US3737851A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Precision vehicle interval detection and signaling system
Assignee: TRAFFIC SAFETY SYSTEMS Inc
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Filing: 1971-04-01
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Granted: 1973-06-05
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Expires: 1991-04-01
Abstract
Abstract A beam of radiant energy, such as from an infrared transmitter, is directed in a path, preferably downwardly, across the center of a traffic lane to impinge upon an appropriate photoelectric receiver or other detector so that a vehicle interrupts the beam path as it travels along the traffic lane. As the vehicle moves on out of the beam path, the beam again impinges on the receiver to produce an output indicating passage of the rear of a vehicle to actuate a first timing delay circuit that produces a minimum timing interval, such as 0.2 seconds. Timing delay circuits defining longer unsafe and/or illegal headway intervals between the rear of one vehicle and the front of a following vehicle are then actuated at the conclusion of this minimum interval to generate a signal from the system indicating unsafe or illegal ''''tailgating'''' conditions if the beam is again interrupted within these defined intervals. However, if the beam is prematurely interrupted during the minimum interval defined by the first timing delay circuit, the system is prevented from responding to indicate arrival of another vehicle or to signal an unsafe or illegal headway interval between vehicles.
Inventors
- 👤 A Marshall
- 👤 J Rinehart
- 👤 C Gregory
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:33
CPC Classifications
G; G08; G08G; G08G1/00; G08G1/01; G08G1/04
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
184 words
A system for detecting and indicating that the headway interval between successive vehicles in a common traffic lane is less than a predetermined minimum safe headway interval, comprising: vehicle detector means responsive to the presence of a vehicle at a given point along said traffic lane for producing a detector signal during presence of a vehicle at said given point; first timing means responsive to the signal from said detector means for producing a first output condition for a predetermined minimum time interval beginning with each cessation of said detector signal; second timing means responsive to the detector signal from said detection means for generating a second output condition defining an unsafe time interval after cessation of a signal from said vehicle detector means indicative of a headway interval less than said predetermined minimum safe headway interval; and, output signaling means responsive to the detector signal from said detection means and to said first and second output conditions for indicating an unsafe condition whenever a signal from said vehicle detection means is initiated during said unsafe time interval but after said minimum time interval.
Claim 2
Independent Claim
184 words
A system for detecting and indicating that the headway interval between successive vehicles in a common traffic lane is less than a predetermined minimum safe headway interval, comprising: vehicle detector means responsive to the presence of a vehicle at a given point along said traffic lane for producing a detector signal during presence of a vehicle at said given point; first timing means responsive to the signal from said detector means for producing a first output condition for a predetermined minimum time interval beginning with each cessation of said detector signal; second timing means responsive to the detector signal from said detection means for generating a second output condition defining an unsafe time interval after cessation of a signal from said vehicle detector means indicative of a headway interval less than said predetermined minimum safe headway interval; and, output signaling means responsive to the detector signal from said detection means and to said first and second output conditions for indicating an unsafe condition whenever a signal from said vehicle detection means is initiated during said unsafe time interval but after said minimum time interval.
Claim 3
Dependent Claim
116 words
The system of claim 1 wherein: said first timing means includes means for generating a trigger signal for actuating said second timing means at the conclusion of each predetermined minimum time interval and for preventing generation of said trigger signal upon a subsequent initiation of said detector signal before conclusion of said predetermined minimum time interval; said second timing means being responsive to the generation of said trigger signal for generating said second output condition only during an unsafe time interval following said predetermined minimum time interval; and, said output signaling means having a first coincidence means responsive to the initiation of said detector signal and to said second output condition for indicating said unsafe condition.
Claim 4
Dependent Claim
36 words
The system of claim 2 wherein: said predetermined minimum time interval is approximately 0.2 second and said unsafe time interval following said minimum time interval is in the range from approximately 0.5 second to 1.0 second.
Claim 5
Dependent Claim
128 words
The system of claim 2 wherein: said second timing means for generating said second output condition further comprises third timing means for generating in response to said trigger signal a third output condition during only that initial portion of said unsafe time interval indicative of a shorter illegal headway interval of shorter time duration than said unsafe time interval; and, said coincidence means constitutes a second coincidence circuit responsive to said third output condition and to initiation of said detector signal only during said initial portion of said unsafe time interval for indicating an illegal headway interval, said first coincidence means being also responsive to said third output condition for preventing indication of an unsafe headway interval until conclusion of said initial portion of said unsafe time interval.
Claim 6
Dependent Claim
65 words
The system of claim 1, wherein: said vehicle detector means includes means for transmitting a narrow beam of radiant energy in a path to Intersect said given point along said traffic lane and receiving means responsive to impingement of said beam for generating said detector signal when presence of a vehicle at said given point interrupts the transmission of said narrow beam in said path.
