Ink pressurizing and relieving system for a recorder

Claim 1

AN INK WRITING SYSTEM FOR AN INSTRUMENT WHICH WRITES ON A RECORD MEDIUM, COMPRISING IN COMBINATION, A RESERVOIR HAVING A GIVEN VOLUME TO CONTAIN SAID INK, A PEN FOR WRITING ON SAID RECORD MEDIUM, AN INK SUPPLY CIRCUIT CONNECTED TO SAID RESERVOIR AND TO SAID PEN TO SUPPLY INK TO SAID PEN, MEANS FOR DRIVING SAID RECORD MEDIUM PAST SAID PEN INCLUDING A DRIVE MOTOR, PRESSURE MEANS FOR APPLYING PRESSURE TO THE OUTSIDE OF SAID RESERVOIR THEREBY TO TEND TO REDUCE ITS GIVEN VOLUME AND INCREASE THE PRESSURE ON THE INK THEREIN, CIRCUIT MEANS CONNECTED TO SAID DRIVE MOTOR AND TO SAID PRESSURE MEANS TO ENERGIZE SAME, AND A TIME DELAY VALVE LOCATED IN SAID INK SUPPLY CIRCUIT BETWEEN SAID RESERVOIR AND SAID PEN TO RELIEVE THE PRESSURE IN SAID PEN BY PERMITTING A SMALL QUANTITY OF INK TO RUN BACK TOWARD SAID RESERVOIR YET TO MAINTAIN SAID INK SUPPLY CIRCUIT VIRTUALLY FULL OF INK UPON TERMINATION OF THE ENERGIZATION OF SAID PRESSURE MEANS.