STRUCTURE OF A BLAST VALVE FOR A CONTAINER

摘要

The purpose of the present invention is to provide a structure of a blast valve for a container which may prevent the formation of a constricted portion in a flat lower portion of a groove portion for fracture and may have a stable thickness of the flat lower portion, even when the groove portion for fracture is formed by plastic working. The structure has a V-shaped cross-section in which a flat lower portion (4a) defines the thickness of a groove portion (4) for fracture and both inclined side walls (4c, 4d) opposite to each other extends from the flat lower portion (4a) to a thin-walled flat portion (3). An inclined angle (&thgr;_1) of one inclined side wall (4c) among both inclined side walls (4c, 4d) is greater than that (&thgr;_2) of the other inclined side wall (4d).