Abstract: An improved nozzle feed assembly is described. The assembly includes temperature-controlled member, preferably cylindrical in shape, having a closed end and an open end. The open end is fitted with standard threads to facilitate attachment of the nozzle member to the feed barrel of a conventional screw-type molding machine. The nozzle member has an internal temperature controlling means and a plurality of feed outlets positioned on the periphery of the nozzle member near the closed end. The temperature maintained in the nozzle member is sufficiently high to maintain the thermosetting molding material within the nozzle member in a plasticized state and sufficiently low that no substantial curing of the thermosetting molding material takes place. In an alternate mode, the assembly includes a sleeve member positioned around the periphery of the nozzle member and moveable to cover and uncover the feed outlets in the periphery of the nozzle member.

Abstract: A process is disclosed for molding a foamed thermoplastic article characterized by a foamed core, a non-foamed exterior shell and a surface that reproducibly and faithfully replicates a predetermined portion of the inner surface of the mold in which the article is made, wherein a foamable mixture comprising molten thermoplastic material and blowing agent is introduced through a nozzle into a mold cavity defined by said inner surface of said mold and expands and is rigidified while in said mold cavity.

Abstract: This invention relates to improved mechanism for actuating injection molding valve pins. In one embodiment, the mechanism is located between two parallel rows of valve pins located in a common plane with their driven ends adjacent the mechanism. The mechanism includes a central elongated member which is longitudinally reciprocable and two parallel elongated transversely reciprocable side members, each located between the central member and one of the rows of valve pins. Each of the side members is connected to the central member by a number of spaced pairs of pivotally connected pins and the central member is secured against transverse motion, while the side members are secured against longitudinal motion. Therefore, the side members are reciprocated transversely when the central member is reciprocated longitudinally by a hydraulic cylinder.

Abstract: An apparatus for the extrusion of thermofusible materials which are applied while being heated comprises a prefusion and feeding chamber, a heating element for the prefusion and feeding chamber, a shaft capable of rotation at the base of the chamber, the shaft while in rotation mixing the thermofusible material and an extruder comprising an extrusion screw axially connected to said shaft. The extrusion screw is located in a cylindrical tubular structure which is provided with an exit for the thermofusible material. Preferably the shaft is located at a predetermined distance from the bottom wall of the prefusion chamber whereby a passageway is formed between the bottom wall and the shaft, the chamber and the shaft being so dimensioned that the shaft during rotation forces the entire mass of thermofusible material through the passageway.

Abstract: An injection gate of a mold cavity comprises an elongate valve rod which passes axially through a flow channel for molten plastic material and is guided in an extension of a thin-walled steel cylinder open at its opposite end toward an adjoining manifold plate. The rod extremity remote from the gate is secured to a tubular neck of a piston inside the cylinder whose stroke length is a fraction of the axial height of the cylinder's interior, a clearance around this neck providing space for drooling plastic while the length of the neck and of the peripheral cylinder wall serves for thermally insulating the manifold plate from the flow channel.

Abstract: A plug or stopper for bores in rocks or the like, which bores, after the lling, are filled with a self-hardening synthetic material, such as commercially available epoxy resin mixtures, polyester resin mixtures, and cyanoacrylate adhesives. The plug is pressed or driven into the bore and consists essentially of an elastically deformable material, especially rubber or rubber-like synthetic resin. The outer diameter of the plug corresponds to the diameter of the rock bore. The plug tapers mainly toward the front and is provided on its outer circumference with grabbing elements. The inside of the plug is provided with an axial bore which becomes narrower toward the back. A closure member which serves as a valve body is axially displaceably arranged in the plug in such a way that it seals off the axial bore when pressure is directed toward the back.

