US3124748A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Secret signalling systems
Assignee: —
•
Filing: —
•
Granted: 1964-03-10
•
Expires: 1981-03-10
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:02
CPC Classifications
H; H04; H04K; H04K1/00; H04K1/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
103 words
THE METHOD OF TRANSFORMING NORMAL SPEECH INTO UNINTELLIGIBLE SIGNALS FOR TRANSMISSION OVER RADIO OR TELEPHONE CIRCUITS WHICH CONSISTS OF SUBJECTING THE VOICE INPUT TO A FIRST BAND PASS FILTER, MODULATING THE FILTERED SIGNAL WITH A RANDOM FREQUENCY CARRIER, SUBJECTING THE MODULATED SIGNAL TO A SECOND BAND PASS FILTERING OPERATION, MODULATING THE BAND PASS FILTERED SIGNAL WITH A SECOND RANDOM FREQUENCY CARRIER OF A FREQUENCY EXACTLY ONEHALF THAT OF THE FIRST MODULATION OPERATION AND SUBJECTING THE SECOND MODULATION SIGNAL TO A THIRD LOW PASS FILTERING ACTION TO PRODUCE A SHIFTING INVERTED BAND OF THE ORIGINAL SPEECH SIGNAL WITHIN THE ORIGINAL SPEECH BAND BUT UNINTELLIGIBLE.
Claim 2
Independent Claim
103 words
THE METHOD OF TRANSFORMING NORMAL SPEECH INTO UNINTELLIGIBLE SIGNALS FOR TRANSMISSION OVER RADIO OR TELEPHONE CIRCUITS WHICH CONSISTS OF SUBJECTING THE VOICE INPUT TO A FIRST BAND PASS FILTER, MODULATING THE FILTERED SIGNAL WITH A RANDOM FREQUENCY CARRIER, SUBJECTING THE MODULATED SIGNAL TO A SECOND BAND PASS FILTERING OPERATION, MODULATING THE BAND PASS FILTERED SIGNAL WITH A SECOND RANDOM FREQUENCY CARRIER OF A FREQUENCY EXACTLY ONEHALF THAT OF THE FIRST MODULATION OPERATION AND SUBJECTING THE SECOND MODULATION SIGNAL TO A THIRD LOW PASS FILTERING ACTION TO PRODUCE A SHIFTING INVERTED BAND OF THE ORIGINAL SPEECH SIGNAL WITHIN THE ORIGINAL SPEECH BAND BUT UNINTELLIGIBLE.
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) | 1967-03-10 | 1967-09-09 | 1968-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-03-10 | 1971-09-09 | 1972-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-03-10 | 1975-09-09 | 1976-03-10 | $7700.00 | Window Closed / Lapsed |