Patent ID: 6375891
Filing Date: 2002-04-23
Classification: B29C,B29L,B60S

Abstract:
A method of manufacturing a resinous tank having a through-hole in a side wall portion of the tank, comprising:providing a pair of cooperating molding dies forming a cavity therebetween; providing a tool with a blade at one of the molding dies such that a portion of said tool protrudes further inwardly into the cavity than the molding surface of the one of the molding dies and a thickness of a resin parison to be formed, said tool being columnar and the blade being located at a distal end of said tool; forming a hollow tank body by expanding said resin parison within the cavity, such that said resin parison is pressed against inner wall surfaces of said molding dies, and brought into close contact with the outer peripheral wall of said tool, such that the outer peripheral wall of said tool forms an inner wall surface of said through-hole, wherein the length of the portion of said tool protruding into the cavity is more than the thickness of said pressed resin parison; completing formation of said through-hole by advancing said tool further into said hollow body, and cutting out a portion of said resin parison hollow body corresponding to the blade of said tool; and removing said tool from said hollow body, opening said molding dies, and removing said tank, wherein the tank's hollow body has said through-hole formed in a side wall portion thereof.