Ball point pen

摘要

The pen, having a tip (105) with a ball (105a) and a coupling (103) to connect the tip to the ink reservoir (104), is made with a valve chamber (105) inside the coupling. The valve chamber is formed by an insert (113) with a conical or spherical seat (114) designed to interact with a valve ball (120). On the other side of the ball the insert has a series of ribs (119) which allow the ink from the reservoir to flow past the ball when the pen is held in its writing position. When the pen is inverted the ball fits against the seat and seals the ink reservoir.