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: Injection molding apparatus wherein a heated probe extends into a well in a cavity plate having a generally spherical forward end. The forward end of the heated probe has at least one conical tip which extends outwardly at an angle into a conical recess leading to the gate. Each conical recess has an included angle of at least 90.degree. and the conical recess and conical tip extend outward along the same central axis at an angle to the longitudinal axis of the probe. This allows the tip to extend fully into the recess without intefering with withdrawal for cleaning or repair. The included angle of the conical tip is substantially less than the included angle of the conical recess which gradually accelerates the flow of melt as it approaches the gate.

Abstract: Injection molding apparatus with integral heating and cooling in the forward portion of a nozzle adjacent the gate. Cooling fluid tubes extend to the forward portion of the nozzle through a surrounding insulative air space which reduces problems of thermal expansion and contraction. A split seating ring is seated in the cavity plate and extends across the insulative air space to receive the nozzle. The seating ring has an outer opening for the cooling fluid tubes to pass therethrough.

Abstract: A valve gated injection molding system having an elongated valve member with an integral electrical heating element received in each nozzle to provide additional heat. An actuating mechanism engages the rear end of the valve member to reciprocate it between a withdrawn open position and a forward closed position. The valve member has a head which projects rearwardly from the nozzle. The heating element has an external terminal which extends outwardly from the head through a slot in a mounting sleeve. Thus, access for connection of an electrical lead to the moving terminal is provided between the fixed nozzle and the fixed cylinder of the actuating mechanism.

Abstract: A cast manifold for distributing pressurized melt in an injection molding system. The melt is received at a central inlet on the rear surface of the manifold to an inlet portion of a melt passage. Four identical outlet portions of the melt passage branch radially outward from the inlet portion to equally radially spaced outlets on the forward surface of the manifold. Each outlet portion extends around a first smoothly curved bend from the inlet portion, along a radial portion, and then around a second smoothly curved bend to the outlet. By casting on a removable ceramic mold, the bends in the melt passage are very smoothly curved and do not all have to extend in a common plane. Furthermore, the radial portions angle a substantial distance rearwardly as they extend outwardly which allows the thickness of the manifold to be reduced.

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: Apparatus for thermal gated injection molding having a cavity forming insert separate from the heated nozzle. The cavity forming insert has a combination of heating and cooling extending around a central melt bore leading to a gate. The cavity forming insert has an integral electric heating element with an inner portion having a number of adjacent coils near the gate. Power to the heating element is switched on and off during the thermal gated cycle, and the combination of heating and cooling in the cavity forming insert improves the thermal response and shortens the cycle time.

Abstract: An insulated injection molding nozzle having several alternating layers of stainless steel and ceramic insulating material surrounding an integral spiral electrical heating element. The coils of the heating element are wound around a central cylindrical portion of the body of the nozzle extending between larger diameter rear and forward collar portions. The alternating layers are plasma sprayed over the coil from a thin inner stainless steel layer to a thick outer stainless steel layer. The heating element and an outer shoulder portion are vacuum brazed in two stages to provide a completely integral structure.

Abstract: A multi-cavity injection molding system or apparatus having a spring and sealing housing mounted between each nozzle and the manifold. Each nozzle reciprocates between a retracted open position and a forward closed position in which the tapered forward end is seated in a gate. The nozzle has a central sleeve portion with a bore which projects rearwardly into a matching bore in the housing. Disc springs received in a channel in the housing which extend around the sleeve portion of the nozzle biases the nozzle to the closed position. Thus, during each cycle injection pressure drives each nozzle to the retracted open position, and then the spring bias drives it to the forward closed position when the injection pressure is released. The spring and sealing housing avoids leakage and misalignment as the nozzle reciprocates.

Abstract: An injection molding thermal gated nozzle having a nose portion which extends forwardly to the cavity. The nozzle has a melt channel which extends through the nose portion to form the gate. An integral electric heating element has a forward portion with a generally rectangular cross section and a number of adjacent coils which form an inwardly tapered inner surface. Part of the inner surface of the forward portion of the heating element forms an inwardly tapered portion of the melt channel adjacent the gate. This direct contact of the heating element with the melt reduces considerably the cycle time of the thermal gate. The forward portion of the heating element is shaped by compressing it between tapered dies. It is then mounted between forward and rearward portions of the nozzle, and the assembly is integrally brazed together in a vacuum furnace.

Abstract: A pre-wired injection molding assembly to be supplied to the customer for installation in a mold. The assembly includes a number of sub-manifolds connected to a main manifold, a wiring frame having a number of elongated fingers connected to the sub-manifolds, and a number of heated nozzles connected to the sub-manifolds. The fingers of the wiring frame extend from a hollow channel member which leads to a connector box. The assembly is pre-wired by the supplier by running the wires from the nozzles along the fingers and through the channel member to the connector box. The pre-wired assembly is mounted from the rear in a matching mold manifold plate which greatly facilitates installation and disassembly for the customer.

