| 摘要 |
<p>Molten metal is delivered from a master furnace (12) to the holding chamber of a low pressure casting machine (14) by a launder assembly (16) having a unitary, quickly replaceable, valve assembly (18). The valve (18) has a plug (130) mounted for rotation in a valve body (96). In a modification, the valve has a port (214) centered in a valve plate and a movable plug of aluminum titanate (212). In operation, the valve (18) is opened to permit the molten metal within the master furnace (12) and the holding vessel (40) to seek a substantially uniform level and closed when the low pressure casting is initiated. While the valve (18) is closed, a pressurizing gas is introduced into the holding vessel (42) so that molten metal will rise up a riser tube (58) into a mold.</p> |
