| 摘要 |
PURPOSE: To improve the durability of a mold by a method wherein an air vent hole is formed in one region, which is one of regions produced by dividing with a straight line passing through the center of the top part while projecting stripes in the other region in a cap, at the bottom of which the projecting stripes for positioning the cap at its installation onto a writing utensil main body are formed and at the top of which the suffocation-preventing air vent hole is formed. CONSTITUTION: A synthetic resin cap A consists of a writing utensil main body housing part having a top part 1 and a straight part 2 and a clipping part 6 having a base part 4 and a pinching part 5. Further, on the top part 1, an air vent hole 7 is formed at the position shifted from the tip part (a central portion) of the top part 1 to the clipping part 6 side. The size and shape of the air vent hole 7 may well be enough large for keeping respiration even when the throat of a child or the like is wrongly stuck with the cap. The preferable shape of the air vent hole to be formed is a fan form. On the other hand, at the bottom of the inner hole 9 of the writing utensil main body housing part 3, a plurality of projecting stripes 11-abutting against a writing utensil main body are formed at the positions opposing to the air vent hole 7 with respect to the center line passing through the center of the top part 1. |
