Abstract: A sprue bushing which eliminates melt leakage and a method of making the same are described. A cylindrical bushing body having a first, preselected uniform diameter has an annular cavity formed therein which axially extends within the bushing body for a predetermined length and which separates the bushing inner core from the bushing body. A heating element in the form of a ceramic insulator sleeve is inserted into the annular cavity and a particulate refractory material is deposited into the annular cavity to fill the remainder of the annular cavity. When filled, the bushing body is swaged down to a second preselected uniform diameter to compact the powdered refractory together with the preformed sleeve to form a solid heating element. A runner passage is then drilled through the inner core so that the inner core is integral with the bushing casing.

Abstract: This mold tooling has a hot drop assembly operatively mounted in a bore formed therein which opens to a mold face. Heated plastic material is fed to a feed tube of the hot drop assembly and this material is heated at a temperature higher than the working temperature of the mold during its transit the face of the tool by electrically energized heater bands encircling the feed tube. The space between the heater bands and bore wall accommodates tubing through which a flow of chilled cooling air is injected. The temperature and amount of the cooling air may be regulated to match the heat energy discharged by the heating bands into the bore and to the body of the tooling. The flow of cooling air transmits heat energy out of the bore so that heat sensitive plastic materials being molded is not degraded by hot drop assembly heat energy that otherwise would be conducted by the tool body to the tool face.

Abstract: A quick set sprue bushing for use in combination with injection molding apparatus. The bushing is made from a beryllium-free alloy that will rapidly dissipate heat. The alloy is of the copper, nickel type and reduces the cure time by between 15% and 20%. The significance of being beryllium-free is that it has been established that beryllium is a carcinogen and endangers workers. A bushing of this type results in the sprue or tail of the molten plastic type cooling as rapidly as possible for removal of the molded product from the mold. The bushing is elongated and has a generally conical passageway along its longitudinal centerline axis that diverges in the direction of the flow of material therethrough, and is further provided with a stainless steel bushing insert at the end that receives the injection mold apparatus nozzle such that the bushing will not conduct heat from the injection apparatus to the mold but will dissipate heat from the mold that comes from the molten material.

Abstract: A combination for heating and dispensing hot melt materials in which the hot melt material is contained in a tube having a cylindrical outer surface portion over a majority of its length, and the hot melt material in the tube is heated by a heater assembly through a heat transfer member having a cylindrical inner surface adapted to closely receive the cylindrical outer surface portion of the tube.

Abstract: A hopper-type hot melt dispenser for use in liquifying and dispensing drum or pail quantities of slug form hot melt includes a hopper size to receive a drum or pail of slug form hot melt. Band heaters around the circumference of the hopper heat the walls of the container suspended in the hopper causing slug form hot melt contained therein to be released as a slug into the hopper. The method of use of the apparatus provides for supporting a container of slug form hot melt in the hopper and heating the container with the band heaters until the slug is released, whereupon the container is removed from the hopper leaving the slug deposited therein.

Abstract: A sealant injector for use in repair is provided with a sealant nozzle formed in a forward end of an injector body. A piston is slidably fitted in the injector body, and cooperates with the forward end of the injector body to define therebetween a sealant chamber capable of being filled with sealant. A coil spring is arranged within the injector body, and is provided with such a shape memory effect that when heated, the coil spring biases the piston toward the forward end of the injector body to inject the sealant through the sealant nozzle. A heating unit is associated with the injector body, for heating the coil spring.

Abstract: The disclosed roller applicator, for applying a coating of molten wax or the like on paper or the like, has a bowl in which wax is melted and heated to a high working temperature by an electrical heating resistor under the thermal control of a first thermistor, directly in series with the resistor across AC power conductors. The thermistor, when heated to the working temperature, makes a transition between a low resistance state and a disproportionately higher resistance state, for greatly reducing the resistor current. An additional resistor, in parallel with the thermistor, bypasses a small keep-warm current through the heating resistor for maintaining the high working temperature. The increased voltage drop across the thermistor is supplied to one input of an operational amplifier, employed as an electronic switch to energize a first LED, signaling "ready".

