Method and apparatus for classifying the tire width of moving vehicles

Claim 3

Apparatus for classifying axles of vehicles moving along a roadway according to tire width, comprising: a plurality of sensing devices; means for supporting said devices in laterally spaced positions across one side of a traffic lane; said devices being divided into groups of equal length measured laterally of the roadway, and said groups being arranged in equal blocks with each block containing at least three groups; a number of output circuits equal to the number of groups in a block, each one of said output circuits being coupled to all the sensing devices in the corresponding group of each of said blocks and adapted to produce an output signal whenever any one of said sensing devices is encountered by a tire; first output means responsive to an output signal produced by any one of said output circuits for indicating that a tire has passed; second output means responsive to the occurrence of output signals in all of said output circuits for indicating that the tire is a dual tire; and third output means responsive to the occurrence of an output signal in said first output means concurrent with the non-occurrence of an output signal in said second output means for indicating that the tire is a single tire.

Claim 4

Apparatus for classifying axles of vehicles moving along a roadway according to tire width, comprising: a plurality of sensing devices; means for supporting said devices in laterally spaced positions across one side of a traffic lane; said devices being divided into groups of equal length measured laterally of the roadway, and said groups being arranged in equal blocks with each block containing at least three groups; a number of output circuits equal to the number of groups in a block, each one of said output circuits being coupled to all the sensing devices in the corresponding group of each of said blocks and adapted to produce an output signal whenever any one of said sensing devices is encountered by a tire; first output means responsive to an output signal produced by any one of said output circuits for indicating that a tire has passed; second output means responsive to the occurrence of output signals in all of said output circuits for indicating that the tire is a dual tire; and third output means responsive to the occurrence of an output signal in said first output means concurrent with the non-occurrence of an output signal in said second output means for indicating that the tire is a single tire.

Claim 5

Apparatus as claimed in claim 2 wherein there are at least two sensing devices in each group, the length of each group is about 7 inches, and there are three groups in each block.

Claim 6

Apparatus as claimed in claim 2 wherein there are at least two sensing devices in each group, the length of each group is about 4 1/2 inches, and there are four groups in each block.

Claim 7

Apparatus as claimed in claim 2 wherein the length of each group is about 3 1/2 inches and there are five groups in each block.

Claim 8

Apparatus as claimed in claim 2 wherein said sensing devices and supporting means comprise: a housing adapted to extend across one side of the traffic lane; at least four continuous conductors extending substantially the full length of said housing, one of said conductors providing a common connection to all of said sensing devices and the others providing said output circuits; insulating means supporting said output circuit conductors in insulated relationship to each other, and normally supporting said output circuit conductors in spaced relationship to said common connection conductor; and said insulating means being so arranged at each sensor location as to permit the appropriate one of said output circuit conductors to conductively engage said common connection conductor in response to the passage of a vehicle tire thereover.

Claim 9

Apparatus as claimed in claim 6 wherein said common connection conductor is a wide flat metal strip, and said output circuit conductors are relatively narrow flat metal strips disposed essentially in side-by-side relationship and occupying a plane parallel to said wide metal strip.

Claim 10

Apparatus for classifying axles of vehicles moving along a roadway according to tire width, comprising: a plurality of sensing devices; means for supporting said devices in laterally spaced positions across one side of a traffic lane, adjacent devices being sufficiently close together so that the narrowest tire to be detected will encounter at least one of said devices; said devices being divided into groups of equal length measured laterally of the roadway, the group length being no greater than the difference in width between the narrowest dual tire to be detected as such and the widest single tire to be detected as such, said groups being arranged in equal blocks with each block containing at least three groups, and the length of one block minus one group being less than the width of the narrowest dual tire to be detected as such; a number of output circuits equal to the number of groups in a block, each one of said output circuits being coupled to all the sensing devices in the corresponding group of each of said blocks and adapted to produce an output signal whenever any one of said sensing devices is encountered by a tire; an OR circuit responsive to an output signal produced by any one of said output circuits for indicating that a tire has passed; and an AND circuit responsive to the occurrence of output signals in all of said output circuits for indicating that the tire is a dual tire.

