System including a pressure switch for counting axles and classifying vehicles

• US 3,914,733 A
• Filed: 04/16/1973
• Issued: 10/21/1975
• Est. Priority Date: 04/16/1973
• Status: Expired due to Term

• Current Assignee: Joseph R. Viracola
• Original Assignee: Joseph R. Viracola
• Inventors: Viracola, Joseph R.
• Primary Examiner(s): Claffy, Kathleen H.
• Assistant Examiner(s): Myers, Randall P.
• Application Number:
  US05/351,421
• Time in Patent Office: 918 Days
• Field of Search: 340/22,31R,38R,240,272 200/81R,81H,82R,83C,83Z,81.4,86R,86A,DIG.35,DIG.37
• US Class Current: 340/940
• CPC Class Codes: G08G 1/015 with provision for distinguishing between two or more types of vehicles, e.g. between motor-cars and cycles

Abstract

The system includes a pressure switch connected to a hose intercepting vehicle tires on a highway lane and includes a bellows which will expand a first given distance when a single tire axle passes over the hose and a second given distance when a dual tire axle passes over the hose, the second given distance being greater than the first given distance because of the increased volume of air provided by the dual tire axles. A first switch means is held open by a stem movable with the bellows and will be released to close when the bellows and stem move through the first given distance. A second switch in turn is normally opened but will be positively closed when the bellows and stem move through the second given distance. First and second electrical signals are provided on first and second lines connected to the first and second switches respectively for feeding into a computer which will count and classify the signals.

Claims

1. A system including a pressure switch for classifying vehicles having single tire axles and dual tire axles comprising, in combination:

a. hose means positioned to intercept a roadway vehicle lane so that one tire of each axle of a single tire axle running over the hose generates a first air pulse of given volume and so that dual tires of each axle of a dual tire axle running over the hose generates a second air pulse of greater volume than said given volume;

b. air chamber means connected to the hose and including an element movable through first and second positions in response respectively to said first and second air pulses;

c. first and second switch means coupled to said element for actuation thereby to provide first and second electrical signals, said first switch means being held in an open position by said element in the absence of any air pulses and released by said element to close when said element passes through said first position, said second switch being normally open and closed by said element only when said element reaches said second position; and

;

d. computer means connected to said first and second switch means to count and display combinations of said first and second electrical signals respectively.

2. A system including a pressure switch for classifying vehicles by providing a first output signal on a first line in response to a single tire axle and a second output signal on a second line in response to a dual tire axle, said system including, in combination:

a. an expandable air chamber means for connection to a hose over which vehicle tires run, said chamber expanding from a normally contracted position to a first distance in response to a pulse of air generated by a single tire axle running over said hose and expanding to a second distance greater than said first distance in response to a pulse of air generated by a dual tire axle running over said hose;

b. a first switch means connected to said first line and coupled to said air chamber means and held in an open position by said air chamber means when in said contracted position, said first switch means being released by said air chamber means to close when said air chamber means expands to said first distance to provide said first output signal; and

, c. a second switch means connecteD to said second line and coupled to said air chamber means, said second switch means being normally opened, said air chamber means positively closing said second switch means when it expands to said second distance to provide said second output signal.

3. A system according to claim 2, in which said expandable air chamber means comprises a housing supporting a bellows having a free end movable from said housing through said first and second distances;

and a switch actuating stem means reciprocably slidable in said housing connected to said free end of said bellows for movement therewith, said first and second switch means being actuated by movement of said stem through said first and second distances respectively.

4. A system according to claim 3, in which said housing includes means for holding said free end of said bellows in a consistent contracted position in the absence of pulses of air.

