Abstract: A DC motor drive-control system with a driver circuit for energizing the DC motor receiving a command signal to the driver circuit to cause the motor to rotate in accordance therewith. An encoder is coupled with the DC motor so as to respond to an angular displacement thereof for providing a first sensing signal representing an angular position of the DC motor and a second sensing signal representing an angular velocity thereof. A processor circuit is responsive to the command signal and the first and second sensing signals to produce a control drive signal and to apply it to the driver circuit so that the motor is driven controlledly as to its angular position and velocity.

Abstract: A method of and apparatus for the surface treatment of a metallic workpiece, e.g. the coating, hardening or other change (referred to generally as metallurgical modification) of the surface makes use of a rotating tool electrode from a shank of which individual elongated conductive pieces extend. The pieces, at rest, converge away from the shank by a spread outwardly when the tool is rotated by a motor to slap against and tangentially contact the workpiece. An electric current is provided between the tool and workpiece so that the slapping contact of the individual pieces is coupled with a spark discharge between the pieces and the workpiece surface.

Abstract: An improved ultrasonic machining method and apparatus wherein the vibratory oscillations applied to an ultrasonic machining tool and transmitted to the machining region are periodically interrupted so that they are applied and transmitted in the form of a series of time-spaced bursts.

Abstract: A densitometer comprising a recorder so adapted as to be capable of recording a set of analytical data obtained with a photometric system twice at a definite recording interval, an index arranged at a position apart by a distance equal to said recording interval from the recording pen of said recorder, a switch for setting boundary point and another switch commanding erasure of boundary point, said densitometer being so adapted as to permit setting and erasing boundary point by using the first recorded densitogram and said index.

Abstract: An EDM method and apparatus for machining a workpiece electrode with a tool electrode wherein a solid-state switching type EDM generator provides a succession of machining current pulses across a machining gap formed between the electrodes flooded with a liquid dielectric, preferably distilled water or a weakly conductive aqueous liquid, through a gap discharge circuit. The total value of stray capacitances in the gap discharge circuit is limited to be less than 0.01 microfarad, preferably at most 0.005 or 0.001 microfarad, to control a rise of peak current at the leading edge of each individual machining current pulse. The gap current at the leading edge of a pulse may be sensed and discriminated to provide a control signal which acts on the DC power supply to control the output voltage thereof so that the initial rise of peak current may be maintained substantially constant, irrespective of a change in the stray resistance in the gap discharge circuit during a given course of machining operation.

Abstract: An EDM parameter control system comprising a microprocessor having a memory for storing therein a programmed set of microinstructions representing selectable values for each of the EDM parameters. A gap monitoring circuit derives from the EDM gap a gap status signal representing characteristics thereof, the gap status signal being applied through an input interface to the microprocessor wherein it is used to microprocess the previously stored parameter data to provide control signals applicable to respective control devices for regulating the machining parameters (e.g. machining pulse on-time and off-time, gap spacing, tool reciprocation commands, dielectric supply control parameters). Preferably, the parameters are weighted in microprocessing and the output interface is constituted by a time-sharing unit for actuating the control devices in preset time divisions.

Abstract: A method of and apparatus for electroerosively machining a desired contour in a workpiece with a wire electrode transported from a supply to a takeup and, in a path therebetween, supported by a pair of wire guide heads to tightly stretch the axially advancing wire electrode across the workpiece. On at least one side of the two opposite surfaces of the workpiece traversed by the wire electrode there is disposed a template blank secured to the workpiece and having a contour shaped to correspond to the desired contour to be machined in the workpiece for holding the axially advancing wire electrode on the surface of the template contour between the wire guide heads across the workpiece. At least one of the wire guide heads is movable and displaced to cause the machining wire electrode to move transversely to the axis thereof along the contour of the template block so that with the transverse movement of the wire electrode, the desired contour is progressively formed in the workpiece by electroerosion.

Abstract: An electrical discharge machining (EDM) system comprising: a mechanical unit constituting an EDM machine tool, a power-supply unit for providing a succession of machining pulses controlledly to an EDM gap formed between a tool electrode and a workpiece in the mechanical unit, a machining-fluid supply unit for delivering a machining fluid controlledly to the EDM gap, an electrical control unit disposed remote from the EDM gap for controlling at least one of the mechanical unit, the power-supply unit and the machining-fluid supply unit, and a gap monitoring electrical unit disposed in the vicinity of the EDM gap in the mechanical unit for providing an electrical signal representing a gap discharge condition, the gap monitoring unit having at its output an electro-optical transducer, the control circuit unit having at its input an opto-electrical transducer, the electro-optical transducer and the opto-electrical transducer being interconnected by an optical transmission line.

Abstract: A method and apparatus of electrically machining a conductive workpiece in which a travelling-wire electrode and the workpiece are relatively displaced transversely to the axis of the travelling-wire electrode and define a machining gap therebetween, a machining liquid is supplied to said gap, and a series of electrical pulses are applied across the workpiece and the electrode to generate machining discharges in the gap to remove material from the workpiece. The improvement comprises imparting a vibration to the travelling wire electrode at a frequency between 1 and 50 KHZ and an amplitude between 1 and 50 microns so that the travelling wire electrode has an undulating oscillatory motion along its axis with more than two nodes and antinodes or loops and with a maximum amplitude smaller than the size of the machining gap.

