Abstract: An EDM circuit arrangement incorporating a minimum-impedance electrical conductor assembly in a tubular form between an EDM pulse generator and a machining gap, the assembly having a first group of conductors connected between one terminal of the pulse generator and a tool electrode to conduct the machining pulses in one direction and a second group of conductors connected between the other terminal of the pulse generator to conduct the machining pulses in the opposite direction. An electrically nonconductive member contouring the tubular form and having these conductors mounted therein in mutually insulating and generally parallel and equally spaced relationship in an endless row, framing the tubular form, between its outer and surfaces and generally concentric therewith is provided. The conductors are arranged in such a manner that each of the conductors in the first group is axially aligned proximate with a conductor of the other group in the endless row.

Abstract: A capacitor-type power supply for electrical machining has a capacitor connected across a machining gap while a high-frequency power generator is disposed at a location remote from the machining gap and provides a high-frequency electric power. A feeder connects the power generator with the capacitor to permit the capacitor to be charged with pulses of the high-frequency electrical power. The system permits the high-frequency source to be located distally from the machining gap.

Abstract: An improved EDM system includes a partition member which separates a space surrounding a workpiece in a worktank into a first chamber which directly surrounds a machining area of the workpiece and a second chamber outside of the first chamber and surrounding a portion of the workpiece. The machining area and the first chamber are contiguous with each other and flooded with a machining medium constituted by a liquid hydrocarbon to allow successive electrical discharges to be effected therethrough to electroerosively remove material from the workpiece in the first chamber. The second chamber is flooded with a coolant constituted by a water liquid, preferably containing a non-ionic surface active agent dissolved in deionized water, in contact with this portion of the workpiece to cool the latter against heating thereof along the machining area by the erosive discharges in the first chamber.

Abstract: A magnetic encoder system comprising a rotary disk formed thereon with a succession of discrete magnetic encoding units each of which consists of a pair of opposed magnetic poles (N, S) and extends in alignment with a radial direction of the rotary disk. These magnetic encoding units are formed successively adjacent to the periphery of the disk and have alternating magnetic polarities. A magnetic sensing head is disposed substantially coplanar with the rotary disk and juxtaposed with the periphery of the disk across a small magnetic gap spacing.

Abstract: A drive mechanism for a machine such as a machine tool or robot includes a rotatable shaft, e.g. a lead screw or spindle, drivingly connected with a movable element, e.g. a worktable or tool support, in the machine, a drive shaft for rotation by a motor and a coupling unit, e.g. clutch or gear transmission, for drivingly connecting the drive shaft with the rotatable shaft to move the movable element in a predetermined form of movement under a variable load in the machine. Encoders are provided in a rotation-sensing relationship with the drive shaft and the rotatable shaft, respectively, to feed two trains of rotation-responsive pulses into a differential counter which provides a difference in angle of rotation signal representing an instantaneous torque produced at the drive coupling unit between the drive and rotatable shafts.

Abstract: A novel, nonflammable, high-performance and economical machining fluid of the invention contains an organic or semi-organic substance other than hydrocarbons at a proportion of 0.1 to 5% by weight and the balance essentially water. The machining fluid may optionally contain further at least one hydrocarbon oil such as kerosene and transformer oil. The substance should contain at least one element which upon discharge decomposition of the machining fluid in the gap produces an oxide of the element for example, silicon oxide or titanium oxide. As preferred but exemplary, the substance may be water-soluble silicone oil which should preferably be a polyether denaturated silicone oil. The machining fluid is preferably used in a machining method of the open-to-air-gap mode.

Abstract: A robot, particularly an industrial robot for performing predetermined tasks in accordance with given programs. When an operating portion of the robot encounters an unexpected obstacle, the robot must immediately stop the motion of the operating portion to prevent the collision with obstacle. For this purpose, the robot is provided with subcontrol units for individually controlling each operating portion of the robot as well as a main control unit for performing overall control of the robot. The subcontrol units serve to control such extra operations other than the inherent operations to carry out the prescribed tasks. Each operating portion is equipped with various detecting devices for sensing obstacles. The subcontrol units are made operative in accordance with outputs from the corresponding detecting devices. As obstacles, there are included humans, gases, radiation, etc. in addition to various objects. This invention can be applied to a robot having a learning function.

