Patent ID: 6298904
Filing Date: 2001-10-09
Classification: B22C

Abstract:
A vent-forming apparatus for making a gas vent in a wall of a mold for casting metal, said vent-forming apparatus comprising:(a) a gas-permeable, liquid-impermeable membrane having an atmosphere facing surface and an opposing mold cavity facing surface;(b) a lead-in tube having a free end and an opposing membrane connection end, said membrane connection end of said lead-in tube being in substantial contact with said mold cavity facing surface of said gas-permeable, liquid-impermeable membrane, and said free end being connectable to the mold cavity and allowing for the passage of gas into said lead-in tube; andc) a breather tube having a free end and an opposing membrane connection end, said membrane connection end of said breather tube being in substantial contact with said atmosphere facing surface of said gas-permeable, liquid-impermeable membrane.