Abstract: A method of molding golf balls using an injection mold. The golf ball includes a plurality of dimples closely distributed on the surface of the ball. The injection mold for golf balls including a pair of separable mold segments (12, 12) defining a spherical cavity (22) when mated along a parting line (PL). A plurality of hollow tubular gates (20) are disposed in the surfaces of the mold segments to be mated along the parting line and in fluid communication with the cavity. Each gate (20) has a non-circular cross section at its outlet. Opposed portions (20-1, 20-2) of the gate cross section separated by the parting line (PL) have an equal area. A stock material is injected into the cavity through the gates to mold a golf ball.

Abstract: A manifold for a hot process injection molding apparatus includes a two piece manifold assembly. A first manifold section which includes a longitudinal melt channel and a nozzle drop to a mold is fixably secured to a manifold cavity of the apparatus. A second manifold section also including a longitudinal melt channel is sealably and slidably coupled with the first manifold section for fluidly communicating molding material from the second melt channel to the first melt channel. Expansion and contraction of the manifold sections are taken up by the slidable coupling.

Abstract: Injection molding apparatus with a guide and sealing ring mounted around the front end of a heated nozzle. The stainless steel ring fits around the nozzle and has fingers which are bent over the front end of the nozzle to hold it in place. A thermocouple element extends through a groove in the ring and is bent into a hole in the front end of the nozzle. One of the fingers is bent over the thermocouple element to hold it in place. The outer surface of the ring has a circumferential beveled surface leading to a ridge which guides the nozzle into place during insertion and provides a secondary seal against melt leakage. A number of rearwardly extending fingers have notches to receive a wire wound around the nozzle to hold the thermocouple element and the ring itself in place.

Abstract: Injection molding apparatus with a central heated manifold, a pair of connector manifolds, and at least four nozzle manifolds mounted to extend in a common plane in a mold. A number of heated nozzles extend from each nozzle manifold. A melt passage branches in each nozzle manifold and the nozzle manifolds are made so thermal expansion slides the branches of the melt passage into exact alignment with central melt bores through the nozzles. The central manifold and the two connector manifolds extend along a central axis and each connector manifold is between each pair of nozzle manifolds which are offset from the central axis. Connector bushings slidably connect each connector manifold rearwardly to the central manifold and sidewardly to each nozzle manifold.

Abstract: Multi-cavity injection molding apparatus having four nozzle manifolds mounted in a common plane with a central inlet manifold having two arms extending in opposite directions. The central manifold has a longitudinal axis extending in a first direction through the two arms. Each nozzle manifold is offset from the central manifold in a second direction that is substantially perpendicular to the longitudinal axis. Each nozzle manifold has a locating pin to locate it in a second direction perpendicular to the first direction. The locating pin allows thermal expansion to slide the nozzle manifold in the first direction into a position wherein each branch of the melt passage is aligned with the melt bore through one of the nozzles extending from the nozzle manifold. A pair of the nozzle manifolds are connected on opposite sides of each arm of the central manifold by connector bushings.

Abstract: A meshed plastic filter of a narrow-pitch net including a net and a frame in a unitary body is produced in either a square or a circular overall shape, and has diverse applications, such as a filter or sieve for gasoline or oil, a dust collector filter and other various filtration. A precision die has developed for producing such a meshed fabric plastic filter. The precision die has grooves called dam/discharge rib grooves radiating from the die center for guiding and pressuring the injected material and the vertical and horizontal rib grooves existing in horizontal and vertical directions for forming the net, so that gas retention inside the die is prevented and the material sneaks uniformly into the vertical and horizontal rib grooves and a frame groove through the dam/discharge rib grooves.

Abstract: A multiple gate injection nozzle is described in which individual insert heaters are utilized, each associated with a respective probe to allow different probe lengths without upsetting proper temperature conditions at each gate. A main heater is also used encircling the main body of the nozzle. Replaceable copper sealing rings expand to a greater extent than the steel main body to increase the sealing pressure during operation.

