Dynamic mold seal

A seal for a mold formed by two mold halfs, said seal comprising:

• a sealing ring mounted to a first one of said mold halfs;
• said sealing ring comprising a first ring portion mounted to a surface of said first one of said mold halfs and a flexible portion joined to said first ring portion, said flexible portion being located inwardly of said ring portion and allowing said mold halfs to separate slightly while molten material is being injected into said mold and preventing leakage of pressurized molten material from said mold, thereby preventing the creation of flash about an article being molded within said mold;
• said first one of said mold halfs having a mold parting line and said flexible portion being formed from a flexible member which protrudes above said parting line so that said flexible member can contact a portion of a second one of said mold halfs when said second one of said mold halfs is spaced from said first one of said mold halfs;
• said first stationary ring portion including a rigid ring portion affixed to said first one of said mold halfs and a sealing ring portion which mates with said rigid ring portion and said sealing ring portion including said flexible member;
• said rigid ring portion and said sealing ring portion being formed from a metallic material;
• and
• said flexible member being formed from a metallic material which has been heat treated to a spring temper.

An injection molding machine comprising:

• a first mold half having at least one of a means for forming a molded article and a mold cavity;
• a second mold half having at least one of a means for forming a molded article and a mold cavity;
• at least one of said first and second mold halfs being movable between a mold open and a mold closed position;
• means for injecting molten material into a mold cavity space formed by said mold halfs when said mold halfs are in said mold closed position;
• sealing means for allowing said mold hafts to separate slightly while said molten material is being injected into said mold cavity space and for preventing leakage of said molten material from said mold cavity space;
• said sealing means comprising a sealing ring mounted to one of said mold halfs;
• said sealing ring including a first stationary ring portion and a flexible member both mounted to said one of said mold halfs, said flexible member preventing said leakage even though said mold halfs are slightly separated;
• said one of said mold halfs having a parting line;
• said sealing ring being held rigidly in place at said mold parting line;
• and
• said flexible member protruding above said parting line so that said flexible member contacts a portion of the mold half to which the sealing ring is not mounted when said mold halfs are slightly from each other.