Expandable writing instrument

摘要

An expandable pen (50) has a pen barrel with an expanding middle section. The pen barrel holds a retractable ball point pen refill cartridge (65). When the pen is expanded, the writing tip (60) of the refill is extended from a retracted position inside the pen barrel to a writing position, while the barrel becomes full length for comfort when writing. The pen may be collapsed for storage, which simultaneously retracts the writing tip (60) inside the pen barrel.