Abstract: A reusable die for the manufacture of molded seat cushions that includes a first device for forming a positive profile of a contoured surface, such as a seating support surface, from data obtained for defining the positive surface profile; and a second device for forming a negative profile of the contoured surface, whereby the first surface is adapted to be maintained in contact with the second surface. The first device includes a plurality of rods adapted to define the positive profile. The second device also includes a plurality of rods and a deformable member, such as a wire mesh, that coact with the rods of the first device to form the negative profile. The rods of both the first device and the second device are adapted to be locked in place. A sealing surface is vacuum formed over the negative profile, which then forms a wall of a foam mold. Liquid foam material is then injected in the mold and permitted to cure thereby forming a contoured seat cushion.

Abstract: In an apparatus for generating clamping force in injection molding machines having stationary and moving platens, between which an injection molding die is mounted, and a traversing mechanism associated with the moving platen for opening and closing of the injection molding die, the present invention provides means for locking the traversing mechanism after the molding die has been closed. The clamping force required during injection is generated by at least one element made of a magnetostrictive material that is mounted between the traversing mechanism and the moving platen. Each magnetostrictive element is surrounded by a magnetic coil that is controllably energized to produce an alternating magnetic field which causes elongation of the associated element, generating the clamping force.

Abstract: A ferromagnetic cable insertion tube is cantilevered from a polymeric conduit extruder and separates an electrical and/or optical cable being pulled through the conduit from the inner surface of the conduit until it has solidified. A d.c. current source is applied to a coil surrounding the cable insertion tube upstream of the extruder so as to induce a magnetic flux in the tube and create a north pole at the downstream free end of the tube and a south pole at the upstream free end of the tube. An array of magnets is assembled about the insertion tube at the downstream free end or north pole thereof. The magnets are arranged with their north poles confronting the north pole of the insertion tube so that the repulsive forces between the like poles magnetically levitate the free end of the insertion tube and keep it from sagging into contact with the extruded conduit.

Abstract: A magnetic plastic rotor disk manufacturing apparatus, includes an injection device for injecting a magnetic plastic material containing a synthetic resin matrix and a magnetic powder; a mold for molding the magnetic plastic material injected thereinto from the injection device, and a device for generating a magnetic field and magnetizing the magnetic powder in a direction along a diameter of the magnetic plastic rotor disks. The mold includes a three-plate type mold constructed of two retainer plates and a single runner stripper plate. One of the retainer plates is formed with a plurality of pin gates corresponding to the cavities so as to supply the magnetic plastic material through the pin gates into the cavities.

Abstract: A method for making an optical fiber bundle which, in one aspect, includes bending each of a plurality of optical fibers to form a bend therein and then suspending the fibers over a suspension member; holding the fibers taut under tension; applying potting material to the fiber bends and curing it; and removing the fibers from the suspension member.

Abstract: A rolling apparatus utilizing magnetic forces established between two main rollers so that a workpiece undergoes a uniform and predetermined pressure throughout the rolling process. At least one of the main rollers has a ply unit preferably made from insulated and laminated silicon steel sheets within it to substantially eliminate undesirable heating and counter-rotational effects resulting from eddy currents generated by the magnetic flux passing through the rollers. Passageways are provided for a fluid medium in the apparatus to forcibly move the heat by circulating the fluid medium.

Abstract: A gas injector having a retractable nozzle with linear gas feed passage therethrough for a gas assist plastics injection molding machine. The injector interfaces with the injection molding tool and has a nozzle with a tip that, in a forward position, protrudes through a port therein leading into the tool cavity or a runner system leading into the cavity for gas injection during molding. The nozzle tip is connected by a nozzle body to a base that is operatively mounted in an actuator housing. The base is connected to an in-line gas routing extension of the nozzle that projects through the outer cover of the housing. The extension is coaxial with an internal spring that seats on the base and holds the nozzle tip in a gas injection position resisting the force of plastics injection pressure.

Abstract: A magnetically detectable plastic pipe having magnetic particles distributed in the wall of the pipe so that it is easily detected from the surface when buried in the ground, in a wall in concrete or other distant or relatively inaccessible locations. The magnetic particles are preferably distributed in the wall of the pipe by extrusion with the plastic at the time the pipe is formed and the pipe is passed through a magnet to magnetize the pipe diametrically with one pole on one side of the pipe and the other pole diametrically opposite. The pipe magnetization polarity may be selectively reversed to encode a unique magnetic signature to the pipe. Changing the magnetization polarity may also be used to encode data on the pipe. The pipe may be rotated and passed linearly through the magnet, or the magnet may be rotated around the pipe to produce a spiralled diametrically oriented magnetic structure. Another magnetic material used is strontium ferrite.

