Mass-flow rate control

Claim 1

A CONTROL SYSTEM FOR CONTROLLING THE MASS-FLOW RATE OF MATERIAL FROM A CONTAINER WHICH IS SUBJECT TO BEING EMPTIED BY THE DISCHARGE OF SAID MATERIAL DURING ONE PORTION OF A CYCLE AND REFILLED DURING ANOTHER PORTION COMPRISING A FIRST MEANS FOR PRODUCING A FIRST SIGNAL REPRESENTATIVE OF A MEASURED VALUE OF THE MASS OF SAID MATERIAL IN SAID CONTAINER, A SECOND MEANS FOR PRODUCING A SECOND SIGNAL CONTINUOUSLY CHANGING DURING SAID DISCHARGE PORTION OF SAID CYCLE, SAID SECOND SIGNAL BEING REPRESENTATIVE OF A CONTINUOUSLY DECREASING SET POINT VALUE FOR THE MASS IN SAID CONTAINER, A THIRD MEANS RESPONSIVE TO THE DIFFERENCE BETWEEN SAID FIRST AND SAID SECOND SIGNAL FOR CONTROLLING THE MASS-FLOW RATE OF THE MATERIAL BEING DISCHARGED FROM SAID CONTAINER SO AS TO TEND TO MAINTAIN SAID DIFFERENCE AT ZERO, A FOURTH MEANS OPERABLE WHEN SAID MASS IN SAID CONTAINER REACHES A PREDETERMINED MINIMUM VALUE TO START SAID REFILLING PORTION OF SAID CYCLE TO REFILL SAID CONTAINER UNTIL IT CONTAINS A PREDETERMINED MAXIMUM MASS, A FIFTH MEANS OPERABLE DURING SAID REFILLING PORTION OF SAID CYCLE FOR MAINTAINING SAID THIRD MEANS UNRESPONSIVE TO THE SAID DIFFERENCE SO THAT THE MASS-FLOW RATE OF SAID MATERIAL FROM SAID CONTAINER IS MAINTAINED AT A SUBSTANTIALLY CONSTANT VALUE DURING SAID REFILLING PORTION OF SAID CYCLE, A SIXTH MEANS OPERABLE TO MAINTAIN SAID SECOND SIGNAL AT A VALUE CORRESPONDING WITH SAID FIRST SIGNAL WHILE SAID CONTAINER IS BEING REFILLED, A SEVENTH MEANS OPERABLE AFTER COMPLETION OF SAID REFILLING PORTION OF SAID CYCLE TO CAUSE RESUMPTION OF THE CONTROL OF SAID DISCHARGE BY SAID THIRD MEANS, AND AN EIGHT MEANS OPERABLE A PREDETERMINED TIME PERIOD AFTER THE BEGINNING OF SAID REFILLING PORTION OF SAID CYCLE TO CAUSE RESUMPTION OF THE CONTROL OF SAID DISCHARGE IF SAID REFILLING PORTION HAS NOT ALREADY BEEN COMPLETED.

Claim 3

A METHOD FOR CONTROLLING THE MASS-FLOW RATE OF MATERIAL FROM A CONTAINER WHICH IS SUBJECT TO BEING ALTERNATELY EMPTIED AND REFILLED DURING ITS CYCLES OF OPERATION SO THAT THE RATE OF DISCHARGE OF MATERIAL IS CONTROLLED DURING SAID EMPTYING PORTION OF THE CYCLES AND IS MAINTAINED AT A PREDETERMINED VALUE DURING THE REFILLING PORTION COMPRISING THE STEPS OF PRODUCING A SIGNAL INDICATIVE OF THE MEASURED VALUE OF THE MASS OF MATERIAL IN SAID CONTAINER, PRODUCING DURING SAID EMPTYING PORTION OF EACH OF SAID CYCLES A CHANGING SIGNAL INDICATIVE OF THE SET POINT FOR SAID MEASURED VALUE REQUIRED TO MAINTAIN A DESIRED PROGRAM FOR THE MASS-FLOW RATE OF SAID MATERIAL FROM SAID CONTAINER, CONTROLLING THE DISCHARGE RATE OF SAID MATERIAL FROM SAID CONTAINER DURING SAID EMPTYING PORTION OF SAID CYCLES TO TEND TO MINIMIZE THE DEVIATION OF SAID MEASURED VALUE SIGNAL FROM SAID SET POINT SIGNAL, ESTABLISHING THE DISCHARGE DURING SAID REFILLING PORTION OF SAID CYCLE AT A RATE WHICH WILL MAINTAIN THE MASSFLOW RATE FROM SAID CONTAINER SUBSTANTIALLY AT THE VALUE EXISTING AT THE END OF SAID EMPTYING PORTION OF SAID CYCLE, MAINTAINING THE VALUE OF SAID SET POINT SIGNAL AT THE EXISTING MEASURED VALUE SIGNAL DURING SAID REFILLING PORTION OF EACH OF SAID CYCLES, AND REESTABLISHING CONTROL OF THE DISCHARGE RATE AFTER A PREDETERMINED PERIOD OF TIME IF SAID CONTAINER IS NOT REFILLED DURING THAT PERIOD TO BEGIN THE EMPTYING PORTION OF NEXT CYCLE WITH SAID SET POINT SIGNAL EQUAL TO SAID MEASURED VALUE SIGNAL.

Claim 4

A METHOD FOR CONTROLLING THE MASS-FLOW RATE OF MATERIAL FROM A CONTAINER WHICH IS SUBJECT TO BEING ALTERNATELY EMPTIED AND REFILLED DURING ITS CYCLES OF OPERATION SO THAT THE RATE OF DISCHARGE OF MATERIAL IS CONTROLLED DURING SAID EMPTYING PORTION OF THE CYCLES AND IS MAINTAINED AT A PREDETERMINED VALUE DURING THE REFILLING PORTION COMPRISING THE STEPS OF PRODUCING A SIGNAL INDICATIVE OF THE MEASURED VALUE OF THE MASS OF MATERIAL IN SAID CONTAINER, PRODUCING DURING SAID EMPTYING PORTION OF EACH OF SAID CYCLES A CHANGING SIGNAL INDICATIVE OF THE SET POINT FOR SAID MEASURED VALUE REQUIRED TO MAINTAIN A DESIRED PROGRAM FOR THE MASS-FLOW RATE OF SAID MATERIAL FROM SAID CONTAINER, CONTROLLING THE DISCHARGE RATE OF SAID MATERIAL FROM SAID CONTAINER DURING SAID EMPTYING PORTION OF SAID CYCLES TO TEND TO MINIMIZE THE DEVIATION OF SAID MEASURED VALUE SIGNAL FROM SAID SET POINT SIGNAL, ESTABLISHING THE DISCHARGE DURING SAID REFILLING PORTION OF SAID CYCLE AT A RATE WHICH WILL MAINTAIN THE MASSFLOW RATE FROM SAID CONTAINER SUBSTANTIALLY AT THE VALUE EXISTING AT THE END OF SAID EMPTYING PORTION OF SAID CYCLE, MAINTAINING THE VALUE OF SAID SET POINT SIGNAL AT THE EXISTING MEASURED VALUE SIGNAL DURING SAID REFILLING PORTION OF EACH OF SAID CYCLES, AND REESTABLISHING CONTROL OF THE DISCHARGE RATE AFTER A PREDETERMINED PERIOD OF TIME IF SAID CONTAINER IS NOT REFILLED DURING THAT PERIOD TO BEGIN THE EMPTYING PORTION OF NEXT CYCLE WITH SAID SET POINT SIGNAL EQUAL TO SAID MEASURED VALUE SIGNAL.