Abstract: A novel electroerosion machining method and apparatus makes use of an elongate, open-ended tubular casing of a heat-resistant material retaining therein discrete metallic bodies (e.g. granular particles, flakes, fine powdery particles or broken wires) in a packed state. The casing is axially juxtaposed with a workpiece to define a machining site in the region of the latter proximate to the open-end portion of the casing and traversed by a machining liquid. A conventional electroerosion power supply furnishes a machining current between the workpiece and the discrete metallic bodies in the casing successively fed into the machining site to electroerosively remove material from the region of the workpiece against the discrete metallic bodies functioning as continuously consumed eletroerosion electrodes in the machining liquid medium.

Abstract: A method of treating a rare-earth mineral or concentrate, e.g. monazite and/or bastnaesite, wherein the rare-earth mineral or concentrate in a pulverized form is mixed with an aqueous solution of electrolyte and subjected to an electrical discharge effected in a region between a pair of electrodes in the presence of the solution.

Abstract: An electroerosive wire-cutting method and apparatus wherein a high-velocity stream of the cutting liquid medium produced through a small-opening nozzle is injected into a low-velocity stream of the cutting liquid medium produced through a large-opening nozzle and directed towards the region of the gap. The high-velocity cutting-liquid stream has a thickness substantially equal to the thickness of the cutting slot being formed behind the advancing wire electrode in the workpiece and is directed at a region of the cutting gap behind the advancing wire electrode. Gases (e.g. oxygen or ozone) and/or abrasive particles may be entrained in the high velocity cutting-liquid stream.

Abstract: A particulate mass to be sintered is imbedded in a mold which comprises a porous mass of particulate refractory material enclosed within a flexible membrane. Six press units are provided for applying compressive pressures externally to the mold, together or in sequence, whereby to subject the sinterable mass to pressures in the respective directions, under the control of a preprogrammed control unit which receives clock pulses from a source and stimulates the respective press units. A flexible heating coil imbedded in the mold is supplied with alternating current from a source to inductively heat up the sinterable mass and the adjacent mold material, to enable sintering to occur. The sinterable mass may have been precompacted into a self-supporting so-called "green compact", or it may be supported in a self-supporting shell carried within and forming part of the mold. The mold preferably comprises three layers having characteristics chosen so as to assist in heating up the sinterable mass uniformly.

Abstract: An machining method and apparatus whereby the EDM efficiency is markedly enhanced by replenishing the liquid machining medium in the machining gap at an amount of 400 to 3000 cc per unit weight by gram of the stock removal from the workpiece. The machining liquid is supplied into the gap under an elevated pressure of at least 10 kg/cm.sup.2, preferably between 30 and 100 kg/cm.sup.2. The rate of flow of the liquid medium to the gap is controlled in conjunction with and/or in response to at least one of the preset or variable parameters of the electrical discharges and/or as a function of other machining parameters such as the depth of the machining cavity so as to maintain the indicated amount of liquid replenishment.

Abstract: An electrical machining (e.g. EDM) apparatus having a worktank for containing a machining liquid and having a workpiece immersed therein; and a tool electrode positionable to be juxtaposed with the workpiece in the worktank to define an electrical machining gap therebetween filled with the machining liquid. The apparatus includes an ultrasonic assembly disposed in the worktank and comprises a head member and a support member. The head member is constituted by a housing having an ultrasonic transducer element supported therein and an opening for permitting only one of the two opposite surfaces of the transducer element to be held in contact with the machining liquid and to communicate with the region of the machining gap via the machining liquid. The head member is supported in the worktank by the support member, which may include a flexible multi-joint pipe or linkage, so that the opening is directed selectively towards the region of the machining gap.

Abstract: A method, electrode assembly and apparatus for forming an electrodeposited metallic layer on a wall of a recess in a workpiece and at least on a bottom area in the recess. The electrode assembly comprises an electrodepositing electrode element and a support member so formed as to incorporate the electrode element therein and have a surface contour complementary to a surface contour of the recess in the workpiece. The support comprises a porous mass composed at least in part of an electrically nonconductive material and having abrasive particles distributed therein at least on the contoured surface thereof. In operation, the assembly and the workpiece are positioned to establish a mating engagement of the support member with the recess and a liquid electrolyte is supplied onto the wall of the recess.

Abstract: An improved electrochemical grinding wheel electrode consisting essentially of electrically conductive abrasive grains bonded together with an essentially nonconductive bonding matrix. The abrasive grains are admixed with an amount of 10 to 30% by volume of the bonding matrix and sintered together to form the porous, homogeneous electrode body, e.g. in the form of a wheel, having a specific resistivity not greater than 100 ohm-cm, preferably between 0.1 and 10 ohm-cm.

Abstract: A magnetic holder for releasably retaining a ferromagnetic object, having a core member composed of a semi-hard magnetic material magnetized permanently by an instantaneous capacitor discharge current passing in a first direction through coils wound on the core member to permanently retain the object. The capacitor discharge current is passed in a second direction opposite to the first through the coils to demagnetize the previously magnetizer core member and allow the object to be magnetically released.

Abstract: A method of and an apparatus for making a composite carbon material from a precompact of granular carbons of different kinds or origins. A localized region of the carbon precompact is subjected to simultaneous heating by electric current flow from a current source at a temperature of 1800.degree. to 3500.degree. C. and pressurization at a pressure of 500 to 5000 kg/cm.sup.2, both being applied preferably impulsively. The localized region subjected to the simultaneous heating and pressurization is displaced so as to be controlledly crystallized and to control the formation of crystalline vacancies therein.

Abstract: A positioning device for a tool electrode on an electrical machine tool, comprising: a tool head and a swivel electrode support for securely holding the tool electrode and adapted to be swivelably carried by the tool head whereby to allow the axis of the tool electrode to be swung relative to the tool head about a fulcrum lying on the axis of the latter. An electrode centering assembly is used to align the axis of the tool electrode with the axis of the tool head and comprises a plurality of axial drive units operative for displacement and pressurization along the respective radially equi-spaced axes, each unit comprising a pressure plate having a pressure surface extending in parallel with the axis of the tool head and slidably received in a casing and resiliently supported thereby to maintain the parallelism. Motors are used to conjointly advance the casings to displace the pressure plates towards and urge them against the tool electrode.

Abstract: An EDM method wherein the surface roughness of the machined workpiece is reduced or the ratio of the removal rate to the surface roughness is increased by controlling at least one of the rate of flow of the liquid machining medium through the discharge gap and the rate of relative displacement between the tool electrode and the workpiece along the machining interface so that each individual discharge crater on the workpiece surface becomes elliptical in shape and has its major axis at least two times greater than its minor axis.

Abstract: An improved method of and apparatus for the electrical discharge machining of a small and deep hole of a diameter of 1 mm or less and a depth-to-diameter ratio of at least 5 into or through a workpiece wherein a water machining fluid medium is used having a specific resistivity of at least 10.sup.4 ohm-cm and is pumped through a tubular elongated electrode into the machining gap at a pressure of at least 20 kg/cm.sup.2, preferably 40 kg/cm.sup.2. An ultrasonic vibration is imparted to the elongated tubular electrode longitudinally thereof or transversely thereto.

Abstract: A method of and apparatus for controlledly moving a movable element in a machine tool having a drive unit drivingly coupled to the movable element, a motor drivingly coupled to the drive unit and a motor driver circuit for energizing the motor to drive the drive means, thereby moving the movable element, wherein a sequence of feed signals are furnished from a command source to energize the motor for the purpose of achieving a corresponding and desired sequence of movements of the movable element.

Abstract: A pulse generator, e.g. for electrical machining such as EDM, is provided which comprises: an on-time setting unit for selectively setting on-times, a first matrix circuit for producing a first output signal on a selected output thereof corresponding to a particular on-time set in the on-time setting unit; an off-time setting unit, independent of the on-time setting unit, for selectively setting off-times; a second matrix circuit, independent of the first matrix circuit, for producing a second output signal on a selected output thereof corresponding to a particular off-time set in the off-time setting unit; a clock pulser for producing clock pulses; a single preset counter for counting the clock pulses; and a circuit for establishing, in the single preset counter, first and second levels to be reached by the clock pulse count in accordance with the first and second output signals, respectively.

Abstract: An electroerosive contouring wire-cutting apparatus using a distilled or deionized water machining medium of a specific resistivity controlled to be in a range between 10.sup.2 and 10.sup.5 ohm-cm, and having abrasive particles of TiC, TiN, B.sub.4 C, BN, SiC, Al.sub.2 O.sub.3 and/or SiO.sub.2 of for example a particle size in the order of microns for delivery by the medium to the machining gap. A high-frequency vibration of a frequency of 1 kHz to 1 MHz is imparted to the wire electrode traveling through the workpiece in a direction transverse to the wire axis to enhance the combined electroerosive and abrasive actions at the machining gap. The machining medium is delivered by a nozzle, retrieved at a collector, and separated into its liquid and solid components in a separator. After deionizing the liquid and extracting the machining products, the abrasive particles and deionized water are mixed and recirculated through the nozzle.

Abstract: A method of and apparatus for inspecting the machined accuracy of a contour in a workpiece, e.g. machined by wire-cutting EDM, to form a desired contour therein make use of a light beam focused on a focal area on the workpiece and an optical lens and mirror system for projecting an optical image of the machined contour upon magnification on a display screen having predetermined indicia. The workpiece is positioned to locate a portion of the machined contour in the focal area in a predetermined X-Y coordinate system. A table carrying the workpiece is displaced by motors in response to drive signals furnished from an NC unit to displace the workpiece in the X-Y coordinate system so that the focal area effectively moves on the workpiece along a path of the desired contour and the light beam focussed thereon scans the machined contour.

Abstract: An arrangement for use with a worktank or machining receptacle in a machine tool, e.g. a wire-cut EDM machine, wherein a machining liquid is supplied to a machining zone defined between a tool and a workpiece wherefrom it is permitted to fall at least in part freely by gravity while entraining the machining products therein. In the receptacle provided for temporarily impounding therein the machining liquid falling directly from the machining zone there is provided a liquid damping member which includes a rugged layer of magnetic material for impingement upon by the falling machining liquid droplets and streams to whereby dissipate splashes thereof while magnetically trapping the ferromagnetic machining products therein.

Abstract: A method of and apparatus for machining, especially electroerosion machining, of a workpiece immersed in a machining liquid received in a worktank with a tool juxtaposed with the workpiece to define a machining interface therebetween filled with the machining liquid. A plurality of ultrasonic assemblies are disposed in the worktank in such a manner that they are spaced apart from each other and arranged to surround the region of the machining interface in a wave-transmitting relationship therewith through the machining liquid and individually energized to provide ultrasonic vibrations of a frequency of 0.05 to 10 MHz which are transmitted to the region of the machining interface through the machining liquid. Each of the ultrasonic assemblies is formed with a fluid injection nozzle and positionable to orient the latter in the direction of the machining interface, through which nozzle a forced flow of the machining liquid is provided from a liquid source.

Abstract: A method of and apparatus for electroerosively forming a 3D contour in a workpiece with a continuous elongate electrode axially transported continuously from a supply unit to a takeup unit to continuously renew a machining surface of the electrode juxtaposed in an electroerosion machining relationship with the workpiece is disclosed in which the continuous elongate electrode traveling between the supply and takeup unit is supported with guide unit carried by a tool head and having an arcuate guide surface juxtaposed with the workpiece to guide the traveling elongate electrode over at least a portion of the arcuate guide surface thereby constituting the machining surface at least in part with at least a portion of the elongate electrode traveling and guided over the guide surface.