To make a melt with a low voscisity flow as smoothly as possible to every corner of a product forming part.
A sprue 10 has a cylindrical shape which becomes wider to its base so as to have larger diameter as it approaches the bottom. An intermediate introducing part 20 has a curved jade-like crosssection curved to the sprue part 10 and the top part is connected with the sprue part 10 so as to bring it into contact with and going along with the side wall of the sprue part 10 and the bottom part is extended downward along with an imaginary extended face of the side wall of the sprue part and the curved jade-like crosssection becomes larger as it becomes to lower side. The top wall 21 of the intermediate introducing part is gradually inclined to the outer side downward and a part connected with a horizontal introducing part 30 on the bottom part side of the intermediate introducing part is also gradually inclined. The horizontal introducing part is extended into a crescent shape and is connected with the end edge of a product forming part 40.
YAMASHIMA SUSUMU
SATO NOBUO
