GAS-VENTING ARRANGEMENT INCORPORATED WITH A MOLD

摘要

GAS-VENTING ARRANGEMENT INCORPORATED WITH A MOLD There is provided an improved gas-venting arrangement incorporated with a mold for use in a casting machine or an injection molding machine, wherein gas-venting valve means, including a movable valve and a valve chamber, is closed by impingement of molten metal or melt flowing out of a cavity defined by the mold, in such a manner that the valve is forced to move relative to the valve chamber from a first position to a second position. The improvement consists in that the arrangement comprises: first means for urging the valve to move relative to the valve chamber from the first position to the second position: second means for withholding the valve at the first position and preventing it from moving toward the second position, against the force of the first urging means, until a part of the melt impinges against the valve, and; third means for actuating the valve to return from the second position to the first position against the force of the first urging means.