Abstract: A method of plating a pattern of metal (e.g. copper or nickel) on a dielectric surface, i.e. surface of a dielectric material such as a synthetic resin or ceramic. The method comprises the preliminary step of masklessly treating the dielectric surface to selectively activate preselected areas thereof so that the dielectric surface in contact with a priming solution becomes catalytic, and thereby receptive to electroless metal deposition, selectively at those areas. The treated dielectric surface is contacted with an electroless plating solution to allow metal therefrom to auto-reductively deposit selectively at those catalized areas, thereby forming the pattern of metal desired on the dielectric surface.

Abstract: A wire-cut EDM method and apparatus in which an electrode wire traveling between a pair of wire-positioning guide members is laterally advanced, generally tangentially along a workpiece contour disposed therebetween to electro-erosively cut a precision contour in the workpiece contour with a depth of cut at most equal to the diameter of the wire. The fluctuating machining pressure, induced by the gap erosive electrical discharges and fluid injection, tends to undulate the traveling wire in the open space flanking the contour being cut and to misalign the axial position thereof away from a prescribed path of advance in the cutting zone.

Abstract: To regulate the flushing liquid medium in the cutting zone of a TW electroerosion apparatus an elongate element is introduced into the cutting slot formed behind the advancing wire electrode and is maintained immediately behind the wire electrode and in parallel therewith, and thus dams the flushing medium in the space between the wire electrode and the element while serving to hold the wire electrode against deflecting rearwards. The elongate element is advantageously a tube having one or more apertures formed in a lateral wall thereof juxtaposed with the wire electrode, through which apertures the cutting liquid medium is discharged into the cutting zone and/or the flushing liquid medium in the cutting zone is sucked to assure an equalized distribution in the rate of flow in the cutting zone across the thickness of the workpiece. During a course of the cutting operation, the elongate element may be axially moved or reciprocated, or laterally oscillated.

Abstract: A traveling-tape electroerosive cutting method and apparatus utilizing a tape supporting guide bar having two opposite, elongate surfaces extending parallel to its longitudinal axis. The bar penetrates the workpiece from one side to the other side to bring the tape advancing between its dispensing site and takeup site into form engagement with those elongate surfaces which are shaped to enable those portions of the traveling tape which are respectively in engagement with the elongate surfaces together form an active electrode surface of convexity generally V-shaped in section and juxtaposed with the workpiece across a fluid-filled machining gap.

Abstract: A gap energizing system for TW electroerosion, in which a fluid delivery assembly has an elongate internal fluid passage longitudinally traversed by a straight-line path for a traveling wire electrode traversing a workpiece while defining a machining gap therewith. The passage is supplied with a machining fluid from an external fluid source and has at its end a nozzle outlet for discharging the supplied fluid as an envelop flow surrounding the electrode towards the workpiece and into the machining gap. Disposed in the internal passage are a precision guide member and an electrode contact means.

Abstract: A flushing fluid recycling system used with an electroerosion machine which includes a regenerating unit, i.e. an ion-exchange column as deionizer, through which the used liquid medium, e.g. water, collected from an electroerosion zone is passed for regeneration and return to the electroerosion zone. A pump is periodically actuated to intermittently pass the liquid medium through the deionizing column with predetermined on-time and off-time regardless of whether the value of an electrical property, e.g. specific resistance of the fluid, determined by a sensing unit lies above a certain level. However, the ratio of the on-time to the off-time is altered depending on the particular value of the electrical property sensed.

