Abstract: In a film cassette, a film spool comprises a spool core supported for rotation in an unwinding direction to thrust a leader section of a film roll coiled about the spool core to the exterior of the cassette and in a winding direction to return the leader to the interior of the cassette, and a pair of flanges positioned along the spool core to overlie opposite sides of the film roll to radially confine the film roll within skirted peripheries of the flanges. The flanges have respective central openings through which the spool core coaxially extends to normally permit the flanges and the spool core to be independently rotated in the two directions.

Abstract: This invention relates to a method and molding screw for injection molding. The molding screw has a fixed inner screw mounted within a rotatable and reciprocally movable outer screw. The outer screw is continuously rotated throughout the injection cycle to (1) counter the back flow of melt material around the screw, (2) subject the melt material surrounding the inner screw to a vigorous mixing action, (3) add additional thrust to inject the melt material into the mold, and (4) return the outer screw to its initial starting position. A rod-type electrical heater is internally positioned in the fixed screw to maintain the temperature throughout the melt material surrounding the inner screw at a substantially constant value which is substantially equal to the barrel temperature.

Abstract: A method of injection molding plastic articles using a rotor assembly that continuously rotates past a stationary extruder that supplies molten plastic material to the assembly. The rotor assembly includes a plurality of mold assemblies, each mold assembly having a pair of separable mating die members which are selectively opened and closed. A plurality of injection chambers is disposed within the rotor assembly in cooperating relationship with each pair of die members. The rotor assembly is continuously rotated past the extruder and molten plastic material is supplied directly into the bottom of each injection chamber. The rotor assembly is then rotated to a position where a ram is driven into the injection chamber to force material in the chamber into a mold cavity formed by the mold assemblies. During rotation of the rotor assembly from the extruder to the ram, the molten material is retained in the injection chamber by adhesion between the material and the walls of the injection chamber.