US3223779A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combined frequency shift and phase shift keying
Assignee: Robertshaw Controls Co
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Filing: 1962-01-23
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Granted: 1965-12-14
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Expires: 1982-01-23
Abstract
No abstract record available.
Inventors
- 👤 Maynard D Mcfarlane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:36
CPC Classifications
H; H04; H04L; H04L5/00; H04L5/02; H04J; H04J9/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
165 words
A COMMUNICATION SYSTEM COMPRISING; MEANS GENERATING A FUNDAMENTAL FREQUENCY, MEANS GENERATING A PAIR OF HARMONICALLY RELATED FREQUENCIES FROM SAID FUNDAMENTAL FREQUENCY, SAID FREQUENCIES BEING CONVEYED IN ADJACENTLY RELATED CHANNELS, MEANS COUPLING SIAD FREQUENCY CHANNELS TO CORRESPONDING FREQUENCY CHANNELS IN A RECEIVING APPARATUS, MEANS EFFECTIVE TO PERMIT ONLY ONE OF SAID FREQUENCIES TO BE TRANSMITTED TO SAID RECEIVING APPARATUS AT ANY INSTANT, MEANS EFFECTIVELY IMPRESSED SIMILAR PHASE SHIFT STEPS OF LESS THAN 180* IN EACH SAID CHANNEL IN ACCORDANCE WITH INFORMATION TO BE TRANSMITTED, FREQUENCY DETECTING MEANS IN SAID RECEIVING APPARATUS INDICATING WHICH OF SAID FREQUENCIES IS INSTANTLY TRANSMITTED, MEANS EFFECTIVE IN SAID RECEIVING APPARATUS DEVELOPING A REFERENCE SIGNAL FROM THE RECEIVED FREQUENCY DEVELOPING OF SAID FREQUENCY SHIFTED INFORMATION AND SYNCHRONIZED WITH SAID GENERATED HARMONIC FREQUENCY, MEANS EFFECTIVE IN SAID RECEIVING APPARATUS FOR COMPARING THE PHASE OF SAID RECEIVED FREQUENCY WITH THE PHASE OF SAID DEVELOPED FREQUENCY, AND MEANS IN SAID RECEIVING APPARATUS FOR INDICATING THE EXISTENCE OF A PHASE SHIFT DIFFERENCE AS AN INFORMATION OUTPUT.
Claim 2
Dependent Claim
165 words
A COMMUNICATION SYSTEM COMPRISING; MEANS GENERATING A FUNDAMENTAL FREQUENCY, MEANS GENERATING A PAIR OF HARMONICALLY RELATED FREQUENCIES FROM SAID FUNDAMENTAL FREQUENCY, SAID FREQUENCIES BEING CONVEYED IN ADJACENTLY RELATED CHANNELS, MEANS COUPLING SIAD FREQUENCY CHANNELS TO CORRESPONDING FREQUENCY CHANNELS IN A RECEIVING APPARATUS, MEANS EFFECTIVE TO PERMIT ONLY ONE OF SAID FREQUENCIES TO BE TRANSMITTED TO SAID RECEIVING APPARATUS AT ANY INSTANT, MEANS EFFECTIVELY IMPRESSED SIMILAR PHASE SHIFT STEPS OF LESS THAN 180* IN EACH SAID CHANNEL IN ACCORDANCE WITH INFORMATION TO BE TRANSMITTED, FREQUENCY DETECTING MEANS IN SAID RECEIVING APPARATUS INDICATING WHICH OF SAID FREQUENCIES IS INSTANTLY TRANSMITTED, MEANS EFFECTIVE IN SAID RECEIVING APPARATUS DEVELOPING A REFERENCE SIGNAL FROM THE RECEIVED FREQUENCY DEVELOPING OF SAID FREQUENCY SHIFTED INFORMATION AND SYNCHRONIZED WITH SAID GENERATED HARMONIC FREQUENCY, MEANS EFFECTIVE IN SAID RECEIVING APPARATUS FOR COMPARING THE PHASE OF SAID RECEIVED FREQUENCY WITH THE PHASE OF SAID DEVELOPED FREQUENCY, AND MEANS IN SAID RECEIVING APPARATUS FOR INDICATING THE EXISTENCE OF A PHASE SHIFT DIFFERENCE AS AN INFORMATION OUTPUT.
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) | 1968-12-13 | 1969-06-14 | 1969-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-12-13 | 1973-06-14 | 1973-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-12-13 | 1977-06-14 | 1977-12-14 | $7700.00 | Window Closed / Lapsed |