Abstract: The invention relates to a process and an apparatus for the electrochemical etching of grooves of very small width, in particular smaller than 1.0 mm, into a workpiece. Etching is performed with a wire electrode or a rod electrode extending across the etching direction. In order that the electrolyte liquid introduced into the work gap does not flow away uncontrolled, but fills out the work gap over the entire working length of the electrode, a baffle acting behind the rear of the electrode is provided. This ensures that the flow of the electrolyte takes place essentially in the work gap and in the longitudinal direction.

Abstract: An apparatus for spark-erosive planetary eroding of a workpiece in which an eroding electrode is lowered into the workpiece as the workpiece is eroded and the workpiece and electrode carry out planetary motion with respect to each other so the operation gap between the narrow periphery of the electrode and the workpiece moves around the periphery of the electrode during planetary motion. A plurality of injection nozzles are positioned around the gap for supplying liquid dielectric thereto in accordance with the planetary movement. A plate having bores therethrough closes a chamber containing such liquid with each bore supplying a nozzle. The bores terminate at a wall of the chamber so that the opening into the chamber and therefore the supply to each nozzle is varied in accordance with the planetary movement.

Abstract: One or more electromagnetic stirring elements are mounted on arms and/or holders, extending from a carriage which runs on a stationary bed and in a direction transversely to the direction of casting. The stirring elements are either directly positioned in the direction of carriage movement or orthogonally thereto. Multiphase elements can be positioned from three different directions to circumscribe the casting.

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: A at discharge oven for heating a large number of production parts which pass through the oven on a conveyor belt and are pushed by a pushing mechanism mounted att the oven, evidence whereby the conveyor belt is attached to a swingable beam and a vibrator is mounted for exerting a force on the belts and parts thereon which has a component in a direction perpendicular to the direction of part movement through the oven.