STRUCTURE OF CLINCH PORTION OF MOUNTING CUP

PROBLEM TO BE SOLVED: To provide a structure of a clinch portion of a mounting cup which a gasket can be held surely between a curl portion and a can bead without allowing the gasket to stick out, and a more reliable seal can be ensured. SOLUTION: The structure of the clinch portion of the mounting cup comprises the curl portion 7 around a center line 2 concatenated, at the inner circumferential edge thereof, to the upper end of the outer circumferential wall 6 of the mounting cup 1, and a curl portion skirt 8 concatenated, at the upper end thereof, to the outer circumferential edge of the curl portion 7, wherein the curl portion 7 is constituted of a plurality of curved surfaces of different radii that spread from the inner circumferential edge to the outer circumferential edge, thereof, and a dead space 31 into which a part of the gasket 34 can go is formed between a virtual curved surface 27, constituting the inner surface of the curl portion with a single radius and a curved surface 25 at the inside portion and/or a curved surface 26 at the outside portion. COPYRIGHT: (C)2010,JPO&INPIT