Abstract: A process of dry polishing molded or lathe cut intraocular lenses to removing flash, sharp edges and/or surface irregularities therefrom. The process includes rotational tumbling of partially protected intraocular lenses in a dry polishing media. The process is suitable for single piece and multipiece intraocular lenses of varying composition.

Abstract: Methods and apparatuses for selectively removing conductive materials from a microelectronic substrate. A method in accordance with an embodiment of the invention includes positioning the microelectronic substrate proximate to and spaced apart from an electrode pair that includes a first electrode and a second electrode spaced apart from the first electrode. An electrolytic liquid can be directed through a first flow passage to an interface region between the microelectronic substrate and the electrode pair. A varying electrical signal can be passed through the electrode pair and the electrolytic liquid to remove conductive material from the microelectronic substrate. The electrolytic liquid can be removed through a second flow passage proximate to the first flow passage and the electrode pair.

Abstract: This invention relates to a vibrating abrasive cleaning apparatus and method which is powered by a hydraulic drive motor mounted to a square tubing fame which is housed within an enclosure that is vibrated by an eccentric shaft assembly directly coupled to the hydraulic drive motor and square tubing frame. The container assembly is mounted on the rigid square tubing frame, on one side by compression springs, on the opposite side by tension springs. The compression springs and tension springs have a different spring rate which produces better rolling of the media and therefore, faster parts circulation and cleaning. To further give flexibility to the cleaning process the hydraulic power supply is equipped with the variable volume piston pump to give infinite speed settings.

Abstract: This invention relates to a vibrating abrasive cleaning apparatus and method which is powered by at least one electric motor specially fabricated to the cleaning container assembly mounted on a rigid square tubing frame on one side by compression springs, on the opposite side by tension springs. The compression springs and tension springs have a different spring rate which produces better rolling of the media and therefore, faster circulation and cleaning. The specially fabricated electric motor attached to the cleaning container provides for enhanced oscillation and much greater cleaning capabilities thereby reducing the cleaning time. The entire vibrating assembly sits on a base and has a lid operated by a cable and counterweight for ease in loading the container for oscillation of the parts.

Abstract: Jet-induced finishing of a substrate surface includes means for covering the surface with an abrasive liquid slurry and means for impinging a jet of fluid, either a gas or a liquid, against the slurry to create a high-shear work zone on the substrate surface whereby portions of the substrate are lifted and removed to alter the shape of the surface towards a predetermined shape and/or smoothness. The surface may be covered as by cascading a flowing layer of slurry over it or by impinging slurry onto the work zone or by immersing the substrate in a pool of the slurry. A nozzle for dispensing the jet fluid is precisely located at a predetermined distance and angle from the surface to be finished. A coarse removal function is provided by disposing the nozzle tip at a first distance from the substrate surface, and a fine removal function is provided by disposing the nozzle closer to the substrate surface.

Abstract: An apparatus and method for removing surface coating of an article carrying jig so as to enable electrical contact between the jig and the or each article to enable the articles to be coated with surface coating in a treatment chamber wherein the surface coating on the jig is removed by subjecting the jig and article to vibration so that the resulting movement between the articles and the jig abrades the surface coating on the jig hence enabling electrical contact between the jig and the articles.

Abstract: A wheel finishing apparatus for abrasively finishing the front faces of automobile wheels. The apparatus has a rotating carousel hub and multiple arms connected to the carousel hub which extend out to wheel mounting ends. A wheel is rotatably mounted to each wheel mounting end such that the front face of each wheel faces a known direction of carousel rotation and forms an impingement with an orbital path traversed by the wheel mounting end. Each wheel may be independently pivoted about a respective pivot axis at each wheel mounting end for variably adjusting the impingement angle. By adjusting the impingement angle to less than ninety degrees, partially submerging the wheels in a media bath, and rotating the carousel drive structure about a central axis of rotation, the abrasive polishing media impinges the submerged portions of the front faces and rotates the wheels about their respective wheel rotational axes to abrasively finish all areas of the front faces.

Abstract: A method and apparatus for removing conductive material from a microelectronic substrate. In one embodiment, a support member supports a microelectronic substrate relative to a material removal medium, which can include first and second electrodes and a polishing pad. One or more electrolytes are disposed between the electrodes and the microelectronic substrate to electrically link the electrodes to the microelectronic substrate. The electrodes are then coupled to a source of varying current that electrically removes the conductive material from the substrate. The microelectronic substrate and/or the electrodes can be moved relative to each other to position the electrodes relative to a selected portion of the microelectronic substrate, and/or to polish the microelectronic substrate. The material removal medium can remove gas formed during the process from the microelectronic substrate and/or the electrodes.

