| 摘要 |
PURPOSE:To prevent ink from flowing backwards and forwards under the state that a pen is postured upwards and downwards by method wherein a valve chamber, which communicates with the rear end of a tip, in the rear of which a ball valve is loosely fitted and at the rear end of which a ball bearing seat is provided, is provided at the axis center line of a joint under the condition that a piece, at the rear end of which ink guiding grooves are provided, is fixed between the front of the ball valve and the rear end of the tip. CONSTITUTION:Under the state that a tip 5 is postured downwards, a ball valve 15 opens a guide hole 20 by abutting against the rear end of a piece 16 so as to run the ink, which reaches a value chamber 13 from an ink storing tube 4 through the guide hole 20, is guided through the ink guiding grooves 16a and the hole 16b of the piece 16 to the rear end of a tip ball 5a. In this state, the tip ball 5a is brought into close contact with the inner edge of a tip holding part by being pressed with a bar shaft part 18, resulting in preventing ink from flowing forwards. Then, through the minute retracting of the tip ball 5a by the pressure of a pen, ink becomes possible to flow out. Further, under the state that the tip 5 is postured upwards, the ball valve 15 comes into close contact with the ball bearing seat 14 of the valve chamber 13 so as to tightly seal the guide hole 20, resulting in preventing the ink from flowing backwards, even under the state that no ink is present just below the tip ball 5a due to the writing in upward posture. |
