| 摘要 |
PROBLEM TO BE SOLVED: To provide a safe cap by providing bulged parts on outer peripheries of the cap substantially both axial ends, forming recesses of spaces between the bulged parts, and forming a vent hole for communicating an insertion port for clamping a front end with a rear end. SOLUTION: Bulged parts 2, 3 of overall circumferences are provided on outer peripheries of a cap 1 substantially both axial ends, and a recess 1b of a space is formed between the parts 2 and 3. An inner cap 8 is formed forward of the rear end 5 of an inner hole of the cap 1. The cap 8 is connected from its outer periphery to a circumferential wall of the hole of the cap 1 by a rib 7, and an air flow passage connected from an insertion port 1a of the cap 1 to the rear end of the cap via a vent hole 6 formed between the ribs is formed. Thus, even when the cap is swallowed, the air flows from the vent hole for its safety. |