Abstract: Hot tip injection molding apparatus having a heated melt distribution manifold for conveying melt to a number of gates. A number of nozzle manifolds are closely mounted to the front surface of the heated manifold. Each nozzle manifold has a number of spaced nozzle portions extending from a rear manifold portion. A melt channel branches from an inlet on the rear surface of the rear manifold portion to an outlet on the conical surface of each nozzle portion. The rear surfaces of the nozzle manifolds are rectangular rather than round to improve the efficiency of heat transfer from the heated manifold to the nozzle manifolds.

Abstract: Electrically heated manifold system in an injection moulding structure, the system comprising a manifold element, the manifold element being adapted to direct molten plastics material from the extruding device to the mould-cavity, and bearing an inlet-gate at one side for connection to the outlet nozzle of a plastics extruding device, an elongate bore system leading from the said inlet-gate to at least one outlet-gate at the other side of the manifold-element to connect with at least one opening in a cavity-plate having a mould-cavity, the bore system branching into as many respective outlet-gates as there are openings in the corresponding cavity-plate, the manifold-element further having at least one elongated electrical heating body provided in heating relationship with the bore system and preferably distinct there from, the electrical heating body having opposite free in- and output ends projecting from the manifold-element, the ends connected by separate electrically isolated lead-elements to the respecti

Abstract: Apparatus for pulsating gas-assisted injection molding hollow tubular plastic parts includes the injection of a molten plastic into a mold cavity in an amount less than the cavity volume and in separate molten plastic flows that flow along the cavity and ultimately unite in a solidifying fusion welding state at an interface. A pressurized gas is injected into the molten plastic to form a central void in the molten plastic extending to opposite sides of the interface leaving a voidless solidifying fusion weld section encompassing the interface. The gas pressure acting on the opposite sides of the interface is trapped and then alternately increased and decreased by a separate gas injection that creates gas pulsations that effect shifting of the molten weld section in opposite directions to force intermingling of the plastic molecules therein and across the interface to enhance the strength of the fusion weld section on solidification and eliminate appearance knit lines.

Abstract: A multitip hot runner system for providing enhanced flexibility in the design, manufacture, and operation of multicavity molds. The system, which is self-contained, comprises a nozzle or manifold interface, externally heated flow passages, and interchangeable or replaceable tips. A fully hardened, generally rectangular parallelopiped shaped body permits a number of different multitip configurations, all of which maintain substantially uniform heating throughout the distribution architecture with the use of only a single thermocouple for temperature control. The parallelopiped shaped body is especially useful in molding parts arrayed in straight lines or in rectangular arrays.

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: The invention provides methods and apparatus in which mold material flows through a gate into a mold cavity that defines the shape of a desired part. An adjustable valve is provided that is operable to change dynamically the effective size of the gate to control the flow of mold material through the gate. The valve is adjustable while the mold material is flowing through the gate into the mold cavity. A sensor is provided for sensing a process condition while the part is being molded. During molding, the valve is adjusted based at least in part on information from the sensor. In the preferred embodiment, the adjustable valve is controlled by a digital computer, which includes circuitry for acquiring data from the sensor, processing circuitry for computing a desired position of the valve based on the data from the sensor and a control data file containing target process conditions, and control circuitry for generating signals to control a valve driver to adjust the position of the valve.

Abstract: A high precision, self-contained runnerless molding system for use particularly in bench top molding machines. The system comprises two mold halves, one affixed to the fixed platen of the machine and the other moveable with the moveable platen of the machine. The fixed halve is integrated with heated sprues and interchangeable tips. One zone of temperature control suffices for regulating plastic temperature in the delivery system. The other half carries the "B"-plates and cooling system. Multiple drops are possible even with only one thermal control zone.