Abstract: The present invention is based on the practice of abrasive machining with no sealed working chamber by the employment of a visco-elastic abrasive medium, behaving predominantly as an elastic solid at the applied strain of the orbital working motion, and applying orbital or other relative working motion to produce strain rates which bring the medium into a predominantly elastic deformation and often near, but not to exceed, the compressive stress limit at the strain rate employed. The preferred visco-elastic abrasive medium is a rheopectic poly(boro-siloxane) filled with viscosity increasing stiffening agents and high loadings of the abrasive of choice and relatively minor amounts of plasticizers.

Abstract: There are disclosed a polishing method and a polishing device in which cleaning of a glass substrate surface can be achieved to a high level. A glass substrate (MD substrate 1) in the shape of a circular disc having a circular hole in a center portion is immersed in an abrasive liquid 50 containing free abrasive grains, and an inner peripheral end surface of the glass substrate is polished using the abrasive liquid containing the free abrasive grains by rotating a rotary brush 4 or a polishing pad in contact with the inner peripheral end surface.

Abstract: A system for abrasively cleaning small parts, and a container for holding small parts undergoing abrasive cleaning. An abrasive cleaning cabinet has a bottom member and a cover hingedly connected to the bottom member. The cover is pivotable between a closed position in which the cover is closed against the bottom member to define a cleaning chamber therewithin and an open position permitting access into the cleaning chamber. The cover has a viewing window and a pair of arm apertures through it, with a glove attached to each arm aperture and extending into the cleaning chamber to permit insertion of a person's hands through the arm apertures and into the gloves in the cleaning chamber.

Abstract: A magnetic wiper for removing magnetorheological fluid from a carrier surface includes a horseshoe magnet having north and south polepieces elongated in a first direction orthogonal to a second direction of magnetic flux in the magnet. The polepieces are generally parallel at their free ends in the first direction and are preferably arcuate such that the inner polepiece forms a trough for receiving magnetorheological fluid removed from the carrier surface and conveying it to an exit tube. The free ends are shaped to conform closely to the shape of the carrier surface, forming a narrow gap therebetween containing a magnetic fringing field extending beyond the free ends.

Abstract: There is disclosed a barrel-polishing apparatus comprising a polishing medium bath with polishing mediums received therein, a base, an arm mounted on the base, and a workpiece attachment device mounted on a distal end portion of the arm and adapted to attach a workpiece to the arm, wherein the polishing mediums are caused to flow within the polishing medium bath by an appropriate device and a pressing plate for pressing the polishing mediums is mounted on the polishing medium bath. A barrel-polishing method is also disclosed.

Abstract: The present invention is based on the practice of abrasive machining with no sealed working chamber by the employment of a visco-elastic abrasive medium, behaving predominantly as an elastic solid at the applied strain of the orbital working motion, and applying orbital or other relative working motion to produce strain rates which bring the medium into a predominantly elastic deformation and often near, but not to exceed, the compressive stress limit at the strain rate employed. The preferred visco-elastic abrasive medium is a rheopectic poly(boro-siloxane) filled with viscosity increasing stiffening agents and high loadings of the abrasive of choice and relatively minor amounts of plasticizers.

Abstract: There is disclosed a barrel-polishing apparatus comprising a polishing medium bath with polishing mediums received therein, a base, an arm mounted on the base, and a workpiece attachment device mounted on a distal end portion of the arm and adapted to attach a workpiece to the arm, wherein the polishing mediums are caused to flow within the polishing medium bath by an appropriate device and a pressing plate for pressing the polishing mediums is mounted on the polishing medium bath. A barrel-polishing method is also disclosed.

Abstract: A tumbler apparatus for abrading and polishing small parts and rocks includes a cylindrical barrel with a closed end and an open end. The inner surface at the open end has a circular sealing edge. A sealing closure for the sealing the barrel at the open end includes a first and a second rigid disc. A resilient band, either an O-ring or a cylinder, is held between the discs. A translating mechanism draws the discs toward one another in a sealing mode, that compresses the band to bulge outwardly to sealingly engage the inner sealing surface of the barrel open end. In a releasing mode, the discs are moved apart, allowing the band to resume it original shape, thereby unsealing the barrel to facilitate removal of the closure for access to the barrel contents. A pressure relief valve at the center of the discs may be optionally provided.