Abstract: A sprue gated injected molding system having nozzles with a removable hollow gate insert received in a seat in the forward end of each nozzle to form the gate. Each gage insert has a forward portion with a tapered outer surface which abuts against a matching tapered surface of an opening through to mold to the cavity. The forward portion of the gate insert is resilient which ensures extremely good contact between them under bearing pressure due to thermal expansion of the nozzle. Thus optimum uniform heat transfer is provided between the gate insert and the cooled mold. The gate insert has a circumferential removal flange to facilitate it being pryed out of the seat if replacement is required. In an alternate embodiment an elongated torpedo is seated centrally in the melt bore of each nozzle. The torpedo has an outer retaining ring and a number of radially extending tapered fins which form melt flow channels between them.

Abstract: An injection molding integral cooled socket holder to be seated in a well in a cavity plate to receive an elongated heated nozzle. A central tube portion extends between a rear collar portion and a forward socket portion to form an elongated socket to receive the nozzle. The tube portion has small diameter inlet and outlet tubes received in longitudinal grooves which carry a flow of cooling water which is received at the rear collar portion to the forward socket portion. The water flows around a circular conduit in the forward socket portion to provide cooling adjacent the gate. The components of the socket holder are integrally brazed together in a vacuum furnace. Socket holders are made with various preselected lengths to match different length nozzles by cutting the central tube portion including the inlet and outlet tubes to different standard lengths.

Abstract: An injection molding steel valve member in which a central cooling shaft is surrounded by a series of concentric insulation chambers. Cooling water is pumped through the cooling chamber to remove heat from the forward end of the valve member so the adjacent melt in the cavity will solidify more quickly. The insulation chambers reduce lateral heat loss to minimize the problem of solidification of melt around the outer cylindrical surface of the valve member.

Abstract: A number of heated injection molding nozzles are mounted along the side surface of a melt conveying manifold. In one embodiment of the invention, a connector collar having a tapered flange portion is bolted to the side surface of the manifold to provide each melt bore outlet. Each nozzle has a matching flange portion with a melt bore inlet extending laterally from a side surface. The nozzle is mounted on the manifold by securing the flange portions together by bolting a wedge clamp having two halves over the aligned flange portions. This accurately aligns the inlet with the outlet and allows the nozzle to be rotated to a particular angular position. In another embodiment, a melt conduit member is mounted between the manifold and each nozzle. The melt conduit member is clamped to the manifold after being rotated to a desired angular position about a first axis.

Abstract: An injection molding nozzle having a self-supported valve member actuating mechanism. The elongated valve member extends rearwardly into a cylinder assembly which is mounted on the main body of the nozzle. The rear end of the valve member is connected to a pneumatically actuated piston to reciprocate it between the open and closed position. A wedge clamp removably attaches the cylinder assembly to a connector member which is bolted to the rear end of the main body of the nozzle.

Abstract: A method of making injection molding nozzles of predetermined desired lengths and capacity which combines the advantages of large scale manufacturing with the flexability of individual assembly. Individual steel components such as a rear portion, an elongated forward portion, and a connector member are manufactured in volume, with the forward portion being made in different predetermined sizes. A forward portion having a particular length and melt bore diameter is then selected, and assembled together with a rear portion and a connector member. If necessary, the melt channel through the rear portion and connector member are enlarged to match the bore of the forward portion. The assembled components are then integrally brazed together to form a nozzle having a particular predetermined length and melt channel diameter.

Abstract: An integral sprue gated injection molding nozzle and method having a melt bore extending centrally therethrough wherein a circular forward end portion of the electrical heating element encircles the melt bore in the nose portion to provide additional heat adjacent the gate. The method includes locating the circular portion of the heating element in a circumferential space between a hub member and a funnel member and integrally brazing them together in a vacuum furnace to form the nose portion of the nozzle. The nose portion is drilled and machined to provide the desired gate and configuration depending upon the particular application.

Abstract: A center entry valve gated injection molding system having a heated nozzle secured in front of a heated manifold with at least a pair of valve member biasing mechanisms extending radially outward from a reciprocating elongated valve member. The melt passage splits into two branches which extend through a manifold outwardly around a rear portion of the valve member. The two branches of the melt passage and the two biasing mechanisms are alternatively evenly angularly spaced around the valve member which considerably reduces the space required. The valve member has an enlarged forward end which opens forwardly into the cavity and is closed in a retracted position in which it seats in the matching mouth of a gate in a nose portion of the nozzle. Each biasing mechanism includes a compression spring which engages a lever member to continuously urge the valve member rearwardly. When injection pressure is applied it overcome the force of the springs and moves the valve member forwardly to the open position.

Abstract: A multi-cavity valve gated injection molding system having an elongated manifold through which a melt passage to a number of heated nozzles. A separate valve member bushing is seated in an opening through the manifold in alignment with each nozzle. The bushing is in bearing contact between the back plate and the rear face of each nozzle. The bushing has a melt duct with two smoothly curved arms which connect between the melt passage in the manifold and the melt passage around the valve member. The bushing provides a seal around the reciprocating valve member and has an outer flange which forms a combination insulative air space and containment chamber for melt which does escape.