Valve for ink-jet pen

摘要

An ink-jet pen (22) for storing at below-ambient pressure has an orifice (54) formed therein for providing air bubbles to prevent the back pressure from rising above a level that would cause malfunction of the pen (22). The amount of air drawn into the reservoir (24) is restricted by the reservoir ink (31) that covers the orifice (54) whenever the pen (22) is in an upright position. The valve (20) operates to occlude the orifice (54) whenever the pen (22) is moved into a position, such as inverted, where the reservoir ink no longer covers the orifice (54). The occlusion of the orifice prevents the unrestricted flow of ambient air into the reservoir (24) that would otherwise eliminate the required back pressure in the reservoir (24). The valve includes a sealing liquid (68) selected so that the liquid occludes a passage (60) between the orifice and ambient air without flowing through that passage (60).