Abstract: A sprue bushing which eliminates melt leakage and a method of making the same are described. A cylindrical bushing body having a first, preselected uniform diameter has an annular cavity formed therein which axially extends within the bushing body for a predetermined length and which separates the bushing inner core from the bushing body. A heating element in the form of a ceramic insulator sleeve is inserted into the annular cavity and a particulate refractory material is deposited into the annular cavity to fill the remainder of the annular cavity. When filled, the bushing body is swaged down to a second preselected uniform diameter to compact the powdered refractory together with the preformed sleeve to form a solid heating element. A runner passage is then drilled through the inner core so that the inner core is integral with the bushing casing.

Abstract: An apparatus for liquefying a thermoplastic plastic, in particular an adhesive on the basis of polyurethane, comprises a heatable sealed supply container having an upper portion for receiving a downwardly open transport container for the thermoplastic plastic and a lower portion serving as buffer volume, a heating means for heating the thermoplastic plastic disposed in the transport container, a base portion arranged beneath the supply container and thus beneath the transport container and accommodating a collecting trough for the liquefied thermoplastic plastic and a cover at the upper end of the supply container. In addition, a heating device, either a heat radiator or a contact heating means, is integrated into the cover to heat the bottom of the transport container and thus increase the discharge rate.Expediently, a resiliently mounted heating plate which comes to bear on the bottom of the transport container is provided in the cover.

Abstract: This invention relates to an improved injection molding nozzle and method of making it. The components are assembled and dipped in lacquer and powdered nickel prior to brazing in a vacuum furnace. This integrally brazes the components together, embeds an electrical heating element in a spiral channel, and provides the surfaces with a protective nickel coating. In one embodiment, the forward end has an integral high speed steel insert and the remote end of the heating element extends into the forward end of the nozzle. In addition to providing the protective coating, carrying out the method with a single vacuum brazing step considerably reduces manufacturing costs.

Abstract: A follower plate assembly for dispensing hot melt material from a drum-like container including a bottom plate which is heated, a top plate spaced from the bottom plate, and a cylindrical member positioned between the top and bottom plates. The cylindrical member includes seals which engage the inside wall of the container from which material is to be dispensed. A plurality of metallic slip rings serve to seal the interface between the bottom plate and the cylindrical member.

Abstract: Ink jet apparatus for use with hot melt ink has an integrally connected ink jet head and reservoir system, the reservoir system including a highly efficient heat conducting plate, such as aluminum, inserted within an essentially non-heat conducting reservoir housing. The reservoir system has a sloping flow path between an inlet position and a sump from which ink is drawn to the head, and includes a plurality of vanes situated upon the plate for rapid heat transfer.

Abstract: A hot melt dispensing apparatus for converting solid thermoplastic material to molten thermoplastic material and for dispensing the molten thermoplastic material comprises a solid thermoplastic material receiving hopper, a vibrated feed chute mounted beneath a bottom opening in said hopper, which vibrated feed chute has a discharge opening laterally offset from the vertical plane of the hopper, and a heated reservoir mounted beneath the discharge end of the feed chute. The reservoir is laterally offset from the hopper so that heat rising from the reservoir does not melt solid thermoplastic material contained within the hopper or within the feed chute. The hopper is rectangular in configuration and comprises three vertical walls and one sloping wall angled relative to a bottom discharge opening of the hopper.

Abstract: An integral heated probe for an injection molding system. The hoop has an insulation and locating hoop portion which bridges an insulative air space and abuts against a circumferential shoulder to accurately locate the probe in a well in the cavity plate. The hoop portion encloses a number of adjacent insulative air chambers which extend circumferentially in the steel body. The hoop portion is brazed in place in a vacuum furnace to be an integral part of the probe. Thus, it provides additional hoop or bursting strength and the air chambers reduce the heat loss through the hoop portion to the cooled cavity plate.