Abstract: A method for finishing a workpiece is disclosed. The method involves placing a ferrofluid finishing material into a vessel. The ferrofluid finishing material including a ferrofluid and a dispersed or colloidally suspended abrasive media. Placing a workpiece in the vessel so that the workpiece is submerged in the ferrofluid finishing material. A magnetic field is then applied in the vicinity of the vessel. The magnetic field produces an increase in viscosity of the ferrofluid. The increased viscosity generates a clamping force on the workpiece that results in increased surface resistance over the entire workpiece. Also, as the viscosity increases, it forces the workpiece to move relative to the ferrofluid. The relative motion between the abrasive media and the workpiece and increased surface resistance causes the abrasive media to finish the surface of the workpiece.

Abstract: A carriage for a hard disc drive polished as final finish has high surface precision of micron order. The finish surface is smooth, a cutting trace does not exist, and the surface layer is hardened uniformly by a magnetic material being hit by magnetic power. A cutting bur the edge of which is very tiny does not fall after installing the hard disc drive. The carriage for the magnetic head of the hard disc are not influenced by a temperature change and a seasonal change. The present invention forms a magnetic polishing brush by keeping magnetic abrasive material between magnetic poles in the carriage as a head arm member formed by extrusion molding or drawing for the magnetic head of the hard disc drive. The carriage of non-magnetic material as an aluminum part of HDD inserted in the above described magnetic polishing brush, is given reciprocation motion and vibration, thus the surface of the above described part is polished. The final finish is made by magnetic beam processing to polish or remove burs.

Abstract: A method for polishing radially expandable surgical stents is disclosed where fluid abrasive media M flows over surfaces of the stent 10 causing the surfaces of the stent 10 to be polished and streamlined. The stent 10 is temporarily provided with cylindrical support ends 20, which are not radially expandable to support the stent 10 during the polishing process. An interior polishing fixture 100 is provided which has cylindrical chambers 135 therein adapted to receive a stent 10 therein. Fluid abrasive media M then flows into bores 108 in the fixture 100 leading to the cylindrical chambers 135 and adjacent the inner diameter surfaces of the stent 10. Surfaces of the stent 10 forming the outer diameter are polished by placing the stent 10 within an exterior polishing fixture 200 which has a cylindrical recess 220 therein.

Abstract: A cutting system by which a material to be worked is cut off by the use of each of abrasive grain-bonded saw wires contained in a saw wire assembly prepared by arranging the abrasive grain-bonded saw wires on a long tape base material along the longitudinal direction thereof in such a way that they are disposed side by side in the direction perpendicular to the above described longitudinal direction, and bonding tentatively these abrasive grain-bonded saw wires onto the tape base material through an adhesive in a releasable manner, comprises means for releasing the tape base material from the saw wire assembly before it reaches the material to be worked; and means for applying a tension to the saw wire assembly and each of the abrasive grain-bonded saw wires.

Abstract: The present invention provides a polishing machine in which the polishing face of the polishing pad is made to contact the polishing object face of the wafer with efficient supply of the polishing agent on the polishing object face of the processing object in the polishing process, the polishing object face of the wafer being polishing by allowing at least either one of them to rotate, wherein the wafer is polished by repeatedly making a contact and non-contact between the polishing pad and wafer during the polishing process in the polishing agent accommodated in the vessel.

Abstract: A method and an apparatus are disclosed wherein works may be finished magnetically by media by utilizing the interaction of the works and media placed within the generated alternating magnetic fields. A method of finishing works magnetically comprises generating multiple alternating magnetic fields and combining them to provide combined alternating magnetic fields covering a specific extensive region and placing media and works in their free motion within those alternating magnetic fields. An apparatus for finishing works magnetically comprises a plurality of alternating magnetic filed generator units each including a plurality of magnets, wherein any combination of those units provides combined alternating magnetic fields within which works and media are placed, with at least the media being placed in its free motion.

