| 摘要 |
PROBLEM TO BE SOLVED: To prevent the direct flow and back flow of ink, upward writing, and writing scratch after impact. SOLUTION: In a ball point pen, a valve chamber 12 in which a valve body is engaged loosely in the rear and a lead hole which makes the valve chamber 12 communicate with an ink receiving tube 16 are formed on the axis of a joint 7 opposite to the rear end of a tip 1, a tapered or spherical valve body receiving seat 13 is installed in the rear part of the valve chamber 12, a spring 3 is inserted into the inner hole of the tip 1, the rear end of the coil part of the spring 3 which is fitted in a step part formed at the rear end of the tip is formed unextractably. The ends of rod shaft parts 4, 5 push the back of a tip ball held freely rotatably in the tip end part, the tip ball is contacted with the inner fringe of the ball holding part of the tip to prevent the outflow of ink, the valve body is contacted with the valve body receiving seat of the rear part of the valve chamber, and the lead hole is closed to prevent the back flow of ink. |
