| 摘要 |
<p>A gas-venting valve includes a sliding valve and either a fixed or movable valve chamber. The valve 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 invention further includes a device for urging the valve to move relative to the valve chamber from the first position to the second position; a device for restraining the valve at the first position and preventing it from moving toward the second position, against the force of the urging device, until a part of the melt impinges against the valve; and a device for actuating the valve to return from the second position to the first position against the force of the urging device.</p> |