Abstract: A mold clamping device in an injection molding machine comprises a first platen for retaining a first mold therein and a second platen for retaining a second mold therein; a platen feeding mechanism for moving said first and second platens relative to each other on said table; electromagnetic coils arranged on the opposite surfaces of the first and second platens; and a control device for controlling the amount of the current supplied to the electromagnetic coils. The mold clamping operation is carried out using the magnetic attracting force generated by the electromagnetic coils.

Abstract: A metal mold device for molding a substrate includes a fixed metal mold, a movable metal mold mounted facing the fixed metal mold for being moved towards and away from the fixed metal mold and for defining a mold cavity between it and the fixed metal mold, a stamper mounted on at least one of the fixed metal mold or the movable metal mold and arranged within the mold cavity, a positioning unit provided on the metal mold on which the stamper is mounted for positioning the loading position of the stamper, and a stamper supporting unit provided on the metal mold on which the stamper is mounted for supporting the stamper by suction. The stamper is positioned by the positioning member and held under suction by the stamper suction unit so that it may be mounted in position on the fixed metal mold or the movable metal mold to permit a disc substrate to be molded highly accurately.

Abstract: A mold clamping device in an injection molding machine comprising a stationary electromagnetic plate and a movable electromagnetic plate provided at the side of the stationary electromagnetic plate away from the movable platen so as to be capable of being moved toward and away from the stationary electromagnetic plate. Both electromagnetic plates are each provided with an electromagnetic coil for generating a magnetic attracting force. The device further comprises a movable platen driving mechanism which is composed of a combination of a feed screw shaft and a nut member and is connected to the movable platen. An operation for closing the molds is performed by the driving mechanism. Subsequently, a mold clamping operation of both molds is performed by a magnetic attracting force from the electromagnetic coil.

Abstract: An apparatus for shaping, and/or directing the flow of deformable materials, wherein the apparatus includes a novel vibrating wall assembly having at least one surface which defines a specific geometric shape over which the deformable material will pass. The novel vibrating wall assembly of this present invention includes the following components: (a) a plurality of pulsating, polygonally-shaped surface elements which are movable between a resting position and an energized position; (b) an energizing device for moving at least one of the plurality of pulsating surface elements from its resting position to its energized position, to form an energized surface element; (c) a biasing device for moving the energized surface element from its energized position back to its resting position; and (d) a linking device for interconnecting the plurality of pulsating surface elements, wherein the linking device allows for the limited pulsating movement of the plurality of pulsating surface elements.

Abstract: Hollow profile elements are formed by shaping a starting workpiece that consists of multiple layers of a material having a large width-to-thickness ratio, e.g., woven fabrics or laid materials. The layers are joined by seams to define elongated pockets or channels. Shaping tools are inserted into these channels to form the profile elements with a desired cross sectional shape, which can be constant or varied. The shaping tools employ one or more endless belts that extend in closed loops around guide rollers; the belts are driven so that during the shaping process sliding friction is substantially eliminated between the material of the workpiece and the respective shaping tool.

Abstract: Method and apparatus for the electromagnetic dynamic plasticating of polymer materials includes a magnetic moving body which is supported both axially and radially by a magnetic levitation gap. The magnetic body is rotated in non-steady state vibration within an electromagnetic winding and cooperates with a stationary body to form a processing space for the polymer material.

Abstract: An apparatus for packing a permanent magnet powder wherein a solenoid coil is provided near the opening of a cylindrical molding space of a mold in such a manner that the direction of the central axis of the solenoid coil substantially coincides with the central axis of the molding space, and an alternating current magnetic field is applied, so that a permanent magnet powder above the opening is packed into the molding space. A magnetic pole may be provided in the center of the solenoid coil. The method of the present invention can be applied to not only a powder for a sintered magnet and cast magnet, but also a powder for a bonded magnet.

