| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a writing utensil to which a first core (e.g., core of oil-based ink) and a second core (e.g., core of gel ink) having larger inner and outer diameters than the first core can be fitted selectively, and which is so designed as to surely prevent the slip-off of the first and second cores even if the cores are of types not being actuated directly by a spiral spring but projecting and retracting while revolving. <P>SOLUTION: In the writing utensil 1, a core holding part 12 which can selectively hold the first core A and the second core B has a bottom 12c with which the rear end of the first core A comes into contact, a core holding pin 30 which is erected from the bottom 12c and pressed in from a rear end opening of the first core A, a protruding portion 31 which is positioned in front of the bottom 12c and protrudes from the inner wall surface of the core holding part 12 so as to be pressed on the outer peripheral surface of the second core B, and a first step 32 which is formed on the inner wall surface of the core holding part 12 at the back of the protruding portion 31 and with which the rear end of the second core B comes into contact. <P>COPYRIGHT: (C)2011,JPO&INPIT |
