Abstract: Injection molding apparatus for side gating to several cavities spaced around a central heated nozzle extending through an opening in the mold. Several side gate seals are seated in a front portion of the nozzle, each in alignment between one of several radial portions of a melt channel through the nozzle and a gate leading to one of the cavities. The side gate seals each have an outer end which extends a sufficient distance outwardly past the inner surface of the opening in the mold to provide room for cooling conduits extending between the cavities and the central opening. The side gate seals are mounted after the nozzle is sealed in the opening in the mold. A gate insert is then mounted radially into position over the outer end of each side gate seal. A gate insert retainer plate secures the gate inserts in place.

Abstract: Injection molding apparatus having several side gate seals extending radially from a heated nozzle. The nozzle has a locating flange portion which is received in an opening in the mold. This laterally locates the nozzle while allowing it to be advanced for mounting of the side gate seals and then retracted to an assembled position where it is longitudinally located by the side gate seals being received in the mold. Thus, the nozzle is longitudinally located in the same plane as the gates and in one embodiment a melt distribution manifold is free to float with the rear ends of the nozzles. This also provides for differences in the thermal expansion due to possible different operating temperatures.

Abstract: An injection molding nozzle with a collar having two segments mounted around the rear end of an elongated central body having a hollow central core. A helical portion of an electrical heating element is cast in a copper alloy conductive portion around the central core. The heating element has a pair of lead portions which extend outwardly through the collar into a ceramic insulative connector. The lead portions extend in stainless steel protective tubes having inner ends rigidly cast in the copper alloy conductive portion over which the insulative connector is mounted.

Abstract: An injection molding nozzle with an elongated body removably seated in a one-piece outer collar. The outer collar has a circular insulation flange which seats in the mold to locate the nozzle. The elongated body has an electrical heating element coiled around a central melt channel. Terminal portions of the heating element extend outwardly through a U-shaped opening in the outer collar into a ceramic connector. The connector is secured in place by an inner lip which slides into a groove around the U-shaped opening.

Abstract: An exhaust ventilation apparatus to be temporarily mounted in a continuous pulp digester or similar elongated vessel to provide local air ventilation from one or more selected worksites in the vessel. An exhaust duct extending upwardly to an outlet opening has numerous inlet ports spaced along it. Venturi type air movers each having an air collection conduit attached to it are connected to several of the inlet ports of the exhaust duct. Each air collection conduit is mounted with an inlet located near one of the selected worksites to draw polluted air out of the vessel through the exhaust duct. The air movers and/or the air collection conduits are easily movable as work progresses.

Abstract: An injection molding melt distribution manifold and method of making it with a melt passage extending from a single inlet to a plurality of outlets. The melt passage has a branching portion formed by machining matching grooves in opposing surfaces of two steel plates and then integrally brazing them together. The manifold has an embedded electrical heating element received in a channel formed by two other matching grooves in the opposing surfaces of the two plates. The channel is then integrally filled with nickel by heating under a partial vacuum. The electrical heating element which extends around and is in or near the same plane as the branching portion of the melt passage to ensure rheological and thermal balance of the melt flowing therethrough.

Abstract: Injection molding apparatus having a number of side gate seals extending outwardly from a heated central nozzle to convey melt to cavities spaced around the nozzle. Each side gate seal has an inner end seated in a front portion of the nozzle and extends outwardly across an insulative air space into a radial opening in a cooled mold leading to a gate to a respective cavity. Each side gate seal has a pointed tip in alignment with the gate and a cylindrical sealing rim which fits in a matching cylindrical portion of the radial opening in the mold. This seal around the side gate seal locates the nozzle longitudinally while allowing the cylindrical sealing rim to slide slightly inwardly and outwardly to allow for thermal expansion and contraction of the side gate seal.

Abstract: An injection molding nozzle to be seated in an opening in a mold with an outer collar extending around an elongated central body. The outer collar is made up of two removable semicircular segments which interlock with the central body. Each of the semicircular segments of the collar have a pair of spaced locating and retaining lug portions which extend outwardly to a longitudinal ridge. This provides sufficient thickness for a threaded hole at each lug portion to receive a screw to tighten the rear end of the nozzle securely against a melt distribution manifold. The ridges of the lug portions fit in contact in the opening in the mold to precisely locate the rear end of the nozzle and retain the two semicircular segments in the interlocking position.

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 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 method of making an injection molding melt distribution manifold wherein the melt passage branches through a number of elbows leading to different gates. Each elbow is preformed in a cylindrical plug which fits in a bore in an outer end of the manifold in alignment with a lateral portion of the melt channel. A brazing hole with an upward mouth is drilled in the outer surface of the plug and nickel alloy brazing powder is poured into it. After insertion into the bore in the manifold, the plug is rotated with a suitable tool to a predetermined position with the mouth of the brazing hole pointed downward. The manifold is then heated in a vacuum furnace to integrally braze the plugs in place simultaneously with brazing an electrical heating element in a channel in the manifold. The melt passage is then completed by drilling an outlet bore from the front face of the manifold to the outlet of each elbow.

Abstract: A method of manufacturing an injection molding nozzle having an integral electrical heating element. The heating element is mounted in a space formed between an inner core, an outer rear collar and an outer sleeve. The space is first sealed by brazing with a nickel alloy brazing material and a copper conductive material is then cast into the space. Both the brazing and casting are done in a single controlled cycle of a vacuum furnace. An insulative cap is placed over the assembly so a supply of inert gas to the vacuum furnace cools the copper conductive material from the bottom up. This produces unidirectional solidification to avoid the formation of voids in the copper conductive material and improve thermal conductivity.

Abstract: A jig which receives a sheet in a selected position to accurately scribe it in a straight line. The jig has front and rear panels which form a vertical slit between them in which the sheet is received. The bottom of the sheet sits on an elongated support bar which extends horizontally in the slit and the line is scribed by running a scribing tool along the upper scribing edge of the front panel. The support bar has a pair of spaced studs which extend out through matching openings in the front panel to allow the support bar to be manually moved between a number of different vertical positions to select the distance the line is scribed from the bottom of the sheet. The openings in the front panel each have a number of spaced slots extending sideways which provide a pair of notches in which the studs are seated in each position. The studs are threaded to receive a retaining knob which are tightened against the front panel to secure the support bar in the selected 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: Injection molding apparatus for hot tip gating wherein a torpedo is screwed into a threaded seat in the forward end of a nozzle. The torpedo has an elongated shaft with a pointed tip mounted centrally in an outer collar by a pair of spiral blades which impart a swirling motion to the melt flowing to the gate. The temperature of the melt in the gate varies according to a continuous thermodynamic cycle in the torpedo. A thermocouple bore extends radially inward through the outer collar and one of the spiral blades to a conductive inner portion of the central shaft of the torpedo. The thermocouple bore is positioned whereby a thermocouple element extends radially outward from it into an insulative air space between the forward end of the nozzle and the mold. The thermocouple element has a substantially 90 degree rearward bend a predetermined distance from its inner end.

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: 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.