MOLD MAKING DEVICE HAVING BLOW NOZZLE

摘要

A series of expendable shell molds is formed in a permanent pattern having a series of connected mold cavities. A passage including the cavities extends through the pattern. A swinging blow-vent nozzle is mounted at each end of the passage, the two nozzles being rotationally fixed to each other. In one position the first nozzle blows into the pattern while the second nozzle vents the pattern. In a second position the second nozzle blows into the pattern while the first nozzle vents the pattern. In a third position one of the nozzles blocks the passage while the other has been swung out of the way to provide access for a sand blow box which can then blow sand into the pattern. The nozzles are clamped against the pattern by a hydraulic cylinder which moves them toward each other on a shaft. The device includes means for separating the pattern, lifting the gang of molds out of the pattern and stripping the molds from pins on which they are formed or by which they are lifted. The device for elevating the finished molds includes means for blowing out the molds as the patterns are raised. The apparatus is particularly suitable for making cores for making tappet bodies and for making molds for casting engine valves.