Abstract: In an optical-disk manufacturing device in which a disklike plate is coated with an ultraviolet-set resin on one side thereof, pressed against a stamper, and irradiated by ultraviolet rays to transfer a pattern provided in the stamper to the ultraviolet-set resin, the optical-disk manufacturing device has a disklike-plate supplying section which can store a plurality of disklike plates; a resin supplying section for supplying the resin to the disklike plate; a transfer section for transferring the pattern of the stamper to the resin; a disklike-plate removing section for removing the disklike plate after transferring; and a transport device to transport the disklike plate from each proceding part to each following part.

Abstract: A protective sheet for a resin pre-impregnated fiber board (prepreg) incorporates ferromagnetic material. This permits effective and safe manipulation of the fiber board during processing (trimming) and in the manufacture of fiber components.

Abstract: In an extrusion device of the type which has a screw rotating in a housing and which has a feed section in which a feed roller, cooperating with the screw, is provided, a stripper blade is used to remove the fed material from the feed roller. The present invention provides a method and an apparatus for maintaining the net force acting on the stripper blade to direct it towards the feed roller constant. To achieve this, the force of the fed material which acts in a direction tending to move the feed roller and the extrusion screw apart is measured. An opposing force is applied to the stripper blade in dependence upon the magnitude of the measured force. By so doing, the net force directing the stripper blade towards the feed roller is maintained constant.

Abstract: A process and device for manufacturing a composite building panel of the type comprising a facing layer made from a plurality of facing elements, such as brick slices or stone slices for example, retained in a spaced apart relationship, and a magnetically attractible particulate material disposed between the facing elements to imitate mortar. A rigid backing layer is provided, spaced from the spacing layer, the space between the facing and backing layers being filled with an insulation/bonding layer. The device for use in manufacturing the building panel comprises a facing element holder in the form of a structure with a plurality of recesses for receiving therein facing elements, also including spacers between recesses in order to maintain the facing elements in a spaced apart relationship. Ceramic magnets are provided on the spacers for retaining temporarily thereto the particulate material against gravity, until the insulation/bonding layer is built which retains all the elements of the panel together.

Abstract: An induction heating system for melting metal cores contained within articles or components made of plastic uses induction heating and redirects flux lines for efficient melting. The system includes a high permeability magnetic core, an induction heating coil about at least a portion of the magnetic core to produce flux circulation in a magnetic circuit formed by the magnetic core, and two magnetic nozzles attached to the magnetic core with a gap therebetween for insertion of a specific shape of plastic article, the magnetic nozzles shaped to direct and position a desired pattern of flux lines to heat and melt the metal core of the plastic article.

Abstract: A parison forming device is disclosed for forming hollow polymer extrudes of variable wall thickness in either the circumferential or longitudinal directions, or in any combination thereof. The parison forming device consists of a die-head assembly and mandrel assembly, concentrically arranged, creating an annual opening. The inner or outer circumferential perimeter of the annular opening may be selectively modified at specific radial locations through radially displaceable slides positioned about the annular opening. The slides, attached to either the die-head assembly or mandrel assembly, may be actuated during parison formation via hydraulic or other methods so as to provide suitable wall thickness profiles for later finished polymer products.

Abstract: Anisotropic rare-earth permanent magnets characterized in that an aggregate of a plurality of blocks, to each of which anisotropy is imparted, is formed using powders of magnetic material containing rare-earth elements, and the adjoining blocks are powder-metallurgically bonded together under pressure into one piece; a method of making anisotropic rare-earth permanent magnets by molding anisotropic blocks by magnetic-field molding, arranging, aggregating and sealing a plurality of blocks in a bag, and cold hydrostatic pressing the aggregate of blocks in the absence of magnetic field; and a suitable metal mold for magnetic-field molding anisotropic permanent magnets of a relatively large size.

Abstract: A method and an apparatus for setting up a concrete form for the subsequent forming of a concrete member therein and for continuously supplying a concrete form with concrete. The apparatus for setting up the concrete form includes a deck brush for cleaning the deck portions of an elongated concrete form, stem brushes for cleaning the stem portions of the concrete form, nozzles for spraying pressurized lubrication fluid onto the form, strand pulling and placing devices for placing reinforcing strands in the stem portions of the concrete form, rams for depressing the strands down into the stem portions after tensioning thereof, and a deck reinforcing material dispensing system which simultaneously straightens and dispenses deck wire onto the deck portion of the concrete form.