Abstract: An improved servo system and method in an EDM machine for controlling the relative electrode displacement or the gap spacing between a tool electrode and a workpiece, wherein the electrodes are brought to a machining position to permit a succession of electrical discharges to be developed therebetween across the machining gap. A counter is used to count the number of machining pulses and, when the number reaches a value preset in conjunction with the machining area defined by the confronting electrodes, to provide an "advance" or "advance-enabling" signal. Only upon development of this signal or concurrent development of it and a usual servo "advance" signal from a gap sensor/servo signal generator responsive to a gap variable, e.g. gap voltage, a servo drive circuit acting on a motor or actuator for driving the movable electrode is actuated to allow the electrode to be advanced or stepped forward to a next machining position.

Abstract: In an EDM method, a continuous wire electrode with an original radius is continuously transported through a machining zone of a workpiece. The machining zone is flushed with a liquid while a succession of electrical machining current pulses are passed between the electrode and the workpiece. Because of these machining pulses, discharge craters with raised formations are formed on the wire electrode. The method includes the step of controlling at least one parameter of the electrical machining current pulses so that the radius of the wire electrode at the location of the raised formations does not exceed the original radius of the wire electrode.

Abstract: A burner system of the type in which a thermocouple or like EMF-generating sensor detects the presence of a pilot flame and controls a main fuel valve to hold the latter open as long as the pilot flame remains lit. According to the invention, the main valve is held open by a solenoid and a resistance is provided in circuit between the sensor and the solenoid to reduce the response time of the latter which results from the inductance contributed by the magnetic coil forming the solenoid.

Abstract: A method of preparing a capillary heat-pipe wicking structure comprises the steps of (a) disposing an inner surface of a tubing in contact with a solution containing a salt of a thermally conductive metal and (b) depositing the metal from said solution upon said surface so as to form a porous metallic layer thereon constituting the capillary heat-pipe wicking structure.

Abstract: A storage-capacitor-type EDM power-supply system wherein the storage capacitor is charged from a DC source to store a predetermined amount of charge thereon under the control of a switch connected between the DC source and the capacitor. The discharge circuit connecting the capacitor with an EDM gap to allow the stored charge to be discharged through the latter also includes a switch which is controlledly rendered conductive by a signal pulse generator which provides a controlled switching signal preprogrammed in a microprocessor such that the capacitor discharge machining current has a predetermined waveform corresponding to the preprogrammed signal. Preferably, the machining current in each capacitor-discharge cycle is in the form of a composite pulse consisting of a series of periodically interrupted pulses of a minimum on-time and off-time.

Abstract: A multiple-axis milling-, sculpturing- or shaving-type EDM machine removes material from a selected surface portion of a workpiece with a continuous traveling-wire electrode guided at an end portion of a tool head and juxtaposed with the workpiece. The wire is continuously advanced and transported from a supply reel to a takeup reel on the tool head by drive means to continuously renew the active electrode surface at the guide section while a position controller moves the tool head in a scanning manner relatively over the workpiece surface. A high-frequency mechanical vibration is imparted directly or indirectly to the wire electrode carried by the guide section while traveling in juxtaposition with the workpiece.

Abstract: A wire-cut electroerosion machine as well as a method of operating the same wherein a wire electrode is axially and continuously transported from supply means to take-up means to travel through a cutting zone between a pair of wire guide members in which a workpiece is positioned. The machine includes rotary traction means having a first rotary shaft for advancing the wire through the cutting zone from the supply means and permitting it to be collected by the take-up means, and rotary brake means having a second rotary shaft for applying a braking force to the wire to cause it to be stretched between the guide members while being continuously advanced through the cutting zone.

Abstract: A position measuring head, especially for locating proximity to a surface of an object to be detected, is mounted on a support and can be displaced relative to this surface. A small vibration is imparted to the head and changes in the mode of vibration on contact or approach to the surface are detected to produce an output signal.

Abstract: An electroforming or electrodeposition system in which the depleted metallic component in the electrolyte is replenished by an electrolyzing unit having an anode chamber communicating with the electroforming electrolyte receptacle and separated by an ion-exchange membrance from a cathode chamber. An anode in the anode chamber is dissolved electrolytically to furnish the metallic component. The electroforming current is measured to indicate the rate of depletion of the metallic component from the electroforming electrolyte, the measurement signal being used to control the electrolyzing current to dissolve the metallic component from the anode so that the ionic concentration of the metal in the receptacle is maintained substantially constant.

Abstract: A fluid-jetting system is combined with an electrical machining apparatus to direct a plurality of jets of the electrical machining liquid (electrolyte in the case of electrochemical machining or dielectric in the case of spark discharge machining) into the region of the machining gap. The jets derive from respective flexible ducts. Vibrational energy is applied to the fluid fed to the ducts.

Abstract: EDM method and apparatus in which the electrical-discharge machining pulses are triggered by the application across the machining gap of a succession of pulse trains of discrete pulses whose durations and intervals may be preset for optimum machining conditions (e.g. surface finish). The instantaneous machining area is detected and a time element, such as the duration of each pulse train or the interval between pulse trains or both, is controlled so as to maintain the current density substantially constant in spite of changing machining areas during the machining process.