Abstract: A manifold assembly for supplying plastic material from a plastic source to a mold assembly in an injection molding machine includes a flexible manifold having an interior conduit connected between the plastic source and the mold assembly. The flexible manifold is configured to define an input connector, a first curved segment attached to the input connector, a second curved segment, an output connector attaching the second curved segment to the mold assembly, and an intermediary segment connecting the first and second curved segments. This provides the flexible manifold with a generally S-shaped configuration that flexes with temperature changes to maintain a substantially constant positioning between the input connector and the output connector, preventing thermally induced movement of the mold assembly with respect to the input connector as heated plastic is injected through the conduit.

Abstract: A nozzle for directing molding material from a material source to a sprue, includes a first surface adapted to connect the nozzle to the material source. The first surface is also adapted to be adjacent to and pivotally movable relative to the material source and in material communication with the material source. A second surface is adapted to be positioned adjacent to and pivotally movable relative to the sprue. The second surface is in material flow communication with the first surface and adapted to be in material flow communication with the sprue. A channel is included for establishing the material flow communication through the nozzle.

Abstract: A multi-cavity mold has flow-distribution adjusting heaters provided for respective ones of main runners branching from a common channel so as to correspond to a plurality of cavities. The amount of resin charged into the cavities is made uniform from one cavity to the next by independently controlling the heaters. Sub-runners leading respective ones of the main runners are respectively provided with heaters for adjusting gate finish. The gate finish and moldability are improved by independently controlling these heaters. The main runners hold enough resin for at least one shot, and pressure loss in the sub-runners is made equal to or greater than pressure loss in the main runners.

Abstract: A heated manifold system for use in the distribution of heated plastic resins to the various cavities of injection molds for thermoplastic materials. The manifold main structure consists of modular components of similar cross-section that are nested into each other by employing similar slots cut out at the points of intersection of the components. The thermoplastic resin passages are bored longitudinally in each modular component; transverse bores at each intersection provide resin passages between the longitudinal bores. The system includes heated nozzles which have slots to receive cartridge heaters and heater covers, also spring clips to retain the covers and heaters, which can rotate around the shank of the nozzle to allow easy replacement of the cartridge heaters in the event of failure. Internal sealed liquid-filled channels or highly conductive metal rods are used to equalize the temperature of the nozzle from one extremity to the other.

Abstract: A manifold is disposed within a pair of abutting pre-load mold plates in a pre-load relationship. Fluid flowing through the manifold is heated by a first heater. The fluid is then divided into a plurality of passages in the manifold. Pairs of passages have a back-to-back in-line relationship. A cylinder between each pair of the in-line passages holds a pair of pistons in the in-line relationship. Each piston in the pair has piston units in an interdigitated relationship with piston units on the other piston in the pair. Each pair of pistons is movable by pressurized fluid (e.g. air) between first and second positions. In the first position, each piston provides for the fluid (e.g. resin melt) flow through one of the passages to a pair of runners in the manifold. In the second position, each piston prevents the resin melt flow through the passages. A first heater heats the resin melt flowing through the passages. A second heater heats the resin melt flowing through the runners.

Abstract: A multitip hot runner system for providing enhanced flexibility in the design, manufacture, and operation of multicavity molds. The system, which is self-contained, comprises a nozzle or manifold interface, externally heated flow passages, and interchangeable or replaceable tips. A fully hardened body permits a number of different multitip configurations all of which maintain uniform heating throughout the distribution architecture with the use of only a single thermocouple for temperature control.

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: An injection molding nozzle with a hollow inner portion and a separate removable outer collar portion which sits on a seat in the mold. The outer collar portion has two separate semicircular segments which extend around and interlock with the inner portion with sufficient strength to prevent longitudinal movement of the inner portion when sealing pressure is applied. A resilient split retaining ring clamps the two semicircular segments together in the interlocking position. In one embodiment, the nozzle has an integral electrical heating element with lead portions which extend radially outward to a ceramic insulator. The ceramic insulator has an inner end portion which is also secured in place in an opening between the two semicircular segments.

