Sand gate for use in a sand distribution apparatus

An apparatus for distributing sand from a hopper into a mold flask in a foundry process, comprising:

• a proximal distribution plate affixed to a lower portion of the hopper, wherein said proximal distribution plate has a plurality of primary apertures therethrough;
• a distal distribution plate slidably mounted subjacent said proximal distribution plate and in abutment therewith, wherein said distal distribution plate has a plurality of pairs of secondary apertures therethrough;
• and
• a masking plate mounted to said distal distribution plate, wherein said masking plate has a plurality of pairs of masking plate bores corresponding to each said pair of secondary apertures, wherein each masking plate bore has a principal diameter traversing said masking plate;
• wherein each pair of said secondary apertures and masking plate bores corresponds to one of said primary apertures such that said distal distribution plate is movable between a closed position, wherein said primary apertures do not overlap said secondary and masking plate bores, and infinitely variable open positions, wherein said primary apertures overlap one secondary aperture and masking plate bore of said pair of secondary apertures and masking plate bores, wherein sand flows from the hopper into the mold flask through said overlapping primary and secondary apertures.

A method for distributing a granular material from a hopper into a mold flask in a foundry process comprising:

• a. providing a proximal distribution plate affixed to a lower portion of the hopper, wherein said proximal distribution plate includes a plurality of uniform primary apertures therethrough;
• b. providing a distal distribution plate in abutment with said proximal distribution plate, wherein said distal distribution plate includes a series of secondary apertures therethrough;
• c. providing a masking plate having a series of masking plate bores, each masking plate bore having a principal diameter extending through said masking plate;
• d. attaching said masking plate to said distal distribution plate such that said masking plate bores are in alignment with said secondary apertures;
• and
• e. selectively moving said distal distribution plate such that said primary apertures will overlap said secondary apertures and said masking plate bores to allow sand to flow through said secondary apertures and said masking plate bores.

An improved apparatus for distributing a granular material from a hopper into a mold flask through a sand gate of the type in which the sand gate includes a fixed distribution plate with a series of primary apertures and a movable distribution plate with a series of secondary apertures in abutment with the fixed distribution plate, and in which the movable distribution plate is urged from a closed position in which the primary apertures do not overlap the secondary apertures to an open position in which the primary apertures do overlap the secondary apertures to allow sand to flow therethrough, wherein the improvement comprises:

• a masking plate having a first surface and a second surface with a series of masking plate bores traversing said masking plate, wherein said masking plate bores include a principal diameter extending through said masking plate;
• wherein said masking plate is mounted to the movable distribution plate such that said masking plate bores are in alignment with the secondary apertures;
• and
• wherein said principal diameter of said plate bore determines the flow of sand through said masking plate.