Abstract: One aspect of the invention is a mechanism for controlling the movements of the plates in a multiple plate mold. The mold is secured to a press in an injection molding system having a support plate and top clamp plate. The mechanism includes a member pivotally mounted to the outside of the mold and an arm attaching the press support plate to the member. In a preferred embodiment, two guides are attached to the press top clamp plate and middle moving plate of a three plate mold. The guides travel in curved channels formed in the member to determine the relative positions of the plates.

Abstract: An injection mold of the type in which a film gate of a resin is formed and in which shearing of the film gate is conducted by a movement of a gate cutter alone. The gate cutter has a stepped cylindrical form with a main cylindrical portion of a greater diameter and a coaxial end cylindrical portion of a smaller diameter. When the mold is closed, the end cylindrical portion being received in the bore of a confronting die leaving therebetween an annular gap of a radial size which determines a gate thickness. The outer peripheral surface of the portion of the gate cutter received in the bore of the die presenting a gate land.

Abstract: Apparatus for molding a composite metal-elastomer styled wheel in which a middle mold part includes a metal wheel disc and rim subassembly. A base mold part seats against the outboard face of the metal wheel in the closed condition of the mold and has a mold cavity surface to provide an ornamental configuration for the outboard face of the decorative plastic body of the composite wheel. A clamp seats against the inboard face of the middle mold part to urge the middle part into sealing engagement with the base mold part. The mold parts are axially separable from one another to open the molding apparatus to clear the middle mold part from said clamp and base mold parts. The clamp includes a funnel adapted for registry with a liquid reaction mixture injection nozzle coupled with injecting mixing apparatus. The funnel has a nozzle passage registering with a bolt-hole pour opening in the disc in the closed condition of the mold.

Abstract: An improved gating needle for use in an injection molding sprue bushing has an elongated central needle portion and at least three radially extending members which extend radially outwardly from the central needle portion. The gating needle is seated in an annular cavity or circular recess disposed at the outlet end of a sprue bushing and is capable of slight axial movement due to the action of the injected melt flowing around it so that the needle maintains a constant position and clearance within the mold cavity gate. The gating needle may include an interior heat transfer portion in the form of either a highly thermally conductive metal core portion or in the form of a sealed hollow tube containing a vaporizable liquid, which interior portion transfers heat from the surrounding melt to the mold cavity gate to maintain the mold cavity gate area at a constant temperature.

Abstract: The invention is embodied as a raw material resin feeding apparatus for a molding machine, such as an injection molding machine or an extruder. In this system, upon carrying out a variable resin-change operation by making use of material to be changed, raw material resin is intermittently fed to a feed section by intermittently opening and closing a resin passageway. The improvements reside in that the apparatus includes a raw resin material feed selection mechanism provided midway along a resin passageway for selectively either feeding a predetermined amount intermittently or continuously to a feed section. A resin-change resin feed start detector mechanism is provided for detecting completion of discharge of the amount of raw material corresponding to the predetermined amount, and a resin-change completion detector mechanism is provided. With this apparatus, raw material can be selectively fed to effect quick resin-change or for normal operation.

Abstract: An injection mold for forming the halves of a magnetic tape cassette includes stationary and movable molds defining a cavity, and confronting slidable cores disposed in holes extending through the molds. An opaque primary resin is injected into the cavity to form an outer portion of a cassette half with the core faces abutting each other, whereafter the cores are retracted to define a central window cavity in which a transparent secondary resin is injected. A lip surrounds the inner edge of the hole through which one of the cores extends to laterally support and guide the core, and to avoid any jamming or inaccuracy in the retracted position of the core due to thermal expansion.

Abstract: An injection screw disposed in a heating cylinder is connected to a rotary driving force receiving mechanism, a linear driving force receiving mechanism, and a back pressurizing mechanism. The rotary driving force of an electric motor is transmitted to the rotary driving force receiving mechanism and the linear driving force receiving mechanism through clutches, which are controlled according to sensors for detecting the position of the screw or the linear driving force receiving mechanism.

Abstract: An injection mold has a valve gate system in which a valve pin is moved through a runner into and away from a gate to open and close the gate. The valve pin is inserted into the gate to close it after each injection stroke and the end face of the valve pin defines a part of the surface of an injection-molded article when the valve pin is in the gate. The end face of the valve pin is provided with a designed irregularity.

Abstract: A plastic injection mold apparatus which includes a multiple tip torpedo heater in a fluid plastic flow passageway. The torpedo heater includes an elongated body having an exposed outer cylindrical surface with tips at opposite ends thereof over which the fluid plastic material may be directed at an elevated temperature. The body is formed with an internal bore at the location of each tip for receiving a respective heating element. The torpedo heater is supported within the fluid plastic flow passageway by means of an outer cylindrical collar portion and three circumferentially spaced radial supporting elements which are formed of a softer metallic material than the body of the torpedo heater, and hence, are susceptible to repeated thermally induced expansion and contraction without undesired cracking or failure which can result in leakage of the flow stream and heater failure.

Abstract: A die apparatus permits the formation of an internal recess in a molded part. The die apparatus includes first and second mold members which are movable between an open and closed position. A core pin assembly includes a first core pin element and a second core pin element supported between the movable mold members for relative movement therewith. A resiliently deformable element is positioned between the first and second core pin elements. The resiliently deformable element is deformably expandable to form an external projection upon relative movement of the mold members to a closed position, and is elastically returnable upon the relative movement of the mold members to an open position.