Abstract: A mold assembly for forming solid molded chocolate shapes is formed from first and second sheet-like mold halves separably joined by permanent magnets and having base flanges that support the mold assembly in an upright position for filling through an edge fill opening. The base flanges for the mold assembly include binary-coded mold fill information utilized in chocolate shape production apparatus and specific to that particular mold assembly.

Abstract: A device for separating and closing a split mold that comprises a base, a stationary platen, and a movable platen extending upward from the base and oriented to oppose each other, electromagnets, a hydraulic cylinder, and a control panel. The movable platen is capable of movement toward and away from the stationary platen by the hydraulic cylinder. The stationary platen has the electromagnets mounted thereon and the movable platen has the electromagnets mounted thereon. In the use of the device, the mold is positioned upon the base such that the first half is positioned against the stationary platen. The movable platen is moved against the second half and the electromagnets are activated. The movable platen is then moved away from the stationary platen, and the mold halves are held against their respective platens by the attractive forces of the electromagnets. Mold halves are thus separated by the movement of the platen away from the stationary platen in activation of the electromagnets.

Abstract: Apparatus for stabilizing the location of a skin or shell in a mold for foaming a part includes magnets on the mold adapted to be releasably interconnected to a shell retention and draw bar. The draw bar connects to an integral shell connector. The draw bar is adjustable to pull the shell with respect to the magnets for removing wrinkles from the shell prior to foaming the part.

Abstract: A process for producing a synthetic resin molded article composed of a film or sheet and an injected resin part, comprising fitting a film or sheet to a cavity of a mold in position and then injection molding a thermoplastic resin, wherein said mold has a magnet buried therein at least at a position of the resin passageway at the gate or its vicinities or positions symmetrical about said passageway to form a magnetic fixing part and said film or sheet has a magnet or a ferromagnetic substance fitted thereto at a position or positions corresponding to said magnet fixing part of the mold. The process makes it possible to automate the step of fitting the sheet to the mold, and provides a large-sized or curved molded article excellent in apearance.

Abstract: In a mold having a pattern forming portion composed of a magnetic material, a pattern is formed by magnetically depositing a magnetic material on the wall of a cavity of the mold, and a resinous material is then injected into the cavity for molding and simultaneously transferring the pattern onto the surface of thus molded article.

Abstract: A hollow cylindrical flux source (HCFS) is formed into a toroidal shape. A hollow toroid of magnetically neutral material is mounted in the central cavity of the toroidal flux source. The hollow toroid has a central coaxial toroidal cavity of given cross-section (e.g., rectangular). The toroid flux source and the hollow toroid are each equatorially split into two halves. When the two halves are brought into juxtaposition and a suspension of magnetic material is deposited in the coaxial toroidal cavity a permanent magnet toroidal ring will be fabricated.

Abstract: A pacified mass is hardened under controlled conditions to produce low tension moulded parts (4) of duroplasts, the shringkage being compensated for by the movement of a lower mould part (2) and/or an upper mould part (3) to follow the mass.

Abstract: Herein disclosed is a method of making a porous mold by using an upper case which bears lines for forming channels for water and air communications.

Abstract: A method of making precision low cost molds by applying a plurality of layers of material to a pattern. The method includes providing a pattern of the part to be formed; orienting the pattern on a surface plate in a molding dam; applying a release coating to the surfaces; applying a thin resin layer to form the mold surface; applying a layer of fiber reinforced tooling resin to the thin resin layer; applying an epoxy-dry plaster bonding layer to the tooling resin; inserting a reinforcement framework into the dam; and applying bulk casting plaster to complete the body of the mold.

Abstract: A method of making a porous mold used in pressure casting for forming ceramic articles, which includes the steps of: removably attaching a plurality of apertured holding members in an array at a desired interval to the inner face of an upper case made of a rigid material; threading a flexible line into the apertures of the holding members in each row to hold it at a predetermined spacing from the inner face of the upper case, at least one of the two ends of the flexible line being extended to the outside of the upper case; casting slurry into a mold cavity which is defined between the upper case and a lower basic case joined to the former case to form a porous mold; removing the upper case from the porous mold after the slurry has cured, while leaving the holding members together with the flexible lines in the porous mold; and extracting the flexible lines from the porous mold to form channels in the porous mold.