Abstract: Apparatus for melting and dispensing thermoplastic material including a hopper for receiving solid thermoplastic material, a flow-through grid melter secured to the bottom of the hopper and a reservoir mounted beneath the grid melter. The grid melter includes multiple parallel ribs extending across the width of the bottom of the grid melter. A single sinuous electrical resistance heater is cast in situ into the ribs of the grid melter. The underside of the grid melter is provided with recesses which function as accumulators to prevent the buildup of pressure on the underside of the grid melter upon remelt of solid thermoplastic material located above the level of the top of the grid melter.

Abstract: This invention relates to an improved injection molding nozzle and a method of making it. The nozzle has an electric heating element integrally vacuum cast in copper in spiral channels set in the outer surface of the tool steel nozzle body. The heating element has a cold terminal at one end which projects out through a hole in a head plate which is rotatable prior to casting to ensure the nozzle has a consistent length of heating element cast in. A sleeve is located over the spiral channel prior to casting to ensure the heating element in the channel is covered with a minimum depth of copper to dissipate the heat from the heating element. The spiral channel can be cut with a varying pitch according to a predetermined profile to provide more heat where there is more heat loss.

Abstract: This invention relates to an improved injection molding nozzle having an integral electrical heating element. The nozzle has an elongated nose portion extending to a forward end from a cylindrical central portion. The heating element is brazed in a spiral channel around a central melt bore in the central portion of the nozzle, and extends into the nose portion to a forward end which is grounded by brazing it in nickel adjacent a high speed steel insert portion at the forward end of the nozzle. This forms a pointed tip at the forward end of the nozzle which is corrosion and wear resistant and can be heated to a predetermined temperature. In alternative embodiments, the forward end of the heating element can be brazed in nickel adjacent the forward end without the high speed steel insert portion and/or the nose portion can be inclined with the forward end of the heating element being grounded adjacent an end gate rather than a separate gate.

Abstract: A hand tool for applying hot melt adhesive which minimizes leakage and enhances the speed and convenience of adhering one material to another. An applicator roller receives liquefied adhesive through an adjacent slot in an upper part of a retention chamber. The slot is at the top level of the liquefied adhesive when the tool is in its rest position. On the outside of the chamber, and below it, a brayer roller is provided for pressing one material to another to complete the adhering process. The tool must be tilted forward to provide adhesive to the applicator roller while it is rolled across the material, and tilted back somewhat to lift the applicator roller and to press down on the material with only the brayer roller.

Abstract: A heater has two, hollow, half-cylindrical heat guides fastened to each other at one side by an articulated connector and at the other side by a bolted joint. Internal surfaces of the heat guides represent the shape of the object being heated. On external surfaces of the heat guides, there are a series of, preferably flat splines. Lamellar heating elements are fastened to the splines. Mutual adherence surfaces of the heating elements and splines are shaped according to geometrical patterns, the appropriate selection of which changes the thermal characteristics of the heater over a wide range. The heater may be supplied from single- or three-phase mains. The heater is applicable especially for heating the cylinders, nozzles and tools of injection moulding and extrusion machines.

Abstract: A electric runner distributor heater for use in passageway of a mold into which a flow stream of fluid plastic material is introduced and which in turn communicates with a plurality of sprue orifices. The heater includes a metal casing having an exposed surface over which the fluid material is directed at an elevated temperature, a plurality of unsheathed electrical heating elements disposed in respective zones of the casing corresponding to the location of selected of the sprue orifices, heat transmitting material compacted in the bore of the casing and surrounding each heating element for electrically insulating the heating element from the casing and filling all air voids between the casing and heating element to effect direct heat transfer to the casing from the heating element, leads coupling the heating elements to a power source, and a control for independently controlling the temperature of the heating elements and thus the temperature of respective zones of the casing.

