Control system for railway car retarders

Claim 1

A CAR RETARDER CONTROL SYSTEM COMPRISING IN COMBINATION, A STRETCH OF RAILWAY TRACK INCLUDING A CAR RETARDER OF THE TRACK BRAKE TYPE HAVING RESPECTIVE ENTERING AND LEAVING ENDS FOR A GIVEN DIRECTION OF TRAFFIC AND HAVING A MULTIPLE POSITION OPERATING MECHANISM FOR GOVERNING THE DEGREE OF RETARDATION, ENTERING DETECTOR MEANS AT THE ENTERING END OF THE CAR RETARDER AND LEAVING DETECTOR MEANS AT THE LEAVING END OF THE CAR RETARDER SUBJECT TO ACTUATION BY CARS RESPECTIVELY APPROACHING AND LEAVING SAID CAR RETARDER, RADAR SPEED RESPONSIVE MEANS HAVING A DIRECTIONAL ANTENNA LOCATED BETWEEN THE TRACK RAILS NEAR ONE END OF THE CAR RETARDER AND DIRECTED TOWARD THE OPPOSITE END OF THE CAR RETARDER, SAID SPEED RESPONSIVE MEANS HAVING SPEED RELAYS SELECTIVELY OPERABLE IN RESPONSE TO DIFFERENT TRAVELLING SPEEDS OF A CAR WITHIN THE RANGE OF SAID RADAR SPEED RESPONSIVE MEANS, AND CIRCUIT MEANS FOR GOVERNING THE DEGREE OF OPERATION OF SAID MULTIPLE POSITION OPERATING MECHANISM PROVIDED THAT A CAR IS WITHIN THE LIMITS OF SAID ENTERING DETECTOR MEANS AND SAID LEAVING DETECTOR MEANS IN ACCORDANCE WITH THE SPEED OF THE CAR AS DETERMINED BY SAID SPEED RELAYS.