Abstract: An injection molding nozzle for cold runner molding thermosetting molding material in a heated mold. A bore extends centrally through the nozzle to convey liquid molding material from a cooled distribution manifold to a gate leading to a cavity. An integral cooling fluid conduit has a helical portion extending concentrically around the molding material bore. Cooling fluid circulates from a radial inlet portion to a radial outlet portion of the cooling fluid conduit to cool the liquid molding material flowing through the central bore.

Abstract: An injection molding nozzle seal around the gate which bridges the insulative air space between the front end of the heated nozzle and the cooled mold. The nozzle seal is provided by two removable inserts mounted in alignment with the central melt bore through the nozzle to convey the melt therethrough forwardly to the gate leading to the cavity. The first insert is screwed into a threaded seat in the front end of the nozzle and the second insert is screwed onto the first insert. The inserts each have a hexagonal portion for engagement by a wrench. Both of the engagement portions extend in the air space around the nozzle which facilitates removal of the inserts for cleaning or replacement without disassembling the mold.

Abstract: The present invention relates to an improved apparatus for forming injection molded plastic articles having an inner wall portion. The apparatus includes a mold cavity portion and a mold core portion defining a cavity space in the shape of the plastic article to be formed. The apparatus further includes at least two hot runner nozzles for injecting molten plastic material into the cavity space. The nozzles are preferably offset to outer portions of the mold core portion so as to provide an increased space in the mold core portion in which cooling conduits, inlets and the like can be placed to increase the cooling capability of the mold core portion. The offsetting of the nozzles also provides the mold core portion with increased strength. Each of the nozzles communicates with inner wall portion of the cavity space via a hook-shaped passageway and an inside gate. Additionally, each of the nozzles has a metal portion for maintaining plastic material in the hook-shaped passageway in molten condition.

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: 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.

Abstract: Multi-cavity injection molding apparatus with hot tip gates extending perpendicular to the direction of mold opening to provide very clean shearing action. The heated nozzles extend diagonally outward in two rows from a pair of diagonal surfaces extending along an elongated melt distribution manifold. Each nozzle has a pointed tip extending outwardly at an angle to its longitudinal axis in alignment with one of the gates. The outward angles of the nozzles themselves and their pointed tips enable the gates to be oriented parallel to the parting line and perpendicular to the direction of mold opening.

Abstract: Injection molding apparatus with a number of spaced inserts removably seated in a heated melt distribution manifold. Each insert is seated in a transverse opening through the melt distribution manifold in alignment with a heated nozzle. The insert has a melt duct with a smoothly curved bend extending through 90.degree. to an outlet in matching alignment with a melt bore extending centrally through the nozzle. The insert has an alignment pin which extends outwardly through a matching aperture in the melt distribution manifold into an opening in the mold to both align the insert in the manifold and locate the manifold in the mold. The alignment pin bore is positioned opposite from and in alignment with the inlet to the melt duct so alignment of the melt duct inlet in the insert with a respective branch of a melt passage in the manifold is very accurate.

Abstract: The present invention relates to an apparatus for injection molding a thin-walled plastic article with substantially equal thickness sidewalls, a base portion, and a lip portion. The apparatus includes a two part mold arrangement in which a first part defines has a mold cavity and a second part defines a mold core. The first and second mold parts in a mold closed position define a mold space in the shape of the article being molded. The apparatus further includes two or more gates adjacent a lip portion of the mold space for injecting molten plastic material into the mold space and a bottom center venting arrangement. The apparatus further includes a restriction in the mold space for improving the operation of the bottom center venting arrangement and providing a more balanced filling in a multi-cavity molding machine.

