Patent US3662330A successfully refreshed from Google Patents.
← Back to Patent Explorer
US3662330A Expired / Lapsed US ⏱️ 0.0 years remaining

Fail-safe vehicle detector system

Assignee: Tamar Electronics Industries Inc
•
Filing: 1971-01-18
•
Granted: 1972-05-09
•
Expires: 1991-01-18
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract Primary and secondary vehicle sensors are utilized to detect vehicles moving along a roadway, this information being available for use in a traffic control system. Primary and secondary counters associated with the primary and secondary vehicle sensors respectively are driven by a timing pulse source. The counters are reset to zero in response to their associated vehicle sensors so that the maximum count thereon is indicative of the time between successive actuations of such sensors. A timing limit selector is utilized to select a timing interval indicative of a probable failure in the operation of either of the vehicle sensors. This selected timing output is separately compared with the outputs of the counters, and when coincidence between the selected timing output and the output of either of the counters is reached, a failure signal is generated. This failure signal is utilized both to actuate an appropriate fail indicator and to control logical gating circuitry to provide an output signal solely in response to the vehicle sensor not associated with this failure signal.

Inventors

  • 👤 Gary L Meredith

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 16:59
CPC Classifications
G; G08; G08G; G08G1/00; G08G1/097

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 148 words
A fail safe vehicle detection system comprising: vehicle sensor means for generating pulse signals in accordance with vehicle sensed thereby, a timing pulse source, counter means for counting the output of said pulse source, means for providing signals for resetting said counter means to zero in response to the output of said sensor means, timing limit selector means for selecting a predetermined timing interval which is greater than the maximum timing interval expected between vehicles actuating said sensor, comparator means for comparing the output of said counter means with the output of said timing limit selector means and for generating a ''''fail'''' control signal when coincidence between said outputs is reached, and logical gating circuit means responsive to the output of said comparator means for providing an output in accordance with said vehicle sensor means signals solely when said comparator means is not generating a ''''fail'''' control signal.
Claim 2
Dependent Claim 148 words
A fail safe vehicle detection system comprising: vehicle sensor means for generating pulse signals in accordance with vehicle sensed thereby, a timing pulse source, counter means for counting the output of said pulse source, means for providing signals for resetting said counter means to zero in response to the output of said sensor means, timing limit selector means for selecting a predetermined timing interval which is greater than the maximum timing interval expected between vehicles actuating said sensor, comparator means for comparing the output of said counter means with the output of said timing limit selector means and for generating a ''''fail'''' control signal when coincidence between said outputs is reached, and logical gating circuit means responsive to the output of said comparator means for providing an output in accordance with said vehicle sensor means signals solely when said comparator means is not generating a ''''fail'''' control signal.
Claim 3
Dependent Claim 31 words
The system of claim 1 and further including means responsive to the output of said comparator means for inhibiting the counting of said counter means when said coincidence condition is reached.
Claim 4
Dependent Claim 22 words
The system of claim 1 and further comprising indicator means for generating a ''''fail'''' indication in response to said ''''fail'''' control signal.
Claim 5
Dependent Claim 59 words
The system of claim 1 wherein said counter means comprises a binary counter having predetermined outputs indicating successively higher counts, said selector means comprising a selector switch having predetermined positions corresponding to predetermined outputs of said counter and said comparator means includes a comparator for comparing each of said corresponding counter and switch position outputs for a coincidence condition.
Claim 6
Dependent Claim 42 words
The system of claim 1 wherein said timing limit selector means includes a plurality of selector switches each set to a predetermined different timing interval and remote selector means for alternatively feeding one of the selector switch outputs to said comparator means.
Claim 7
Dependent Claim 212 words
A fail safe vehicle detection system comprising: primary and secondary vehicle sensor means for generating pulse signals in accordance with vehicles sensed thereby, a timing pulse source, primary and secondary counter means for counting the output of said pulse source, means for providing signals for resetting said primary and secondary counters to zero in response to the outputs of said primary and secondary vehicle sensors respectively, timing limit selector means for selecting a predetermined timing interval which is greater than the maximum timing interval expected between vehicles actuating said sensors, comparator means for separately comparing the outputs of said primary and secondary counter means respectively, with the output of said timing selector means and for generating a ''''fail'''' control signal when coincidence between the compared signals is reached, logical gating circuit means responsive to the outputs of said comparator means for alternatively providing an output in accordance with the primary sensor means signals when there is not a ''''fail'''' output from the comparator means associated therewith and an output in accordance with the sensor signals for the secondary vehicle sensor means when there is a ''''fail'''' signal from the comparator means associated with the primary sensor and there is not a ''''fail'''' output from the comparator means associated with the secondary sensor.
Claim 8
Dependent Claim 212 words
A fail safe vehicle detection system comprising: primary and secondary vehicle sensor means for generating pulse signals in accordance with vehicles sensed thereby, a timing pulse source, primary and secondary counter means for counting the output of said pulse source, means for providing signals for resetting said primary and secondary counters to zero in response to the outputs of said primary and secondary vehicle sensors respectively, timing limit selector means for selecting a predetermined timing interval which is greater than the maximum timing interval expected between vehicles actuating said sensors, comparator means for separately comparing the outputs of said primary and secondary counter means respectively, with the output of said timing selector means and for generating a ''''fail'''' control signal when coincidence between the compared signals is reached, logical gating circuit means responsive to the outputs of said comparator means for alternatively providing an output in accordance with the primary sensor means signals when there is not a ''''fail'''' output from the comparator means associated therewith and an output in accordance with the sensor signals for the secondary vehicle sensor means when there is a ''''fail'''' signal from the comparator means associated with the primary sensor and there is not a ''''fail'''' output from the comparator means associated with the secondary sensor.
Claim 9
Dependent Claim 32 words
The system of claim 6 and further including means responsive to the outputs of said comparator means for inhibiting the counting of the associated counter means when said coincidence condition is reached.
Claim 10
Dependent Claim 21 words
The system of claim 6 and further comprising indicator means for generating ''''fail'''' indications in response to said ''''fail'''' control signals.
Claim 11
Dependent Claim 56 words
The system of claim 6 wherein each of said counter means comprises a counter having predetermined outputs indicating successively higher counts, said selector means comprising a selector switch having predetermined positions corresponding to predetermined outputs of said counter and a comparator for comparing each of the corresponding counter and switch position outputs for a coincidence condition.

References Cited (Backward Citations)

US3350547A Cited
US3406395A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-05-09 1975-11-08 1976-05-09 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-05-09 1979-11-08 1980-05-09 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-05-09 1983-11-08 1984-05-09 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag