| 摘要 |
PURPOSE:To provide a loosening preventive device relatively easily without changing a structure of respective helical thread portions on the container body side such as a bolt and on the covering cap body side. CONSTITUTION:In a covering cap B for screw threaded engagement with helical thread protrusions 2 provided on the outer or inner circumferential surface of an opening 1 of a container body A, a loosening-preventive protrusion 15 is provided adjacent to an innermost helical thread protrusion out of helical threaded protrusions 12 provided, in the space 11 of the cap B, on the inner or outer circumferential surface of the cap B so as to be opposed to a part of thread protrusion 2 of the body A so that the protrusion 15 is pressed against the protrusion 2. |
