Investment molding flask assembly

Abstract

An investment molding flask assembly having a base with a central positioning boss protruded from a center thereof and at least one positioning annular groove defined therein around the central positioning boss, and a conical sleeve formed with a small opening end to be securely positioned on the base without any displacement in horizontal directions by means of the central positioning boss or the positioning annular groove. Whereby, the conical sleeve can be readily removable from a solidified semi-finished investment mold, and then the solidified semi-finished investment mold is sent into an oven independently for heating. Therefore the sleeve can be used repeatedly, and the investment mold can be manufactured rapidly and readily.

What is claimed is:  
     
         1 . An investment molding flask assembly comprising: 
 a base formed as a circular plate having a central positioning boss protruded from a center of a top surface thereof, and at least one positioning annular groove defined in the top surface around the center thereof, wherein the central positioning boss is formed with a cylindrical-shaped lower portion and a cone-shaped upper portion;    a sleeve formed as a cone having a small opening end thereof to be securely positioned on the base without any horizontal displacement;    whereby after a wax pattern is fixed on a top end of the central positioning boss, an investment material is charged into an internal space of the sleeve to embed the wax pattern in the sleeve so as to form a solidified semi-finished investment mold, and then the solidified semi-finished investment mold is allowed to be removed from the sleeve to be heated in an oven independently, therefore a finished investment mold is rapidly obtained, and the investment molding flask assembly can be used repeatedly.    
     
     
         2 . The investment molding flask assembly as claimed in  claim 1 , wherein the base is defined with two positioning annular grooves in the top surface around the center thereof.  
     
     
         3 . The investment molding flask assembly as claimed in  claim 1 , wherein the sleeve has a small opening end defined with a diameter slightly larger than an outer diameter of the cylindrical-shaped lower portion of the central positioning boss.  
     
     
         4 . The investment molding flask assembly as claimed in  claim 1 , wherein the sleeve has a small opening end defined with a diameter to be properly inserted into the at least one positioning annular groove.  
     
     
         5 . The investment molding flask assembly as claimed in  claim 1 , wherein a positioning recess is defined in an upper end of the cone-shaped upper portion of the central positioning boss.  
     
     
         6 . The investment molding flask assembly as claimed in  claim 1 , wherein the sleeve is formed as a cone.  
     
     
         7 . The investment molding flask assembly as claimed in  claim 1 , wherein the sleeve is formed as a multi-stepped cone.  
     
     
         8 . The investment molding flask assembly as claimed in  claim 1 , wherein the sleeve is defined with a maximum volume mark at an inner surface near the large opening end thereof.  
     
     
         9 . The investment molding flask assembly as claimed in  claim 1 , wherein the sleeve is defined with a maximum volume mark at an outer surface near the large opening end thereof.  
     
     
         10 . The investment molding flask assembly as claimed in  claim 1 , wherein a gasket ring is provided on the top surface of the base between the sleeve and the central positioning boss, an inner edge of the gasket ring is formed therearound with a flange having an inner cone surface extending in flush with an outer surface of the cone-shaped upper portion of the central positioning boss.