AN IMPROVED GAS PERMEABLE METAL CASTING MOLD HAVING GAS COLLECTION VOIDS

摘要

pUnitary, rigid, self-supporting, gas permeable, low temperature bonded, sand grain molds having peripheral side surfaces extending between vertically spaced upper and lower surfaces with mold cavity means spaced therebetween connected to gate passage means having lower open ends exposed at said lower surface, adapted to be filled with molten metal through the gate passage means by applying reduced pressure to the top surface of the mold while its lower surface with the gate passage means lower open ends are submerged in molten metal, are provided with enclosed gas collection void means adjacent to and spaced from each of the mold cavity means, the gate passage means and the upper and lower mold surfaces for collecting gases from the cavity means and gate passage means during filling of the cavity means for controlled removal of gases from the void means through the upper mold surface by application of reduced pressure thereto./p[US4532976A]