Abstract: A needle valve nozzle (1) with a nozzle housing (3), a needle valve (10) arranged axially displaceably in it in the center, and a needle guide (4) constructed as a bushing, has its material feed channel (5) completely in the interior of this needle guide (4). The needle guide (4) has a corresponding radial dimension on the face (11) of the needle valve nozzle (1) and of the nozzle housing (3), and jointly forms the face (11). It is furthermore provided that this bushing-like needle guide (4) has an insulating spacing from nozzle housing (3), in particular on its exterior, preferably with the aid of an air gap, so that a heat outflow though the nozzle housing (3) and its abutment (16) is largely ruled out.

Abstract: A mold gate and a method of using the same, in which the mold gate has an adjustable-area and width, annular access opening to each mold cavity. As the area is adjusted, the flow of molten plastic to the cavity is controlled for the injection molding of plastic parts. The adjustment may be made by rotating an outer rotary bushing relative to an inner stationary bushing, which is surrounded by the outer rotary bushing in one embodiment, and which projects beyond it in another. The position of a hot probe is thus controlled to vary the area of the access opening. Cooling lines in the vicinity of the hot probe may be provided for significant improvement of operation. Also, a method is disclosed in which the gate operates without closure by means of metal parts. Rather, the frozen molding compound itself serves to close the gate between mold shots.

Abstract: A melt ducting arrangement for an injection molding system having a heated nozzle, a valve pin axially slideable in the heated nozzle and a guide bushing for the valve pin which extends into a manifold and of the heated nozzle. The melt ducting arrangement includes a groove in the heated nozzle extending at least part way around the guide bushing. A melt passage extends between the groove and a melt passage in a manifold. The guide bushing has a hole extending generally axially therethrough. The hole has a narrower diameter portion facing away from the heated nozzle and a wider diameter portion facing into the heated nozzle. The narrower diameter portion slideably receives and guides a valve pin. The wider diameter portion provides space to receive melt between the valve pin and the bushing. Radially spaced openings extend through the bushing and register with the groove and to provide a melt conduit between the bushing and the wider diameter portion of the hole.

Abstract: An apparatus for preparing flowable reaction mixtures from at least two flowable reactants in which the components are injected into a mixing chamber by means of injection nozzles, the force of the reactant acting upon the nozzle needle is at least substantially compensated to avoid impairing the mixing ratio during a change-over of the nozzle needle. The rear end of the nozzle needle is provided with a chamber communicating with the component supply line.

Abstract: A valve gate injection nozzle includes a valve stem for guiding molten resin to a molding area. The valve stem includes an input area for receiving the molten resin, a central area following the input area for processing the molten resin and an output area following the central area for connection of the nozzle with the molding area. The central area includes a first zone for splitting the molten resin into a plurality of streams, a second zone for mixing and homogenizing the molten resin, and a third zone for combing the plurality of streams and forming recombined molten resin for subsequent direction in a homogenized state to the output area. The nozzle further includes a nozzle body portion for enclosing the valve stem, wherein the nozzle body portion preferably includes means for heating the resin. An injection molding system incorporating this nozzle as well as a method for homogenizing molten resin are also disclosed.

Abstract: Method and apparatus for adjusting either the flow area to a constant size mold gate or the area of a variable mold gate opening in order to control the flow of molten plastic to a mold cavity for the injection molding of plastic parts, such adjustment being made by rotating an outer rotary gate bushing relative to an inner stationary hot sprue bushing which is surrounded by said outer rotary gate bushing.

Abstract: An apparatus and method for sequentially molding a plurality of plastic articles within a single mold unit. A first mold section is provided with a runner system and a plurality of gates and a second mold section is provided with a plurality of recesses in operable alignment with the gates of the first mold section. When the second mold section is clamped into mating engagement with the first mold section, a plurality of discrete mold cavities are formed, each having at least one corresponding gate provided on the first mold section. A central processing unit signals an injection assembly as to the proper injection parameters for each discrete mold cavity. The central processing unit opens the gates sequentially, with each discrete mold cavity being filled according to its own set of injection parameters. By the present method, it is possible to mold a plurality of articles having different injection parameters, while using a single mold unit.