Claim 7
Dependent Claim
181 words
In a system for detecting and indicating an unsafe headway interval between successive vehicles in a common traffic lane, wherein an unsafe driving condition is indicated when presence of a later arriving vehicle is detected within a predetermined unsafe time interval following departure of a previous vehicle, the improvement comprising: timing delay means having set and reset states, including input means responsive to detection of the departure of each vehicle from said given point for switching said timing delay means to said set state and to the presence of a vehicle at said given point for placing it in said reset state, a delay circuit operative during said set state to generate a trigger signal for returning said timing delay means to its reset state upon completion of a timing cycle having a duration equal to a predetermined minimum time interval; and, means actuated by said trigger signal to respond to detection of the later arrival of a vehicle during said unsafe interval indicating said unsafe condition only after completion of said predetermined minimum time interval following departure of each vehicle.
Claim 8
Dependent Claim
181 words
In a system for detecting and indicating an unsafe headway interval between successive vehicles in a common traffic lane, wherein an unsafe driving condition is indicated when presence of a later arriving vehicle is detected within a predetermined unsafe time interval following departure of a previous vehicle, the improvement comprising: timing delay means having set and reset states, including input means responsive to detection of the departure of each vehicle from said given point for switching said timing delay means to said set state and to the presence of a vehicle at said given point for placing it in said reset state, a delay circuit operative during said set state to generate a trigger signal for returning said timing delay means to its reset state upon completion of a timing cycle having a duration equal to a predetermined minimum time interval; and, means actuated by said trigger signal to respond to detection of the later arrival of a vehicle during said unsafe interval indicating said unsafe condition only after completion of said predetermined minimum time interval following departure of each vehicle.
Claim 9
Dependent Claim
137 words
The improvement of claim 6 wherein: said actuated means comprises additional timing delay means having set and reset states including first input means responsive to said trigger signal to be placed in said set state and second input means responsive to the presence of a vehicle to be placed in said reset state, and an unsafe timing delay circuit operative during said set state to generate a reset timing signal upon completion of said timing cycle for returning said additional timing delay means to its reset state, said timing cycle having a duration equal to said predetermined unsafe time interval, and output means actuated only during said set state to respond to detection of the presence of a vehicle prior to completion of each unsafe timing cycle for generating an output signal indicative of said unsafe condition.
Claim 10
Dependent Claim
29 words
The improvement of claim 7 wherein: said minimum time interval is approximately 0.2 second; and, said unsafe time interval is in the range from approximately 0.5 to 1.0 second.
Claim 11
Dependent Claim
97 words
The improvement of claim 7 further comprising: detection means coupled to said input means of said timing delay means for generating detection signals indicative of the presence or absence of a vehicle at a given point along said common traffic lane, said detection means including means for transmitting a narrow beam of radiant energy in a path to intersect said given point and receiving means responsive to impingement of said beam for generating said detection signals in accordance with whether a vehicle is present at said given point to interrupt transmission of said beam along said path.
Claim 12
Dependent Claim
165 words
An improved system for detecting and registering the passage of vehicles past a given point in a roadway comprising: vehicle detection means including a transmitter for directing a narrow beam of radiant energy in a path to intersect said given point and a receiver located in the path of said beam for responding to impingement of said beam for generating detection signals whereby a vehicle present at said given point interrupts said beam to prevent its impinging on said receiver; timing means responsive to detection signals from said detector means for producing a first output condition for a predetermined minimum time interval following the initial impingement of said beam on said receiver after each interruption; and, register means responsive to said detection signals generated by said detection means upon each interruption of said beam and to said first output condition of said timing means for registering the passage of a single vehicle only wHen said beam is not interrupted during said predetermined minimum time interval.
Claim 13
Dependent Claim
165 words
An improved system for detecting and registering the passage of vehicles past a given point in a roadway comprising: vehicle detection means including a transmitter for directing a narrow beam of radiant energy in a path to intersect said given point and a receiver located in the path of said beam for responding to impingement of said beam for generating detection signals whereby a vehicle present at said given point interrupts said beam to prevent its impinging on said receiver; timing means responsive to detection signals from said detector means for producing a first output condition for a predetermined minimum time interval following the initial impingement of said beam on said receiver after each interruption; and, register means responsive to said detection signals generated by said detection means upon each interruption of said beam and to said first output condition of said timing means for registering the passage of a single vehicle only wHen said beam is not interrupted during said predetermined minimum time interval.
