Writing instrument

A writing instrument, comprising:

• a barrel being an elongated hollow barrel structure that has an upper portion forming an upper barrel chamber of a larger external diameter, an intermediate section forming a lower barrel chamber, and a lower section forming a barrel channel of an even smaller internal diameter;
• an ink reservoir having a closed upper end and an open lower end, a lower section thereof having an external diameter corresponding to the internal diameter of said upper barrel chamber and being adapted to receive ink;
• a liquid outlet ring that is an annular ring having an upper end provided with a plurality of rib portions that extend towards a central portion, said central portion forming a ring hole, a lower end of said liquid outlet ring having an outer wall projecting outwardly to form a ring projection;
• a control valve including a valve seat, a valve cap, and a spring, said valve seat being centrally provided with a through seat hole that runs longitudinally through to a seat clearance of a smaller size at a lower end, an upper portion of said valve seat being centrally provided with a seat rod that projects therefrom, a seat wing being provided near a lower portion in a projecting manner, a lower section of said valve seat forming a seat post having said seat clearance;
• said valve cap having a lower portion forming a cap hole and an upper portion provided with a cap post of a smaller external diameter and projecting therefrom, said cap post having a top end corresponding to said ring hole and a cap clearance corresponding to said seat rod, an intermediate section of said cap post having an enlarged periphery forming a cap flange that has a plurality of cap ribs connected to an end portion of said cap post to confine a plurality of spaces communicated with said cap hole;
• said spring being an elongated coil that has an internal diameter of a size larger than said valve seat but smaller than the external diameter of said seat wing;
• an ink absorbing sponge adapted to absorb ink;
• a core seat having an upper section forming a hollow sponge chamber communicated with a core tube of a smaller size at a lower section thereof;
• a nib having an intermediate section the external diameter of which corresponds to said core tube;
• and
• a cap having an interior space corresponding to the size and shape of the lower section of said barrel, and a cap stepped portion;
• whereby said nib is inserted into said core tube and said ink absorbing sponge is disposed in said sponge chamber, said core chamber being insertably disposed in said lower section of said barrel such that said core tube and said nib are exposed on the outside, said valve cap being insertably fitted at a top end of said valve seat, said spring being fitted over said valve seat and insertably disposed in said barrel, said liquid outlet ring being fitted to a lower end of said ink reservoir and insertably disposed in said barrel, said cap, after being fitted in position, urging upwardly against said core tube to cause said valve seat and said valve cap to urge upwardly so that said valve cap conceals said ring hole to block outflow of ink, said cap being removed to allow said spring to rebound and said cap post to disengage from said ring hole so that ink can flow from said ring hole through said cap hole, said seat hole, and said seat clearance to said ink absorbing sponge.