Abstract: An injection molding station includes a mold manifold plate housing a plurality of injection molding nozzles and housing heaters for the plurality of injection molding nozzles; at least one printed circuit board associated with the mold manifold plate; and a power source; wherein the at least one printed circuit board electrically connects the power source with the heaters. Each printed circuit board has at least one power layer printed with a plurality of power supply tracks, the power supply tracks being connected at a first end to the power source and at a second end to a respective heater. Each nozzle may also have a respective temperature sensing device, the printed circuit board having at least one sensor layer printed with sensor tracks, the sensor tracks being connected at a first end to a respective temperature sensing device, and at a second end to a controlling device.

Abstract: A heated injection molding nozzle having a cylindrical locating flange extending forwardly from a rear collar portion to mount the nozzle in a well in a cooled mold. The nozzle has a cylindrical central portion with an insulative air space extending between it and the surrounding cooled mold. A hollow thermocouple tube extends through the rear collar portion and along the inner surface of the locating flange to removably receive a thermocouple element which extends from the rear end of the nozzle and through the insulative air space to monitor the operating temperature near the forward end of the nozzle. In the event of pressurized melt escaping to fill the air space, contact of the thermocouple tube with the locating flange cools the melt which flows into the thermocouple tube sufficiently to freeze it and prevent leakage out amongst the wiring in other parts of the mold.

Abstract: A hot runner system (10) for injection molding which includes a block-shaped casing (12) with a bore (14) for facewise insertion of at least one cartridge-like unit (16) having a material flow tube (32) enclosed by a heating device (38), and by a thermoconductive casting (V), and opposite flow transfer openings (35, 36), there are radial supports (40) protruding over the outer diameter (D) of the cast body (30) with an engaging face that is recessed relative to the bore (14) and serves for form-fit to nozzles (11), further units (16), additional flow tubes (32), etc. the supporting element for the cast body (30) being symmetrically arranged in either axial direction to form hollow compartments, including thin spiders (49), ribs (50), supporting segments (51) and tube-type studs (68), axial abutting members (18, 19) providing for tight closure of the hot runner system (10).

Abstract: Apparatus includes a mold cavity and a molten plastic inlet channel for communication with the mold cavity for transmission of molten plastic to the mold cavity. A valve stem is provided with substantially no net resulting forces on the valve stem due to melt pressure acting on the projecting area of its upstream and downstream faces.

Abstract: Injection molding apparatus wherein a torpedo is mounted in the front end of a heated nozzle. The torpedo has spaced blades extending inwardly from an outer collar to an elongated shaft which extends centrally in the melt bore. The torpedo shaft has an elongated central portion which is securely press fitted in a steel outer sleeve from which the blades extend. The elongated central portion of the torpedo shaft extends forwardly into the gate, and is formed of an engineered ceramic such as silicon carbide which is very thermally conductive as well as abrasion and corrosion resistant. In one embodiment, the gate extends through a gate insert which is also formed of a thermally conductive and abrasion and corrosion resistant engineered ceramic material.

Abstract: An injection molding nozzle and method of making it having an electrical heating element extending in a pair of alternating coils in a spiral channel around a central melt passage. The heating element has a U-shaped bend near the forward end of the nozzle and two ends at an external terminal near the rear end. A central wire in the heating element has a fine coiled heating portion extending between two larger diameter conductive portions which extend to the terminal. One of the conductive portions of the central wire is a predetermined length longer than the other and extends in one of the alternating coils of the heating element along a rear portion of the nozzle adjacent the terminal. The heating portion of the wire extends in both of the alternating coils of the heating element along a forward portion of the nozzle so the heating element provides substantially less heat along the rear portion than along the forward portion of the nozzle.

Abstract: A seating and sealing insert for mounting a heated injection molding nozzle in a well in a mold. The hollow insert has a cylindrical central portion extending between a rear seating portion and a forward sealing portion. The rear seating portion is outwardly flanged to seat in the well in the mold and forms an inner seat to receive a cylindrical support flange of the nozzle to accurately support the nozzle in the well in the mold. The forward sealing portion has a V - shaped forward face and inner and outer surfaces which are forced outwardly by melt pressure to seal against the nozzle and the mold. Thus, the seating and sealing insert provides an insulative air space between the heated nozzle and the surrounding mold and the forward sealing portion prevents the escape of pressurized melt into the insulative air space.

