Patent US3238503A successfully refreshed from Google Patents.
US3238503A
Expired / Lapsed
US
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Frequency responsive signalling system employing selective plural frequencies
Assignee: US Philips Corp
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Filing: 1960-02-23
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Granted: 1966-03-01
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Expires: 1980-02-23
Abstract
No abstract record available.
Inventors
- 👤 Uitermark Gerardus Martinus
- 👤 Veldstra Jan Max Mathijs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:51
CPC Classifications
H; H04; H04W; H04W88/00; H04W88/18; H04W88/185; H04W88/188
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
98 words
A TRANSMISSION SYSTEM FOR SELECTIVE TRANSMISSION OF CODED INFORMATION BETWEEN A TRANSMITTER AND A RECEIVER, SAID TRANSMITTER COMPRISING A SOURCE OF A PLURALITY OF PREDETERMINED KEY FREQUENCY OSCILLATIONS, AND MEANS FOR TRANSMITTING A CALL SIGNAL IN THE FORM OF A SELECTED COMBINATION OF SAID KEY FREQUENCY OSCILLATIONS AND FOR SUBSEQUENTLY TRANSMITTING A CODED INFORMATION SIGNAL IN THE FORM OF AT LEAST ONE FREQUENCY OF SAID SELECTED COMBINATION, SAID RECEIVER COMPRISING A PLURALITY OF FREQUENCY SELECTIVE DETECTOR MEANS EACH RESPONSIVE TO A SINGLE FREQUENCY OF SAID SELECTED COMBINATION, MEANS FOR RECEIVING SAID SIGNALS AND APPLYING THEM TO SAID DE-
Claim 2
Dependent Claim
98 words
A TRANSMISSION SYSTEM FOR SELECTIVE TRANSMISSION OF CODED INFORMATION BETWEEN A TRANSMITTER AND A RECEIVER, SAID TRANSMITTER COMPRISING A SOURCE OF A PLURALITY OF PREDETERMINED KEY FREQUENCY OSCILLATIONS, AND MEANS FOR TRANSMITTING A CALL SIGNAL IN THE FORM OF A SELECTED COMBINATION OF SAID KEY FREQUENCY OSCILLATIONS AND FOR SUBSEQUENTLY TRANSMITTING A CODED INFORMATION SIGNAL IN THE FORM OF AT LEAST ONE FREQUENCY OF SAID SELECTED COMBINATION, SAID RECEIVER COMPRISING A PLURALITY OF FREQUENCY SELECTIVE DETECTOR MEANS EACH RESPONSIVE TO A SINGLE FREQUENCY OF SAID SELECTED COMBINATION, MEANS FOR RECEIVING SAID SIGNALS AND APPLYING THEM TO SAID DE-
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-02-28 | 1969-08-30 | 1970-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-02-28 | 1973-08-30 | 1974-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-02-28 | 1977-08-30 | 1978-03-01 | $7700.00 | Window Closed / Lapsed |