Abstract: An apparatus for simultaneously casting a large volume of wax patterns in a reduced amount of time in an air-free environment. The invention utilizes a direct controlled pressure wax injection system to inject melted wax into a central portion of a multi-cavity rubber mold having an upper and lower portion, and then provides an evenly distributed clamping pressure to the mold.

Abstract: A system for injection molding of large components is disclosed that provides for the production of higher quality large molded components with a reduction in both molding cycle time and molding costs. Plasticized material communicates with a mold, having at least one single cavity, through a manifold that has at least two spaced valve gates that are independently opened and closed as directed by a controller to selectively communicate plasticized material to the mold cavity at separate locations in the mold cavity. The controller directs the valve gates to sequentially open and close during the filling phase so as to achieve the desired melt front advancement within the mold cavity. Once the mold cavity has been filled as desired, the valve gates are closed to effectively seal the manifold from the mold cavity.

Abstract: A valve member locating insert to be mounted in the front end of an injection molding nozzle. The locating insert has an outer mounting collar portion and a concentric inner collar portion which receives the reciprocating valve member to accurately locate it to prevent damage around the gate. The inner collar portion is connected to the outer collar portion by a single connecting vane portion. Melt flows through the locating insert in a C-shaped space between the collar portions. The vane portion and the inner collar portion have upstream and downstream ends which extend diagonally to be washed by the melt flow to avoid deadspots and reduce turbulence.

Abstract: An injection molding valve member having a smaller neck portion leading to a short head portion. This facilitates the backflow of melt around the head portion as the valve member is driven forwardly to the closed position. In one embodiment, the neck portion is formed by a number of flutes spaced around the valve member having lands between them.

Abstract: An injection nozzle has gearing which drives a valve pin to open and close a mold gate, with a venting chamber in a nozzle body allowing vapors to escape before reaching the gearing to avoid fouling of the gearing. The valve pin is actuated by a hydraulic cylinder driving the gearing, which includes a pair of pinion gears driving gear teeth on either side of the upper end of the valve pin. An adjustable stop is provided limiting piston travel in either direction, allowing adjustment of both the closed and open positions of the valve pin.

Abstract: A valve for use in introducing a foamable reactive mixture into a cavity, with the valve being of such size that it can be positioned within the cavity and when so-positioned is in contact with at least one of the walls of the cavity, with the valve including:a) two essentially rotationally symmetrical coaxial cages, with said coaxial cages being spaced from each other, with the inner cage;i) having an axial opening for the introduction of the reactive mixture and at least two radial openings for the passage of the reactive mixture into the annular space formed between the inner and the outer cage; ii) having a ball, capable of moving freely within said inner cage and capable of closing the inlet opening following completion of the introduction of the reactive mixture; iii) having a convex surface opposite said inlet opening, with said convex surface being directed inward, so that during the introduction of the reactive mixture the ball assumes a position outside the inner cage axis; andb) with said outer cag

Abstract: Injection molding apparatus comprising a platen, a die which is fixed to the platen and which defines a mold cavity having an inlet, a co-injection manifold mounted on the platen, the manifold including a nozzle housing having forward and rearward ends, the nozzle housing including an outlet which is located adjacent the forward end and which communicates with the mold cavity inlet, first and second spaced apart inlets which are located adjacent the rearward end and which are respectively adapted to communicate with first and second injection nozzles, a first passageway communicating between the first inlet and the outlet, and a second passageway communicating between the second inlet and the outlet.

Abstract: A mold assembly is provided for use in an injection molding machine and includes a cavity plate defining a cavity adapted to receive a moldable material, and a manifold positioned behind the cavity plate. The manifold includes a passageway for guiding the flow of the moldable material to the cavity plate. A support plate is positioned adjacent the manifold and includes a rear face into which a cup shaped recess extends, a front face opposite the rear face, and a bore extending between the front face and the recess. A nozzle is provided between the passageway in the manifold and the cavity in the plate for directing the flow of material into the cavity, and a valve gate pin extends into the nozzle. The valve gate pin is movable between a forward flow-blocking position and a rearward flow-permitting position, and a cylinder unit moves the valve gate pin between these positions. The actuator includes a drop-in pneumatic actuator secured within the recess of the support plate.

