| 摘要 |
PROBLEM TO BE SOLVED: To provide a rigidity-increased closing piece to cover the opening of a container body in which beverage is stored.SOLUTION: In a cover member 300, a portion of a base part 310 is deformed by pressing the portion of the base part 310 in the thickness direction of the base part 310 using a pressure member (not shown in figure) and forming a first protrusion 371. More specifically, bending rigidity of the cover member 300 is increased by forming the star-shaped first protrusion 371. Besides, a second protrusion 372 protruding in a direction opposite to the protruding direction of the first protrusion 371 is provided on the periphery of the first protrusion 371. By providing the first protrusion 371 on the base part 310, the rigidity of the base part 310 is increased. Besides, when the second protrusion 372 is provided in addition to the first protrusion 371, the rigidity of the cover member 300 is more increased as compared with a case when only the first protrusion 371 is provided. |
