposed between said moving element and said two fixed electrodes respectively in said two rest positions, said spacer means comprising spacers forming air gaps between said moving element and said two fixed electrodes in said two rest positions, respectively.
Claim 4
Dependent Claim
113 words
Electret bistable system comprising: a moving element inserted between two fixed electrodes forming a capacitor: at least one layer of electret material arranged within said capacitor for holding said moving element in either of two rest positions; and means positioned within said capacitor for lowering the electrostatic force holding said moving element near one of said two fixed electrodes, said force being created by said layer of electret material, said means comprising spacer means interposed between said moving element and said two fixed electrodes respectively in said two rest positions, said spacer means comprising spacers forming air gaps between said moving element and said two fixed electrodes in said two rest positions, respectively.
Claim 5
Dependent Claim
28 words
System as claimed in claim 2, wherein said spacers are cut from a solid dielectric material; said spacers being fastened to the inner faces of said fixed electrodes.
Claim 6
Dependent Claim
23 words
System as claimed in claim 2, wherein said spacers are made by a tip configuration of the inner faces of said fixed electrodes.
Claim 7
Dependent Claim
96 words
Electret bistable system comprising: a moving element inserted between two fixed electrodes forming a capacitor; and at least one layer of electret material arranged within said capacitor for holding said moving element in either of two rest positions; and means positioned within said capacitor for lowering the electrostatic force holding said moving element near one of said two fixed electrodes, said force being created by said layer of electret material, said means comprising in the extent of said layer of electret material areas of substantially reduced charged density, said areas surrounding islands of higher charge density.
Claim 8
Dependent Claim
96 words
Electret bistable system comprising: a moving element inserted between two fixed electrodes forming a capacitor; and at least one layer of electret material arranged within said capacitor for holding said moving element in either of two rest positions; and means positioned within said capacitor for lowering the electrostatic force holding said moving element near one of said two fixed electrodes, said force being created by said layer of electret material, said means comprising in the extent of said layer of electret material areas of substantially reduced charged density, said areas surrounding islands of higher charge density.
Claim 9
Dependent Claim
100 words
Electret bistable system comprising: a moving element inserted between two fixed electrodes forming a capacitor having the form of a dihedron; at least one layer of electret material arranged within said capacitor for holding said moving element in either of two rest positions; and means positioned within said capacitor for lowering the electrostatic force created by said layer of electret material and holding said moving element near either of said two fixed electrodes, said force being created by said layer of electret material said moving element being a flap pivoting between said fixed electrodes about the axis of said dihedron.
Claim 10
Dependent Claim
100 words
Electret bistable system comprising: a moving element inserted between two fixed electrodes forming a capacitor having the form of a dihedron; at least one layer of electret material arranged within said capacitor for holding said moving element in either of two rest positions; and means positioned within said capacitor for lowering the electrostatic force created by said layer of electret material and holding said moving element near either of said two fixed electrodes, said force being created by said layer of electret material said moving element being a flap pivoting between said fixed electrodes about the axis of said dihedron.
Claim 11
Dependent Claim
24 words
System as claimed in claim 6, wherein the charge density carried by said layer of electret material decreases radially with distance from said axis.
Claim 12
Dependent Claim
77 words
Electret bistable system comprising: a moving electrode inserted between two fixed electrodes forming a capacitor; two layers of electret material respectively covering the inner faces of said fixed electrodes for holding said moving electrode in either of two rest positions; and means positioned within said capacitor for lowering the electrostatic force holding said moving electrode near said two layers of electret in said two rest positions, respectively said force being created by said layer of electret material.
Claim 13
Dependent Claim
77 words
Electret bistable system comprising: a moving electrode inserted between two fixed electrodes forming a capacitor; two layers of electret material respectively covering the inner faces of said fixed electrodes for holding said moving electrode in either of two rest positions; and means positioned within said capacitor for lowering the electrostatic force holding said moving electrode near said two layers of electret in said two rest positions, respectively said force being created by said layer of electret material.
References Cited (Backward Citations)
US4078183A
Cited
US4065677A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-05-27 | 1983-11-26 | 1984-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-05-27 | 1987-11-26 | 1988-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-05-27 | 1991-11-26 | 1992-05-27 | $7700.00 | Window Closed / Lapsed |