US3576403A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multifrequency signal receiver
Assignee: Int Telephone & Telegram Corp
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Filing: 1968-05-14
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Granted: 1971-04-27
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Expires: 1988-05-14
Abstract
Abstract A plurality of electromechanical, piezoelectric filters are tuned to particular frequencies. A multifrequency electrical signal causes mechanical resonance at the correspondingly tuned mechanical filters. Logical equipment interprets the outputs of those filters and generates the indicated number of DC pulses.
Inventors
- 👤 Daniele Sellari Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:04
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/46; H03H9/54; H03H9/545; H04; H04L; H04L27/00; H04L27/26; H04L27/30; H04Q; H04Q1/00; H04Q1/18; H04Q1/30; H04Q1/44; H04Q1/444; H04Q1/45; H04Q1/453
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
145 words
A telephone multifrequency dialing response and signal generating network, comprising a subscriber station capable of generating at least one multifrequency dialing signal, an amplifier receptive of received dialing signals, a plurality of electromechanical filters connected in multiple to the output of said amplifier, means in each of said filters for tuning the response to the filter to a predetermined signal frequency within the range of frequencies used in telephone dialing, mechanical means at each of said filters for resonating in response to a signal of at least a predetermined duration at the frequency to which tuned to generate an output signal, trigger means for each filter responsive to an output signal therefrom for emitting a pulse, a plurality of gate circuits connected to respond to emitted pulses from said trigger circuits to code the response therefrom into a code signal corresponding to a dialed digit.
Claim 2
Dependent Claim
145 words
A telephone multifrequency dialing response and signal generating network, comprising a subscriber station capable of generating at least one multifrequency dialing signal, an amplifier receptive of received dialing signals, a plurality of electromechanical filters connected in multiple to the output of said amplifier, means in each of said filters for tuning the response to the filter to a predetermined signal frequency within the range of frequencies used in telephone dialing, mechanical means at each of said filters for resonating in response to a signal of at least a predetermined duration at the frequency to which tuned to generate an output signal, trigger means for each filter responsive to an output signal therefrom for emitting a pulse, a plurality of gate circuits connected to respond to emitted pulses from said trigger circuits to code the response therefrom into a code signal corresponding to a dialed digit.
Claim 3
Dependent Claim
102 words
A network as claimed in claim 1, further comprising means for translating a dialed digit into a series of pulses of finite duration including a first set of gate circuits means responsive to receipt of a code signal for actuating certain of said gate circuits, further gate circuits responsive to actuated gate circuits for further coding a received digit into binary form, means for storing a binary received digit, and outpulsing means comprising a multivibrator productive of a pulse output, and means for signalling said multivibrator to cease outpulsing at the conclusion of a series of outpulses corresponding to a dialed digit.
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) | 1974-04-26 | 1974-10-26 | 1975-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-26 | 1978-10-26 | 1979-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-26 | 1982-10-26 | 1983-04-27 | $7700.00 | Window Closed / Lapsed |