US4652704A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Keyboard switch
Assignee: Unisys Corp
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Filing: 1985-12-30
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Granted: 1987-03-24
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Expires: 2005-12-30
Abstract
Abstract An improved multiple circuit keypad switch of the type in which a rigid key having a shorting puck on its underside is supported over exposed traces of a printed circuit card by a flexible membrane so that the puck shorts designated exposed traces to close all circuits when the key is depressed, the improvement arising from the layout of the exposed traces in which individual circuits are arranged in concentric rings and the shorting puck contains shorting elements arranged in corresponding concentric rings.
Inventors
- 👤 Gerald K. Franklin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:40
CPC Classifications
H; H01; H01H; H01H13/00; H01H13/70; H01H13/78; H01H13/807; H01H13/702; H01H13/785; H01H2201/00; H01H2201/022; H01H2201/032; H01H2203/00; H01H2203/02; H01H2203/036; H01H2203/054; H01H2225/00; H01H2225/01
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
142 words
In a keypad switch of the type including a key having shorting pucks on its underside and supported above exposed trace patterns on a printed circuit card by a flexible membrane whereby pressure on the key collapses the membrane and permits the shorting pucks to contact with the exposed trace patterns thereby closing the switch, the improvement wherein said shorting pucks include a central circuit puck electrically isolated from an annular puck thereabout, said annular puck being co-planar and concentric with said circular puck, and wherein said exposed trace patterns are formed in a circular region and an annular region co-planar and concentric with said circular region, exposed trace patterns in said circular region being electrically isolated from trace patterns in said annular region, said circular region and said annular region being correspondingly aligned with said circular puck and said annular puck.
Claim 2
Dependent Claim
142 words
In a keypad switch of the type including a key having shorting pucks on its underside and supported above exposed trace patterns on a printed circuit card by a flexible membrane whereby pressure on the key collapses the membrane and permits the shorting pucks to contact with the exposed trace patterns thereby closing the switch, the improvement wherein said shorting pucks include a central circuit puck electrically isolated from an annular puck thereabout, said annular puck being co-planar and concentric with said circular puck, and wherein said exposed trace patterns are formed in a circular region and an annular region co-planar and concentric with said circular region, exposed trace patterns in said circular region being electrically isolated from trace patterns in said annular region, said circular region and said annular region being correspondingly aligned with said circular puck and said annular puck.
Claim 3
Dependent Claim
24 words
The switch of claim 1 wherein said exposed trace patterns include a plurality of electrically isolated exposed trace elements each having a switch terminal.
Claim 4
Dependent Claim
107 words
The switch of claim 2 wherein said exposed trace pattern in said circular region includes two trace elements formed along a circumferential border of said circular region, said two exposed trace elements each including a plurality of exposed trace fingers being further arranged so that said exposed trace fingers coupled to one of said two exposed trace elements are interposed between said exposed trace fingers coupled to the other of said two exposed trace elements, a third exposed trace element comprising electrically connected segments interposed between said exposed trace fingers of said two exposed trace elements and extending continuously in said circular region in a zigzag fashion.
Claim 5
Dependent Claim
32 words
The switch of claim 3 wherein said exposed trace fingers of said two exposed trace elements and said segments of said third exposed trace element are arranged to be a parallel relationship.
Claim 6
Dependent Claim
112 words
The switch of claim 2 wherein said plurality of exposed trace elements of said annular region includes a first trace element formed along an inner circumferential border of said annular region, a second exposed trace element formed along an outer circumferential border of said annular region, and a third exposed trace element extending in a continuous, undulating manner in said annular region between said first and second trace elements, said first and second trace elements further including exposed trace fingers alternately positioned in an interleaved manner in said annular region and said third trace element having electrically connected segments interposed between said exposed trace fingers of said first and second trace elements.
Claim 7
Dependent Claim
34 words
The switch of claim 5 wherein said exposed trace fingers of said first and second exposed trace elements and said segments of said third exposed trace element extend along radials of said annular region.
References Cited (Backward Citations)
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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) | 1990-03-23 | 1990-09-22 | 1991-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-23 | 1994-09-22 | 1995-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-23 | 1998-09-22 | 1999-03-24 | $7700.00 | Window Closed / Lapsed |