| 摘要 |
A widely used marking pen for dispensing viscous substances comprises: a casing with a dispensing tip, a ball being spring biased to selectively reveal a dispensing tip orifice that permits pressurized flow therefrom, a flexible bulb member with orifice therein permitting repeatable finger actuated pressurization of the casing interior, and a valve positioned between the liquid/semi-paste substance and the flexible bulb member. The valve maintains, on the downstream side, air under pressure to ensure good flow of the substance. The invention herein offers improvements over such valves by reducing the number of parts that are commonly used, thereby reducing complexity of its assembly, while offering improved results in terms of the longevity in maintaining pressure within the casing. The valve may comprise a stand-alone diaphragm with a specially contoured and resilient diaphragm wall having a self-sealing slit therein that independently permits pressurized fluid flow in only the desired direction. |
