Abstract: The machining efficiency is markedly increased in EDM by having a plurality of vibration horn assemblies in engagement with a tool assembly at preselected different positions on the surface thereof. The electromechanical transducers in the horn assemblies are individually energized to provide a burst of mechanical vibrations from the vibration output face of the horn member in each vibrator assembly in contact with the tool assembly and to allow the burst to be transmitted to the machining surface of the machining electrode to vibrationally activate a selected area thereof. The plurality of the vibrational bursts produced at the different locations on the tool assembly are combined, by being applied sequentially or at a time, to allow the machining surface of the electrode to be vibrationally activated uniformly over the entire area thereof. The arrangement is advantageously applicable to a variety of electrodes which may be large and to machining a deep and narrow, and/or intricate cavity in the workpiece.

Abstract: The disclosed method and apparatus are related to the machine for and process of cutting a desired contour in a workpiece with an axially traveling elongate tool by relatively displacing the workpiece and the elongate tool transversely to the traveling axis of the latter along a predetermined cutting path describing the contour whereby the workpiece is progressively divided, along the cutting path, into a first portion held secured with a work support and a second portion tending, by its own gravity, to fall off the first. The fall-off is prevented according to the invention with a plurality of attractable members, e.g. permanent magnets, which are spacedly juxtaposed with the workpiece and releasably retained with respective support holders on a support assembly.

Abstract: Apparatus for supplying a working fluid and a wire electrode to a wire region of a wire-cut electrical discharge machine comprising a housing supported by a support member and having opposed aligned openings through which a wire electrode is passed into operation association with a workpiece at the work region to be operated on by the electrode. A working fluid is supplied under pressure into the housing and the working fluid passes through a nozzle supported in the housing against the workpiece. The nozzle is positioned in the housing to surround the wire electrode which travels therethrough and it projects from the housing to discharge the working fluid against the workpiece at a gap formed therewith. A guide die is supported in the housing to guide the wire electrode through the housing and the nozzle.

Abstract: A mechanical member employs an inclined ring body having a frustoconical profile and comprising a multiplicity of tough and elastic, inclined ring elements each individually having a frustoconical profile and formed with a centrally located opening for slidably accepting therethrough a first member which is cylindrical and an outer peripheral edge adapted for engagement with a second member. The ring element has a plurality of outer slits extending radially inwardly from the outer peripheral edge towards the centrally located opening and a plurality of inner slits extending radially outwardly from the edge defining the centrally located opening towards the outer peripheral edge. An inclination adjusting member is carried by one of the first and second members so as to maintain a bearing contact with the inclined ring body and adapted to be displaced on the one member to change a given angle of the frustocone, thereby regulating the state of engagement of the ring body with the first and second members.

Abstract: A traveling-wire electroerosive machining method and apparatus in which a pressure created by and accompanying electrical machining discharges and tending to deflect the traveling electrode wire away from a straight line path defined between a pair of wire-guide members is compensated for by the machining fluid controlled both as to its direction and pressure. The apparatus shown includes a first sensor for sensing an angularity of the prescribed cutting path advanced by the traveling electrode wire to produce a first signal and a second sensor for sensing the electroerosive machining current passing between the electrode wire and the workpiece to produce a second signal.

Abstract: A travelling-wire electro-erosion machine which has a head assembly comprising a tubular support formed with a plurality of roller guides positioned to define a path for a travelling wire forming an electrode for electroerosion. Above the tubular support, there is provided a boxlike housing with a supply wheel and a takeup wheel for the wire and a bevel gear on the tubular support cooperates with a pinion on a motor which enables rotation of the entire assembly. A worm-gear arrangement may be used instead of the bevel gears and a different construction of the guide rollers may be provided as well, e.g. on the downwardly extending projection from the tubular body.

Abstract: An EDM method of and apparatus for machining the surfaces of a cavity in an electrically conductive workpiece utilize an electrode assembly comprising a plurality of segmented electrodes having their respective machining surfaces which collectively form a contour corresponding in shape to the cavity and being supported so as to be spaced apart and movable relative to each other in the assembly. An EDM power supply is used to electrically energize the segmented electrodes individually with respect to the workpiece and a plurality of drive units are provided to individually displace the segmented electrodes, independent of one another, relative to the workpiece, along their respective predetermined paths of translational motion, thereby permitting electrical discharges to develop between each of the surfaces of the cavity and the machining surface of each of the segmented electrodes brought proximate thereto across a fluid-filled machining gap during the individual translational motion thereof.

