Hot-box detector gating circuit

Claim 1

A HOT-BOX DETECTOR CIRCUIT, COMPRISING A HEAT DETECTOR, INCLUDING HEAT-RESPONSIVE MEANS PRODUCING AN ELECTRICAL SIGNAL IN RESPONSE TO INCIDENT RADIANT ENERGY AND ADAPTED TO BE MOUNTED ON ONE SIDE OF A LENGTH OF RAILROAD TRACK, OPTICAL MEANS IMAGINING SAID HEAT-RESPONSIVE MEANS ON PASSING RAILROAD JOURNAL BOXES WHEN SO MOUNTED, SIGNAL-INDICATING MEANS COUPLED TO THE OUTPUT OF SAID DETECTOR, AND INCLUDING GATING MEANS DETERMINING THE PASSAGE OR NOT OF A SIGNAL FROM SAID DETECTOR TO SAID SIGNAL-INDICATING MEANS, FIRST WHEEL-RESPONSIVE MEANS MOUNTED IN SAID SECTION OF TRACK AND ADAPTED TO PRODUCE AN ELECTRICAL SIGNAL IN RESPONSE TO COINCIDENT DETECTION OF WHEELS SEPARATED BY A GIVEN CAR-TRUCK WHEEL BASE, SAID FIRST WHEEL-RESPONSIVE MEANS BEING LOCATED ALONG THE TRACK AT A LOCATION PRIOR TO DETECTION BY SAID HEAT DETECTOR OF HEAT FROM EITHER OF THE JOURNALS OF THE PARTICULAR CAR TRUCK, SECOND WHEELRESPONSIVE MEANS MOUNTED IN SAID SECTION OF TRACK AND ADAPTED TO PRODUCE AN ELECTRICAL SIGNAL IN RESPONSE TO COINCIDENT DETECTION OF WHEELS SEPARATED BY SAID GIVEN CAR-TRUCK WHEEL BASE AND LOCATED ALONG THE TRACK AT A LOCATION BEYOND THE LOCATION AT WHICH SAID DETECTOR OBSERVES JOURNAL HEAT FROM SAID CAR TRUCK, MEANS OPERATIVE BY SAID FIRST WHEEL-RESPONSIVE MEANS FOR OPENING SAID GATING CIRCUIT, AND OPERATIVE BY SAID SECOND WHEEL-RESPONSIVE MEANS FOR CLOSING SAID GATING CIRCUIT.