Abstract: The present invention relates to a rotary type injection molding machine including a base plate provided in its surface with a rotary disk having hold molds at three portions on the lower surface thereof and having required core insert holes bored at stop positions of the hold molds, a support post on a machine bed vertically movably supporting the base plate and the rotary disk in the central portion thereof, the support post being intermittently rotated together with the rotary disk, a vertical clamping device on the machine bed in which one of the stop positions of the hold molds serves as an injection molding section and a clamping plate having a core mold at the lower side thereof is connected by movable tie bars on opposite sides to be positioned upwardly of the base plate, and an injection mold secured to the machine bed of the injection molding section, the base plate being movably supported by the movable tie bars and linked to the clamping device, an upper portion of the support post being carried b

Abstract: A nozzle for injecting viscous fluid such as a thermoplastic into a mold cavity of a mold body includes a tip section and a nozzle body secured thereto. The tip section serves as a sprue of the mold body. The mold body includes a core portion, a cover portion and a clamp plate for securing the core portion to the cover portion. The nozzle body having an inlet end, a discharge end, which communicates with the tip section, and a flow passage for viscous fluid extending from the inlet to the discharge end. A valve element is mounted for reciprocation in the nozzle body flow passage to control the flow of viscous fluid through the nozzle body discharge end. At least the tip section of the nozzle body is located in the mold body cover and the nozzle body is substantially positioned between the mold body cover and the clamp plate. The valve element can be a shut-off needle which is disposed for reciprocating movement in the nozzle body flow passage.

Abstract: An arrangement is disclosed for independently controlling shutoff and flow to a cavity gate in a multicavity injection mold apparatus, in which a plurality of valve pins are mounted to a movable holder plate, each aligned with a cavity gate and movable thereinto to control shutoff and a plurality of fixed position plunger sleeves are each mounted over a respective valve pin and adjustably positioned with respect to a restriction feature in the supply passage upstream of the associated gate.

Abstract: A mold clamping device is provided for an injection molding machine having a stationary mold half and a movable mold half supported by a movable plate. A drive rod is connected at one end to this movable plate and is received at the other end by a driving ring piston having at least one recess within its inner shell. At least one coupling member such as a split flap is swivably connected to the other end of the rod. A suitable actuator such as a piston driven lever arm is provided to operatingly engage the coupling member with the recess, whereby the mold is clamped.

Abstract: A stringiness-preventing pad having a resin passage hole defined by partition leaves is interposed between a sprue bush and an injection cylinder nozzle so that the partition leaves are spread by the pressure of molten resin material being injected into a mold and elastically closed upon completion of injection. The resin material solidified in the sprue is prevented from stringing by virtue of the partition leaves when removing a molded object from the mold.

Abstract: An injection mold unit is provided for an alternate feed, injection molding of parts of a plasticized material and has first and second plasticizing and injection devices, with a respective bores and a mold comprising a heating channel block and a mold cavity. The heating channel has a first passageway connected to the bore of the first plasticizing and injection device, the first passageway having first and second branches in fluid communication with the mold cavity. The heating channel also has as well as a second passageway connected to the bore of the second plasticizing and injection machine and having first and second branches in fluid communication with the mold cavity. One way valves are located in each of the first and second branches of the first and second passageways.

Abstract: A system for cleaning the bottom of a filled mold in a fixed surface molding process including providing a cleaning spatula in sliding contact with the surface of the mold while the mold is stationary and a device for raising the spatula above the mold when the spatula is returned to its intial position. A hopper is provided for receiving material removed by the spatula during the cleaning sweep.

Abstract: A barrier injection apparatus for injecting a barrier at a site characterized by a holder for holding the apparatus in place against the force of injection; at least one injector for injecting a medium for a barrier at the injections site when in place; respective conduit system extending from the storage unit, and including a pump for inducing pressure onto the medium, to the injection site for injecting the medium at the injection site under pressure; storage unit for storing the medium at atmospheric pressure and being connected with a suction side of a pump that will introduce pressure; a second conduit connected with the barrier injection apparatus and adapted to remove unused medium from the site, an adjusting mechanism for adjusting the injectors to a correct distance; and a gasket sealingly surrounding the injection site for constraining the medium to flow into the site under pressure and insulate the medium from a holding mechanism. Also disclosed are specific preferred embodiments.

Abstract: An injection molding machine having an extruder, a nozzle, and an housing mounted between the extruder and nozzle. The housing encloses a pressure assist nozzle and a fluidic passage connecting the extruder and the extruder nozzle. A bore within the housing extends into the fluidic passage to define a portion of the passage between the extruder and the extruder nozzle. The bore has an aperture within a side wall which acts as a valve opening within the passage which, when closed, prevents flow between the extruder and the nozzle. An annular sleeve is reciprocated within the bore between a retract position, in which the annular sleeve is withdrawn from the passage, and an extend position, in which the annular sleeve is projected into the passage so as to close the aperture. A plunger piston reciprocally resides within the annular sleeve. The plunger piston is held in a retracted position by the annular sleeve while the annular sleeve is in its retracted position.

Abstract: In an injection moulding tool for the production of a magnetic tape cassette casing constructed, in part, in two layers the apparatus has a fixed core (1a) provided, on the rim, with a projection (5) which provides a sealing strip relative to the moving core (2a). After the injection moulding process into the first mould cavity (4), the moving core (2a) is moved axially downwards by about half the wall thickness, whereupon the second mould cavity (3, 3') is filled by injection through a second needle shut-off nozzle (FIG. 1b).