Abstract: An improved design for an injection molding apparatus for creating of products from fluid plastic material wherein a hydraulic flow divider can be used for simultaneously actuating of multiple hydraulic injectors which need not be linearly positioned. This molding apparatus is usable with a hydraulic flow divider since a unique configuration of a fixed frame with a cage mounted movably therein and a hydraulic cylinder assembly mounted movably within the cage allows the injection molding apparatus to use the same amount of hydraulic fluid during each and every stroke regardless of the length of the stroke of the rod relative to the nozzle. This unique capability is achievable by allowing the hydraulic cylinder assembly in its entirety to move within a predefined cage configuration even after the entire stroke is completed in order to allow the cylinder to accept the amount of powering hydraulic fluid associated with a single complete stroke.

Abstract: A multi-plate injection molding tool has multiple cavities. It includes a hot-runner plate, a hot-runner distribution block adjacent to the hot-runner plate, and a plurality of hot-runner nozzles. The hot-runner distribution block is a monolithic seamless metal block. A lower die plate is removably attached to the hot-runner plate, and an upper die bolster is adjustably attached to the lower die plate and is movable along fixed guide columns. The upper die bolster comprises a base plate, a stripping plate and a slide plate. A plurality of form cores are supported on the upper die bolster, and a plurality of annular stamps are attached to the lower die plate, each being around a form core and each having a conical exterior surface tapered towards the lower die plate, and cooperating with a die; a plurality of dies is carried by the lower die plate, and each has a mating conical surface for receiving the conical surface of a stamp in close fit therewith when the molding tool is closed.

Abstract: An injection molded metal mold is provided to eliminate defects such as appearance defects of molded products, functional defects of products, or the like, caused by formation of a concave portion in a surface opposite to a gate as a metal mold is used over a long period of time. An injection molding metal mold 1 in which when a melted resin is injected first from a gate into an injection cavity, the rate of resin at the gate is not less than 5 m/sec, and the distance between the gate 5 and a portion opposite to the gate is 0.2 mm to 2.0 mm. In the mold, an exchangeable gate-opposition metal mold member, in the form of an ejection pin, is buried in the portion opposite to the gate. Further an injection molding method using this metal mold is provided. The forward end of an ejection pin bites into a plastic molded product so that the molded product is held ejected when the metal mold is opened.

Abstract: A pressure molding apparatus for molten resin in which an oil-pressurized cylinder internally holding an end of gate pin can freely move in compatibility with thermal elongation or contraction of a manifold pipe. In addition, a limit switch to be activated by the descending movement of this cylinder in correspondence with the descending movement of the gate pin is interlinked to a molten-resin supply source. By provision of these mechanisms, molten resin can smoothly be delivered to the interior of a molding unit without obstruction. Since substantial space is provided around this cylinder, pipes can easily be installed. Furthermore the inner later surface of the gate aperture on the side of the gate pin is provided with an obtuse angle wider than the tip angle of the gate pin, and a tapered hole having an adequate length and tapered diameter expanding itself from the gate aperture to the inner surface of the molding unit is provided.

Abstract: A hot runner valve gated system comprising at least one nozzle housing adapted to be positioned in a manifold plate. The nozzle housing includes a gate orifice and a reciprocal valve stem positioned therein. The system also includes a mechanism for moving the valve stem for opening and closing the gate valve and is designed to maintain the mechanism for moving the valve stem in a substantially cooled state. The mechanism for moving stem is positioned coaxially relative to the nozzle housing.

Abstract: An injection molding apparatus particularly usable for low pressure structural foam molding with improved control device for providing adjustment and controlling relative positioning between the injection molding apparatus and the mold. A novel device is included for adjusting the nozzle body with respect to the injection molding apparatus and for adjusting the nozzle rod with respect to the nozzle body. An improved device is also included for facilitating adjustment of injection stroke length and of the position of the nozzle body as well as automatic adjustment of positioning of limit switches responsive to indicate the extremes of movement during the cyclical injection stroke. Automatic and manual devices are also included for maintaining alignment between the nozzle rod and the nozzle body extending therearound.

