| 摘要 |
PURPOSE: To provide a driven-in type cap which can be easily opened by simply displacing downward without breaking a tightening ring, and also has a sure improper opening-preventive function. CONSTITUTION: An improper opening-preventive cap consists of two members of a cap main body 2 and tightening ring 3, and an engaging protuberance 8 is provided on the inner peripheral surface of an external wall 7 of the cap main body 2, and an engaging recessed part 9 is formed on the outer peripheral surface of the external wall 7. Then, a flap piece 17 is formed at the lower end inner peripheral part of the tightening ring 3. The tightening ring 3 can be displaced from a cap opening-preventing position where the cap is prevented from opening by fitting in the external wall 7 of the cap main body and restraining the diameter of the external wall 7 from expanding, but the tightening ring 3 cannot return to the original state from the cap openable position to the cap opening-preventing position because the flap piece 17 is obstructed by the external wall 7, and an improper opening of the cap can be easily judged. |