5. A system including a pressure switch for classifying vehicles by providing a first output signal on a first line in response to a single tire axle and a second output signal on a second line in response to a dual tire axle, said system comprising, in combination:

a. a switch housing having an air input opening for connection to a hose over which vehicle tires run;

b. an air bellows secured to the housing with its interior in communication with said inlet opening and its free end movable away from and towards the housing in response to air pressure pulses, the volume of air in each pulse determining the distance of travel of said free end;

c. a switch actuating stem reciprocably mounted in said housing with one end secured to said free end of the bellows so that said stem assumes different longitudinal positions depending upon the movement of said free end of said bellows, said stem including in its central portion first and second longitudinally spaced engaging means;

d. a first resilient switch arm cantilevered to extend into said housing in a direction normal to the stem, the free end of the arm including upper and lower contacts and terminating in a position such that it is engaged and biased upwardly by said first engaging means on said stem when said free end of the bellows is in a retracted position close to said housing;

e. a common resilient switch arm cantilevered to extend into said housing below said first arm in a direction normal to the stem in generally parallel spaced relationship to said first arm, its free end terminating short of the stem in a contact positioned to be engaged by the lower contact of said first arm when said free end of the bellows extends a first given distance from the housing;

f. a second resilient switch arm cantilevered to extend into said housing above said first arm in a direction normal to the stem in generally parallel spaced relationship to said first arm, its free end including a contact and terminating in a position such that it is engaged and biased downwardly by said second engaging means on said stem to contact the upper contact on said resilient arm and thereby make electrical connection to both said first arm and the contact on said common resilient arm when the free end of said bellows extends a second given distance from the housing greater than said first given distance;

g. first and second output signal lines connected respectively to said first and second resilient switch arms; and

, h. means for providing an electrical output signal on said first output line in response to closing of the lower contact on said first resilient switch arm with the contact on said common resilient arm, and an electrical output signal on said second output line in response to closing of the contact on said second resilient switch arm with the upper contact on said first resilient switch arm and said contact on said common resilient switch arm, the volume of air in an air pulse generated when a single tire axle runs over the hose causing the bellows to extend a distance at least as great as said first Given distance but less than said second given distance and the volume of air in an air pulse generated when a dual tire axle runs over the hose causing the bellows to extend to at least said second given distance.

6. A system according to claim 5, including a magnetic responsive member secured to and movable with the free end of said bellows, said housing including permanent magnet means adjacent to the secured end of the bellows in a position to attract and hold the magnetic member and thereby the free end of the bellows in its retracted position close to the housing in the absence of any air pulses.

7. A system according to claim 5, including computer means connected to said first and second output signal lines for receiving signals thereon and classifying various combinations of such signals to provide a count of the number of two single tire axles and the number of one single tire axle followed by one or more dual tire axles whereby a classification of different types of vehicles can be effected.

8. A system according to claim 5, in which the longitudinal positioning of said second engaging means on said stem is adjustable whereby the second given distance through which said stem must travel to close said second resilient switch arm may be adjusted.

9. A system for counting single axles including, in combination:

a. hose means positioned on a roadway so that a tire running over the hose means generates an air pulse;

b. air chamber means connected to the hose and including an element movable in response to said air pulse;

c. a switch means including a resilient switch arm normally biased to close but engaged to be held open by said element in the absence of any air pulses, movement of said element in response to a pulse of air disengaging said switch arm to thereby permit it to close; and

d. counting means connected to said switch means for counting the number of times the switch arm is closed.

10. A method of classifying vehicles having a single tire axle and dual tire axles in accordance with their axle arrangements while the vehicles are passing along a roadway, comprising the steps of:

a. generating a first air pulse of given volume in response to passing of a single tire axle;

b. generating a second air pulse of volume greater than said given volume in response to passing of a dual tire axle;

c. mechanically converting said first air pulse into a first electrical signal;

d. mechanically converting said second air pulse into a second electrical signal;

e. detecting the first electrical signal; and

detecting the simultaneous presence of the first and second electrical signals; and

, f. counting and displaying combinations of said first and second electrical signals in a manner to provide totalized counts of two single tire axles and one single tire axle followed by one or more dual tire axles whereby vehicle types such as automobiles and various types of trucks can be distinguished and separately classified.