Patent ID: 7654817

Claim:
A vent piece for use with a mold and to be inserted in an insertion hole penetrating a wall surface of the mold, said vent piece having a cylindrical shape such that the vent piece connects an inside of the mold to an outside of the mold, the insertion hole of the mold having a taper on the inside of the wall surface of the mold, said vent piece comprising: a first end to face toward the inside of the mold; a second end to face toward the outside of the mold; a central hole through the vent piece to communicate the inside and outside of the mold; a valve element, located on the first end, for opening and closing the central hole; a lock for locking the vent piece to the mold so as to prevent movement of the vent piece toward the outside of the mold, said lock having a screw-head-shaped end with a taper projecting radially outward to be fitted to the taper of the insertion hole on the inside of the mold; and a nut to be mounted threadedly to the second end of the vent piece.