| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a pressurizing-type writing utensil of such a design that a barrel diameter can be reduced and the pressurizing effect can be diminished following the discharging of a writing fluid. <P>SOLUTION: This pressurizing-type writing utensil is configured as follows: an annular recess 41 is formed on the outer peripheral surface of a piston member 40 inside a barrel 10, and an annular airtight member 42 for the piston member 40 is arranged inside the annular recess 41 so as to allow the piston member 40 to move in the axial direction. Further, a first vent channel 40b1, which makes the annular recess 41 communicate with the outside of the barrel 10, is arranged to the centrifugal side rather than to an airtight contact part 41a which comes into contact with the annular airtight member 42 for the piston member 40 at the inner rear end of the annular recess 41. Also, a second vent channel 40b2 which makes the annular recess 41 communicate with a pressurizing space part S1, is arranged to the centripetal side rather than to the airtight contact part 41a. Besides, the pressurizing space part S1 of the refill 20 backward side can be pressurized and released by the reciprocation of the piston member 40 and the movement of the airtight member 42 inside the annular recess 41. <P>COPYRIGHT: (C)2008,JPO&INPIT |