Abstract: An automatic TW (traveling-wire) electroerosion machining system for machining a plurality of workpieces of different types required to acquire different contours includes a TW machine having a wire setting unit and located adjacent a predetermined path. A work dispensing unit successively dispenses the different workpieces onto the path from a store thereof located adjacent the path. This unit and a work handling and transfer unit operate under control commands from an NC unit and, in conjunction with the TW machine, with the wire setting unit to carry out a plurality of work processing operations sequentially. In each operation, each individual workpiece selected from the store is transferred as it is carried on a pallet for loading onto and unloading from the TW machine. The tank of the TW machine has a movable front wall to facilitate this operation. The electrode setting unit on the machine acts both to form a start hole and thread a wire-type electrode through the formed hole in the workpiece.

Abstract: An electrical discharge machine is provided with at least one weight measuring apparatus for detecting the weight of one or both of an electrode and a workpiece, and a control unit for selecting or controlling the working conditions in response to the output of the weight measuring apparatus. The weights of the electrode and the workpiece are measured after the working operation has been interrupted temporarily, or while continuing the working operation. Well-known various accurate balances or force measuring apparatuses may be used as the weight measuring apparatus. A microcomputer including a numerical control unit may be used as the control unit.

Abstract: According to the present invention there is provided a magnetic retainer assembly adapted for selective attachment to and detachment from a magnetic object, which assembly comprises: a plurality of permanent magnet members of a uniform shape and size arranged regularly in a predetermined set of positions in the assembly for individually producing magnetic fields of a uniform field strength; support means in the assembly for holding the permanent magnet members securely therein and positioning said members spaced apart from one another in an essentially magnetically insulating relationship; and magnetic path-forming means in the support member for providing a magnetic path for each of the permanent magnet members to be magnetically conducted with the magnetizable object, thereby magnetically securing the assembly to the object.

Abstract: A CNC process for displacing a movable member along a path on an intricate surface in a three-dimensional coordinate system is disclosed in which the surface is divided into a plurality of elementary characteristic regions each individually definable as one of different geometrical categories such as toroidal, spherical, cylindrical and planar surfaces. The process comprises establishing a general equation for each of these categories and storing the established general equations into a memory unit for a computer. Data required to adapt each of the stored general equations to a corresponding one of the characteristic regions in the three-dimensional coordinate system are inputted into the computer to reduce the general equations to their respective specific equations in which no more than three coordinates are variable.

Abstract: A traveling-wire (TW) electroerosion apparatus in which at least one of wire guides which are disposed at opposite sides of the cutting zone has a plurality of guide elements with respective circular wire-receptive guide openings each of which is of a diameter substantially larger than a nominal diameter of the electrode wire and which are arranged to be mutually eccentric to make up a composite guide opening such that the diameter of an imaginary cylinder which can be inscribed therein is substantially equal to the nominal wire diameter. Preferably, the guide elements are arranged to be displaceable relative to one another and in their respective planes to change the eccentricity of these guide openings and thus to change the diameter of the imaginary cylinder.

Abstract: A method of and an apparatus for machining an electrically conductive workpiece with a wire electrode which is originally ferromagnetic or becomes ferromagnetic in the machining zone wherein the magnetic properties of the wire are detected as it passes out of the machining zone and the detected magnetic properties are used to control a machining parameter.

Abstract: An improved method and apparatus for automatically resetting a wire electrode in an operating setup on an electroerosion (e.g. EDM) machine is disclosed. Upon termination of a given machining operation commenced with a starting hole in the workpiece, the wire electrode spanning in a continuous stretch between a supply side and a collection side is broken in a region adjacent to the workpiece and at one of the opposite sides thereof by forming the wire electrode in the region with at least two coplanar grooves substantially symmetrical about the axis thereof and then applying tension to the wire electrode to break the latter in the region. The broken wire electrode is threaded its broken end into and through a new starting hole preformed in a workpiece for machining a contour therein in a subsequent machining operation to reestablish the continuous stretch of the wire electrode between the supply and collection sides.