Abstract: A penetration hole of plasticized resin is pierced in a screw head, so that the resin may be accumulated in uniform temperature distribution without sacrificing the function of the injection screw. More specifically, a penetration hole 15 of plasticized resin is pierced inside a screw head 13 at the front end of a screw 12 from the front middle to the rear periphery so as to communicate between the screw peripheral parts and the screw head front space. A ring valve 17 for opening and closing a rear opening 15a of the penetration hole 15, and closing the gap around the screw head is fitted to the rear periphery of the screw head 13 so as to be free to move back and forth.

Abstract: The present invention relates to an apparatus for injecting molten plastic material. The apparatus includes a novel bushing arrangement have a threaded portion which forms part of a mechanical connection between the bushing and an air piston housing so as to reduce the possibility of plastic material leaking between the bushing and the air piston housing. The bushing has a melt channel for mating with a melt channel in a manifold in which the bushing is housed and with an axial channel in a nozzle body. The bushing is sized to fit within a bore in the manifold so as to reduce the possibility of leakage between the bushing and the manifold. The bushing also serves to close off or plug holes or channels drilled into the manifold. In one embodiment of the present invention, the bushing has a passageway through which a valve stem for closing off a gate in the nozzle body passes.

Abstract: A method and system for the injection molding of plastic articles in an injection molding system including a chamber in a mold of the system which stores a charge of pressurized gas immediately prior to use. The mold has an injection aperture and a mold cavity for receiving molten resin. A resin flow path fluidly communicates the injection aperture and the mold cavity within the mold. An orifice in the mold opens the chamber to the mold. A gas receiver initially stores the charge of pressurized gas and a fluid circuit selectively introduces the charge of pressurized fluid into the chamber. A valve mechanism in the chamber selectively fluidly communicates the chamber to the flow path under control of a controller. When communicated to the flow path, the charge of gas distributes the molten plastic within the mold cavity in one embodiment of the invention.

Abstract: Injection nozzle for a mould, with a straight sprue. The shutoff valve is accommodated in a suitable seat which obliquely intersects the sprue and opens out in the gate. During injection the head of the shutoff valve leaves the sprue clear. After injection the head of the shutoff valve shuts off the gate.

Abstract: An injection apparatus having a pressure holding device of a novel constitution, capable of preventing flow-out and decrease of resin when holding pressure, and eliminating instability in pressure holding due to volume changes, by forming the front end of the pressure holding plunger obliquely disposed between front and rear resin paths or penetrating a passage between the resin paths.

Abstract: The injection nozzle has a thin-walled centering bushing inserted between the tip insert and the mold insert. The centering bushing engages a shoulder of the mold insert and thus achieves a mutual centering and sealing of the tip insert and the mold insert. This avoids the inflow of molding material into the cavity between the tip insert and the mold insert which would impair or delay the changing of colors of the material, and the injection needle is effectively centered so that a cylindrical tip portion can close a very short cylindrical portion of a gate bore. The heat transfer between the heated nozzle parts and the mold insert is nevertheless maintained at a low level since the mutual centering is obtained by narrow contact sites.

Abstract: A rotary actuated gate valve for directing melt from a channel in a manifold to a mold gate includes a valve stem extending through and rotatable within the manifold. The valve stem includes a groove in fluid communication with the channel, wherein the groove is adapted to be rotated into alignment with the mold gate and channel for allowing the melt to flow into the mold gate. The groove is also adapted to be rotated out of alignment with the mold gate and channel for blocking the melt from flowing into the mold gate. The gate valve also includes a mechanism for rotating the valve stem. Another embodiment includes a rotatable housing having a groove, which operates in a manner similar to the valve stem design.