Abstract: A hot passage nozzle system including a manifold block, nozzle plate and one or more sprue bushings. At one end the sprue bushings are screwed into mating receptacles in the manifold block and centered at the exit openings of the material passageways in the block. The other ends of the sprue bushings are centered in the nozzle plate. The sprue bushings have annular grooves adjacent the connection with the manifold block creating points of flexure in order to accommodate dimensional changes due to temperature changes during use, and also to accommodate manufacturing tolerances.

Abstract: A heated injection molding nozzle having a rear member and a forward member which is removable. A channel extends through the rear and forward members to convey pressurized melt to one or more gates extending through the mold to a cavity. The rear member has an electrical heating element with a spiral portion which extends around the melt channel. The forward member has a tapered rear portion which extends rearwardly into a matching tapered well in the rear member. The taper is sufficient so the tapered portion is frictionally retained in the well to removably mount the forward member to the rear member. This allows the forward member to be easily turned or driven out of engagement in the well to replace it with a new forward member or a forward member having a different configuration to provide a different type or arrangement of gating.

Abstract: A pressure molding apparatus for supplying molten resin to a mold includes a gate unit having an aperture therein for passage of molten resin into a mold cavity of the mold, a gate pipe connected for communication with the gate unit, and a gate pin which is axially movable within the gate pipe. The gate pin has a gate pin end at one end and a tip at another end thereof, the tip being engageable with the aperture for controlling flow of molten resin through the gate unit. The apparatus also includes a manifold pipe for supplying molten resin to the gate pipe, a connection arrangement for connecting the gate pipe to the manifold pipe. The connection arrangement includes a receiving portion for receiving molten resin from the manifold pipe, the gate pin passing completely through the receiving portion and the gate pin end extending beyond the connection arrangement.

Abstract: The present invention provides a multi-ply molding hot-runner mold including a plurality of nozzle bodies for injecting a plurality of different resin materials to form a multi-ply product. The hot-runner mold comprises a plurality of hot-runner blocks each having a runner for conducting each resin material into the corresponding nozzle body. The hot-runner blocks are stacked one above another with a thermal insulation layer therebetween. Each of the hot-runner blocks includes temperature control means for maintaining the hot-runner blocks at its own molding temperature. Connecting blocks for conducting the resin material from the lower block to the upper block are provided between each adjacent hot-runner block. Between each adjacent hot-runner block there are provided holding members and thermal insulation layers.

Abstract: A heated manifold, for use in the distribution of heated plastic resins to the various cavities of injection molds for thermoplastic materials. The parts of the manifold interlock with each other and contain the high pressures generated by the injection molding presses. The components of the manifold are fitted with seals of metals dissimilar to the manifold, and with a higher coefficient of expansion than the manifold material. The system includes heater bushings which channel the plastic materials to the individual cavities and are fitted with a removable tip which can be adjusted to change the overall length of the bushing. A duct structure provides passages for the heated plastic, and electrical heaters extend generally along the passages, secured in channels in the duct structure by heater covers; a snug assembly of the heaters in the channels provides excellent heat transfer, utilizing heater covers of a metal that is mechanically forced to flow into undercuts in the channels.

Abstract: This invention relates to a hot tip gated injection molding apparatus having a heated manifold to distribute melt to a number of spaced gates. An unheated sealing and conductive member is mounted directly between the heated manifold and the cooled cavity plate in alignment with each gate. The sealing and conductive member has an elongated hot tip shaft which is connected to extend centrally through the bore of an outer collar portion by a number of spaced spiral blades. The collar portion bridges an insulative air space between the hot manifold and cooled cavity plate to prevent melt leaking into it. Heat received through the rear end of the collar portion which abuts directly against the heated manifold is transferred through the blades and the hot tip shaft to the gate area which is aligned with the pointed forward end of the hot tip shaft. The rear end of the hot tip shaft extends rearwardly into a branch of the melt passage to pick up heat from the surrounding melt.

