Abstract: A current supply device for movable electrodes of spark erosion machines comprises a plurality of individual contacts and includes in leads connecting the contacts with a current generator, electrical components in the form of pulse transformers for a pairwise negative feedback of partial currents or additional impedances stepped according to a mathematical series for uniform current distribution over the individual contacts. The current supply device is particularly suitable for the current transmission of high energy short pulses, such as are used for an erosive wire cutting. The current supply device operates in an almost wear-free manner and can also fulfill the function of guide for the electrode.

Abstract: A coarse interpolator is adapted for use in a numerical control system for performing path interpolation calculations for the control of highly dynamic processes. These processess have different path contour geometries wherein a vector having a length L connects in linear form a first point P1 to a second point P2. These points are located in three dimensional Cartesian space having axes X, Y, and Z, Length L has Cartesian components X, Y and Z and is subject to an angular rotation C about the z axis. The interpolator responds to a group of predetermined vector lengths, starting with the maximum length, in order to calculate the path elements L, X, Y, Z and C for the maximum length vector. A path error E is then determined for the path elements so calculated. The error E is then compared with a praedetemined maximum error value. If the error E does not exceed the maximum value, the calculated path elements are outputted.

Abstract: An electroerosion process and apparatus are used to produce crude electrodes which are shaped thereafter into finished form by wire cutting erosion. The finished electrodes are used in subsequent countersinking of workpieces by electroerosion.

Abstract: A pulse generator for spark-erosive metal working contains a charge regulator circuit for charging a storage capacitor. A storage capacitor is sinusoidally discharged across a switching device to a spark gap. Charging always occurs in a defined manner independently of the preceding pulses, so that uniform pulses can be generated. The storage capacitor is charged with an energy excess of required for discharge and the energy still remaining after spark discharge is recovered in a d.c. voltage source. The switching device (3) is non-conductive only when the discharge current has substantially decayed.

Abstract: An electroerosion process and apparatus are used to produce crude electrodes which are shaped thereafter into finished form by wire cutting erosion. The finished electrodes are used in subsequent countersinking of workpieces by electroerosion.

Abstract: A pulse generator for spark erosive machining of a conductive workpiece, including a d.c. voltage source, a switching element such as a switching transistor connected in circuit with an inductive coil and the work gap across the voltage source, and a high frequency transformer, where one winding of the transformer is connected in parallel with the voltage source and the other winding is connected in parallel to the series circuit consisting of the inductance coil and the work gap. When the switching element is turned on, a machining pulse is applied to the gap; when the switching is turned off, stored energy in the inductance coil is dissipated across the gap and, owing to the transformer connection, generates a recuperation current flowing into the voltage source. The switching element is preferably controlled on the basis of the magnitude of the current flow through the circuit.

Abstract: A circuit arrangement for producing machining pulses in a spark erosion installation from a direct current power source that functions without the use of ballast resistors. There are at least two controllable circuits which are parallel to the spark gap and to one another and whose output currents are additively superimposed for a total current flowing through the spark gap. The control inputs of the circuits are connected to a control circuit, which produces time-associated control signals, the nature of the time circuit cooperates with the control elements of the circuits, so that a current pulse is only allowed to pass to the spark gap if the switches controlled by the control elements are simultaneously open.

Abstract: In the electroerosive machining of workpieces with the aid of a tool electrode, a pulse-like d.c. voltage is applied between the workpiece and electrode, the applied voltage being in the form of pulse groups where the pulse groups are formed of individual pulses having current amplitudes of selected magnitudes. Preferably, the individual current pulses belonging to the pulse group have successively rising amplitudes. Several individually controllable power switching circuits are connected in parallel to the work gap. The primary side of a pulse transformer connected to each power switching circuit is driven by a control device for the time shaping of the pulse groups. At least one controlled switch belonging to each power switching circuit is connected to a second control device for shaping the current pulse amplitudes.

Abstract: The invention describes methods and means for optimum process control in spark erosive machining when there are considerable changes to the machining surface. By following a mathematically described process control strategy, it is possible to work in all spark erosion machining ranges without any interventions in the process control on the part of the operator.

Abstract: The disclosed method involves generating cartesian coordinate information representative of the electrode deflection from a rest position of a wire electrode electrical discharge cutting machine, feeding this information into an electronic processing system to convert it to appropriate control instructions, and then feeding the instructions into a drive system, which can then correct the relative positions of the wire electrode and the workpiece accordingly, so that the deflection of the wire electrode does not adversely influence the configuration of the cut made in the workpiece by it.The apparatus for performing the method comprises a wire electrode position pickup system, which can be a photoelectric system picking up the shadow of the wire or a system which measures the spacing between the wire and sensing electrodes by sensing the electrolytic current through a dielectric fluid which fills the space between them.

Abstract: A head assembly for an electro-erosion machine tool comprises, in a housing, a guide for guiding the moving filamentary or strip-form tool electrode and first contact means for supplying erosion energy to the electrode. The scavenging medium is fed into the housing so as to cool the contact means and guide, and leaves it by way of a nozzle through which also the electrode leaves the housing on its way to another head assembly arranged on the opposite side of the location where machining is performed, the scaverging medium being thereby fed to the machining location as an envelope coaxial to the electrode. Second contact means for contacting the workpiece to be machined are fixed to the nozzle and the connections to each contact means are arranged for low inductive energy loss.

Abstract: A generator for machining by means of electrical discharges between a tool electrode and a workpiece electrode. The generator consists of a main voltage source connected between the tool electrode and the workpiece electrode through an improved switching circuit which is activated by an adjustable oscillator. The switching circuit delivers short pulses of high pulse current and consists of a plurality of identical impulse amplification stages. A first one of these impulse amplification stages drives all the additional ones. Power transistors are used. With a base current regulating system, the turn-off delay of these power transistors is eliminated by keeping them far away from saturation. Resistance-capacitance and resistance-inductance elements and a special cabling are used to eliminate certain impulse transmission problems.

Abstract: A pulse generator for use in forming the erosion pulses of an electro-erosion machine tool comprises means for forming two envelope curve signals representing upper and lower limit levels for the instant level of the output pulse, a comparing device for comparing the actual current level of the output pulse with the envelope curve signals, and a current supply for forming the pulse under the control of a switch which is turned on and off by the comparing means in such a way as to maintain the output pulse current level in the region represented by the space between the envelope curves.