Abstract: The invention concerns a machine for drying, polishing and burnishing cutlery, crockery and metal tableware with the help of a drying material. It includes a tank (11,21) suspended on springs (13,23) on a supporting base (12,22) and connected to a motor driven vibrator (14,24) to maintain it in continual vibration, where said tank contains the drying material and is used to receive the objects to be treated with this material. The tank make also be equipped with a chute (25) for loading the items to be treated and on one side of the tank an exit chute (26) for the treated items.

Abstract: Magnetic-abrasive machining of a parts is performed by generating a magnetic field by two different poles located near one another so as to form a magnetic gradient region with magnetic flux lines which extend from one pole in one direction and then in an opposite direction to another pole and therefore are round in a predetermined plane, placing a part to be machined exclusively at one side of the two poles, introducing a magnetic-abrasive powder between the poles and the part to be machined so that a portion of the part to be machined is located in the magnetic gradient region with the round magnetic flux lines, and moving the part to be machined relative to the poles in the same plane transversely to the round magnetic flux lines of the magnetic gradient region so that portions of the part to be machined successively pass the magnetic gradient region with the round magnetic flux lines and are machined by the magnetic-abrasive powder retained in the magnetic gradient region with the round magnetic flux line

Abstract: A method of cleaning a solid surface which is particularly effective for a surface having a complicated structure including slots and holes comprises immersing the solid surface in a cleaning slurry comprising a cleaning liquid and abrasive particles which are soluble in the cleaning liquid, the cleaning liquid comprising a saturated solution so as to greatly reduce the dissolution of the abrasive particles in the cleaning liquid.

Abstract: A centrifugal finisher uses centrifugal and rotational forces for finishing at least one object. A fixed, non-rotatably outer vessel has an inner surface and a central axis. At least one inner vessel is positioned inside the outer vessel and is adapted to hold an object to be finished. The inner vessel has an outer surface. At least one intermediate roller is positioned between the inner surface of the outer vessel and the outer surface of the inner vessel and engages the surfaces of respective outer and inner vessels. A drive mechanism rotates the inner vessel around the central axis of the outer vessel, thereby causing rotation of the inner vessel by engagement of the inner vessel with the intermediate roller which moves by rotation along the inner surface of the outer vessel.

Abstract: This invention relates to a spiral-flow barrel finishing machine having a cylindrical stationary metallic barrel equipped with a lining layer at a lower inside portion. A rotating barrel is equipped with a lining layer on a metallic rotational body and is loosely engaged with the lower part inside of the cylindrical stationary barrel so as to rotate freely. A constant clearance is kept between the inner wall of the stationary barrel and the outer wall of the rotating barrel, regardless of the temperature change and the moisture content change. A measure to allow for thermal expansion having a specific vertical width, properly corresponding to the vertical width of the clearance, is circularly arranged between the inner wall of the metallic stationary barrel and the outer wall of the lining layer on the metallic stationary barrel. This makes an allowance for thermal expansion of the lining layer on the stationary barrel toward wall side of the metallic stationary barrel.

Abstract: This invention relates to a vibrating abrasive cleaning apparatus and method which is powered by a hydraulic drive motor mounted to a square tubing frame which is housed within an enclosure that is vibrated by an eccentric shaft assembly directly coupled to the hydraulic drive motor and square tubing frame. The container assembly is mounted on the rigid square tubing frame, on one side by compression springs, on the opposite side by tension springs. The compression springs and tension springs have a different spring rate which produces better rolling of the media and therefore, faster parts circulation and cleaning. To further give flexibility to the cleaning process the hydraulic power supply is equipped with the variable volume piston pump to give infinite speed settings. The eccentric shaft assembly with the eccentric weight positions set at different relative positions to one another gives the operator the ability to adjust the machine to produce optimum results with all parts, sizes, and weights.

Abstract: A magnetic barrel tumbler for polishing precious metal articles, including a motor case adapted to firmly support a motor therein, an outer housing mounted to an upper portion of the motor case, a magnetic disc placed in a space defined by both the outer housing and the motor case, the magnetic disc including a disc plate coupled to a shaft of the motor, and a plurality of magnets attached to an upper surface of the disc plate, the magnets being arranged in a fashion that those having opposite polarities face each other diametrically so that variations in magnetic field are induced during a rotation of the disc plate, a fixed plate spaced from an upper surface of the magnetic disc and fixedly mounted at an outer edge thereof to an inner surface of the outer housing, the fixed plate being made of a nonmetallic material, a polishing barrel laid on the fixed plate, the polishing barrel being provided with a protrusion at the central portion of an inner bottom surface thereof and with a chamber for containing art