Abstract: A thermal gate for turning on or off the flow of molten molding material into a mold cavity comprises a narrow passage formed by an extremely thin-walled tube of iron-nickel alloy surrounded by a thin sleeve of insulation, this sub-assembly being inserted into a water-cooled mold. When the tube is supplied with electric current, it rapidly heats to a temperature above the melting point of the molding material, permitting such material to flow into the mold cavity. The thin insulating sleeve maintains a temperature gradient across its wall thickness to permit the tube to remain at the desired temperature without undue power input. When it is desired to stop flow of material through the passage, the current is shut off, and the low thermal inertia of the tube and sleeve permit the tube to rapidly transfer its heat to the water-cooled mold, thereby freezing the molding material in the passage.

Abstract: At least one of the heated side walls of the oil container of a deep fryer is unbent to have planar interior and exterior surfaces. A sheet metal channel member, secured to the exterior surface of that side wall by flanges that flatwise overlie it, defines a tubular pocket which is open at one end. An electric heating element is embedded in an elongated heating body of electrically insulating material that is lengthwise slidably received in the tubular pocket with a close fit to be readily replaceable. Heat that the heating body radiates outwardly away from the wall is imparted to the channel member, the flanges of which transfer such heat to the wall in zones adjacent to the heating body.

Abstract: A nozzle cartridge installed between a wall and a counter platen has a spreader arranged in a shell which extends as far as the rear end of the spreaded and is formed with a plane end face which contacts a plane area of the counter platen, the shell being clamped between the wall and the counter platen so that movements of the counter platen relative to the wall cannot affect the position of the spreader relative to the shell and thereby the influence on the plastic stream emitted from the nozzle is greatly reduced.

Abstract: A device is provided for forming a plastic weld, to repair a crack in a plastic article or join two plastic parts. The device comprises a barrel having an internal chamber. A nozzle is part of the barrel and forms a restrictive orifice outlet. Plastic filler rod can be forced by drive rolls into the chamber through an inlet. A heater coil is provided to heat the barrel. In use, the drive rolls are actuated to fill the chamber with filler plastic and generate a high pressure (e.g. 2500 psi). Concurrently, the heater coil heats the plastic in the chamber to a molten state. The molten plastic is forcefully ejected through the orifice outlet. To effect the weld, the hot tip of the nozzle is buried in the workpiece and drawn along the crack; it plasticizes the weld area plastic as it moves along. At the same time, the molten filler plastic is jetted into the molten weld area plastic and forcefully intermixed therewith to generate a competent bead.

Abstract: A heater is incorporated in a pointed conical heat-generating means fixed with a projectile heat-generating body. The heater is a ceramic columnar body having a heat resisting and insulating property. Disposed within the ceramic columnar body is a coiled heating wire of which winding diameter is formed as small as possible. Due to discontinuous energizing process of the heater, thermoplastic synthetic resin adjacent a gate can be heated and fused, or cooled and solidified intermittently, thereby the gate communicated with a cavity can be opened or closed effectively.

Abstract: An electrically operated heating element for a hot-runner tool has a heat conductor and is positioned in a hot runner and in runners that derive from the heat conductor and lead to a series of outflow channels 8 from the hot-runner tool. The heat conductor is a flat body with tongues on the side toward the outflow apertures, each tongue extending to the vicinity of one outflow aperture.

Abstract: An electrically operated heating element for a hot-runner tool has a heat conductor and is positioned in a hot runner and in runners that derive from the heat conductor and lead to a series of outflow channels 8 from the hot-runner tool. The heat conductor is a flat body with tongues on the side toward the outflow apertures, each tongue extending to the vicinity of one outflow aperture.

Abstract: An electrically heated hose for simultaneously heating and feeding melted adhesive and pressurized air to an adhesive spraying head includes a tubular central flexible plastic core for feeding the adhesive therethrough, a resistance heating type helically wrapped around the core with adjacent turns spaced from each other and an outer layer of thermal insulation surrounding the tape and core so that a helically-shaped air passage is formed between adjacent spaced helical turns of the heating tape, the inner wall of the outer layer and the outer wall of the core. A pressurized air admitting tube is connected to one end of the helical passage and a pressurized air discharge tube is provided at the opposite end thereof for supplying the pressurized air in a preheated condition to the spraying head for atomization of the melted adhesive.

