REGULATOR FOR INK JET PEN

摘要

PURPOSE: To prevent the leakage of ink from a printing head by always keeping the negative pressure in an ink sump constant. CONSTITUTION: The regulator 20 provided inside the venting hole 32 of an ink sump 22 is equipped with a valve seat 36 having a port 42 and the valve element 38 mounted adjacent to the seat 36 to open and close the port 42. The valve seat 36 and the valve element 38 are attracted by magnetic force and the valve element 38 moves away from the seat against magnetic force when the negative pressure in the ink sup 22 becomes constant pressure or more to enable the passing of the open air from the port 42 and approaches the seat by magnetic force when the negative pressure returns to the constant pressure or less.