PRESSURE SENSITIVE ACCUMULATOR FOR INK JET PEN

摘要

PURPOSE: To provide an accumulator prescribing a change in the back pressure of the ink sump of an ink jet pen to prevent the leakage of ink from the printing head of the pen and enabling the printing head to perfectly empty the ink sump 24. CONSTITUTION: An accumulator includes a spring 44 having an expansible bag 42 attached thereto. The spring 44 and the bag 42 are positioned within the ink sump 24 of an ink jet pen 22 and the inside of the bag allows the air outside the ink sump 24 to communicate with a fluid. The spring 44 and the bag 42 are constituted so that the bag reacts with a change in the fluid pressure in the ink sump 24 and a change in the peripheral pressure outside the ink sump to expand and contract. The spring is bent by the expansion of the bag and the bag is pressed to a contraction position or the min. container position by the bent spring.