Ink pump for writing implement has air chamber with piston biased by spring to pressurize ink fed through tickler

摘要

The ink pump for a writing implement has an air chamber (1) to receive a piston (2) with a weak bias spring (3) which also engages the pen end cap. A tickler (4) at the opposite end of the chamber and incorporated into the ink tube (6) connects to the air space above the ink level. The piston compresses the air in the chamber to press against the tickler which pressurizes the ink.