Abstract: Apparatus for melting and dispensing thermoplastic material including a hopper for receiving solid thermoplastic material, a flow-through grid melter secured to the bottom of the hopper and a reservoir mounted beneath the grid melter. A pump is mounted in the bottom of the reservoir and is connected to the reservoir outlet via a flow passage which contains a gate valve operable to enable the passage to be blocked and the pump removed for repair or replacement without the need to first drain the reservoir of molten material. The pump is driven by a motor which is mounted upon a pivotally supported plate such that the motor may be easily and quickly disconnected from the pump to further facilitate quick repair or replacement of the pump.

Abstract: This invention is to disclose an insulated heated sprue bushing in plastic molding apparatus, and comprises a plastic molded segment as a thermal barrier to insulate or break the heat flow between the sprue bushing shoulder and neck section of the stem of the sprue bushing, and a heater band placed on the head of the sprue bushing.

Abstract: Apparatus for melting and pumping molten liquid material from a drum of material which is solid at room temperature and which includes a platen assembly having a top platen and a lower heating platen suspended from the top platen but movable vertically relative thereto. A flexible, expansible sealing element extends between the peripheral edges of the top platen and the lower heating platen so that when the platen assembly is lowered into the open top of a drum of solid material and contacts the top of the solid material, subsequent downward movement of the top platen is operable to move the top platen downwardly toward the heating platen and cause the expansible sealing element to expand radially outward into contact with the interior surface of the drum. When the platen assembly is lifted from the drum, the top platen moves away from the lower heating platen and thereby contracts the diameter of the expansible element so as to move it out of contact with the interior surface of the drum.

Abstract: Apparatus and method for removing combustibles from drill cuttings are provided wherein the drill cuttings are forced under pressure through an extrusion section having no moving parts. The extrusion section comprises a fixed mandrel coaxial with an outer cylindrical shell and having a thin annular chamber therebetween for heating the drill cuttings passing through the extrusion section. The drill cuttings then enter a separating means for removing the volatile combustibles from the solid drill cuttings.

Abstract: This heating cylinder device for a molding machine includes a cylinder member along the axial direction of which and within which are defined several heating zones for material to be molded, each of the heating zones being provided with a heater, wherein the heating capacities and the thermal conductivities to the exterior of the heating zones are suitably arranged so as to correspond to the temperatures and operational performances required from the heating zones. Each of the heaters may optionally surround the portion of the cylinder member defining its heating zone.

Abstract: An electrically heated spray nozzle, such as for spraying plastics, includes a highly compressed tubular heating body wound about a spray nozzle as a plurality of coil windings. The heating body has a tubular steel inner jacket containing a pair of spaced electric heating elements embedded in a high compressed powdered insulating material. A copper outer jacket encases the inner jacket and a hard solder connection joint as least as broad as the diameter of the outer jacket connects the outer jacket and hence the heating body to the nozzle. The number of coil windings per unit length of nozzle body is larger near the ends of the nozzle than near its middle. A steel wear-resistant lining may cover the surface of the nozzle bore.

Abstract: A hot-melt tank having side walls and a bottom wall with a melt unit mounted on the bottom wall in the lower region of the tank, a melt zone. The melt unit includes a base mounted in the lower region and upwardly extending, spaced apart, parallel fins having a sloping upper end. The base does not block a material outflow port in the bottom wall of the tank, but is oriented so that the lowest portion of the sloping upper end of the fins is distal to the outflow port. A shelf, parallel to the bottom wall is positioned over the outflow port parallel to the base, intercepting the fins and secured thereto for blocking direct material inflow from the top of the tank into the outflow port. Rather, material flow is equalized in the lower region of the tank, being drawn to the outflow port from both short and long paths.

Abstract: An electrically operated heating element for a hot-runner tool has a heat conductor and is positioned in a hot runner and in runners that derive from the heat conductor and lead to a series of outflow channels from the hot-runner tool. The heat conductor is a flat body with tongues on the side toward the outflow apertures, each tongue extending to the vicinity of one outflow aperture.

