Abstract: An apparatus for injection molding an article includes a pair of mold members, at least one of which is movable toward and away from the other. Each mold member includes a base plate, a manifold plate and a cover plate. Each base plate has inner and outer surfaces with a mold cavity in its inner surface and an annular recess in its outer surface. A plurality of connected grooves is in the bottom of the recess to form a channel. The manifold plate is an annular plate which is seated in the recess in its respective base plate. The manifold plate has inlet and outlet passages which extend to separate ones of the grooves in the base plate. The cover plate extends across the outer surface of the base plate and the manifold plate to hold the manifold plate in the recess. One of the base plates has a hole therethrough from its outer surface to its mold cavity to allow the flow of molding material into the mold cavity.

Abstract: A mold for forming a recorded disc includes a base plate and a cap plate mounted on the base plate. Bolts extending through the base plate and threaded into the cap plate secure the outer portions of the plates together. A hub projecting from the cap plate extends through a hole in the base plate and a nut threaded on the hub and engaging a surface of the base plate secures the inner portions of the plates together. The cap plate has a plurality of sets of grooves in its inner surface which mates with a surface of the base plate. The grooves in each set are radially spaced, concentric, circular grooves connected by slots. An inlet passage extends through the base plate to one of the grooves of each set and an outlet passage extends through the base plate to a groove of each set to provide for a separate flow of a temperature control medium through each set of grooves. The base plate and cap plate are made of materials having suitable physical properties for the specific plate.

Abstract: A preform molding apparatus includes a mold cup which has opposed top and bottom mold members and a carrier arm between the mold members. The top mold member has a concave mold recess in its bottom surface and a semi-cylindrical rim extending downwardly from the edge of the mold recess. The bottom mold member has a concave mold recess in its top surface and a mold material inlet opening into the bottom of the mold recess. The carrier arm has a semi-cylindrical opening therethrough at one edge thereof. Pneumatic cylinders have piston rods connected to the mold members and the carrier arm for moving the mold members toward and away from each other and the carrier arm transversely across and away from the mold members.