Claim 14
Dependent Claim
144 words
An improved system for detecting the headway interval between vehicles passing a given point in a roadway comprising: vehicle detection means including a transmitter for directing a narrow beam of radiant energy in a path to intersect said given point and a receiver located in the path of said beam for generating detection signals in response to impingement of said beam, whereby a vehicle present at said given point interrupts said beam to prevent its impinging on said receiver; first timing means responsive to said detection signals for producing a first output condition for a predetermined minimum time interval following initial impingement of said beam on said receiver after each interruption; means responsive to said first output condition and to said detection signals for generating an output indicative of the relative magnitude of the headway interval between each two successive vehicles in the roadway.
Claim 15
Dependent Claim
144 words
An improved system for detecting the headway interval between vehicles passing a given point in a roadway comprising: vehicle detection means including a transmitter for directing a narrow beam of radiant energy in a path to intersect said given point and a receiver located in the path of said beam for generating detection signals in response to impingement of said beam, whereby a vehicle present at said given point interrupts said beam to prevent its impinging on said receiver; first timing means responsive to said detection signals for producing a first output condition for a predetermined minimum time interval following initial impingement of said beam on said receiver after each interruption; means responsive to said first output condition and to said detection signals for generating an output indicative of the relative magnitude of the headway interval between each two successive vehicles in the roadway.
Claim 16
Dependent Claim
182 words
An improved method for determining whether or not a safe driving spacing exists between two successive moving vehicles comprising: directing a narrow beam of radiant energy in a path from a transmitter to a receiver to intersect a given point in the roadway to be interrupted by the presence of a vehicle; signaling the interruption of the beam by the presence of a passing vehicle; signaling the reestablishment of said beam along said path; establishing in response to the signaling of the reestablishment of said beam a predetermined minimum time interval following said reestablishment; identifying whether the signaling of the interruption of the beam occurs during said minimum time interval and signaling the completion of said minimum time interval without interruption of said beam; establishing in response to the signaling of the completion of said minimum time interval without interruption of said beam a predetermined unsafe time interval following said minimum time interval; and, identifying whether interruption of the beam occurs during said predetermined unsafe time interval to indicate that the spacing between two successive vehicles in the roadway is not safe.
Claim 17
Dependent Claim
182 words
An improved method for determining whether or not a safe driving spacing exists between two successive moving vehicles comprising: directing a narrow beam of radiant energy in a path from a transmitter to a receiver to intersect a given point in the roadway to be interrupted by the presence of a vehicle; signaling the interruption of the beam by the presence of a passing vehicle; signaling the reestablishment of said beam along said path; establishing in response to the signaling of the reestablishment of said beam a predetermined minimum time interval following said reestablishment; identifying whether the signaling of the interruption of the beam occurs during said minimum time interval and signaling the completion of said minimum time interval without interruption of said beam; establishing in response to the signaling of the completion of said minimum time interval without interruption of said beam a predetermined unsafe time interval following said minimum time interval; and, identifying whether interruption of the beam occurs during said predetermined unsafe time interval to indicate that the spacing between two successive vehicles in the roadway is not safe.
Claim 18
Dependent Claim
81 words
The improved method of claim 12 further comprising: establishing, in response to the signaling of the completion of said minimum time interval without interruption of said beam, a predetermined illegal time interval following said minimum time interval and having a duration substantially shorter than said predetermined unsafe time interval; and, identifying whether interruption of the beam occurs during said predetermined illegal time interval to indicate that the spacing between two successive vehicles in the roadway consitutes an illegal reckless driving condition.
Claim 19
Dependent Claim
126 words
An improved method for detecting and registering the passage of the front and rear of each vehicle past a given point in the roadway comprising: directing a narrow beam of radiant energy in a path to intersect said given point in the roadway to be interrupted by the presence of a vehicle; signaling interruption of the beam by the presence of a passing vehicle; signaling reestablishment of said beam along said path after each interruption; establishing in response to said signaling a predetermined minimum time interval following reestablishment; identifying whether signaling a later interruption of the beam occurs during said minimum time interval; and, registering the passage of a vehicle only when a later interruption of said beam does not occur during said minimum time interval.
Claim 20
Dependent Claim
126 words
An improved method for detecting and registering the passage of the front and rear of each vehicle past a given point in the roadway comprising: directing a narrow beam of radiant energy in a path to intersect said given point in the roadway to be interrupted by the presence of a vehicle; signaling interruption of the beam by the presence of a passing vehicle; signaling reestablishment of said beam along said path after each interruption; establishing in response to said signaling a predetermined minimum time interval following reestablishment; identifying whether signaling a later interruption of the beam occurs during said minimum time interval; and, registering the passage of a vehicle only when a later interruption of said beam does not occur during said minimum time interval.
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) | 1976-06-04 | 1976-12-04 | 1977-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-04 | 1980-12-04 | 1981-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-04 | 1984-12-04 | 1985-06-05 | $7700.00 | Window Closed / Lapsed |