Abstract: A process and apparatus for effecting injection molding of plastic resin products on an injection molding apparatus including a metal mold composed of a slidable mold element and a fixed mold element defining together the mold cavity, an actuator for sliding the slidable mold element and an injection nozzle for adjusting the nozzle flow path section, which comprises a first molding step of injecting a molten resin into the mold cavity which has been preset by the slidable mold element so as to include a post-compression margin to be compressed afterwards in a second molding step, to effect the injection under a reduced molding pressure, while causing a temperature elevation and, thus, a viscosity reduction of the molten resin, until the mold cavity has been filled up, and a second molding step of compressing the resin so charged in the mold cavity by operating the slidable mold element to compress the charged resin to compensate the post-compression margin, so as to allow an effective pressing force to be imp

Abstract: A method for runnerless injection molding of a synthetic resin, provided with a novel valve gate for performing intermittent temperature control to forcibly change the property of a molten or solidified resin material adjacent to the gate, capable of performing a precision molding operation without leaving an improper gate mark. The apparatus therefor comprises a runner 3 with a temperature maintaining means for storing a molten resin and forming an injection passage, a gate 1 in communication with a cavity 2 connected to the end of the runner 3, a valve pin 4 enclosed within the runner 3, and an intermittent temperature control assembly P.

Abstract: A device for injection molding articles of plastics material having hollow spaces. The device includes a molding tool with a mold cavity. Plastics material melt is fed to the mold cavity through a nozzle. Another pressurized medium is supplied to the mold cavity through a hollow needle at a location different from the location of the nozzle. A needle core is mounted in the hollow needle. The needle core is axially displaceable within certain limits. The opening of the hollow needle to the mold cavity can be opened and closed or its cross-sectional area can be varied by moving the needle core.

Abstract: An apparatus for injecting a viscous fluid and a non-viscous fluid into a mold cavity of a mold body includes a nozzle body having a discharge end a flow passage for the viscous fluid extending to the discharge end. A valve element is mounted for reciprocation in the nozzle body flow passage to control the flow of the viscous fluid through the nozzle body discharge end. The valve element includes a barrel having a first end and a second end and a first bore extending longitudinally in the barrel. A tip is detachably secured to the barrel first end for selectively engaging a portion of the nozzle body discharge end to prevent a flow of the viscous fluid therepast. The tip has a first end, a second end and a second bore extending longitudinally through the tip from the first end to the second end. A pin is located in the second bore. The pin has a first end located adjacent the tip first end, such that the pin and the tip define between them an annular opening at the tip first end.

Abstract: Valve gated stack injection molding apparatus with an upstream heated nozzle seated in a fixed mold platen and a downstream heated nozzle seated in a movable mold platen. The melt flows through a melt passage across a parting line from an upstream gate to an aligned downstream gate. A first elongated valve member is reciprocated between a retracted open position and a closed position in which the tip of the valve member is seated in the upstream gate. A second elongated valve member is similarly reciprocated between a retracted open position and a closed position in which the tip of the valve member is seated in the downstream gate. In the closed position, the faces of the tips of the valve members abut against each other along the parting line. One of the valve members has a vent bore extending diagonally from its face to avoid a piece of plastic film being formed from melt trapped between them in the closed position.

Abstract: A sprueless disc mold including: a gate insert; a hot plunger adapted to come into sliding contact with the gate insert and heated and held; drive means for moving the hot plunger to open/close the gate; and a cooling air passage. The hot plunger includes a shoulder portion formed at its leading end portion. The gate insert includes: a leading end face forming a portion of a cavity face together with the shoulder portion of the hot plunger; an annular recess for forming the disc into a shape having one face raised to the crest of a stack rib; and an inner circumference extending from the inner circumferential edge of the circumferential recess toward the gate.

Abstract: To provide a resin molding method and apparatus that may realize a sprue runnerless system with a very simple structure and at a low cost, a molten resin 4 is fed from a resin supply portion 1 into a pair of cavities 3 through a resin passages 2 such as a sprue portion 2A and a pair of runner portion 2B for molding the resin. The method includes the following steps of: moving a resin return member 5 toward the resin supply portion 1 after supplying the molten resin 4 into the cavities 3, the resin return member 5 being disposed so as to be projectable into the resin passage 2 and movable through the resin passage 2; and returning a waste molded resin 6 under a molten/solid condition within the resin passage 2 back into the resin supply portion 1 under a molten condition by a heat of the resin supply portion 1.