Claim 11

Apparatus for classifying axles of vehicles moving along a roadway according to tire width, comprising: a plurality of sensing devices; means for supporting said devices in laterally spaced positions across one side of a traffic lane, adjacent devices being sufficiently close together so that the narrowest tire to be detected will encounter at least one of said devices; said devices being divided into groups of equal length measured laterally of the roadway, the group length being no greater than the difference in width between the narrowest dual tire to be detected as such and the widest single tire to be detected as such, said groups being arranged in equal blocks with each block containing at least three groups, and the length of one block minus one group being less than the width of the narrowest dual tire to be detected as such; a number of output circuits equal to the number of groups in a block, each one of said output circuits being coupled to all the sensing devices in the corresponding group of each of said blocks and adapted to produce an output signal whenever any one of said sensing devices is encountered by a tire; an OR circuit responsive to an output signal produced by any one of said output circuits for indicating that a tire has passed; and an AND circuit responsive to the occurrence of output signals in all of said output circuits for indicating that the tire is a dual tire.

Claim 12

Apparatus as claimed in claim 8 which includes an additional AND circuit for indicating that a single tire has passed, having one input coupled to the output of said OR circuit and another input coupled through an inverter to the output of said first-named AND circuit.

Claim 13

Traffic counting and classifying apparatus comprising: a row of equally spaced sensors extending across about half a traffic lane of a roadway and each adapted to selectively close an electrical circuit in response to the movement of a vehicle tire thereover; said sensors being arranged into groups containing equal numbers of sensors, said groups being arranged into blocks of equal length; a common electrical return conductor extending down said row and connected to one side of each of said sensors; a plurality of signal lines extending down said row, each of said signal lines being connected to the other side of each sensor of one group of each block of sensors; each signal line being connected to different sensor groups than every other signal line, and the sensor groups to which each signal line is connected forming an equally spaced series; housing means adapted to support said sensors, return conductor, and signal lines in their proper relative positions; and which further includes an OR circuit responsive to an output signal produced by any one of said signal lines for indicating that a tire has passed.

Claim 14

Traffic counting and classifying apparatus comprising: a row of equally spaced sensors extending across about half a traffic lane of a roadway and each adapted to selectively close an electrical circuit in response to the movement of a vehicle tire thereover; said sensors being arranged into groups containing equal numbers of sensors, said groups being arranged into blocks of equal length; a common electrical return conductor extending down said row and connected to one side of each of said sensors; a plurality of signal lines extending down said row, each of said signal lines being connected to the other side of each sensor of one group of each block of sensors; each signal line being connected to different sensor groups than every other signal line, and the sensor groups to which each signal line is connected forming an equally spaced series; housing means adapted to support said sensors, return conductor, and signal lines in their proper relative positions; and which further includes an OR circuit responsive to an output signal produced by any one of said signal lines for indicating that a tire has passed.

Claim 15

Apparatus as claimed in claim 10 wherein each of said sensors is an electrical switch, and said return conductor is a flat metallic conductor which extends the full length of said row of sensors and forms a part of each of said switches.

Claim 16

Apparatus as claimed in claim 11 wherein each of said signal lines is a flat metallic conductor which extends the full length of said row of sensors and forms a part of the respectively associated group of switches.

Claim 17

Apparatus as claimed in claim 11 which further includes a continuous sheet of insulating material disposed between said return conductor and said signal lines and having an opening therein at each sensor location, the opening being so situated as to permit selective engagement with said return conductor by the particular signal line belonging to that sensor location.

Claim 18

Apparatus as claimed in claim 10 which further includes an AND circuit responsive to the occurrence of output signals on all of said signal lines for indicating that the tire is a dual tire.

Claim 19

Apparatus as claimed in claim 14 which includes an additional AND circuit having one input coupled to the output of said OR circuit, and another input coupled through an inverter to the output of said first-named AND circuit, for indicating that a single tire has passed.