Abstract: An induction heating device for printers, copiers and the like includes a magnetic coil assembly and a heated metal body that form a closed magnetic circuit. To compensate for the effects of heat radiation at the ends of the heated metal body, a greater amount of heat is generated at the ends of the body than at the center thereof. In one approach, the amount of heat is varied by changing physical parameters of the magnetic circuit, such as the spacing of the coil assemblies from the heated body, the relative sizes of the cores, and/or the relative magnetic permeability of the cores. In another approach, the electrical connection of the coils of multiple assemblies are arranged such that the coils in the center of the heated body are in parallel, and the coils at the ends of the body are in series with the parallel central coils.

Abstract: An electric cooker is provided, which can grill foods by heat rays from a metal heating member using induction heating and is hardly affected by drops from the foods. This electric cooker comprises a work coil wound in a substantially pipe-like shape for generating an alternating magnetic flux, a metal heating member having a substantially pipe-like shape disposed inside and coaxially with the work coil for being heated by the alternating magnetic flux generated by the work coil so as to generate heat rays, and an insulator having a substantially pipe-like shape disposed between the work coil and the metal heating member. A wire mesh for supporting the foods is disposed adjacent to the upper opening of the insulator. A receiving pan is disposed adjacent to the lower opening of the insulator for receiving drops from the foods. The metal heating member preferably has a shape suitable for collecting the heat rays to the upper opening.

Abstract: A wrap tool having first and second coil regions and flange regions for inducing oscillating magnetic fields to fuse a plastic coupling having heating elements to a substrate. The first and second coil regions are wrapped around a selected plastic coupling and substrate to induce fusion currents causing melting and fusion of plastic pipes inserted into a magnetically energizable pipe coupling. The flange regions of the wrap tool are positioned adjacent each other overlappingly or inner surface to inner surface, permitting opposite current coil portions to cancel the other's magnetic fields and reduce coil inductance.

Abstract: The induction-heating apparatus of this invention contains a conductive member, a power source, and a first and a second induction coil connected to the power source and adapted for causing the conductive member to generate an induced current, the first and the second induction coil being parallelly connected. The induction coil is formed by winding a copper wire round a core in such a manner that the numbers of turns of the copper wire gradually decrease from the lowermost layer approximating most closely to the core to the upper layers. This heating apparatus has the thickness of the induction coil in the range of 0.2-0.8 mm. The gap between the induction coil and the conductive member is in the range of 0.5-4.0 mm. This heating apparatus has the induction coil thrust out of the conductive member. The induction coil is formed of a Litz wire.

Abstract: The load balancer incorporates link coil circuits that inductively couple to induction heating coils, which are connected in parallel across a power source. A capacitor is electrically connected in the link coil circuit. By varying degree to which the link coil is inductively coupled to the heating coil or by changing the capacitance, either using a variable capacitor or switching among different capacitors, changes in the amount of reactance coupled into the heating coil are effected. Thus, the current in the corresponding heating coil can be varied, enabling adjustment of the heating of the workpiece. Accordingly, the resulting system is efficient since only a single coil rather than multiple series coils are used. This aspect can be enhanced when litz cable is used in coil construction. Further, the system is compatible with active control.

Abstract: An induction cooker comprises at least one cooking heater comprising an inductor, a generator delivering a AC current to supply the inductor and an element made of a non-magnetic, electrically conductive material to provide shielding against the disturbances generated by the inductor. The shielding function is improved by electrically connecting the element to the mains by means of a high-frequency filter of the generator. Preferably, the electrical link between the shielding and the filter comprises a capacitor.

Abstract: An induction heating coil apparatus for heating continuous strip material comprising at least a pair of generally rectangular full-turn coils arranged in parallel relation and separated from each other to permit continuous strip material to pass axially through the open interiors of the coils. Each coil has an opening in a first end portion thereof such that continuous strip material may pass into or out of the interior of the coil apparatus. The coil apparatus further comprises a pair of shunt conductors connecting the respective coils to each other. The shunt conductors are arranged on opposite sides of the openings in the end portions of the coils for providing a continuous current path from one rectangular coil to the adjacent coil. In one preferred embodiment there is an opening in the second end portion of one coil. Two more conductors, one on each side of this opening, provide connection to the respective poles of an alternating current power source.

Abstract: A method and a system for heat treating an impact beam of an automotive vehicle door. Hot rolled steel sheets are prepared having a composition consisting essentially of 0.18% to 0.22% carbon; 1.0 to 1.5% manganese; 0.15 to 0.4% silicon; not more than 0.025% phosphorous; not more than 0.008% nitrogen; not more than 0.0010% sulfur; 0.01 to 0.04 aluminum; 0.001 to 0.003% boron; 0.1 to 0.3% chromium; 0.01 to 0.035% titanium; and the balance essentially iron, roll-forming and welding the steel sheets to make a tube-shaped impact beam. The heat treatment is carried out by high frequency induction heating and air cooling the impact beam, and water cooling the heat treated and air cooled impact beam.

Abstract: An electromagnetic induction heater in which magnetic flux diffusing members are fixed to at least two ends of an iron core wrapped with an electric wire to form a coil, and a metal plate is connected to the magnetic flux diffusing members to heat a wide area of the metal plate uniformly. By supplying a commercial low frequency alternating power source of 50-60 Hz to the coil, magnetic flux is generated in the iron core. The magnetic flux, flowing in the magnetic flux diffusing members, is diffused in a longitudinal direction. Diffused magnetic flux flows through the metallic plate to generate Joule heat over the plate. Therefore, the entire surface of the metal plate is heated uniformly. Either a single-phase or three-phase alternating power source is used in this invention.

Abstract: Device for the induction heating of flat metallic products on the move with the aid of electrical coils provided on magnetic armatures arranged on either side of the large faces of the product to be heated, which moves continuously between the said coils, wherein the inductors are mechanically independent of each other and they are arranged symmetrically in relation to the median plane of the product so that the magnetic fields generated are in phase opposition, leading to a ring-like distribution of the currents induced in the product to be heated up.

Abstract: Solenoid coils are provided that produce relatively low irradiation of electromagnetic fields with intense fields internally thereof for purposes of heating a metallic element, preferably a ferromagnetic element having a Curie temperature selected for the purpose for which the coil structure is to be employed, the coil structure in one embodiment comprising two coaxial coils of substantially equal diameter interconnected to produce in response to an alternating current being applied thereto out of phase magnetic fields that do not substantially interfere with one another as a result of the spacing between the coils. In a second embodiment the two coils are located between two additional coils that buck axial fields thereby together with fall off of the fields as the cube of the distance from the main coils provide a structure with low external radiation.

Abstract: A godet for heating an advancing yarn including a rotatably mounted godet casing of magnetically conductive material, a stationary primary winding, and a power supply for powering the primary winding at least about 300 Hz. The godet casing is formed of iron and acts as both the secondary winding and core for the primary winding. Accordingly, the godet casing does not need a separate and defined secondary winding, nor does the godet casing include a copper insert or copper coating on the interior of the casing.