Materials sorting apparatus

Claim 1

IN A SYSTEM FOR SORTING MATERIAL FRAGMENTS ACCORDING TO THE INTENSITY OF AN ENERGY FIELD DETECTABLE REMOTELY FROM SAID FRAGMENT, SAID INTENSITY BEING SUBSTANTIALLY RELATED TO THE VOLUME OF A CONSTITUENT DISPERSED IN SAID FRAGMENT, SAID SYSTEM COMPRISING A SECTION CONSTITUTING A VERTICALLY EXTENDING SORTING ZONE, FRAGMENT HANDLING MEANS FOR INTRODUCING FRAGMENTS INTO THE UPPER PART OF SAID ZONE FOR SUBSTANTIALLY FREE FALL THERETHROUGH, A LIGHT SOURCE AND A LIGHT DETECTOR SPACED APART ACROSS SAID ZONE AND EFFECTIVE TO DERIVE A FIRST SIGNAL PROPORTIONAL TO THE SIZE OF EACH SAID FRAGMENT, A DETECTOR RESPONSIVE TO THE INTENSITY OF SAID ENERGY FIELD POSITIONED ADJACENT SAID ZONE AND EFFECTIVE TO DERIVE A SECOND SIGNAL PROPORTIONAL TO THE DETECTED INTENSITY, MEANS TO COMPARE SAID FIRST AND SECOND SIGNALS AND TO DERIVE A THIRD SIGNAL HAVING A MAGNITUDE RELATED TO THE DIFFERENCE OF SAID FIRST AND SECOND SIGNALS, MEANS RESPONSIVE TO THE ENTRY OF SAID FRAGMENT INTO SAID ZONE TO PRODUCE A FOURTH SIGNAL DELAYED WITH RESPECT TO TIME OF SAID ENTRY, A FLUID NOZZLE HAVING A CONTROL FOR FLUID FLOW THERETHROUGH, SAID CONTROL BEING RESPONSIVE TO SAID FOURTH SIGNAL TO INITIATE A FLUID STREAM FOR IMPINGEMENT UPON SAID FRAGMENT FOR A PREDETERMINED PERIOD AT A PREDETERMINED TIME AFTER MOVEMENT OF SAID FRAGMENT INTO SAID ZONE TO DEFECT SAID FRAGMENT FROM ITS PATH, AND MEANS RESPONSIVE TO SAID THIRD SIGNAL TO INHIBIT SAID CONTROL AND PREVENT FLUID FLOW IN SAID NOZZLE WHEN SAID THIRD SIGNAL EXCEEDS A PREDETERMINED VALUE.