Control system for a press

Claim 1

IN A PRESS OF THE TYPE HAVING PERFORATE WALL MEANS HAVING AN INLET PASSAGE AND DEFINING A COMPRESSION CHAMBER WHICH LEADS TO A DISCHARGE OPENING, MEANS IN SAID CHAMBER FOR ADVANCING MATERIAL FROM SAID INLET PASSAGE UNDER PRESSURE TOWARD SAID OPENING, SAID MEANS DEVELOPING A REACTION PRESSURE WHICH VARIES IN ACCORDANCE WITH THE DENSITY OF THE ADVANCING MATERIAL, AND A CHOKE MOVABLE IN SAID DISCHARGE OPENING FOR VARYING THE SIZE OF THE OPENING; A CONTROL SYSTEM FOR MAINTAINING A CONSTANT DENSITY OF THE EXPRESSED MATERIAL COMPRISING FIRST DRIVE MEANS FOR ACTUATING SAID MATERIAL ADVANCING MEANS, SECOND DRIVE MEANS FOR MOVING THE CHOKE IN SAID OPENING, AND MEANS RESPONSIVE TO CHANGES IN SAID REACTION PRESSURE FOR ACTUATING SAID FIRST AND SECOND DRIVE MEANS AND THEREBY TO VARY THE SPEED AT WHICH SAID MATERIAL ADVANCING MEANS MOVES THE MATERIAL TOWARD SAID OPENING IN DIRECT RELATION TO THE CHANGE IN SAID REACTION PRESSURE AND ALSO TO CHANGE THE SIZE OF SAID OPENING IN DIRECT RELATION TO THE CHANGE IN SAID REACTION PRESSURE.