US3573376A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signalling system with upper and lower case designations
Assignee: Telex Computer Products Inc
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Filing: 1969-12-29
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Granted: 1971-04-06
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Expires: 1989-12-29
Abstract
Abstract A signalling system for remote operation of a calculator which requires 22 distinguishable input signals. A standard 12-key key set is used at the local station. One key is designated a shift key, and the central office equipment is arranged to direct the signal next following actuation of the shift key to a different input of the calculator from the one to which it would otherwise be directed.
Inventors
- 👤 William F Bartlett
- 👤 Barrie Brightman
- 👤 Uno Randmere
- 👤 Richard Scott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:15
CPC Classifications
H; H03; H03M; H03M11/00; H03M11/02; H03M11/04; H03M11/14; H03M11/18
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
195 words
Signalling apparatus for producing plural separately identifiable output signals responsively to multifrequency telephone type input signals of the kind produced by a standard touch-tone key set, the number of frequency combinations produced by the key set being less than the number of output signals, said apparatus comprising a detector for decoding input signals from the key set and producing respective pairs of intermediate signals, first and second matrices of AND gates, means for applying said intermediate signals to said AND gates for selectively partially enabling them, a flip-flop having a first output applied to said first set of AND gates for maintaining them partially enabled during times when said flip-flop is in its reset condition and for disabling them during times when said flip-flop is in its set condition, said flip-flop having a second output applied to said second set of AND gates for keeping them disabled during times when said flip-flop is in its reset condition and for keeping them partially enabled during times when said flip-flop is in its set condition, and means for setting said flip-flop responsively to an output signal from a selected one of said gates of said first set.
Claim 2
Dependent Claim
195 words
Signalling apparatus for producing plural separately identifiable output signals responsively to multifrequency telephone type input signals of the kind produced by a standard touch-tone key set, the number of frequency combinations produced by the key set being less than the number of output signals, said apparatus comprising a detector for decoding input signals from the key set and producing respective pairs of intermediate signals, first and second matrices of AND gates, means for applying said intermediate signals to said AND gates for selectively partially enabling them, a flip-flop having a first output applied to said first set of AND gates for maintaining them partially enabled during times when said flip-flop is in its reset condition and for disabling them during times when said flip-flop is in its set condition, said flip-flop having a second output applied to said second set of AND gates for keeping them disabled during times when said flip-flop is in its reset condition and for keeping them partially enabled during times when said flip-flop is in its set condition, and means for setting said flip-flop responsively to an output signal from a selected one of said gates of said first set.
Claim 3
Dependent Claim
215 words
Signalling apparatus for producing plural separately identifiable output signals responsively to multifrequency telephone type input signals of the kind produced by a standard touch-tone key set, the number of frequency combinations produced by the key set being less than the number of output signals, said apparatus comprising a detector for decoding input signals from the key set and producing respective pairs of intermediate signals, first and second matrices of AND gates, means for applying said intermediate signals to said AND gates for selectively partially enabling them, a flip-flop having a first output applied to said first set of AND gates for maintaining them partially enabled during times when said flip-flop is in its reset condition and for disabling them during times when said flip-flop is in its set condition, said flip-flop having a second output applied to said second set of AND gates for keeping them disabled during times when said flip-flop is in its reset condition and for keeping them partially enabled during times when said flip-flop is in its set condition, means for setting said flip-flop responsively to an output signal from a selected one of said gates of said first set, and means for resetting said flip-flop responsively to an output signal from any one of said gates of said second set.
Claim 4
Dependent Claim
215 words
Signalling apparatus for producing plural separately identifiable output signals responsively to multifrequency telephone type input signals of the kind produced by a standard touch-tone key set, the number of frequency combinations produced by the key set being less than the number of output signals, said apparatus comprising a detector for decoding input signals from the key set and producing respective pairs of intermediate signals, first and second matrices of AND gates, means for applying said intermediate signals to said AND gates for selectively partially enabling them, a flip-flop having a first output applied to said first set of AND gates for maintaining them partially enabled during times when said flip-flop is in its reset condition and for disabling them during times when said flip-flop is in its set condition, said flip-flop having a second output applied to said second set of AND gates for keeping them disabled during times when said flip-flop is in its reset condition and for keeping them partially enabled during times when said flip-flop is in its set condition, means for setting said flip-flop responsively to an output signal from a selected one of said gates of said first set, and means for resetting said flip-flop responsively to an output signal from any one of said gates of said second set.
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) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |