Detector of stopped or passing vehicles

Claim 1

APPARATUS FOR DETECTING A VEHICLE STOPPED IN A GIVEN LOCATION, AND DISTINGUISHING IT FROM A PASSING VEHICLE, COMPRISING: (A) FIRST CONTROL MECHANISM ON SAID VEHICLE; (B) SECOND CONTROL MECHANISM LOCATED ALONG THE WAYSIDE OF THE PATH OF MOVEMENT OF THE VEHICLE; (C) ONE OF SAID CONTROL MECHANISMS COMPRISING SOURCE MEANS FOR PRODUCING A BEAM OF RADIOACTIVE RAYS DIRECTED TRANSVERSELY TO SAID PATH; AND (D) THE OTHER OF SAID CONTROL MECHANISMS COMPRISING SOURCE A DETECTOR FOR SAID BEAM OF RAYS AND MOUNTED IN A POSITION INTERSECTED BY SAID BEAM OF RAYS AS THE VEHICLE MOVES ALONG SAID PATH; WHEREIN THE IMPROVEMENT COMPRISES: (E) ENERGIZABLE TIME DELAY MEANS IN SAID OTHER CONTROL MECHANISM COMPRISING: (1) A CONTROL ELEMENT; AND (2) MEANS EFFECTIVE AFTER A PREDETERMINED TIME INTERVAL OF THE ORDER OF A FEW SECONDS FOLLOWING ENERGIZATION OF THE TIME DELAY MEANS TO SHIFT THE CONTROL ELEMENT FROM AN INACTIVE CONDITION TO AN ACTIVE CONDITION; (F) ELECTRIC CIRCUIT MEANS ENERGIZED IN RESPONSE TO DETECTION OF A BEAM OF RAYS BY THE DETECTOR TO INITIATE ENERGIZATION OF THE TIME DELAY MEANS; AND (G) HOLDING MEANS RESPONSIVE TO SHIFTING OF THE CONTROL ELEMENT TO ITS ACTIVE CONDITION TO CONTINUE THE ENERGIZATION OF THE ELECTRIC CIRCUIT MEANS WITHOUT REGARD TO THE CONTINUED DETECTION OF THE BEAM BY THE DETECTOR, (H) WHEREBY THE CONTROL ELEMENT IS SHIFTED TO ITS ACTIVE CONDITION ONLY WHEN THE VEHICLE IS STOPPED WITH SAID SOURCE MEANS ALIGNED WITH THE DETECTOR, SO THAT THE BEAM FROM THE SOURCE MEANS IMPINGES ON THE DETECTOR FOR A TIME GREATER THAN SAID PREDETERMINED INTERVAL.