Abstract: A modular manifold system is described. A plurality of generally cylindrical manifold components engage a melt distribution element. The manifold components each have a generally cylindrical body which has an annular cavity formed therein which axially extends with the component body for a predetermined length which separates the component body from a component inner core. A melt runner passage extends axially through the inner core. A heating element in the form of a ceramic insulator sleeve occupies a portion of the annular cavity with a particulate refractory material occupying the remainder of the annular cavity.

Abstract: A process and apparatus for injection molding thin-walled plastic articles having comparatively thick lip portion. The apparatus has a mold cavity and a mold core defining a cavity space in the shape of the article and at least one injection gate adjacent a portion of the cavity space defining the lip portion through which molded plastic is injected into the cavity space. The direct lip gating approaches employed in the apparatus do not sacrifice core/cavity alignment and conventional mold motions along the machine axis and form plastic articles having substantially no gate vestiges on the lip sealing surface or on the outer perimeter of the lip.

Abstract: An apparatus for use in gas-assisted injection molding of plastic material so as to form an injection molded product includes a pair of mold members defining, when closed, a sealed cavity. A first opening is provided in one of the mold members for allowing the injection of a plastic material into the mold cavity and a second opening is provided in one of the mold members, and spaced from the first opening. A sleeve extends through the second opening. A probe extends through the sleeve and is adapted to be reciprocated therein from a retracted position to an extended position. The probe includes a first end adapted to selectively extend into the cavity, a second end and a longitudinally extending bore which terminates adjacent the second end. A reciprocating device is provided for reciprocating the probe in the sleeve held in the second opening of the one mold member in relation to the cavity.

Abstract: A method and apparatus for molding plastic articles in two colors, particularly, the bodies of magnetic tape cassettes, in which a strong bonding force is provided between the two portions without having to form a recess and projection on the joining edges of the two portions. A slide core, which is moved in and out of a primary molding cavity between the molding of the two portions of the article, is provided with a tubular passage having an opening within the primary molding cavity along edge portions of the slide core. The slide core is fully inserted into the primary molding cavity to mold the first portion, then partially withdrawn to form a secondary molding cavity in which the second portion is subsequently molded. After molding the first portion, an adhesive is injected through the tubular passage along the edges of the first portion which will join corresponding edges of the second portion to thereby firmly join the two portions.

Abstract: An elongated probe which extends into the melt passage in an injection molding system. The probe has an integral electrical heating element which extends longitudinally from a terminal near the rear end. The probe also has a longitudinal bore which extends beside the heating element to receive a thermocouple wire to monitor the temperature near the forward end of the probe. The heating element extends off center in the body of the probe which provides the body of the probe with the combination of a minimum outer diameter and sufficient thickness between and around the heating element and the thermocouple bore. A forward portion of the probe has a number of outwardly projecting locating fins. The thermocouple wire bends to extend radially outwardly through a groove at the rear end and is retained in place by a retaining screw received in a threaded bore. A ground wire extends in through a hole in a rim portion around the threaded bore and is also clamped in position by the retaining screw.

Abstract: Multi-cavity injection molding apparatus to coinject pressurized melt from two or more melt sources. An inner melt passage extends through the central bore of a melt distribution plate and an adjacent heated nozzle. The nozzle has a tapered nose portion which extends into an adjacent heated cavity forming insert having a gate leading to one of the cavities. An outer melt passage is separated by curved conduits on opposite faces of the melt distribution plate into four channels which are radially spaced around the central bore of the nozzle. The four channels lead to a melt funnel duct which extends in the adjacent cavity forming insert around the nose portion of the nozzle. Thus the melt from the outer melt passage is evenly distributed around the melt from the inner melt passage when they join just before entering the gate.

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.