Abstract: The invention relates to an inductor having two parallel main heating conductors which are interconnected at one of their ends via a bridge-shaped branch and are connected at their other end to a transformer, the connections also forming a bridge-shaped conductor branch. The characterizing feature of the invention is that disposed at least at one end of the parallel main heating conductors is a separate auxiliary inductor which is mounted displaceably in relation thereto and has two conductor portions parallel with the main heating conductors and inductively coupled thereto which are collectively interconnected at one of their axial ends via a bridge-shaped conductor branch determining the end of the heating zone and at the other end via a tunnel-shaped return conductor which over the whole displacement length is disposed beneath the bridge-shaped branch of the main heating conductors and is inductively coupled thereto.

Abstract: Arrangement for providing an enhanced wear-resistant contact region for a cast iron mechanical control element such as a rocker arm. The control element is cast in a desired shape. It is then preheated to a temperature between room temperature and the Ms temperature of the iron element (Ms temperature is a function of the carbon content of the iron) to adjust the total hardness of the iron element. A surface region of a cast iron control element, intended for forming the contact region, is partially melted and then cooled to create a hard ledeburitic structure which has a mixed crystal structure and is at least partly martensitic and has a mixed hardness of at least 670 Hv.

Abstract: An apparatus for tempering the surfaces of mutually displaced cams of a cast-iron camshaft in which heat energy sources are movably disposed at a distance from each cam. The apparatus holds the camshaft to be tempered in a vertical orientation for rotation about its axis and the heat sources are positioned about the camshaft axis at relative angles of rotation equal to the relative angles of rotation of the corresponding cams so that the cams may be heated simultaneously and syncronously with the rotation of the camshaft.

Abstract: A process in which pipes, particularly thick walled pipes, are inductively heated to the austenization temperature, quenched with a coolant to form martensite in the surface zone, then drawn, with additional heat added when necessary and left to cool with the not-quenched layers forming an interstage structure.

Abstract: A process for heating at least two metal pipes wherein each pipe is individually preheated in response to sensors detecting its initial temperature and wall thickness. The pipe then passes through a continuous heater which applies an equal amount of energy to each portion of the pipe, after which each pipe emerges having a predetermined temperature independent of both its initial temperature and the wall thickness.

Abstract: An apparatus for surface hardening an irregularly shaped workpiece made of hardenable material by inductive heating whereby a clamped workpiece is rotated past a linear conductor disposed along the envelope circle formed by the cam of the workpiece which extends farthest from the workpiece axis. The conductor has a plurality of yoke sheets to heat the workpiece surface uniformly.

Abstract: An electrical conductor of the type having a central cavity which extends along the longitudinal axis of the conductor to conduct refrigerating fluid which cools the conductor heated by high current density current flow whereby, to increase thermal efficiency and decrease deposits on the walls of the cavity which reduce the lifetime of the conductor, the cavity walls have non-smooth undulations, forming for example isosceles triangles.

Abstract: A method for producing a welded and quench hardened steel pipe and pipe whereby the weld seam running spirally or longitudinally along the pipe length has a lower austenization temperature than the pipe and/or a higher electrical resistance. The ratio of the pipe to seam resistance is preferably greater than one half and the whole of the square of the ratio between pipe wall thickness and mean seam thickness. The seam preferably includes amounts of C, Si, and Mn in the same percentage as the pipe plus nickel between 2-6%.

Abstract: Apparatus for inductive hardening of the bearings of crankshafts by a rotational process, wherein various parts of the surface of the workpieces are heated by variably shaped inductors, and wherein the workpiece is loaded horizontally with a hardening carriage, which supports a transformer plate for supporting a transformer connected to a medium frequency current source and an inductor attached to the transformer plate, and an automatic control to move the transformer plate to load and unload separate inductors for treating variably shaped workpiece surfaces.

Abstract: An apparatus for inductive hardening different types of production parts, such as automobile axles, in a device of the type having a pair of rotatable spiders with a plurality of arms for clamping therebetween the parts for indexing movement from a clamping station to a releasing station, the parts being sequentially presented to the clamping station by a lifting bar conveyor. The type of part presented for clamping and type of part which the arms at the clamping station can clamp are compared and the part only clamped when the types are the same.