Abstract: A method and apparatus for induction heating and quench hardening of an undulating cylindrical surface, such as that defined by gear or sprocket teeth, provide a hardness pattern uniformly distributed to a controlled depth across and between the teeth surfaces by means of axial scanning of the workpiece relative to a single induction heating coil. A distinct final heating scanning process follows a preheating scanning process whereby preheating and final heating can be conducted at differing controlled axial velocities. Axial scanning of the workpiece repeatedly past a single inductor coil enables preheating and final heating of workpieces which cannot be axially shifted directly between separate inductor coils, such as internal planetary ring gears having a closed end or external gears having a flange or shoulder protruding radially from the cylindrical gear teeth surface.

Abstract: A method and apparatus for inductively heating in an inductor and quench hardening the finished ground cam lobes of steel camshafts to a uniform shallow pattern depth with minimal lobe surface deformation. The inductor is shaped to correspond to the contour of and encircle the individual cam lobes with a minimal uniform induction coupling gap therebetween of less than 0.1 inch, and it is energized with high intensity power at a high frequency greater than 200 KHz, with sufficient power to create a power density of at least 25 KW/inch.sup.2 at the surface of the cam lobe being heated in the inductor, for only a short heat time less than 1.0 second so as to effect the rapid inductive heating of the cam lobe surface to a uniform elevated temperature and uniform shallow depth therearound without causing unacceptable reheating and resultant drawing back or tempering of the previsouly hardened next adjacent cam lobe.

Abstract: Method and apparatus for hardening the outwardly facing teeth surfaces of a gear is disclosed. First and second induction heating coils with power sources controlled by an appropriate microprocessor preheat the gear when in the first coil at precisely controlled cycles to generate an unstable circular band of high temperature positioned radially inwardly from the tips of the gear. Before the band can dissipate, the microprocessor actuates an appropriate drive to locate the gear in the second coil energized by an appropriate power source to impart a high skin temperature to the teeth. A liquid spray quench in the second coil is immediately actuated to effectively quench the gear. By sizing the cycles, the gear teeth are rapidly hardened at minimal power levels.

Abstract: A method and apparatus for progressively hardening an elongated workpiece having an outer generally cylindrical surface concentric with the central axis including the concept of providing closely spaced first and second induction heating coils each having workpiece receiving openings generally concentric with the axis of the workpiece; energizing the first coil with a low frequency such as a frequency less than about 50 KHz; energizing the second coil with a high radio frequency, such as the frequency exceeding 100 KHz; causing relatively axial and progressive motion between the workpiece and the first and second closely spaced coils in a direction entering the first coil and exiting the second coil whereby the cylindrical surface is progressively first preheated by the first coil and then immediately final heated by the second coil; and, then immediately quenching the cylindrical surface as it passes from the second coil whereby the cylindrical surface is progressively preheated, heated and quench hardened a

Abstract: A method and apparatus for installing steel liner sleeves in the cylinder bores of an aluminum engine block comprises axially sliding the liner sleeves onto slide portions of respective mandrels, over an inductor coil on the free outer end of each mandrel. After axially moving the mandrels to insert their inductor coils into the cylinder bores and then energizing the coils to inductively heat the walls of the cylinder bores to a predetermined elevated temperature to expand the bores to a diameter sufficient to axially receive the liner sleeves therein with a snug sliding fit, the coils are de-energized and the liner sleeves then immediately axially slid along the mandrels to a position over the de-energized coils and within the annular coupling gap space between the coils and the bore walls, and into their axially inserted position within the heated cylinder bores, in which position they are maintained until the cylinder bore walls cool and contract to form a tight shrink fit around the liner sleeves.

Abstract: A method of monitoring a heating cycle of an induction heating system wherein an inductor encircles a metal workpiece and an alternating current is applied through the inductor from a power supply during the heating cycle. This method comprising the steps of generating an analog signal representative of the voltage across said inductor, as the voltage varies during said heating cycle by changes in the electromagnetic characteristics of the workpiece as the workpiece is being heated; digitizing the voltage representative analog signal; creating a trace of the digitized voltage representative analog signal, with the trace being indicative of the electromagnetic characteristic of the workpiece as sensed by the inductor voltage during the heating cycle; and, comparing the created trace with a preselected pattern.

Abstract: A method of heat treating a valve seat insert and the resultant combination of the valve seat insert within an engine component is disclosed where the volumetric increase of a portion of the valve seat insert resulting from the heat treatment is utilized to maintain or increase the insert retention forces.

Abstract: An apparatus for hardening the outwardly facing teeth surfaces of a gear is disclosed. First and second induction heating coils with power sources controlled by an appropriate microprocessor heat the gear when in the first coil at a precisely controlled cycle to generate an unstable, circular band of high temperature positioned radially inwardly from the tips of the gear. Before the band can dissipate, the microprocessor actuates an appropriate drive to locate the gear in the second coil energized by an appropriate power source to impart a high skin temperature to the teeth. A liquid spray quench in the second coil is immediately actuated to effectively quench the gear. By sizing the cycles, the apparatus is thus able to rapidly harden the gear teeth at minimal power levels.

