| 摘要 |
PROBLEM TO BE SOLVED: To improve the can-openability by a method wherein the location of a tab stop is shifted to the opposite side of an opening part from the center of a can lid, and at the same time, the length from the center of the tab stop to a finger engaging/pinching part, and the length between the center of the tab stop to the operating part of the tab, etc., are formed so as to satisfy specified conditions. SOLUTION: A tab 4 is fixed with a rivet at a location which is on the symmetrical axis of a breakable opening 3, and is away to the opposite side of the breakable opening 3 from the center of a central panel part 1 by a distance (a). Then, in this case, if the length between the center of a tab stop to a finger engaging/pinching part 4b is taken as L, the length between the center of the tab stop and the operating part 4a is taken as 1, and an angle between the tab central line at an opening impossible location and the tab central line at an opening possible location is taken as θ, the internal diameter of a can lid is taken as (d), and the outer diameter of the can lid is taken as (D), it is set so that the relationships of (D-d)/2<a<d/2-1, d-1>L>d/2-a, and -1<cosθ<1/(2×a×L)× (d/2)<2> -(L<2> +a<2> )} may be satisfied. |
