Abstract: A motor-operated die clamp mechanism produces a great clamping force even with use of small-output motors, and is adapted for use in a motor-operated injection-molding machine. Screw portion (13a, 13b), threaded reversely to each other, are formed on a ball screw (13) which is rotated by a motor (15). Ball nuts (11, 12), which are threadedly engaged with the screw portions (13a, 13b), respectively, and a movable wedge (6) are coupled to one another links (9, 10). As the motor rotates, the links contract or spread, thereby advancing or retreating the movable wedge with a great force. When the movable wedge advances, it is engagedly pressed against a fixed wedge (5) formed on the mold base (4) of a die (3), thereby causing the die to be fixedly mounted on a stationary board (1) or a movable board (2).

Abstract: A device for the injection of a plastic material in a mold having an injection head with an injection face designed to be placed in contact with the mold feeder channel. The injection head has an injection chamber supplied with plastic material by a feeder conduit. The plastic material is injected from the injection chamber to the mold feeder channel by means of a clack-valve system. The device also has a support for the injection head and an injection rod.

Abstract: An injection molding apparatus for high pressure injection molding of thermoplastic materials reduces counteractive deformation of desynchronously filled coaxially located molded cavities. The apparatus includes a clamping apparatus having left, center and right molding blocks for movement with respect to each along a common axis and defining first and second molding cavities. The center block includes left and right platens separated by a multitude of supporting columns. At least one of the columns is at least partly positioned above a first horizontal plane which is located at least 30% of a distance from the axis to a top of the platens and at least one of the columns is at lest partly positioned below a second horizontal plane which is located at least 30% of a distance from the axis to a bottom of the platens. Columns are similarly positioned in relation to first and second vertical planes.

Abstract: An extruder having an extruder head that forms a tubular passageway, an extruder screw rotatably disposed in the tubular passageway, and a first motor connected to the extruder screw for rotating that screw to force an extrudable material through the tubular passageway. The extruder further has a feed hopper for holding the extrudable material, and having an outlet in communication with an inlet of the extruder head for conducting the material thereinto. The feed hopper defines a supplemental opening adjacent the inlet of the extruder head, and a feed assist roller is rotatably supported on the extruder and extends partly through this supplemental opening to a location adjacent the inlet of the extruder head. A second motor is connected to the feed assist roller for rotating that roller to facilitate moving the extrudable material from the feed hopper and into the tubular passageway of the extruder head.

Abstract: This invention relates to an injection molding system having two heated nozzles mounted in tandem. The rearward nozzle is considerably longer than the forward nozzle and has a melt bore which is considerably larger in diameter than the melt bore of the forward nozzle. The smaller forward nozzle has a backplate secured to its rear end with a thin flanged portion which extends outwardly and rearwardly into bearing contact against a rearward mold core to secure the forward nozzle in position in a well in a forward mold core. The rear face of the backplate has a seat extending around the melt bore to receive a cylindrical forward portion of a gate insert mounted on the forward end of the rearward nozzle. Thus thermal expansion of the larger rearward nozzle is taken up by the forward portion of the gate insert sliding in the seat.

Abstract: High strength composite tape is prepared for laying in side-by-side strips upon a work surface by precutting the strips to a predetermined length and mounting the strips upon a carrier belt in longitudinally spaced relation to one another, so that the pressure foot of the machine applying the tape to a work surface may press to the end of one tape strip without pressing the end of the following tape strip. Improved laying of the tape is achieved by stretching a strip of tape entirely across the area on which the tape is to be laid before pressing any part of the tape against the work surface, and then pressing the tape against the surface while the tape is stretched across and adjacent the work surface. The tape is held and stretched across the work surface on supply and take up reels on opposite sides of the work surface, so that the reels need not move along the tape with the moving pressure foot.