Method and apparatus for fabrication of casting from patterns

Abstract

A stereolithography machine is employed to solidify a pattern including a series of stacked grids forming the pattern having an outer skin and inner labyrinth and any number of gates. The hollow pattern is mounted on a central sprue through runners at the gate of the pattern. The pattern is dipped in ceramic slurry and sifted in a refractor grain in order to coat the hollow pattern. The hollow pattern is melted to form a mold.

What is claimed is:  
     
         1 . A method for fabrication of casting patterns comprising the steps of: 
 receiving an investment pattern having an outer skin, a fill riser and an inner labyrinth;    curing said investment pattern in an ultraviolet oven;    positioning said investment pattern on a support;    coating said investment pattern in a coating solution;    sifting said coated investment pattern in a refractory medium to form a mold;    removing said investment pattern;    filling said mold with casting material in order to form a casting; and    removing said mold to release said casting.    
     
     
         2 . A method for fabrication of casting patterns as in    claim 1   , wherein said receiving step includes the step of draining said inner labyrinth of ultraviolet material.  
     
     
         3 . A method for fabrication of casting patterns as in    claim 1   , wherein said method further comprises the step of forming the investment pattern from at least two stacks.  
     
     
         4 . A method for fabrication of casting patterns as in    claim 1   , wherein said method step comprises the step of forming the investment pattern from a first stack having a first predetermined pattern and a second stack having a second predetermined pattern.  
     
     
         5 . A method for fabrication of casting patterns as in    claim 1   , wherein said method further comprises the step of flushing said mold.  
     
     
         6 . A method for fabrication of casting patterns as in    claim 1   , wherein said method further comprises the step of flushing said mold -with air and water.  
     
     
         7 . A method for fabrication of casting patterns as in    claim 3   , wherein said forming step further comprises the step of forming said investment pattern with two stacks, each of said stacks having a different cross section.  
     
     
         8 . A method for forming a pattern adapted to be used in the production of casting patterns, comprising the steps of: 
 positioning a first grid to form a first portion of said pattern, said grid having a first cross section;    positioning a second grid to form a second portion of said pattern, said grid having a second cross section;    arranging said first and said second grid so that said second cross section is not aligned with said first cross section; and    curing said pattern in an ultraviolet light source.    
     
     
         9 . A method for forming a pattern as in    Claim 8   , wherein said curing step includes the step of curing said pattern in an ultraviolet oven.  
     
     
         10 . A investment pattern adapted to be used in the production of casting patterns, said investment pattern comprises: 
 a first stack forming a portion of investment pattern, said first stack having a first cross section;    a second stack forming a portion of the investment pattern, said second stack having a second cross section;    a gate to drain said investment pattern, said first stack and said second stack being positioned adjacent so that liquid ultraviolet solution flows through said gate.    
     
     
         11 . An investment pattern as in    claim 10   , wherein each of said grids comprises at least two elements coupling at least two sides of each of said grids.  
     
     
         12 . An investment pattern as in    claim 11   , wherein each of said at least two elements are substantially perpendicular to the other of said at least two elements.  
     
     
         13 . An investment pattern as in    claim 12   , wherein a first element of said first grid and a second element of said second grid forms an angle of substantially 45°.