| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent the flowing of ink outside through the rear end opening of an ink housing tube in a pen refill at the back-flowing of ink developing at the writing with the writing end part of the ball-point pen fronting upwards, realize the prevention of the falling off of the pen refill and, at the same time, the easy exchange of outside air for the air in the ink housing tube so as to execute a smooth writing by causing no running short of ink. <P>SOLUTION: The front end mounting part 12 in an operating member 7 is inserted and fitted in the rear end opening 5a of the ink housing tube 5 in the pen refill 3. A narrow and deep air circulating groove 15, the width L of which is so small as to check the ink 4 filled in the ink housing tube 5 from leaking therethrough and the bottom of the groove of which is located near the central axis a of the front end mounting part 12, is provided along its axis line direction on the outer peripheral surface of the front end mounting part 12 in the operating member 7 and, at the same time, the exchange of outside air for the air in the ink housing tube 5 is executed through the air circulating groove 15. <P>COPYRIGHT: (C)2009,JPO&INPIT |
