Proximity detector

• US 3,324,647 A
• Filed: 08/11/1964
• Issued: 06/13/1967
• Est. Priority Date: 08/11/1964
• Status: Expired due to Term

• Current Assignee: Leo Jedynak
• Original Assignee: Leo Jedynak
• Inventors: LEO JEDYNAK
• Application Number:
  US04/388,856
• Time in Patent Office: 1,036 Days
• US Class Current: 368/6
• CPC Class Codes: G07F 17/246 provided with vehicle proximity-detectors detecting hidden masses, e.g. metal detectors, G01V, e.g. G01V3/00; proximity switches per se H03K17/00; traffic control systems G08G1/00
• CPC Class Codes: Y10S 56/09 Detachable implement

Claims

11. IN PARKING METER APPARATUS COMPRISING A CLOCK MECHANISM, AN INDICATOR MECHANISM, AND, MEANS COUPLING SAID CLOCK MECHANISM TO SAID INDICATOR MECHANISM TO ADVANCE SAID INDICATOR MECHANISM TO INDICATE ELAPSED TIME, VEHICLE DETECTOR APPARATUS COMPRISING A VEHICLE SENSING ANTENNA ELEMENT MOUNTED ADJACENT SAID PARKING METER INDICATOR AND ADAPTED TO COOPERATE WITH A VEHICLE TO FORM A VARIABLE CAPACITANCE ELEMENT, A CAPACITIVE BRIDGE CIRCUIT INCLUDING FOUR LEGS, EACH HAVING A CAPACITOR ELEMENT, SAID ANTENNA ELEMENT BEING CONNECTED TO SAID BRIDGE CIRCUIT, AN OSCILLATOR CIRCUIT INCLUDING AN INDUCTOR CONNECTED ACROSS SAID BRIDGE CIRCUIT SO THAT SAID INDUCTOR AND SAID BRIDGE CIRCUIT FORM THE OSCILLATOR TANK CIRCUIT, MEANS PROVIDING AN OSCILLATOR OUTPUT SIGNAL, MEANS TO PROVIDE A BRIDGE CIRCUIT OUTPUT SIGNAL THAT VARIES AS A FUNCTION OF SAID VARIABLE CAPACITANCE ELEMENT,