US3699398A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sensor for vehicular traffic counters
Assignee: Individual
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Filing: 1971-10-12
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Granted: 1972-10-17
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Expires: 1991-10-12
Abstract
Abstract A pneumatic road tube, an electromagnetic transducer and an electronic circuit provide a vehicle sensor mechanism for use in a traffic counting system. A complex air pressure wave is produced within the tube each time a vehicle runs over the tube, the wave is sensed by the transducer which responds by producing an electric signal. The electric signal is coupled to the circuit which blanks out unwanted portions of the signal and shapes the remainder into a signal suitable for application to a counting device.
Inventors
- 👤 Reed A Newmeyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:33
CPC Classifications
G; G08; G08G; G08G1/00; G08G1/01; G08G1/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
112 words
A sensor mechanism for use in a vehicular traffic counting system comprising: a. a pneumatic road tube having at least one end open, said tube producing a multi-pulse pressure wave within the hollow bore thereof when contacted by the vehicle; b. an electromagnetic transducer coupled to the open end of said pneumatic road tube for sensing the pressure wave produced therein and generating an electric signal in response thereto, the characteristics of which are determined by the characteristics of the pressure wave sensed; and c. an electronic circuit coupled to receive the electric signal from said electromagnetic transducer and produce a single output signal for each pressure wave sensed by said transducer.
Claim 2
Dependent Claim
112 words
A sensor mechanism for use in a vehicular traffic counting system comprising: a. a pneumatic road tube having at least one end open, said tube producing a multi-pulse pressure wave within the hollow bore thereof when contacted by the vehicle; b. an electromagnetic transducer coupled to the open end of said pneumatic road tube for sensing the pressure wave produced therein and generating an electric signal in response thereto, the characteristics of which are determined by the characteristics of the pressure wave sensed; and c. an electronic circuit coupled to receive the electric signal from said electromagnetic transducer and produce a single output signal for each pressure wave sensed by said transducer.
Claim 3
Dependent Claim
81 words
A sensor as defined in claim 1 wherein said electro-magnetic transducer comprises: a. a magnet; b. a coil of conductive wire wound on the poles of said magnet; and c. a metallic diaphragm disposed to sense the pressure wave from said road tube and move in response thereto, said diaphragm mounted adjacent to the poles of said magnet to provide an air gap therebetween so that movements of said diaphragm will electromagnetically induce a voltage in said coil of conductive wire.
Claim 4
Dependent Claim
127 words
A sensor as claimed in claim 1 wherein said electromagnetic transducer comprises: a. a housing; b. a metallic diaphragm mounted within said housing and positioned therein to provide a first and a second chamber within said housing; c. fitting means on said houSing for coupling said road tube to said housing, said fitting means communicating with the first chamber provided in said housing to allow the pressure wave to impingingly move said diaphragm; d. a magnet fixedly mounted in the second chamber of said housing and positioned so that the poles of said magnet are adjacent to said diaphragm; and e. a coil of conductive wire wound on the poles of said magnet in which a voltage is electromagnetically induced in response to movements of said diaphragm.
Claim 5
Dependent Claim
69 words
A sensor as claimed in claim 1 wherein said electronic circuit comprises: a. a threshold circuit coupled to receive the electric signal from said transducer and produce an output signal in response thereto; and b. signal interrupting means coupled to receive the output signal from said threshold circuit for relaying the occurrence of this signal and then blanking out subsequent signals from said threshold circuit for a predetermined time.
Claim 6
Dependent Claim
104 words
A sensor as claimed in claim 1 wherein said electronic circuit comprises: a. a variable threshold circuit coupled to receive the electric signal from said transducer and respond thereto by producing a threshold output signal the value of which is determined by the highest pulse amplitude of the electric signal received, the threshold output signal having a predetermined decay time for masking lower pulse amplitudes of the electric signal received; and b. signal interrupting means coupled to receive the threshold output signal from said threshold circuit for relaying the occurrence of this signal and then masking subsequent threshold output signals for a predetermined time.
Claim 7
Dependent Claim
16 words
A sensor as claimed in claim 5 wherein said signal interrupting means comprises a monostable multivibrator.
Claim 8
Dependent Claim
27 words
A sensor as claimed in claim 1 wherein the output signal from said electronic circuit is employed to energize a relay for electrically isolating said electronic circuit.
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) | 1975-10-17 | 1976-04-17 | 1976-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-17 | 1980-04-17 | 1980-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-17 | 1984-04-17 | 1984-10-17 | $7700.00 | Window Closed / Lapsed |