Patent US4378478A successfully refreshed from Google Patents.
US4378478A
Expired / Lapsed
US
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Double-domed elastomeric keyboard element
Assignee: Alcatel Lucent NV
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Filing: 1981-08-27
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Granted: 1983-03-29
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Expires: 2001-08-27
Abstract
Abstract A double-domed elastomeric keyboard element is disclosed in which a solid contact disc is connected to the junction of the domes of the keyboard element housing. The inner dome is provided on its inside with a downwardly extending projection which engages the contact disc when the keyboard element is depressed to press the disc against a pair of conductors on a printed circuit board below the element. Because of the non-positive connection between the key plunger and the conductors, the contact pressure is almost equal to the operating force.
Inventors
- 👤 Reinhard Deeg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:30
CPC Classifications
H; H01; H01H; H01H13/00; H01H13/70; H01H13/702; H01H2203/00; H01H2203/024; H01H2205/00; H01H2205/016; H01H2205/022; H01H2213/00; H01H2213/002; H01H2215/00; H01H2215/004; H01H2215/006; H01H2217/00; H01H2217/02; H01H2227/00; H01H2227/032; H01H2229/00; H01H2229/058
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
98 words
In a keyboard element having a hollow double-domed elastomeric housing including an upper dome and a lower dome of greater diameter than said upper dome, said domes intersecting at an annular junction, and a conductive elastomeric moving contact member mounted inside said housing connected to said junction, said moving contact member being adapted to bridge conductors on a substrate below said housing, the improvement which comprises: a projection extending downwardly from an upper region of said upper dome over said moving contact member; and said moving contact member embodying an upwardly facing supporting surface engageable by said projection.
Claim 2
Dependent Claim
98 words
In a keyboard element having a hollow double-domed elastomeric housing including an upper dome and a lower dome of greater diameter than said upper dome, said domes intersecting at an annular junction, and a conductive elastomeric moving contact member mounted inside said housing connected to said junction, said moving contact member being adapted to bridge conductors on a substrate below said housing, the improvement which comprises: a projection extending downwardly from an upper region of said upper dome over said moving contact member; and said moving contact member embodying an upwardly facing supporting surface engageable by said projection.
Claim 3
Dependent Claim
35 words
A keyboard element as set forth in claim 1 wherein: said housing has a central vertical axis with respect to which said domes are concentric; and said projection is concentric with respect to said axis.
Claim 4
Dependent Claim
30 words
A keyboard element as set forth in claim 1 wherein: said moving contact member is a solid contact disc formed with an air-escape channel communicating the interiors of said domes.
Claim 5
Dependent Claim
23 words
A keyboard element as set forth in claim 1 wherein: the undersides of both said projection and said contact disc have crowned faces.
References Cited (Backward Citations)
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Cited
US3950627A
Cited
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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) | 1986-03-28 | 1986-09-27 | 1987-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-03-28 | 1990-09-27 | 1991-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-03-28 | 1994-09-27 | 1995-03-29 | $7700.00 | Window Closed / Lapsed |