Abstract: An EDM electrode wire changer has a plurality of conduits, one for each available electrode wire, all conduits converging towards the threading axis of a selected electrode wire through the workpiece or, alternatively, disposed substantially parallel on a slide that is indexable such as to dispose the outlet of a selected one of the conduits in alignment with the threading axis. A common motor-driven threading roller is disposed proximate the inlet of the conduits in a stationary position relative to the conduits, and a pinch roller for each wire co-operates with the threading roller for feeding the selected one of the wires through its corresponding conduit by forcing the selected wire against the peripheral surface of the common threading roller, while the other pinch rollers are remaining in a position away from the threading roller.

Abstract: A tool changer for an EDM apparatus provided with a reciprocable machining head having a tool holder mounted on the end of the machining head. The tool changer comprises a rotatable indexable turret supporting a plurality of electrode tools each integrally provided with a support member for attachment of the electrode tool/support member assembly to the turret. Successive machining operations are effected by the machining head carrying an appropriate electrode tool, and at the end of each machining operation the electrode tool/support member assembly is attached to the turret.

Abstract: An orientable unitary assembly for the support and guide member for the electrode wire of a travelling wire EDM apparatus, the assembly also comprising a nozzle supplying a machining fluid jet coaxial to the electrode wire. The assembly is supported by a cross-slide table permitting to incline the axis of the wire relative to a wire support and guide member disposed on the other side of a workpiece. The displacements of the slides of the cross-slide table are effected by leadscrews each driven by a servo motor, and the orientation of the assembly is controlled by the same servo motors via second screwthreads of different pitch each displacing a nut which, through a push-rod, controls the inclination of the assembly.

Abstract: An adjustable and controllable electrode wire support and guide mechanism for traveling wire EDM apparatus wherein an electrode wire, longitudinally fed, is stretched between a pair of support and guide members, and wherein at least one of the support and guide members is in the form of a helically grooved cylindrical member directly driven by a servo-motor. The helical groove defines guiding surfaces for the electrode wire which is in engagement with opposite sidewalls of the groove and, by rotating the helically grooved support and guide member by the servo-motor, the electrode wire is caused to take a predetermined inclination relative to the workpiece.

Abstract: A machine tool provided with a movable table supported by a stationary table, the movable table being displaceable relative to the stationary table in all directions and being supported by the stationary table by pressurized fluid bearing. The movable table is positioned by at least three actuators pivotally connected at one end to the stationary table and at their other end to the movable table such that the lengths of the actuators, controlled by an appropriate numerical control system, result in a predetermined position of the movable table relative to a reference position.

Abstract: A correction system for a travelling wire EDM machine cutting a workpiece by means of a travelling electrode wire stretched between two guide members and comprising a pair of servo motors for effecting displacement of the guide members relative to their respective support arms, such as to incline the electrode wire relative to the workpiece for providing the cut in the workpiece with an appropriate predetermined conicity or draft. One of the servo motors providing such displacement is, in addition, controlled such as to compensate for thermally-induced expansions or contractions of one of the support arm guide members relative to the other.

Abstract: An electrode tool holder for an EDM apparatus which can support either an electrode tool of large size or an electrode tool of small size. The EDM apparatus is provided with a ram consisting of two separate, preferably concentric, linearly movable slide members. One of the slide members, linearly displaceable by a servo motor, carries a holder for an electrode tool of small dimension. The second slide member, although normally linearly displaceable relative to the first slide member, is arranged to be coupled to the first slide member for supporting an electrode tool of large dimension, both coupled slide members being thus driven by the same servo motor.

Abstract: An EDM apparatus for machining by electrical discharges an electrode workpiece by one of a plurality of electrode tools individually and selectively mounted by an automatic tool changer on the apparatus electrode tool holder. The tool changer comprises a tool transfer carriage provided with a grasping mechanism adapted to take hold of electrode tool supports of diverse shapes provided with cut-out portions enabling connection with the carriage for carrying the electrode tools from a storage magazine to the electrode tool holder and back from the electrode tool holder to the magazine.

Abstract: An apparatus for displacing at least one of the electrodes of an electrical discharge machine laterally in a plane perpendicular to the axis of relative longitudinal feed of the electrodes, with an amplitude proportional to the longitudinal displacement of the electrodes. The apparatus comprises a rotatable shaft longitudinally controlled as a function of the axial position of one of the electrodes. An eccentric member is driven in rotation by the shaft, and the amount of eccentricity of rotation of the eccentric member is controlled by a moveable camming member supported at three points, one of the points being a fixed pivot point on the axis of the shaft and the two other points having an axial position and a radial position varying as a function of the longitudinal displacement of the shaft and defining the amount of eccentricity of the eccentric member.