Abstract: A multi-strand wire electroerosion machining method and apparatus are disclosed wherein a plurality of wires dispensed from respective wire sources are fed separately into a wire travel path and are assembled via wire guides into a bundle thereof. The bundle of the wires traversing a fluid-flushed cutting zone defined between machining electrode guides constitutes a single traveling electrode for electroerosively machining a workpiece. The wires from the cutting zone are taken up into a collection site while they are held sufficiently taut between the electrode guides. The workpiece is displaced relative to the bundle of traveling wires transversely to the axis thereof to machine a desired contour in the workpiece. Preferably, the wires in the bundle are twisted. Also disclosed is a rotary die for shaping the wires in their travel path to provide the bundle with a predetermined cross-sectional contour spaced from the wall of the workpiece across the machining gap.

Abstract: Electroerosion machining method and apparatus in which the machining gap formed between a tool electrode and a workpiece is immersed in a water liquid to surround and enclose the gap therewith in the absence of a hydrocarbon liquid surrounding the gap. The hydrocarbon liquid is injected in a forced flow under an external pressure into the machining gap immersed in, and surrounded by and enclosed with, that water liquid, whereupon electrical discharges are initiated with a discharge medium which is at least predominantly constituted with the injected hydrocarbon liquid. The water liquid may be of a relatively static mass retained in a worktank, in which mass the workpiece and at least that portion of the tool electrode which is juxtaposed therewith are immersed. The injected hydrocarbon liquid upon undergoing the electrical discharges is allowed to diffuse into the water liquid surrounding the gap to float onto the surface thereof.

Abstract: Uncontrolled transverse mechanical oscillations of an electrode wire in the traveling-wire electroerosion machining apparatus are effectively and efficiently prevented by provision of a novel assembly comprising a mass of magnetic fluid retained in a pair of magnetic pole pieces and disposed in a straight line path defined between a pair of machining wire guide and support members to accommodate the traveling electrode wire. A magnetic field is established between the pole pieces to actuate the magnetic fluid, thereby damping uncontrolled oscillations as caused in the traveling electrode wire.

Abstract: A high-hardness and high-strength carbon material is produced by disposing a body of graphite carbon, e.g. precompacted graphite or a mass of powdery graphite carbon, of a predetermined shape and dimension in a collapsible receptacle shaped and dimensioned to tightly retain the body therein, the receptacle being collapsible at least one-dimensionally under external pressure while holding the body against expansion. High pressure is applied to the body while the body is heated to an elevated temperature and for a sufficient period such as to cause a central region of the body to be liquefied and the remainder thereof to be sintered. While under continuous pressure, the body is cooled to give in carbon material.

Abstract: An ion-processing method and apparatus utilizing a slender tubular member having an open end and communicating with an inlet conduit. The tubular member is positioned to bring the open end in spaced juxtaposition with a workpiece across a small gap of a size of 10 and 1000 .mu.m in an evacuated an ionizable material is supplied into the slender tubular member through the inlet conduit for feeding it into the small gap through the open end. A power supply is provided to energize the supplied gas to form ions thereof and to apply an accelerating potential to the formed ions to propel them in a beam across the small gap to impinge upon a limited area of the surface of the workpiece juxtaposed with the open end of the slender tubular member. The pressure within the small gap, ranging between 10.sup.-4 and 10.sup.-1 Torr, is maintained in excess of the pressure of the surrounding the gap, ranging between 10.sup.-6 and 10.sup.-4 Torr.

Abstract: An EDM method utilizing an improved tool electrode made of a sintered carbonaceous body consisting essentially of 50 to 90% graphitized carbon and the balance nongraphitized carbon uniformly distributed therein. The body may be prepared by sintering a mass of graphitized carbon particles and nongraphitized carbon particles mixed uniformly together in an optimum proportion under pressure. During sintering, the mass may be compressed bi-axially but is preferably tri-axially or isostatically compressed. The carbonaceous body of the invention may be prepared by sintering together graphitized carbon particles and a predecessor of the nongraphitized carbon, by sintering a uniform mixture of a predecessor of graphitized carbon and a predecessor of nongraphitized carbon. The predecessor of nongraphitized carbon is advantageously constituted by phenol and/or furan.

Abstract: A method of forming a cavity of a desired three-dimensional contour in a workpiece utilizes two steps of machining operation. In the first step (a), a multiplicity of holes are mechanically drilled in the workpiece substantially all over but within a three-dimensional region which is destined to constitute the cavity and which is bounded by a programmed outline corresponding to the desired three-dimensional contour whereby only a minimum of stock is left unmachined in the workpiece within the region.

Abstract: An improved machining-liquid supply system for traveling-wire electroerosion machining is disclosed which comprises a machining-liquid ejecting nozzle disposed on one side of a workpiece and traversed by the traveling wire electrode for injecting a thin stream of the machining liquid into the cutting zone in the workpiece. A cover member is disposed proximate to and so as to surround, the end of the cutting zone on the other side of the workpiece and is formed with a drain duct communicating with a suction source to forcibly draw the machining liquid injected into the cutting zone by the machining-liquid ejecting nozzle. The system further comprises a coolant-ejecting nozzle disposed so as to coaxially surround the machining-liquid ejecting nozzle for ejecting a stream of coolant and enclosing therewith the stream of the machining liquid being injected into the cutting zone.

Abstract: An EDM method and apparatus wherein a localized magnetic field is produced so as to be concentrated at least predominantly on a region of the EDM gap which constitutes only a limited portion of a preselected entire area of juxtaposition between the tool and workpiece electrodes. The region of concentration of the localized magnetic field is successively shifted to sweep it over the entire area of juxtaposition between the electrodes. A control device is provided to control at least one parameter of production and sweeping of the localized magnetic field in response to at least one process parameter of the EDM process.

Abstract: A traveling-wire electroerosive cutting method using a worktank filled with a liquid machining medium in which a workpiece is immersed. A continuous wire electrode is transported from a supply unit to a takeup unit to axially travel and thereby traverse the workpiece in a cutting zone defined between a pair of cutting guide members spanned by the electrode. A nozzle is arranged in the cutting zone to inject a high-velocity stream of the coolant liquid machining medium into the machining gap which is formed in the workpiece juxtaposed with the traveling wire electrode and which is filled with and disposed in the relatively static liquid machining medium contained in the worktank. The liquid stream injected from the nozzle has a pressure in excess of 2 kg/cm.sup.2 and preferably has a velocity in excess of 3 m/sec. A high-frequency (e.g. of a frequency of 1 kHz to 1 MHz) mechanical vibration is imparted to the traveling wire electrode in a direction transverse to the wire axis.

Abstract: A method of and apparatus for electroerosively machining a 3-dimensional cavity in a workpiece with a slender, preferably tubular and continuous, tool electrode whose contour is generally independent in shape of the desired cavity. A horn-type sonic or ultrasonic assembly or a motor-driven mechanical reciprocation unit is used to laterally oscillate the slender electrode to cause the machining tip portion thereof to oscillatorily move at a rate of movement, preferably in excess of 5 m/minute, substantially in a plane normal to the electrode axis. The machining liquid is pumped into the tubular electrode and delivered therethrough into the machining gap at a pressure in excess of 10 kg/cm.sup.2.

Abstract: An EDM pulse forming circuit arrangement and method employs an oscillator to produce a succession of quantum signal pulses of a pulse duration .tau.on.q and a pulse interval .tau.off.q. A gating circuit is used to gate the quantum signal pulses and to turn on and off a power switch in circuit between a DC voltage supply and a gap discharge circuit with the gated quantum signal pulses to develop a train of quantum machining voltage pulses across the machining gap within each time period Ton of the gating pulses. The gap discharge circuit incorporates an impedance such that the quantum voltage pulses of an extremely short duration result in a substantially continuous, unitary and pulsed current flow through the gap within the gated time period Ton, constituting an individual machining electrical discharge of a duration .tau.on which is substantially equal to the time period Ton.

Abstract: An EDM method and apparatus in which a continuous DC voltage is applied across the EDM gap via a first switch held conductive, and a stray capacitance distributed in the supply circuit including the EDM gap is recurrently charged and discharged to produce successive electrical discharges between the tool electrode and the workpiece. A gap sensor monitors the magnitude of high-frequency signals contained in the successive discharges and, when the sensed magnitude falls below a threshold level, provides a trigger signal which is used to turn on a second switch connected across the EDM gap in parallel with the DC source to short-circuit the EDM gap, thereby terminating the successive discharges. The conducting second switch serves to discharge the residual charge on the stray capacitance and prevents charge build-up thereon. Then the first switch may be turned off.