Patent ID: 6769763
Filing Date: 2004-08-03
Classification: B41J

Abstract:
A cylinder pump unit comprising:a cylinder pump including a reciprocally movable piston and a cylinder main body having a first cylinder chamber partitioned at one side of said piston and introduced with air and a second cylinder chamber partitioned at the other side of said piston and introduced with ink, wherein said second cylinder chamber has an input port for sucking ink and an output port for discharging ink; a piston driving means for reciprocally moving said piston of said cylinder pump, wherein a piston shaft of said piston is extended to outside said cylinder main body through said second cylinder chamber and connected to said piston driving means; and a port switching means for performing switching of opening and closing of said input port and said output port in association with movement of said piston so that when said second cylinder chamber is pressure reduced by movement of said piston, said output port is closed and said input port is opened, and when said second cylinder chamber is pressurized by movement of said piston, said input port is closed and said output port is opened.