Abstract: An injection molding one-piece gate and cavity insert to be mounted between a heated nozzle and a cavity. The insert has a cooling fluid chamber extending around the central gate with a thin cavity wall portion extending between the cooling fluid chamber and a convex portion of the cavity. Alternating frontwardly and rearwardly projecting rib portions extend radially into the cooling fluid chamber to form a pair of tortuous passages between them for cooling fluid flowing each way around the insert from an inlet to an outlet. In addition to providing more cooling because of turbulent flow of the cooling fluid and their increased surface area, these rib portions also substantially increase the strength of the insert to withstand repetitive injection pressure in the cavity.

Abstract: A molding apparatus for plastic parts which includes a stationary core plate and a moveable cavity plate used to form a mold cavity, and an ejector plate with pins utilized to eject the molded part from the apparatus. The valve used to inject the liquid plastic, which may be coupled to the core plate or the cavity plate, is always located on the same side of the plastic part as the ejector plate.

Abstract: The invention relates to an apparatus for injection molding the shells of a mini-disk cartridge or the like. More particularly, the device includes a main cavity having a shape of mini-disk shell. The mold contains various projections and indentations on the first and second surfaces, respectively, which are adapted to form a shutter recess near a first edge of the lower shell, a read/write port for a media disk in a vicinity of the first edge within the shutter recess, a shutter guide track on the outer surface of the lower shell close to and parallel to the first edge, a drive port for rotating a media disk, and various fastening bosses for fastening the upper and lower shells of the mini-disk cartridge together. A single hot-runner valve gate is placed in the mold close to one corner such that small cavities within the cavity are filled with polymer melt first.

Abstract: In order to facilitate the formation of a plastic member with an aperture in a central portion thereof, a ring gating valve arrangement is provided with a multi-piston servo arrangement which enables a specially configured pin to be stepwisely reciprocated back and forth within a molding device. The pin is formed with a land at one end which is dimensioned and shaped to produce the required aperture. The pin further features a channel structure which includes an annular recess adapted to permit plastic to flow into the center of the mold cavity area when the pin is thrust to a predetermined location. After the cavity is filled with hot plastic, the pin is retracted to a position wherein the annular recess is located within a removable gate bushing and the shaped land is pulled up until it is appropriately located in the mold cavity area. As the injected plastic cools and solidifies, the shaped land acts as the aperture molding pin and forms a clean aperture in the molded part.

Abstract: An injection molding ring valve assembly, having a concentrically disposed axially translatable center valve body member which when in a first axial position allows mass flow through the valve assembly and a separate front valve seat member in the shape of a torus in cooperation with a check ring, thereby providing smooth and unrestricted annular flow through the valve assembly during the priming process of the injection sequence. The check ring, formed from a cylindrical outer ring disposed about the center valve body member, sealingly engages an outer valve seat portion of the torus or front valve seat member. The torus further includes a center hub portion and at least one radially projecting web portion connecting the hub portion and the annular outer portion, resulting in one or more substantially axial semi-annular openings for the smooth and unrestricted passage of molding material.

Abstract: Valve gated injection molding apparatus wherein the reciprocating valve member extends into the melt passage through a sealing bushing. The sealing bushing has a thin steel collar portion which extends forwardly into the melt passage and fits around the valve member to form a seal against leakage of melt rearwardly along the valve member. In the preferred embodiments, the collar portion is thin enough that it is slightly compressed around the valve member by the pressure of the surrounding melt in the melt passage to improve the seal.

Abstract: A needle shut-off nozzle for plastic injection moulding compounds with an internal chamber for a spring acting on a shut-off nozzle has a basic body. The end of the shut-off needle (11) facing the spring (7) is designed as a cylinder (12) which is closed on the end facing the tip of the needle. The cylinder (12) engages an opposing cylinder (13), designed as a hollow cylinder, in sliding fashion, producing a sealing effect.

Abstract: A valve gate injection molding apparatus, in which the gas produced within a heating probe is discharged through a gas discharge outlet groove from the base side of a valve pin, leak of the resin melt is prevented by flowing a cooling fluid for controlling the temperature to increase viscosity of the resin melt, and preventing overheat of the valve pin actuating assembly caused by heat conduction from the heated and pressurized resin melt.