Abstract: A sheet (10) of anisotropically conductive material may be fabricated by mixing a quantity of electrically conductive, ferromagnetic particles (16), typically spheres, in an uncured polymer (12). The polymer is then cured in a magnetic field which causes the particles to align in chains (14) each parallel to the lines of the field. In accordance with the invention, a spatially varying magnetic field, comprised of first and second substantially uniformly spaced regions (22 and 24) of high and low field strength, respectively, is applied to the polymer (12) during curing. The difference in the strength of the magnetic field in the first and second regions is such as to give rise to a lateral force on the particles which urges them into the first regions of high field strength where the particles align into chains. Since the first regions of high field strength are substantially uniformly spaced, the chains of particles in the polymer will be likewise substantially uniformly spaced.

Abstract: An extrusion die for two-ply seamless plastic tubing, includes an extrusion head with a first nozzle provided with a first centering means; a first hollow mandrel placed within said nozzle; an elongate carrier bearing a second mandrel, a second nozzle and a spider in turn supporting a distributor splitting an extrudate. The first nozzle and the distributor define a first annular extrusion orifice for an outer parison of the tubing while the second nozzle and the second mandrel define a second annular extrusion orifice for the inner parison of the tubing. A threaded member longitudinally adjusts said carrier to vary the size of the first extrusion orifice. A coupling means interconnects the carrier and the first mandrel and allows only the axial, without rotation, movement of the carrier. A second centering means mounts the distributor uniformly spaced around the spider.

Abstract: A formwork wherein the marginal portions of neighboring forms are attracted to each other by magnets. The rear sides of the forms can carry additional magnets for attachment of braces, beams, rods and like parts. The magnets can be assisted by mechanical coupling elements in the form of tongues and grooves, bolts, hooks, bolts and nuts or like parts. Each magnet can be recessed into the marginal portion of the respective form or is separably secured thereto by one or more elastic clips or the like.

Abstract: A process and system for providing a design pattern in a material wherein a seleced medium is applied to the material, the material being positioned adjacent a surface of a template which surface has selected surface characteristics either topographical or non-topographical in nature. The material is held against the template surface at a selected pressure and for a selected time period, at least a portion of the medium coming into contact with the template surface. The surface characteristics of the template interact with the material and the medium as the medium comes into contact with the surface to produce the desired pattern.

Abstract: Disclosed is an improved packerhead or drycast concrete product forming apparatus and method for making a concrete product therewith. The apparatus typically includes a mold having a lower curing pallet, a platform for supporting said mold at the pallet, and a vibrator table having a vibrator ring for association with said curing pallet. The improved apparatus of the present invention preferably comprises a vibrator ring having selectively engageable (and disengageable) means to rigidly connect the vibrator ring to the curing pallet when said vibration means is activated. The preferred vibrator ring selectively engageable means comprises electromagnet means and the preferred product of the process comprises concrete pipe.

Abstract: There are disclosed an apparatus and method of forming magnetic recording media having surfaces thereof replicated while being in the process of being cured.

Abstract: An apparatus for processing of residential or industrial solid wastes, including first grinding means, magnetic separation means, first screening means, whose screenings are directed to second grinding means, drying means comprising a hot air generator, gravity separation means, cyclone separation means, second screening means, and press granulating means.The apparatus is used for production of solid fuels in granules, whose net calorific value can be modified by causing the mesh size of the first and second screening means to vary.

Abstract: A method of producing a permanent magnet in which a material containing ferromagnetic powder is molded into a columnar or cylindrical molded body through injection molding, compression molding, or the like, in a magnetic field capable of orienting and magnetizing the ferromagnetic powder. The method comprises the steps of applying a magnetic field to the molded body in the unidirection perpendicular to an axis of rotation of the molded body to orient and magnetize the molded body so as to have two magnetic poles of N and S; demagnetizing the magnetized molded body; and divisionally remagnetizing the demagnetized molded body on its outer or inner surface to form at least two stripes of N and S poles arranged alternately and extending parallel to the axis of rotation of the molded body.

Abstract: A press apparatus for magnetic injection molding machines in which only the portion of a movable table in close contact with a lower metal mold is made ferromagnetic material and the other portion of the movable table is made of non-magnetic material, thereby fully utilizing the magnetic flux generated by magnetic coils with high efficiency and reducing the magnetic resistance of the magnetic circuit.