Abstract: A nozzle shut-off valve for placing between the injection apparatus and the mold cavity uses two pins of different lengths for the valve elements and switches air pressure back and forth between pistons on opposite (outer) ends of the pins. The pistons have no fixed connection to the pins. Each pin is actuated either by force from the piston on its outer end or pressure by the plastic melt on its innermost other end. The longer pin has a length sufficient to extend completely across the injection passage and block it to prevent any flow. The shorter pin is deliberately made short enough that it cannot block the passage. The valve is actuated by air pressure on the two pistons in timed relation to injection molding events. Pressure on the piston engaging the longer pin compels blocking of the injection passage during plastication. Switching of pressure to the other pin during injection permits the pressure of molten plastic to spread the pins apart whereupon injection proceeds in the ususal manner.

Abstract: A machine and method for injecting structural foam or other thermoplastic materials into one or more mold cavities. The machine comprises at least one mold-mounted shut-off bushing having a material delivery chamber formed between an outer body and a shank, with a shut-off pin slidably mounted in the shank, a heater being disposed between the pin and shank so as to heat the material passage as well as the shut-off pin tip. Closing of the shut-off bushings is independent of material pressures and is carried out from the space between a mold half and its platen by a cylinder operated cam rod.

Abstract: A shut-off nozzle for the injection molding of fluid plastics. The nozzle includes an axial body component with a bore for transfer of the fluid plastic from the molding machine to the molding cavity through a nozzle head. The nozzle body carries thereon an actuating cylinder mechanism for selective actuation of a core plug and valve assembly. The valve is reciprocated to fully close or fully open a delivery bore in the nozzle head.

Abstract: Process and apparatus for injection molding plastic to provide a foamed core with an unfoamed outer skin.

Abstract: A casting head for cooperation with a mold in which hardenable synthetic resins can be cast under a high temperature, comprising: a stationary and a respectively movable head part; at least one hydraulic cylinder in the stationary head part to change the relative position of a portion of the movable part, between a closed rest position and a casting position, in which latter a passage of the casting head is open to feed the resin to an inlet opening of the mold; the movable head part includes a housing with bottom and top parts; at least one toggle lever is slidably journaled and pivotable in the bottom housing part while the movable head part has therein a lengthwise movable closure rod, the outer end of the latter carrying a closure head which acts on the passage to open and close the same; and spring means for closing the passage when the pressure applied to the cylinder has been released, the spring means being compressed by way of the closure rod and the closure head when the passage is being opened.

Abstract: An injection molding apparatus having a non-return valve assembly mounted on the front end of an extruder screw within a heated barrel for accummulating a charge of thermoplastic material in the forepart of the barrel by the retrograde and rotary movement of the screw when the valve is in open position, and by ejecting the charge through a nozzle mounted at the front of the barrel by the reverse reciprocating movement of the feedscrew, which simultaneously forces the valve to close and prevents escape of the material backward into the barrel along the screw. The valve is formed of two components, one of which is shaped with a convexly contoured annular protuberance which is alternately spaced from the other one, and in close abutment therewith, in the alternate movements of the feedscrew, with only screws or bolts connecting the two, to permit freedom of movement therebetween.

Abstract: An extravertable-wall container is formed by extruding a parison into a blow-mold cavity having a pair of oppositely diverging halves which are joined at their widest portions, one half being slightly smaller than the other so that the frusto-conical wall of the container formed in this half can be pushed (compressed) into the other half to produce a stackable cup-shaped structure. When the container is to be filled, the inner wall portion is extraverted to form an extension of the container, e.g. the bottom. The container may have a frustoconical upwardly widening base which is geometrically smaller but inverted with respect to the larger frustoconical head. A neck or filling opening may be provided on this head.

Abstract: In an injection molding apparatus, wherein a plasticizing chamber has a nozzle attached to one end thereof, with the nozzle having a passageway therein and being in communication with the sprue of a mold, the improvement which constitutes a compact, pneumatically-powered, reciprocable spool-type device having a passageway therein, operated by alternately actuated opposed pistons, interposed between the nozzle and the plasticizing chamber, in one position blocking the communication between the plasticizing chamber and the nozzle and in the other position allowing molten material to enter the nozzle.