Patent ID: 7108269

Claim:
A plug for sealing an opening in a sheet, said plug comprising an integral body, an entirety of said body being made of the same material, said body including: a cap portion having an annular shirt portion and a cover portion connected to one end of the shirt portion, the shirt portion having a free end opposite to the cover portion and tapering on an outer side thereof towards the free end, the free end having an outer diameter adapted to be smaller than the diameter of the opening, wherein said cover portion is configured to prevent liquid from passing therethrough; a flange portion approximately at the level of the cover portion, which flange portion extends obliquely outwardly and downwardly; and an annular sealing surface approximately at the same level as the connection of the cover portion to the shirt portion and below a connection of the flange portion to the cover portion, a height of the sealing surface being adapted to be larger than the thickness of the sheet, an outer diameter of the sealing surface being adapted to be slightly larger than the diameter of the opening; wherein the cover portion and its connection to the shirt portion is formed such that the plug body can be urged into the opening by an axial pressure on the cover portion under temporary reduction of the outer diameter of the sealing surface; and wherein the connection of the flange portion to the cover portion, the connection of the shirt portion to the cover portion, and dimensioning of said portions are Such that an outward pivoting of the flange portion upon insertion of the plug body into the opening approximately into the plane of an associated side of the sheet exerts a radial expansion force and/or a pivoting force on the sealing surface so that the material of said body in an area of the sealing surface, on an opposite side of the sheet, is formed against said opposite side of the sheet.