Abstract: A method and apparatus for inductively heating in an inductor and quench hardening the finished ground cam lobes of steel camshafts to a uniform shallow pattern depth with minimal lobe surface deformation. The inductor is shaped to correspond to the contour of and encircle the individual cam lobes with a minimal uniform induction coupling gap therebetween of less than 0.1 inch, and it is energized with high intensity power at a high frequency greater than 200 KHz, with sufficient power to create a power density of at least 25 KW/inch.sup.2 at the surface of the cam lobe being heated in the inductor, for only a short heat time less than 1.0 second so as to effect the rapid inductive heating of the cam lobe surface to a uniform elevated temperature and uniform shallow depth therearound without causing unacceptable reheating and resultant drawing back or tempering of the previously hardened next adjacent cam lobe.

Abstract: A method and apparatus for progressively hardening an elongated workpiece having an outer generally cylindrical surface concentric with the central axis including the concept of providing closely spaced first and second induction heating coils each having workpiece receiving openings generally concentric with the axis of the workpiece; energizing the first coil with a low frequency such as a frequency less than about 50 KHz; energizing the second coil with a high radio frequency, such as the frequency exceeding 100 KHz; causing relatively axial and progessive motion between the workpiece and the first and second closely spaced coils in a direction entering the first coil and exiting the second coil whereby the cylindrical surface is progressively first preheated by the first coil and then immediately final heated by the second coil; and, then immediately quenching the cylindrical surface as it passes from the second coil whereby the cylindrical surface is progressively preheated, heated and quench hardened as

Abstract: A method and apparatus is disclosed for obtaining an improved bond between two structural members. Spherical particles, preferably graded steel shot, are interspersed within the adhesive and move in sliding and rolling contact relative to one another to establish an accurate space between opposing face surfaces of the structural members as the structural members are brought into pressured contact with one another. An induction coil may then be used to accurately heat the spherical particles and thus establish a heat source to thermally set the adhesive from within the spaced gap between the structural members established by the spherical particles.

Abstract: A method of hardening the radially, outwardly facing surfaces of a generally circular, toothed workpiece adapted to rotate about a central axis generally concentric with the outwardly facing surfaces whereby the extremities of the surfaces define an outer circle by the tips of the teeth of the workpiece. This type of workpiece is generally a gear.

Abstract: An inductor for inductively heating the valve seat of an engine component includes electrically non-conductive spacer pads on the inductor coil which engage the valve seat surface to establish the inductive coupling gap, and a centering nose which enters the valve stem bore and coacts with a universal coupling between the inductor and the inductor frame to provide concentricity between the valve seat and the core and to accommodate angular variations between the valve seat and the inductor frame.

Abstract: Process and apparatus are provided for selective heating a portion of a workpiece to achieve improved ausforming and isoforming processes when the workpiece is plastically deformed by mechanical working above the M.sub.s temperature. The process and apparatus includes a preheating step where a larger portion of the workpiece is preheated to less than the austenitic critical temperature while the final heating step conducted at a temperature higher than the austenitic critical temperature heats a smaller portion of the workpiece which is subsequently subjected to plastic deformation.

Abstract: A camshaft heat treating apparatus and method for processing a plurality of apparatus and method designs, which camshaft identifies and thereafter automatically inductively heats, quenches and inspects the camshaft in accordance with its design parameters.

Abstract: Method and apparatus for inductively heating and quench hardening axially spaced cams on a steel camshaft having a longitudinally extending rotational axis concentric with a plurality of axially spaced bearings, which method and apparatus utilizes an induction heating coil having an inner surface surrounding the rotational axis of the camshaft with an insulating gap and integral quench openings for directing quenching liquid inwardly from the heating coil for the workpiece, and a high frequency power supply for selectively energizing the heating coil with a power density within the heating coil of about 20KW/in.sup.2 and an auxiliary cooling assembly fixed with respect to the heating coil and including an arrangement for spraying a cooling liquid toward the camshaft.

Abstract: Compacted, unsintered powdered metallurgical workpieces are sequentially shuttled to a series of induction heating units in controlled environments to expel volatile and progressively raise the temperature of the workpiece to an effective sintering temperature.

Abstract: Ferrous parts are heat treated by preheating the part to an elevated temperature, inductively heating the preheated part to an austenitizing temperature followed by quenching and isothermal transformation in a media maintained at a predetermined isothermal transformation temperature.

Abstract: A method and apparatus for shaping, in a planar direction, an elongatd generally flat surface formed in a steel workpiece and having a geometric continuous configuration, such as the outer facing surface of a cam on a camshaft for an internal combustion engine, which involve providing an inductor having a generally continuous heating surface matching the cam surface and generally parallel with the cam surface, forming at least one elongated uniformly cross-section groove in the inductor heating section and extending in a preselected linear location with respect to the heating surface and coterminous with the inductor heating surface, positioning the camshaft with the cam surface facing the parallel matching heating surface of the inductor with an air gap between the parallel matching surfaces so that the groove in the inductor surface faces a preselected band of the cam surface, such as the middle portion of the cam surface, energizing the inductor with a current having a frequency of less than about 25 KHz f

Abstract: A crushed powder metal workpiece preform is enclosed in a shell or envelope of a ceramic liquid die material and is inductively heated through the ceramic material and then transferred to a pressure vessel wherein the liquid die material is pressurized to provide a rapid omnidirectional compaction of the powder metal preform and thus a fused powder metal workpiece.