Container having damage-resistant finish ring

1. A container having a damage-resistant finish ring and an opening sealable by a closure member that is removable by a hook-type opener, comprising:

a) a locking ring on said finish ring, said locking ring comprising a convex outer surface having a locking ring radius and a height and extending from a first circumferential edge to a second circumferential edge;

b) an upper convex outer surface portion on said finish ring adjacent to and directly above said locking ring, said upper convex outer surface portion having a radius that is larger than said locking ring radius and a circumferential edge at an intersection of said locking ring and said upper convex outer surface portion; and

c) a concave outer surface portion on said finish ring adjacent to and directly below said locking ring, said concave outer surface portion having a radius that is larger than said locking ring radius and a circumferential edge at an intersection of said locking ring and said concave outer surface portion;

d) wherein said locking ring has a relatively smooth outer surface, and wherein said intersection of said locking ring and said upper convex outer surface portion and said intersection of said locking ring and said concave outer surface portion are each relatively smooth, such that said hook-type opener may pass by said locking ring unimpeded upon removal of said closure member by said hook-type opener; and

e) wherein said locking ring radius and said height of said locking ring are sufficiently large to provide said relatively smooth outer surface, and said locking ring radius and said height are sufficiently small to retain said closure member on said container prior to removing said closure member with said hook-type opener.

2. The container of claim 1 , wherein:

a) said circumferential edge of said upper convex outer surface portion is tangent to said first circumferential edge of said locking ring at said intersection of said locking ring and said upper convex outer surface portion; and

b) said circumferential edge of said concave outer surface portion is tangent to said second circumferential edge of said locking ring at said intersection of said locking ring and said concave outer surface portion.

3. The container of claim 1 , said locking ring radius being between about 0.045 inch and about 0.053 inch, and said height being between about 0.027 inch and about 0.033 inch.

4. The container of claim 1 , said locking ring radius being about 0.05 inch and said height being about 0.03 inch, said radius of said upper convex outer surface portion being about 0.156 inch, and said radius of said concave outer surface Dortion being about 0.094 inch.