Sealing mechanism for a vessel with a cap closure

摘要

A cap (1) has a plug portion (4), a seal plug (5) and a sleeve (6). The plug portion (4) has a top board (11) to cover an opening portion (3) of a vessel (2), a side wall (12) projecting from the top board along its axis (X) which wall has an inner circumferential surface fits on an outer circumferential surface of the opening portion (3), and a cylindrical wall (15) forming a receiving chamber (14) having an opening mouth (13) at its under end face which wall projects from the top board at inner side of the side wall (12). The seal plug (5) has outer diameter (D1) which is larger than outer diameter (D2) of the cylindrical wall (15) and an seals the opening mouth (13). The sleeve (6) is loosely fitted on the cylindrical wall (15) and opens the opening mouth (13) by separating the seal plug (5) from the cylindrical wall (15) at relative movement of the cap (1) to the vessel toward direction where they separate from each other. A sepal portion (16) on the outer circumference of the sleeve (6) has outer diameter larger than inner diameter (D3) of the opening portion (3) and has flexibility to passe the inner diameter (D3) bending so as to avoid backward moving.