Patent US3668696A successfully refreshed from Google Patents.
US3668696A
Expired / Lapsed
US
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Ring core keyboard entry device
Assignee: Data Electronics Corp
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Filing: 1970-09-28
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Granted: 1972-06-06
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Expires: 1990-09-28
Abstract
Abstract A keyboard entry device which employs a plurality of ring cores which are selectively threaded in a different combination by leads from a plurality of keys in a keyboard. The keys serve to connect the cores to an a-c power source, and each core is coupled to an output circuit which is resonant at about the frequency of the power source.
Inventors
- 👤 Harry E Brawley Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:49
CPC Classifications
H; H03; H03M; H03M11/00; H03M11/22; H03M7/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
165 words
A keyboard entry device comprising: a plurality of switching means for connecting said entry device to a source of substantially time-varying electrical power; a plurality of ring cores; a first plurality of electrically conductive means selectively threaded through said cores, each one of said conductive means being threaded through a unique combination of said cores and being connected to a corresponding separate one of said switching means so as to be connectable by the latter to said power source; and individual electrically conductive means coupled to each one of said cores so that upon actuation of any one of said switching means an output signal is generated in corresponding individual conductive means dependent upon the unique combination of cores which are threaded by said one of said first electrically conductive means connected to said actuated switching means, and means connected to each of said individual conductive means so as to provide a circuit resonant substantially to the fundamental frequency of the power from said source.
Claim 2
Dependent Claim
165 words
A keyboard entry device comprising: a plurality of switching means for connecting said entry device to a source of substantially time-varying electrical power; a plurality of ring cores; a first plurality of electrically conductive means selectively threaded through said cores, each one of said conductive means being threaded through a unique combination of said cores and being connected to a corresponding separate one of said switching means so as to be connectable by the latter to said power source; and individual electrically conductive means coupled to each one of said cores so that upon actuation of any one of said switching means an output signal is generated in corresponding individual conductive means dependent upon the unique combination of cores which are threaded by said one of said first electrically conductive means connected to said actuated switching means, and means connected to each of said individual conductive means so as to provide a circuit resonant substantially to the fundamental frequency of the power from said source.
Claim 3
Dependent Claim
34 words
A device as set forth in claim 1 wherein said individual electrically conductive means each is a secondary winding and said means connected to each of said individual conductive means includes a resonating capacitor.
Claim 4
Dependent Claim
14 words
A device as defined in claim 2 wherein said capacitor shunts said secondary winding.
Claim 5
Dependent Claim
22 words
A device as set forth in claim 1 including rectifying means for detecting the output signal generated in said second conductive means.
Claim 6
Dependent Claim
21 words
A device as set forth in claim 1 wherein said ring cores are made of material having substantially linear hysteresis characteristics.
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) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |