| 摘要 |
PROBLEM TO BE SOLVED: To reduce a frictional resistance force generated when the gripping member of a writing utensil is fitted by fitting a barrellike elastic body as the gripping member into a recessed part formed in the outer wall of the shaft barrel of the writing utensil and at the same time, forming a collar part with a deformed outer periphery at a position in the pen-point direction rather than the gripping member of the shaft barrel. SOLUTION: A recessed part 12 for fitting a barrellike elastic body 11 of a styrene elastomer is formed on the periphery of the outer wall of a shaft barrel 1, and a collar 13 is arranged adjacent to the recessed part 12 on the tip side of the shaft barrel 1. The collar part 13 has a hexagonal sectional shape and the angular part of the collar part 13 is radiused by chamfering. Thus when the barrellike elastic body 11 is fitted into the recessed part 12, the inner wall face of the barrellike elastic body 11 passes while coming into contact with the outer peripheral face of the collar part 13 and the barrellike elastic body 11 is fitted into the recessed part 12. It is possible to reduce the contact area of the collar part 13 with the inner wall face of the barrellike elastic body 11 or divide the magnitude of a press-fitting force into the high press-fitting part of a largest dia. part corresponding to the angular part of the hexagon and the low press-fitting part corresponding to the side part by making the sectional shape of the collar part 13 hexagonal. Thus the frictional resistance force can be reduced. |