Abstract: This relates to a dispenser for a hot melt material which is supplied in rod-like form from a spool and which is heated to the required semi-liquid dispensing state. The dispensing head is provided with a heating passage which provides for uniform heating of the rod-like hot melt material and there is further provided a special piston having a throughbore through which hot melt material is fed into a pumping cylinder as the piston retracts after a pumping stroke so as to eliminate in the dispensing head downstream of the piston any momentary voids. There is also a feed mechanism which will feed the hot melt material in accordance with the demand of the dispensing head and which will urge the rod-like hot melt material into the heating passage of the dispensing head under a preselected pressure so as to assure flow not only through the heating passage, but also through the piston.

Abstract: A method of melting sulphur, in block form, uses a heating device having lower heating surfaces and means for withdrawing sulphur. The device is positioned on a block of sulphur so that the heating surface(s) are inclined downardly to a collection location spaced inwardly from sides of the sulphur block. The heat is supplied to the heating surfaces to melt sulphur, and molten sulphur is withdrawn by the means for withdrawing it. As sulphur is melted, the heating device is progressively lowered through the block of sulphur. A corresponding apparatus having inclined heating surfaces is provided. As the sulphur is melted so that molten sulphur runs down towards the collection location, the device can be used right up against the edge of a block of sulphur.

Abstract: A system for discharging coal frozen in railroad gondola cars includes provision for passing current through the shell of a gondola to melt the icy interface between coal and gondola, and for dropping the frozen coal out of the gondola by inverting the gondola; an embodiment includes shaking the gondola while inverted, after which the coal may be mechanically broken; special articulated electrodes or high current bus bars with electromagnets for self-holding of the bus bars to the sides of a gondola are disclosed.

Abstract: Ink jet apparatus for use with hot melt ink has an integrally connected ink jet head and reservoir system, the reservoir system having a sloping flow path between an inlet position and a sump from which ink is drawn to the head, the reservoir being housed in a housing of good heat conductivity material with a heater connected thereto, and further having one or more heat conducting elements positioned between the inlet position and the sump, which elements are constructed to act both as baffles and as heat conducting fins.

Abstract: The heating element has a heat conductor in the form of a metal tube. The molten plastic is conveyed to the tube through an inflow aperture. The end of the tube that is remote from the inflow aperture is shaped into a point and has flowthrough apertures. The tube is welded in the vicinity of the point to an outer jacket made out of a material with a low specific electric resistance. Outside the welding point, there is a layer of insulation between the tube and the outer jacket. The layer is between 0.1 and 0.5 mm thick and can be made out of ceramic. The electric energy supplied to the tube is so low that the molten plastic is not subjected to thermal overload in the vicinity of the point.

Abstract: An electrical solder pot has a base with a hollow interior. A housing member also having a hollow interior attaches to the top of the base. The housing member further includes an opening at its top. A threaded socket is fitted in the base so as to accept a heating element which is oriented vertically within the hollow interior of the combined base and housing member. The heating element includes a threaded connector positioned near the opening in the top of the housing and accepts a threaded solder container. The solder container attaches to the top of the heating element and is positioned above the opening in the housing. The heating element includes an internal thermal conducting member located within a tube with an appropriate socket connector on the tube so as to connect to the socket in the base. A monolithic burnt ceramic heater is positioned within a cavity in the thermal conducting member.

Abstract: This invention relates to hot tip bushing means for a synthetic resin injection molding machine, which can reduce the pressure loss at the injection molding time and determine the position of a heating tip easily and accurately. To attain this purpose, a straight resin flow passage is formed axially in a cylindrical body of the hot tip bushing means and the fused resin passing through the straight resin flow passage is heated by an outer heater. Further, a cylindrical body of the hot tip bushing means which is near the heating tip is fit to a mold sprue, thereby the position of the heating tip is determined easily and accurately.