Abstract: A plasticizing assembly for use in an injection molding machine for processing synthetic materials having a plasticizing cylinder at which a nozzle body is mounted and that is provided with a rotatable feed screw disposed in a cylindrical chamber with an inside diameter substantially corresponding to the diameter of the feed screw. The inside diameter of the nozzle body section is tapered to the inside diameter of the nozzle channel, taking as starting point the rear end diameter in a transition section between the plasticizing cylinder and the nozzle body. A chamber is provided in the transition section between the plasticizing cylinder and the nozzle body for spatial fixing of an adapter, which has an outlet transversely disposed with respect to an injection axis and which adapts the inside diameter of the chamber to the rear end diameter of the nozzle body. In such an arrangement, the plasticizing cylinder can be changed without necessarily changing the nozzle body, too.

Abstract: A pin closure nozzle for injection molding molds has several working pistons acting on the same closure pin. These working pistons are arranged on a common throughgoing piston rod. Each piston rides in its own chamber and the piston rod passes through and is slidingly guided in openings in the chamber floors. The piston rod thus has at least two sliding guides and is accordingly prevented from tilting.

Abstract: This invention concerns an injection molding nozzle device (25) provided with an operating valve (31) installed movably in the axial direction inside a nozzle body (4) possessed of a resin passage (12) and enclosing therewith a fluid passage (10) incorporating therein a check valve (11). This injection molding nozzle device is furnished with a fluid discharge open-shut device capable of opening or shutting a fluid discharge passage (17) formed separately of the fluid passage (10) or the check valve (11) of the fluid passage (10).

Abstract: The present invention relates to an apparatus for injecting molten plastic material. The apparatus includes a novel bushing arrangement have a threaded portion which forms part of a mechanical connection between the bushing and an air piston housing so as to reduce the possibility of plastic material leaking between the bushing and the air piston housing. The bushing has a melt channel for mating with a melt channel in a manifold in which the bushing is housed and with an axial channel in a nozzle body. The bushing is sized to fit within a bore in the manifold so as to reduce the possibility of leakage between the bushing and the manifold. The bushing also serves to close off or plug holes or channels drilled into the manifold. In one embodiment of the present invention, the bushing has a passageway through which a valve stem for closing off a gate in the nozzle body passes.

Abstract: In an injection molding machine, a skin layer resin 26 is injected from a first hot runner 10b into a cavity C in a mold or molds and then a resin passage between the first hot runner 10b and the cavity C is closed, thereby finishing the injection of the skin layer resin 26. A core layer resin 28 is injected from a second hot runner 12b into the cavity C in the mold(s) at a predetermined timing during the period between the start and end of injection of the skin layer resin 26, thereby molding a sandwich molded product without hesitation marks.

Abstract: A molding apparatus for plastic objects which includes a valve which allows ejector pins to be positioned in close proximity to the valve needle. The valve includes a valve body and a flange surrounding at least a portion of the valve body such that the outer edges of the valve body and/or the flange may have slots which extend lengthwise from the top to the bottom of the valve. Depressed portions in the side portions of the flange and corresponding outer edges of the valve body may also extend through the length of the valve. The slots and depressed portions may be utilized for positioning ejector pins in close proximity to the valve needle.

Abstract: A multiple closure pin nozzle assembly serves for the simultaneous charging of several individual molds in an injection molding mold and has two or more closure pins arranged in a common housing and driven by a common piston drive. Each closure pin closes a nozzle orifice arranged relative thereto and can be pulled back from this in order to allow the injection of molding material. In the region of the respective nozzle mouth, a heating device is arranged. In the common housing, feed channels are provided with branches which lead to the individual closure pins and their mouths. The common housing is split up below this common feed channel and its branches into separate housing portions connected with the common housing and each accommodating an individual closure pin and nozzle mouth. The housing portions have walls which run around the pins and interspaces between these walls to enable supports for the multiple nozzle assembly to be introduced below the common housing region between the housing portions.