Patent ID: 7111763

Claim:
A coupling structure for a double-wall container, comprising: a hollow portion having a through-hole as a fluid passage; a flange portion provided at an upper end of the hollow portion; a first connecting portion provided at a lower end of the hollow portion and adapted to be connected with an opening portion of an inner container; a second connecting portion provided in the vicinity of the flange portion and adapted to be connected with an opening portion of an outer container; at least one annular elastic fin provided between the first connecting portion and the second connecting portion, said annular elastic fin extending outward and downward, wherein an edge of the fin is adapted to be in contact with an inner wall of the opening portion of the outer container, and at least one groove as an air passage formed and extending through the flange portion and the second connecting portion, said groove remaining open when the opening portion of the outer container is connected with the second connecting portion, wherein the hollow portion has at least one through-bore which communicates (i) a space defined between the inner container connected with the first connecting portion and the outer container connected with the second connecting portion, and (ii) a space defined on top of the flange portion, and which is isolated from the hollow of the hollow portion, wherein the through-bore is formed from between the fin and the first connecting portion to the top through the flange portion.