US4508942A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Keyboard switch
Assignee: Nippon Mektron KK
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Filing: 1983-11-28
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Granted: 1985-04-02
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Expires: 2003-11-28
Abstract
Abstract A membrane keyboard with a circuit means having a plurality of snap action domes formed therein has a cover sheet thereon. A plurality of cavities formed between the cover sheet and the domed circuit layer has air passages connecting each cavity with the ambient environment. The structure of the present invention permits lower tensile force during actuation and results in improved snap action and tactile feel.
Inventors
- 👤 Masaichi Inaba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:55
CPC Classifications
H; H01; H01H; H01H13/00; H01H13/70; H01H13/702; H01H2213/00; H01H2213/002; H01H2215/00; H01H2215/004; H01H2215/008
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
212 words
A membrane keyboard including: first electrical circuit means having a plurality of first switch contacts; second electrical circuit means having a plurality of second switch contacts corresponding to said first switch contacts, said plurality of first switch contacts being equal to said plurality of second switch contacts; at least one tactile protrusion formed in said second circuit means, said tactile protrusion projecting out of said second circuit means and away from said first circuit means, said tactile protrusion supporting at least one of said second switch contacts for selective contact with said first switch contacts; insulating means between said first and second circuit means, said insulating means having at least one opening aligned with said protrusion to permit selective contact between said first and second switch contacts, said opening being hermetically sealed from the ambient environment; flexible cover sheet means planar with the upper surface of said protrusion, said cover sheet enclosing said second electrical circuit means; spacer means between said flexible cover sheet means and said second circuit means, said spacer means having at least one cavity surrounding said protrusion; and channel means connecting said spacer means cavity with said ambient environment, said channel means being located through at least said first and second electrical circuit means and said insulating means.
Claim 2
Dependent Claim
212 words
A membrane keyboard including: first electrical circuit means having a plurality of first switch contacts; second electrical circuit means having a plurality of second switch contacts corresponding to said first switch contacts, said plurality of first switch contacts being equal to said plurality of second switch contacts; at least one tactile protrusion formed in said second circuit means, said tactile protrusion projecting out of said second circuit means and away from said first circuit means, said tactile protrusion supporting at least one of said second switch contacts for selective contact with said first switch contacts; insulating means between said first and second circuit means, said insulating means having at least one opening aligned with said protrusion to permit selective contact between said first and second switch contacts, said opening being hermetically sealed from the ambient environment; flexible cover sheet means planar with the upper surface of said protrusion, said cover sheet enclosing said second electrical circuit means; spacer means between said flexible cover sheet means and said second circuit means, said spacer means having at least one cavity surrounding said protrusion; and channel means connecting said spacer means cavity with said ambient environment, said channel means being located through at least said first and second electrical circuit means and said insulating means.
Claim 3
Dependent Claim
32 words
A keyboard as in claim 1 wherein said first electrical circuit means includes: a layer of insulating material with electrically conductive means on one surface thereof facing said second electrical circuit means.
Claim 4
Dependent Claim
33 words
A keyboard as in claim 2 wherein said second electrical circuit means includes: a layer of flexible insulating material with electrically conductive means on one surface thereof facing said first electrical circuit means.
Claim 5
Dependent Claim
24 words
A keyboard as in claim 1 wherein: said cover sheet means has a stepped down planar portion surrounding said protrusion defining a corrugated surface.
Claim 6
Dependent Claim
53 words
A keyboard as in claim 1 wherein: at least a portion of said first electrical circuit means, said second electrical circuit means and said insulating means are in abutting relationship; and wherein: said channel means is located through said abutting portion of said first and second electrical circuit means and said insulating means.
Claim 7
Dependent Claim
169 words
An electric switch including: first electrical contact means; second electrical contact means; at least one tactile protrusion formed in said second contact means, said tactile protrusion projecting out of said second contact means and away from said first contact means, said tactile protrusion supporting said second contact means for selective contact with first contact means; insulating means between said first and second contact means, said insulating means having at least one opening hermetically sealed from ambient and being aligned with said protrusion to permit selective contact between said first and second contact means; flexible cover sheet means planar with the upper surface of said protrusion, said cover sheet enclosing said second electrical contact means; spacer means between said flexible cover sheet means and said second contact means, said spacer means having at least one cavity surrounding said protrusion; and channel means connecting said spacer means cavity with the ambient environment, said channel means being located through at least said first and second electrical contact means and said insulating means.
Claim 8
Dependent Claim
169 words
An electric switch including: first electrical contact means; second electrical contact means; at least one tactile protrusion formed in said second contact means, said tactile protrusion projecting out of said second contact means and away from said first contact means, said tactile protrusion supporting said second contact means for selective contact with first contact means; insulating means between said first and second contact means, said insulating means having at least one opening hermetically sealed from ambient and being aligned with said protrusion to permit selective contact between said first and second contact means; flexible cover sheet means planar with the upper surface of said protrusion, said cover sheet enclosing said second electrical contact means; spacer means between said flexible cover sheet means and said second contact means, said spacer means having at least one cavity surrounding said protrusion; and channel means connecting said spacer means cavity with the ambient environment, said channel means being located through at least said first and second electrical contact means and said insulating means.
Claim 9
Dependent Claim
33 words
An electric switch as in claim 6 wherein said first electrical contact means includes: a layer of insulating material with electrically conductive means on one surface thereof facing said second electrical contact means.
Claim 10
Dependent Claim
34 words
An electric switch as in claim 7 wherein said second electrical contact means includes: a layer of flexible insulating material with electrically conductive means on one surface thereof facing said first electrical contact means.
Claim 11
Dependent Claim
25 words
An electric switch as in claim 6 wherein: said cover sheet means has a stepped down planar portion surrounding said protrusion defining a corrugated surface.
Claim 12
Dependent Claim
54 words
An electric switch as in claim 6 wherein: at least a portion of said first electrical contact means, said second electrical contact means and said insulating means are in abutting relationship; and wherein: said channel means is located through said abutting portion of said first and second electrical contact means and said insulating means.
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) | 1988-04-01 | 1988-10-01 | 1989-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-01 | 1992-10-01 | 1993-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-01 | 1996-10-01 | 1997-04-02 | $7700.00 | Window Closed / Lapsed |