Patent US3205441A successfully refreshed from Google Patents.
US3205441A
Expired / Lapsed
US
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Frequency shift signaling system
Assignee: Western Union Telegraph Co
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Filing: 1962-10-01
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Granted: 1965-09-07
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Expires: 1982-10-01
Abstract
No abstract record available.
Inventors
- 👤 Harry C Likel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:52
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/10; H04L27/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
193 words
A SYSTEM FOR PRODUCING FREQUENCY SHIFT KEYING SIGNALS, COMPRISING A SOURCE OF SIGNALS OF A SINGLE FREQUENCY, A FIRST BINARY DIVIDER CHAIN CONNECTED TO SAID SOURCE TO PRODUCE A FIRST GROUP OF SIGNALS OF LOWER FREQUENCIES THAN SAID SINGLE FREQUENCY, A KEYING SIGNAL SOURCE, A GATE CONNECTED TO THE KEYING SIGNAL SOURCE AND KEYED THEREBY, SAID GATE HAVING INPUTS CONNECTED IN CIRCUIT TO THE FIRST CHAIN FOR PASSING THERETHROUGH TWO SELECTED SIGNALS DERIVED FROM SAID GROUP, A SECOND BINARY DIVIDER CHAIN CONNECTED TO AN OUTPUT OF THE GATE FOR DERIVING FURTHER SIGNALS OF FREQUENCIES LOWER THAN SAID TWO SELECTED SIGNALS, A FILTER CONNECTED TO SAID SECOND CHAIN FOR CONVERTING SAID FURTHER SIGNALS TO SINE WAVEFORM, A CARRIER SIGNAL SOURCE, A HETERODYNING MODULATOR CONNECTED IN CIRCUIT WITH SAID CARRIER SIGNAL SOURCE AND SAID FILTER FOR PRODUCING SIDEBANDS CONTAINING FREQUENCY SHIFT KEYING SIGNALS AT DESIRED LINE FREQUENCIS, WHEREIN SAID CARRIER SIGNAL SOURCE COMPRISES A THIRD BINARY DIVIDER CHAIN CONNECTED TO THE FIRST CHAIN FOR DERIVING A CERTAIN ONE OF SAID GROUP OF SIGNALS AND FOR PRODUCING A CERTAIN CARRIER SIGNAL THEREFROM, AND MEANS CONNECTING THE THIRD CHAIN TO THE MODULATOR FOR APPLYING SAID CARRIER SI
Claim 2
Independent Claim
193 words
A SYSTEM FOR PRODUCING FREQUENCY SHIFT KEYING SIGNALS, COMPRISING A SOURCE OF SIGNALS OF A SINGLE FREQUENCY, A FIRST BINARY DIVIDER CHAIN CONNECTED TO SAID SOURCE TO PRODUCE A FIRST GROUP OF SIGNALS OF LOWER FREQUENCIES THAN SAID SINGLE FREQUENCY, A KEYING SIGNAL SOURCE, A GATE CONNECTED TO THE KEYING SIGNAL SOURCE AND KEYED THEREBY, SAID GATE HAVING INPUTS CONNECTED IN CIRCUIT TO THE FIRST CHAIN FOR PASSING THERETHROUGH TWO SELECTED SIGNALS DERIVED FROM SAID GROUP, A SECOND BINARY DIVIDER CHAIN CONNECTED TO AN OUTPUT OF THE GATE FOR DERIVING FURTHER SIGNALS OF FREQUENCIES LOWER THAN SAID TWO SELECTED SIGNALS, A FILTER CONNECTED TO SAID SECOND CHAIN FOR CONVERTING SAID FURTHER SIGNALS TO SINE WAVEFORM, A CARRIER SIGNAL SOURCE, A HETERODYNING MODULATOR CONNECTED IN CIRCUIT WITH SAID CARRIER SIGNAL SOURCE AND SAID FILTER FOR PRODUCING SIDEBANDS CONTAINING FREQUENCY SHIFT KEYING SIGNALS AT DESIRED LINE FREQUENCIS, WHEREIN SAID CARRIER SIGNAL SOURCE COMPRISES A THIRD BINARY DIVIDER CHAIN CONNECTED TO THE FIRST CHAIN FOR DERIVING A CERTAIN ONE OF SAID GROUP OF SIGNALS AND FOR PRODUCING A CERTAIN CARRIER SIGNAL THEREFROM, AND MEANS CONNECTING THE THIRD CHAIN TO THE MODULATOR FOR APPLYING SAID CARRIER SI
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) | 1968-09-06 | 1969-03-08 | 1969-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-09-06 | 1973-03-08 | 1973-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-09-06 | 1977-03-08 | 1977-09-07 | $7700.00 | Window Closed / Lapsed |