Abstract: A drawing recipient borne by a body is associated with heating means. A filtering recipient is also associated with heating means and in the operational position is raised and laterally off-set with respect to the drawing recipient. A spout serves as a spill-way from the bottom of the filtering recipient to the drawing recipient. The filtering recipient is pivotably mounted with respect to the body, between the aforesaid operational position in which it overhangs the body, and a fold-away position in which it is brought back over the drawing recipient.

Abstract: A crucible useful for continuous preparation of single crystals with selected crystal orientation or for depositing thin films of crystalline materials such as silica on substrates such as graphite by the pendant drop growth (PDG) method, the crucible base being tapped with one or more capillary bores having a length equal to or greater than the retention height of the molten liquid used to prepare the crystal of film at the temperatures and pressures used, the crucible being improved by "capping" its bottom with a conical baffle plate supported by feet on the bottom of the crucible, the improved crucible providing single crystals having high dimensional regularity and containing no bubbles or unmelted inclusions and the single crystals being broadly useful in jewelry, horology, and electronics.

Abstract: A new type of apparatus for dispensing "frozen" solid ink and the ink for use therein for printing on paper is disclosed. The ink dye vehicle is chosen to have a melting point above room temperature, so that the ink which is melted in the apparatus will not be subject to evaporation or spillage during periods of non-printing. The vehicle is also chosen to have a low critical temperature to permit the use of the solid ink in a thermal ink jet printer.

Abstract: A reclaiming machine for scraps of expanded foam thermoplastic material including an electrical source, a housing having a first and second material feeding poet formed therein, a first and second cylinder positioned within the housing and in communication with the first and second port, respectively, a first and second threaded screw shaft rotatably mounted in the first and second cylinder, respectively, wherein the thread diameter of the first and second screw shafts increase in a direction away from the first and second port, respectively, a mechanism operatively associated with the first and second shafts for selectively driving the first and second shafts; a third cylinder positioned between the first and second cylinder and forming a discharging port located adjacent the first and second material feeding port, first and second tubes interconnecting the first and second cylinders to the third cylinder at an end thereof opposite the first and second port; and band heaters enclosing an external wall of the

Abstract: A thermoplastic material-dispensing apparatus of the type wherein solid thermoplastic adhesive material is melted in a heated well and is dispensed from the apparatus due to force exerted on the molten material by means of a piston. The apparatus comprises a loading chamber which comprises an intermediate barrel section and a magazine. The intermediate barrel section is situated between the heated well and a piston chamber which houses the piston. The magazine is adapted to contain a plurality of thermoplastic adhesive slugs and to deliver the thermoplastic adhesive slugs to the intermediate barrel section when the intermediate barrel section is empty.

Abstract: This invention relates to an improved connector assembly for an electrically heated injection molding sprue bushing and a method of making the same. The sprue bushing has a helical portion of the heating element extending around a central core portion which conveys pressurized melt from a molding machine to a cavity in the mold. It is formed by filling the space between the stainless steel core portion and a stainless steel outer sleeve by a highly conductive copper alloy. The heating element has a lead portion which extends out through an aperture. The aperture provides a seat which receives two split washers with central openings therethrough for the lead portion. The washers are each formed of two half washers which are oriented so that the divisions therebetween are not aligned. A connector sleeve is inserted over the projecting lead portion with a flared end which is received in the aperture against the washers. The washers and connector sleeve are brazed in position in a vacuum furnace.

Abstract: This invention relates to a spacer clip for an injection molding electric heating element. A number of clips, each formed of a continuous band, are slipped over one end of the heating element and slid along to predetermined positions. Each clip is then crimped to the heating element in that position which forms a finger which extends radially from the heating element in a predetermined orientation. The heating element with the spacer clips attached is located in a suitable mold for casting and the fingers of the clips locate each coil of the element with sufficient clearance from the mold and the other coils. The thickness of the conductive heater cast around the heating element is important to provide uniform heat transfer. The spacer clips are formed of a material such as stainless steel which has sufficient pliability to be securely crimped to the heating element, but sufficient strength to reliably retain the heating element in position.