Abstract: A tumbling mill includes an inlet area, an outlet area, and a tumbling area between the inlet and outlet areas. The mill is formed as a tri-cyclical member having an outer cylinder extending along the tumbling and outlet areas, and an inner cylinder concentric with the outer cylinder and extending through the inlet, outlet and tumbling areas. The inner and outer cylinders define a space therebetween. The inner cylinder is perforated to allow sand to fall into the space between the inner and outer cylinders. The inner cylinder includes an inner helical vane to urge sand, media, and castings toward the outlet area, and an outer helical vane to urge sand and media toward the inlet area. A reclassifying screen is provided in the inlet area to classify sand. Sand particles that are sufficiently small passes through the screen and out a chute. Sand particles that are not small enough are recirculated through the tumbling mill to be further broken down.

Abstract: A magnetic barrel finishing machine causes multiple different flows or motions of the abrasive media and workpieces by varying magnetic fields, thereby freeing the workpieces from the abrasive media and subjecting the workpieces to finishing action by the abrasive media. The machine includes a rotator made of magnetic material and a plurality of permanent magnets rigidly mounted on the rotator. A container is located above the rotator with a small gap therebetween, and contains workpieces to be finished and an abrasive medium of magnetic material, or workpieces to be finished and an abrasive medium including a magnetic material. The permanent magnets are arranged irregularly in such a way that they provide magnetic lines of force acting in the circumferential direction as well as the radial direction of the rotator.

Abstract: A method of cleaning a solid surface which is particularly effective for a surface having a complicated structure including slots and holes comprises immersing the solid surface in a cleaning slurry comprising a cleaning liquid and abrasive particles which are soluble in the cleaning liquid, the cleaning liquid comprising a saturated solution so as to greatly reduce the dissolution of the abrasive particles in the cleaning liquid.

Abstract: A non-contact polishing tool that combines two orthogonal slurry flow geometries to provide flexibility in altering the shape of the removal footprint. By varying the relative contributions of the two flow geometries, the footprint shape can be varied between the characteristic shapes corresponding to the two independent flow regimes. In addition, the tool can include a pressure activated means by which the shape of the brim of the tool can be varied. The tool can be utilized in various applications, such as x-ray optical surfaces, x-ray lithography, lenses, etc., where stringent shape and finish tolerances are required.

Abstract: A washing liquid and a granular substance in the quantity equivalent to or more than the liquid in the specific gravity are accommodated in a barrel in a manner to position the surface of the liquid above the top surface of a granular substance layer at a stationary state of the barrel, and the barrel is swung with an object to be washed which is accommodated therein to wash away stains firmly stuck.In the same manner, various treatment liquid such as a plating liquid and a granular substance which possess conductivity or without conductivity are accommodated in the barrel with an object to be treated. By swinging the barrel, the treatment liquid and the granular substance are stirred and flow in the barrel so that the fluidity of the treatment liquid and granular substance relative to the object to be treated is improved to raise treatment effect and uniformity in the process. Thus, high quality surface treatment can be accomplished in high productivity.

Abstract: A method of polishing an object is disclosed. In one embodiment, the method comprises the steps of creating a polishing zone within a magnetorheological fluid; determining the characteristics of the contact between the object and the polishing zone necessary to polish the object; controlling the consistency of the fluid in the polishing zone; bringing the object into contact with the polishing zone of the fluid; and moving at least one of said object and said fluid with respect to the other. Also disclosed is a polishing device. In one embodiment, the device comprises a magnetorheological fluid, a means for inducing a magnetic field, and a means for displacing the object to be polished or the means for inducing a magnetic field relative to one another.

Abstract: A medal cleaning apparatus for mixing and jumbling medals and cleaning material, cleaning the medals, separating the medals and the cleaning material and then expelling the medals comprises a transporting pipe, the lower end of the transporting pipe having an inlet for taking-in the medals and the cleaning material and the upper end of the transporting pipe becoming a medal expulsion outlet, a spiral member, installed within the transporting pipe, for mixing, jumbling and transporting the medals and the cleaning material, a driving mechanism for rotating the spiral member, a filter, set up around and extending from one side of the upper end of the transporting pipe, and a return pipe for guiding the cleaning material separated at the filter to the lower end of the transporting pipe, with the filter being arranged so as to be inclined downwards in the direction of progress of the medals and the plane of the medal expulsion outlet at the upper end of the transporting pipe being inclined downwards in the directi

Abstract: An apparatus for polishing medals for a game machine, and for separating an abrasive from the medals. An intake port (2) for the medals and the abrasive is provided on the lower end side of a polishing pipe (1) set upright, while a medal delivery port (3) is provided on the upper end side. A rotatable screw element (4) is mounted inside the polishing pipe (1) so as to lift up the medals and the abrasive while stirring them. A separation unit (A) which separates the abrasive from the medals and which feeds the separated abrasive to the intake port (2), is joined to the upper part of the polishing pipe (1).

