US3346856A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inductive loop vehicle detector
Assignee: General Precision Systems Inc
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Filing: 1964-07-06
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Granted: 1967-10-10
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Expires: 1984-07-06
Abstract
No abstract record available.
Inventors
- 👤 Robert N Doble
- 👤 Robert J Miller
- 👤 Sepe Lawrence
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:23
CPC Classifications
B; B61; B61L; B61L13/00; B61L13/04; B61L13/047; G; G08; G08G; G08G1/00; G08G1/01; G08G1/042
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
144 words
A VEHICLE DETECTION SYSTEM COMPRISING A FIRST OSCILLATOR INCLUDING AN INDUCTIVE LOOP, A SECOND OSCILLATOR, A MIXER CIRCUIT COUPLED TO BOTH OSCILLATORS FOR GENERATING DIFFERENCE FREQUENCY SIGNAL, A DISCRIMINATOR COUPLED TO THE MIXER CIRCUIT FOR GENERATING A DIRECT SIGNAL LEVEL CORRESPONDING TO THE DIFFERENCE FREQUENCY, MEANS FOR AMPLIFYING THE DIRECT SIGNAL LEVEL, AN AUTOMATIC FREQUENCY CONTROL CIRCUIT COUPLED TO CONTROL THE FREQUENCY OF THE SECOND OSCILLATOR FROM THE DIRECT SIGNAL LEVEL, A MEANS FOR STORING A SIGNAL LEVEL CORRESPONDING TO THE DIRECT SIGNAL LEVEL, A SIGNAL STORING MEANS HAVING DUAL TIME CONSTANT SPATHS WHEREBY A SIGNAL LEVEL MAY BE RECEIVED RELATIVELY- FAST AND MAY BE DISSIPATED RELATIVELY SLOWLY, AND A SWITCHING MEANS COUPLED TO THE DIRECT SIGNAL LEVEL AND TO THE SIGNAL LEVEL STORING MEANS, AND SWITCHING MEANS BEING RESPONSIVE TO THE RELATIVE VALUES OF THE DIRECT SIGNAL LEVEL AND THE STORED SIGNAL LEVEL.
Claim 2
Dependent Claim
144 words
A VEHICLE DETECTION SYSTEM COMPRISING A FIRST OSCILLATOR INCLUDING AN INDUCTIVE LOOP, A SECOND OSCILLATOR, A MIXER CIRCUIT COUPLED TO BOTH OSCILLATORS FOR GENERATING DIFFERENCE FREQUENCY SIGNAL, A DISCRIMINATOR COUPLED TO THE MIXER CIRCUIT FOR GENERATING A DIRECT SIGNAL LEVEL CORRESPONDING TO THE DIFFERENCE FREQUENCY, MEANS FOR AMPLIFYING THE DIRECT SIGNAL LEVEL, AN AUTOMATIC FREQUENCY CONTROL CIRCUIT COUPLED TO CONTROL THE FREQUENCY OF THE SECOND OSCILLATOR FROM THE DIRECT SIGNAL LEVEL, A MEANS FOR STORING A SIGNAL LEVEL CORRESPONDING TO THE DIRECT SIGNAL LEVEL, A SIGNAL STORING MEANS HAVING DUAL TIME CONSTANT SPATHS WHEREBY A SIGNAL LEVEL MAY BE RECEIVED RELATIVELY- FAST AND MAY BE DISSIPATED RELATIVELY SLOWLY, AND A SWITCHING MEANS COUPLED TO THE DIRECT SIGNAL LEVEL AND TO THE SIGNAL LEVEL STORING MEANS, AND SWITCHING MEANS BEING RESPONSIVE TO THE RELATIVE VALUES OF THE DIRECT SIGNAL LEVEL AND THE STORED SIGNAL LEVEL.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-10-09 | 1971-04-10 | 1971-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-10-09 | 1975-04-10 | 1975-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-10-09 | 1979-04-10 | 1979-10-10 | $7700.00 | Window Closed / Lapsed |