Collector type writing instrument

摘要

In a free-ink type collector writing instrument, the collector is formed with a partitioning portion for substantially shutting off the ink tank from the outside air, auxiliary retaining grooves are formed on the ink tank side with respect to the air/liquid exchanger of the partitioning portion while main retaining grooves are formed on the front side with respect to the air/liquid exchanger of the partitioning portion, a wide groove formed across the auxiliary retaining grooves for connecting the air/liquid exchanger and the ink tank is formed with a narrow groove extending from the air/liquid exchanger side to the ink tank side and lateral grooves capable of leading ink into the auxiliary retaining grooves. It is further effective if the capacity "ie' of the auxiliary retaining grooves and the capacity "is' of the main retaining grooves are designed so as to satisfy a relation "is>ie>0.05.is' or if effective partitioning portion grooves are formed.