Abstract: This invention relates to a vibrating abrasive cleaning apparatus and method which is powered by a hydraulic drive motor mounted to a square tubing frame which is housed within an enclosure that is vibrated by an eccentric shaft assembly directly coupled to the hydraulic drive motor and square tubing frame. The container assembly is mounted on the rigid square tubing frame, on one side by compression springs, on the opposite side by tension springs. The compression springs and tension springs have a different spring rate which produces better rolling of the media and therefore, faster parts circulation and cleaning. To further give flexibility to the cleaning process the hydraulic power supply is equipped with the variable volume piston pump to give infinite speed settings. The eccentric shaft assembly with the eccentric weight positions set at different relative positions to one another gives the operator the ability to adjust the machine to produce optimum results with all parts, sizes, and weights.

Abstract: A method of polishing an object is disclosed. In one embodiment, the method comprises the steps of creating a polishing zone within a magnetorheological fluid; determining the characteristics of the contact between the object and the polishing zone necessary to polish the object; controlling the consistency of the fluid in the polishing zone; bringing the object into contact with the polishing zone of the fluid; and moving at least one of said object and said fluid with respect to the other. Also disclosed is a polishing device. In one embodiment, the device comprises a magnetorheological fluid, a means for inducing a magnetic field, and a means for displacing the object to be polished or the means for inducing a magnetic field relative to one another.

Abstract: A magnetic barrel finishing machine includes multiple different flows or motions of an abrasive medium and workpieces by varying magnetic fields, freeing the workpieces from the abrasive medium and subjecting the workpieces to a finishing action with the abrasive medium. The machine includes a rotary disk made of nonferromagnetic material, a plurality of permanent magnets rigidly mounted on the rotary disk, and a container located above the rotary disk with a small gap therebetween for containing the abrasive medium and the workpieces being finished thereby. The permanent magnets are arranged irregularly such that they provide magnetic lines of force acting in a circumferential direction as well as in a radial direction of the rotary disk.

Abstract: A surface finishing vibratory apparatus and method for using such to simultaneously surface finish a plurality of elongated parts with loose particulate finishing media. The apparatus includes a single tub having a plurality of transversely disposed longitudinally extending troughs wherein the troughs are isolated from each other such that finishing media and the workpieces placed in each trough cannot move to another trough during the surface finishing process. The troughs mat use fixed or removable compartment walls that divide one or more of the troughs into separate isolated compartments to use for shorter workpieces.

Abstract: A workpiece to be ground is immersed in a processing solution with abrasive grains suspended therein. The processing solution is contained in an ultrasonic processing tank equipped with an ultrasonic vibrator. Ultrasonic energy is radiated from said ultrasonic vibrator into said processing solution to ground surfaces of the workpiece. The processing solution is drawn from the ultrasonic processing tank, cooled to a temperature lower than a boiling point thereof, deaerated, and then returned to the ultrasonic processing tank.

Abstract: An abrasive flow machining and polishing apparatus is provided having a hydraulically actuated reciprocating piston (42) and a extrusion medium chamber (10) adapted to receive and extrude a visco-elastic dispersion of an abrasive unidirectionally across the internal surfaces of a workpiece (40) having internal passages (41) formed therein to perform abrasive work on said surfaces. A fixture (24) directs flow of the viscoelastic abrasive dispersion from said hydraulic extrusion medium chamber (10) into the inlet of internal passages (41) in a workpiece (40), while a collector (30) is set to gravitrimetrically collect flow of the viscoelastic abrasive dispersion as it extrudes from an outlet of the internal passages and drops into the collector. The extrusion medium chamber (10) is provided with an access port (16) to periodically receive gravimetric return flow of the viscoelastic abrasive dispersion from the collector (30) into extrusion medium chamber (10).