Injection molding apparatus for molding a disc having a replaceable die

A die assembly for molding a disc wherein die replacement can be achieved at a location away from the die assembly, the die assembly comprising:

• a) a stationary die half, comprising:
• 1) a stationary platen;
• 2) a pair of retaining members on an inner side of the stationary platen, each retaining member comprising:
• (A) a fixing member extending longitudinally in a transverse direction with respect to the stationary platen, and
• (B) a rectangular clamp member, a clamp screw associated with the clamp member and rotatable from an outer side of the stationary platen for moving the clamp member toward and away from the inner side of the stationary platen;
• 3) a die receiving member at one side of the stationary platen and extending longitudinally in a vertical direction thereof,
• whereby an installation space is defined at the inner side of the stationary platen by said retaining members and said die receiving member;
• and
• 4) a first insert die half removably retained in the installation space by the retaining members and the die receiving member, the first insert die half comprising:
• (i) a first insert having a cavity formed therein and a stepped portion, and
• (ii) a first mirror surface board removably received in said cavity of said first insert, said first mirror surface board including a stamper placed on a surface of said first mirror surface board, an inner ring fitted through said first mirror surface board and an outer ring fitted onto said first mirror surface board, said stamper being immovably retained by said inner ring and said outer ring, and a rear surface of said outer ring being fitted onto said stepped portion of said first insert,
• wherein said first insert die half can be slidably installed into and removed from said installation space in a transverse direction relative to said stationary platen such that replacement of said first mirror surface board and said stamper can be achieved at a location spaced away from the die assembly,
• said fixing member comprising a pair of block-shaped bases and a laterally extending long plate, the bases being integrally formed at respective rear sides of both ends of said long plate, respective inside portions of the bases having stepped portions for receiving the first insert of the first insert die half,
• the rectangular clamp member being positioned at an inner side of the long plate in a space between the bases, an inner side of the rectangular clamp having a stepped portion that is aligned with the above-mentioned stepped portions of the bases, and
• said first insert die half is fixed to the stationary platen by inserting said first insert die half guided by said fixing members into a space between the stepped portions of the fixing members and the clamp member and the inner side of the stationary platen, and by moving the clamp member toward the stationary platen inner side by turning the clamp screw, thereby removably retaining the first insert die half in the installation space;
• and
• b) a movable die half, comprising:
• 1) a movable base that forms a main body of said movable die half, said movable base having a recessed portion;
• and
• 2) a second insert die half comprising (i) a second insert fixedly received into said recessed portion of said movable base;
• and (ii) a second mirror surface board received on said second insert so as to correspond to said first mirror surface board on said first insert.

A die assembly for molding a disc wherein die replacement can be achieved at a location away from the die assembly, the die assembly comprising:

• a) a stationary die half including:
• 1) a stationary platen, at an inner side of the stationary platen:
• A) retaining members, each retaining member comprising:
• (i) a fixing member extending longitudinally in a transverse direction with respect to the stationary platen, and
• (ii) a clamp member and screw means associated with the clamp member to be operable from an outer side of the stationary platen for moving the clamp member toward and away from the inner side of the stationary platen, and
• B) a die receiving member;
• 2) a first insert die half removably retained at the inner side of the stationary platen by the retaining members and the die receiving member, the first insert die half comprising:
• A) a first insert having a cavity formed therein and a stepped portion, and
• B) a first mirror surface board removably received in said cavity of said first insert, said first mirror surface board including a stamper placed on a surface of said first mirror surface board, an inner ring fitted through said first mirror surface board and an outer ring fitted onto said first mirror surface board, said stamper being immovably retained by said inner ring and said outer ring, and a rear surface of said outer ring being fitted onto said stepped portion of said first insert,
• wherein said first insert die half is removable from said stationary platen such that replacement of said first mirror surface board and said stamper can be achieved at a location spaced away from the die assembly,
• said fixing member comprising a pair of bases and a plate, the bases being attached at respective rear sides of both ends of said plate, respective inside portions of the bases including means for receiving the first insert of the first insert die half,
• the clamp member being positioned at an inner side of the plate in a space between the bases, an inner side of the clamp member having means for receiving the first insert of the first insert die half, and
• said first insert die half is fixed to the stationary platen by inserting said first insert die half guided by said fixing members into a space between the inner side of the stationary platen and the means for receiving the first insert of the fixing members and the clamp member, and by moving the clamp member toward the stationary platen inner side by operation of the screw means, thereby removably retaining the first insert die half on the stationary platen;
• and
• b) a movable die half, comprising:
• 1) a movable base that forms a main body of said movable die half, said movable base having a recessed portion;
• 2) a second insert die half comprising (i) a second insert fixedly received into said recessed portion of said movable base;
• and (ii) a second mirror surface board received on said second insert so as to correspond to said first mirror surface board on said first insert.