Abstract: A grinding machine for grinding a workpiece comprises a machine frame, a bearing device provided on the machine frame and movable along guides, in which a cup-shaped grinding wheel is rotatably drivable about a grinding wheel axis and electrically insulated. The grinding wheel is electrically connected to a generator. The device for profile dressing, sharpening and cleaning the grinding wheel consists of a single cup-shaped electrode, which is drivable about its central axis and is placed on a slide, which allows a working gap to exist between the machining surface of the cup-shaped electrode and the annular abrasive surface. A spark erosion discharge occurs in the gap when a voltage is applied. The grinding wheel can thereby be optimally conditioned by electric discharge machining.

Abstract: The invention relates to a device and a method for electrical discharge machining of a work piece by means of a working electrode. A sequence of working pulses is applied on the work gap between the working electrode and the work piece. The working pulses comprise eroding pulses for eroding material off the work piece and measuring pulses during which an ignition voltage is applied on the work gap in order to initiate a discharge within the work gap and to measure the corresponding, ignition delay time. The ignition voltage and/or the gap width are adjusted such that the ignition delay time is smaller than an oscillation time of the working electrode oscillating within the work gap due to the electrostatic attraction force and the mechanical restoring force.

Abstract: A grinding machine for grinding a workpiece comprises a machine frame, a bearing device provided on the machine frame and movable along guides, in which a cup-shaped grinding wheel is rotatably drivable about a grinding wheel axis and electrically insulated. The grinding wheel is electrically connected to a generator. The device for profile dressing, sharpening and cleaning the grinding wheel consists of a single cup-shaped electrode, which is drivable about its central axis and is placed on a slide, which allows a working gap to exist between the machining surface of the cup-shaped electrode and the annular abrasive surface. A spark erosion discharge occurs in the gap when a voltage is applied. The grinding wheel can thereby be optimally conditioned by electric discharge machining.

Abstract: The invention relates to a device and a method for electrical discharge machining of a work piece by means of a working electrode. A sequence of working pulses is applied on the work gap between the working electrode and the work piece. The working pulses comprise eroding pulses for eroding material off the work piece and measuring pulses during which an ignition voltage is applied on the work gap in order to initiate a discharge within the work gap and to measure the corresponding ignition delay time. The ignition voltage and/or the gap width are adjusted such that the ignition delay time is smaller than an oscillation time of the working electrode oscillating within the work gap due to the electrostatic attraction force and the mechanical restoring force.

Abstract: A drive device for a load (18a) comprises a device for detecting accidental collisions with a motor (14a), a first, respectively a second position sensor (15a, 16a) disposed upstream, respectively downstream of a transmission assembly (12a) providing first and second values of position. A calculation unit (20) makes it possible to calculate an error signal (d) corresponding to the difference of these position values. Ways to discriminate are devised so as to analyze the successive error signals as a function of the path (xR) traversed by the load in a spatial reference frame (xR, d). Filters with rectangular spatial window or with exponential spatial window are particularly adapted for discriminating between errors due to an accidental collision and those due to other causes attributable to normal operation. One thus obtains particularly reliable and sensitive collision detection with a very low detection threshold.

Abstract: A device and method for measuring and adjusting an electrode used during electrical discharge taper machining, referenced on three axes, Y and Y horizontal and Z vertical, whereas two linear geometric references, bottom and top, which may be intersected by a wire, each of them lying in a plane XY, the references being offset from one another in a direction XY by a sufficient distance to make it possible to insert a vertical electrode between the two without either of them being intersected by the wire, a base element serving as a support to the references and as an attachment stay on the work bed of the machine.

Abstract: A device and method for measuring and adjusting an electrode used during electrical discharge taper machining, referenced on three axes, Y and Y horizontal and Z vertical, whereas two linear geometric references, bottom and top, which may be intersected by a wire, each of them lying in a plane XY, the references being offset from one another in a direction XY by a sufficient distance to make it possible to insert a vertical electrode between the two without either of them being intersected by the wire, a base element serving as a support to the references and as an attachment stay on the work bed of the machine.

Abstract: A drive device for a load (18a) comprises a device for detecting accidental collisions with a motor (14a), a first, respectively a second position sensor (15a, 16a) disposed upstream, respectively downstream of a transmission assembly (12a) providing first and second values of position. A calculation unit (20) makes it possible to calculate an error signal (d) corresponding to the difference of these position values. Ways to discriminate are devised so as to analyze the successive error signals as a function of the path (xR) traversed by the load in a spatial reference frame (xR, d). Filters with rectangular spatial window or with exponential spatial window are particularly adapted for discriminating between errors due to an accidental collision and those due to other causes attributable to normal operation. One thus obtains particularly reliable and sensitive collision detection with a very low detection threshold.