Railway car retarder control system

Claim 1

APPARATUS FOR CONTROLLING THE SPEED OF A FREE ROLLING CAR IN A STRETCH OF RAILWAY TRACK EXTENDING FROM A HUMP TO A DESIRED DESTINATION IN A CLASSIFICATION TRACK COMPRISING, A CAR RETARDER AT AN INTERMEDIATE POINT IN SAID STRETCH OF TRACK, SAID CAR RETARDER BEING OPERABLE SELECTIVELY TO ANY ONE OF A PLURALITY OF BRAKING POSITIONS AND TO NONBRAKING POSITION, VELOCITY INDICATING MEANS FOR GENERATING A SIGNAL CONTINUOUSLY RELATED TO THE VELOCITY OF THE CAR AS IT PASSES THROUGH THE RETARDER, TRACK CHARACTERISTICS DETERMINING MEANS FOR SELECTING A SIGNAL CORRESPONDING TO THE TRACK CHARACTERISTICS FROM SAID RETARDER TO SAID DESTINATION, COMPUTING MEANS INCLUDING SAID TRACK CHARACTERISTIC DETERMINING MEANS AND AT LEAST ONE PARAMETER RELATING TO THE FREE ROLLING BEHAVIOR OF THE CAR FOR COMPUTING AN ANALOG OF THE EXIT SPEED AT WHICH THE CAR SHOULD LEAVE THE RETARDER TO ARRIVE AT ITS DESTINATION AT A DESIRED COUPLING SPEED, A PLURALITY OF MULTIPLE CONDITION DEVICES ACTUATED JOINTLY TO ONE CONDITION IN RESPONSE TO THE GENERATION OF A RELATIVELY HIGH SIGNAL BY SAID VELOCITY INDICATION MEANS AND ACTUATED TO ANOTHER CONDITION UPON REDUCTION OF THE SPEED OF THE CAR TO DIFFERENT SPEEDS RESPECTIVELY RELATED TO SAID ANALOG OF THE EXIT SPEED, AND MEANS FOR CONTROLLING SAID RETARDER TO ACTUATE IT TO A BRAKING POSITION SELECTED BY SAID DEVICES TO PROVIDE AN EXTENT OF BRAKING DETERMINED BY THE NUMBER OF SAID DEVICES THAT IS IN SAID ONE CONDITION, SAID CAR RETARDER BEING ACTUATED TO A NONBRAKING POSITION WHEN SAID DEVICES ARE ALL IN SAID ANOTHER CONDITION.