Abstract: A plastic magnet injection molding machine comprises a stationary platen side and a movable platen side block each made of a ferromagnetic material and fixed to or integrated with a stationary and a movable platen, a stationary platen side and a movable platen side exciting coil arranged at the outer circumferences of respective ferromagnetic blocks, and a stationary platen side and a movable platen side cover each made of a non-magnetic material and attached to respective platens so as to surround the outer circumferences of the respective exciting coil and ferromagnetic block. The stationary platen side ferromagnetic block and non-magnetic cover have, respectively, surfaces each being in opposition to the movable platen and being flush with each other in a single plane parallel with the stationary platen.

Abstract: Apparatus for making dentures comprising a base, an articulating member pivotally mounted to the base and adjustable with respect thereto, magnets on the base adapted to hold a metal plate in a fixed position on the base, and a probe on the articulating member for spacing the articulating member a predetermined distance above the base. Measurements are taken on a patient's mouth and his preexisting dentures are placed on the plate. Plaster of paris or other suitable material is placed on the articulating member in a non-solidified state and retained thereto. The measurements taken are used to adjust the probe and the relation of the dental cast to the plate, and the denture may be raised or lowered with respect to the base, using loose magnets and shims, to provide the desired position and angularity to the denture.

Abstract: An improved molding structure for producing a building panel or the like of expanded cellular core material having reinforcing strips flush with surfaces thereof and including one or more indentations or depressions having reinforcing elements extending therein and anchored within the core.

Abstract: An apparatus for centrifugally casting a rectangular access floor panel includes a turntable, a drive for rotating the turntable about a generally vertical axis in a generally horizontal plane, and a mold clamped to the turntable. The mold is vibrated during rotation to insure void-free distribution of a lightweight concrete mixture throughout a metal pan retained within the mold. A hopper and an auger feed the concrete mixture to the mold through a sprue. The mold retains corner pads and silencer buttons. The corner pads cooperate with pedestal heads to eliminate the need for stringers.

Abstract: A method of vibrating mass material in moulds or forms is described, there being used a vibrator attached to the mould, for such as the vibration of refractory masses for lining metallurgical vessels or the vibration of concrete in forms. The invention is distinguished in that vibration takes place continuously during movement of the vibrator on the mould in time with the mould being filled with mass material. The vibrator, which is attached to a plate having a built-in magnet, preferably an electromagnet, is attached to the mould and moved on it with the aid of a device acting on the vibrator itself, the device being controlled by a driven member, e.g. a screw, a power ram or the like.

Abstract: Methods and apparatus are provided for permanently and rapidly imparting surface characteristics, such as texture or graining, to decorative coverings for substrates, such as wall coverings in the absence of any degradation thereof, so that when the coverings are subsequently applied to the substrate, such as an aircraft bulkhead, by heat application, the texture previously imparted will remain intact. The process and apparatus uses magnetic attraction in tenter frames to carry and expose continuous webs of thermoplastic to high temperature embossing with simultaneous and subsequent rapid cooling. The arrangements and process avoid lengthy press application at high temperature which has the effect of degrading color and other characteristics of the material being treated.

Abstract: A mold for producing an anisotropic magnet from a composition essentially consisting of magnetic powder and a binder, a mold body, a cavity for molding the composition in the presence of an anisotropically oriented magnetic field produced by a plurality of first magnets for providing magnetic fluxes for the magnetic field in the cavity, yokes, each provided between the cavity and the first magnets, and second magnets provided on both circumferential sides of the yokes for preventing the leakage of the magnetic fluxes. The first and second magnets are made of permanent magnets such as rare earth cobalt magnets. The mold may be provided at both ends with third magnets for preventing the axial leakage of the magnetic flux from the axial ends of the yokes. Two or more molds may be combined in a single molding apparatus while sharing the first magnets. This mold is suitable for the injection, extrusion or insert molding of bonded magnet rolls, motor rotors, etc.

Abstract: In a heating device for use in a vulcanizing apparatus in which a green tire is vulcanized by using a metal mold, three magnetic cores around each of which an electromagnetic coil is wound are arranged equidistantly on at least one surface of the metal mold, and a magnetic yoke is arranged on these magnetic cores. Then, three phase alternating currents are respectively supplied to the electromagnetic coils to generate uniform magnetic fluxes passing through portions of the metal mold between adjacent magnetic cores. Therefore, it is possible to obtain the heating device for use in the vulcanizing apparatus which can realize the uniform eddy current distribution i.e. the uniform temperature distribution in the metal mold by a simple construction.