DISPOSITIVO DE OBTURACION PARA EL CANAL DE SALIDA DE AIRE DE UN MOLDE DE FUNDICION.

摘要

A device for regulating the flow of moldable material from a mold which has two mold parts which are separable along a parting plane or surface with a vent passage defined along the plane which extends from the interior of the mold to atmosphere or to a venting apparatus such as a venting pump. One of the mold parts is provided with a recess adjacent the mold separating plane which includes a block having a vent continuation passage which communicates with the vent passage. The vent continuation passage includes a first elongated vent continuation passage portion which communicates with the lower end of a piston bore for a regulating piston which is displaceable in the bore against biasing means by an outflow of the moldable material. In addition the vent continuation passage includes a second vent continuation passage portion which extends between the first vent continuation passage portion and it communicates at one end of a transverse valve bore defined through the piston when the piston is in an initial position in which no moldable material enters into the first vent continuation passage portion. The other end of the piston transverse valve bore continues up through the block to an outer vent passage. The second vent continuation passage may comprise one or two passage portions as well as additional mold material flow areas to increase the area in which the moldable material may flow. Upon the entrance of moldable material to the base of the piston it is displaced so as to close the valve bore in the piston by displacing it from communicaton between the second vent continuation passage and the outer vent passage.