| 摘要 |
PROBLEM TO BE SOLVED: To obtain reliable locking and favorable rotational operability by rapidly increasing a sliding frictional resistance force at a position near a threadably coupling limit arranged in a screwing device for generating a necessary sliding frictional resistance force between a screw cap and a bottle mouth by means of the resilient contact of a locking protruding piece and preventing the occurrence of looseness of screwing. SOLUTION: Locking protruding pieces 4 are protrusively provided in such a manner that one of the protruding pieces 4 approaches one side of a thread 11 of a bottle mouth 10 and a screwing thread 3 of a screw cap 1, which are screwed on rach other, and that the other protruding piece 4 is resiliently contacted with the other side thereof. The protruding height of the portion of the locking protruding piece 4 which is resiliently contacted with the other side of the screwing thread 3 and the thread 11 at a position near a threadably coupling limit is made higher than that of the portion of the other locking protruding piece 4. By this method, a sliding frictional resistance force is greatly exhibited at the position near the threadably coupling limit, and the sliding frictional resistance force is arranged to be appropriate at other ranges. |
