Patent ID: 6102601
Filing Date: 2000-08-15
Classification: B43K

Abstract:
An ink chamber pressure enhancing control device installed in the barrel of a writing instrument and controlled to enhance the pressure of an ink chamber defined in the barrel, the device comprising:a valve block mounted in the barrel of the writing instrument above the ink chamber, the valve block including a tubular top flange, a tubular bottom coupling portion fitted into the barrel of the writing instrument at the top thereof, and an axially extended through hole having a narrow valve port;a cap mounted in the tubular top flange of said valve block and movable up and down within said valve block above said valve port, said cap including an air inlet at the center of a top side wall thereof;a piston mounted inside the barrel ofthe writing instrument and inserted into the tubular bottom coupling portion of said valve and movable to close/open said valve port, said piston including a piston rod, which opens the air inlet at said cap when said valve port is closed by said piston and closes the air inlet at said cap when said piston opens said valve port, and a stop flange extending around a bottom periphery of the piston, which stop flange engages the bottom coupling portion of said valve block when said valve port is closed by said piston;a spring member mounted inside the barrel of the ink chamber and disposed between said ink chamber and the stop flange of said piston; andwherein said piston is forced upwards by said spring member to close said valve port, enabling an air chamber to be formed within said cap and said valve block above said valve port, and outside air passed through the air inlet at said cap and into the valve port may be forced into the ink chamber in the writing instrument when said cap is depressed.