Abstract: The invention relates to a device (2) for grinding and/or finishing a workpiece (8) mounted on and/or in a workpiece mounting (22, 28). The workpiece (8) and the workpiece mounting (22, 28) may be set in an oscillating movement (86) by means of a drive device (60, 108) and form an oscillating unit (96) or part of an oscillating unit (96), at least one balancer unit (94) being provided which is driven to run counter to the oscillating movement (86) of the oscillating unit (96).

Abstract: The invention relates to a grinding center for the simultaneous grinding of multiple main bearings and rod bearings and/or central sections of crankshafts (22). Two rod bearing grinding spindles (14, 15), wherein the first can be displaced only in the Z direction and the second can be minimally displaced only in the X direction, are mounted on a common rod bearing crosslide (11). In the final phase of the grinding, a correction of dimension deviation between the two machined rod bearings is carried out via a separate control of the second rod bearing grinding spindle (15), as a dimension or roundness correction. The deviations are detected by measuring devices.

Abstract: In order to grind bar-shaped workpieces which have a non-circular cross-section and flat faces which are parallel to each other, two partial operations are performed consecutively. First, the bar-shaped workpiece is rough ground and finished on the faces by way of double-disk face grinding. The bar-shaped workpiece is clamped on the longitudinal sides in the first clamping position thereof, and the bar-shaped workpiece is transported between two clamping jaws, which clamp the workpiece in the second clamping position thereof on the faces. The first clamping position is then released, and the bar-shaped workpiece is rotated by the clamping jaws. A CNC-controlled peripheral grinding step is performed based on CX interpolation principles. This rough grinds and finishes the longitudinal sides of the bar-shaped workpiece. Transport from the first to the second clamping position is effected by a clamping station, which concomitantly forms the holder for the face grinding operation.

Abstract: A method and apparatus for grinding spheres of ceramic material, including the spheres with at least one grinding wheel containing abrasive grains bound in a synthetic resin. The abrasive grains comprise more than 50% diamond and less than 5%, Cr2O3.

Abstract: A method for treating bearing components includes treating the bearing components in a tumbling-type cutting surface treatment; treating the bearing components in a tumbling-type burnishing treatment; and treating the bearing components in a tumbling-type cleaning and polishing treatment, to provide finished components.

Abstract: In one aspect of the present invention, an outer diameter (O.D.) centerless grinding machine for use in grinding a diamond workpiece has a grinding wheel positioned parallel to a regulating wheel which is adapted to press a cylindrical workpiece into the grinding wheel as the regulating wheel rotates. Electronic equipment may be adapted to adjust a pressure of the regulating wheel against the grinding wheel. Also, a carrier may be adapted to house the workpiece, the carrier being attached to a translation mechanism adapted to move the carrier between the wheels such that the workpiece is in contact with both wheels.

Abstract: Disclosed is a method for grinding a machine part that is used as a drive shaft, for example, rotates about the longitudinal axis thereof during the grinding process, and is provided with a journal at one axial end thereof and a recess at the opposite end thereof. The grinding process is carried out in one and the same grinding machine. In said grinding method, the machine part is brought into different clamped states by means of a chuck of a workpiece spindle head with releasable clamping jaws and a centering tip, a backrest, and/or a tailstock quill. Changing the clamped states has the advantage that the machine part remains in the same position in a single grinding machine, i.e. the clamped position, in all the different clamped states such that more accurate sizes, shapes, and positions can be obtained in an economical manner and all areas of the machine part which are to be ground are successively accessible to the grinding disks.

Abstract: In one aspect of the present invention, an outer diameter (O.D.) centerless grinding machine for use in grinding a diamond workpiece has a grinding wheel positioned parallel to a regulating wheel which is adapted to press a cylindrical workpiece into the grinding wheel as the regulating wheel rotates. Electronic equipment may be adapted to adjust a pressure of the regulating wheel against the grinding wheel. Also, a carrier may be adapted to house the workpiece, the carrier being attached to a translation mechanism adapted to move the carrier between the wheels such that the workpiece is in contact with both wheels.

Abstract: Methods for cylindrical grinding a workpiece are disclosed. The method includes cylindrical grinding, with a bonded abrasive wheel having a permeable structure that includes interconnected porosity, a workpiece at a specific cutting energy of less than about 12 Hp/in3·min (29.7 J/mm3), and a material removal rate of at least about 1 in3/min·in (10.8 mm3/sec/mm)grinding. The bonded abrasive wheel may include at least about 3 volume percent of a filamentary sol-gel alpha-alumina abrasive grain having an average length-to-cross-sectional-width ratio of greater than about 4:1, or agglomerates thereof. In one embodiment, the workpiece is ground in the presence of a water soluble oil.

Abstract: A disc-like grinding wheel 5 is formed with a circumferential groove 5a, the opposite walls of which define grinding surfaces 5b. A rotated carrier 3 brings a load pin 55 into rotary movement relative to the grinding wheel 5 rotated about an axis 5z, so as to pass the load pin 55 through space between the grinding surfaces 5b, whereby opposite end faces 55a of the load pin 55 are ground simultaneously. Thus, time taken by a grinding process may be reduced as compared with a conventional method wherein one end face is ground at a time.

Abstract: A device and method for positioning and blocking steady rests for rolling milly cylinders in grinding machines and grinding machines employing the same. A positioning and blocking device for steady rests includes a substantially flat carriage including a translation mechanism and a blocking mechanism, wherein the blocking mechanism is magnetic.

Abstract: A neck portion grinding apparatus and method is designed to reduce working man-hours and to improve processing accuracy with respect to a processing of a workpiece. The neck portion grinding apparatus includes a grinding device having a disc-like grinding wheel and a wheel rotating device for rotating the grinding wheel, and a machine tool having a main shaft for rotatably supporting a rotating tool and a table mounting the grinding device thereon, and relatively moving the main shaft and the table by numeral control. A shape of a neck portion of the rotating tool can be changed by relatively moving the main shaft and the table while mutually rotating the rotating tool and the grinding wheel, and grinding the rotating tool by the grinding wheel.

Abstract: A grinding wheel comprising a cylindrical hub of a desired material having a first band of yieldable material on its outer circumferential surface, and a second band of abrasive material on the outer circumferential surface of the first band. The first band of yieldable material can be flexible or semi-flexible and provides support for the second band. An adhesive can be used to avoid relative motion between the hub and the first belt, and between the first and second belts.

Abstract: Method for manufacturing improved contact surfaces, particularly contact surfaces in rolling bearing components such as rings or rolling bodies, is disclosed. The method subjects a surface of the rolling bearing component to a hard turning machining operation for forming by means of a hard turning tool a rolling or sliding contact surface. The hard turned surface is subjected to a finishing operation to remove the basic turning groove structure in a light machining way such that micro-pockets created in the hard turning operation remain. The hard turning tool during the hard turning machining operation is subjected to a vibration, substantially in the longitudinal direction of the tool, thereby creating in a controlled manner in the hard-turned surface a number of indentations, which are substantially arc-shaped in cross-sectional direction, prior to the finishing operation. Indentations improve lift-off and lubricating properties during later operation of the rolling bearing.

Abstract: A non-glazing dressing wheel (10) suitable for dressing a grinding wheel surface to be used for maintaining a certain tolerance to assure reliability and quality control of ground parts during the grinding operation. The dressing wheel includes at least a first dressing wheel component (12) including at least one interrupted cutting outer surface, wherein the interrupted cutting surface is embodied in a cutting wheel (10) with a plurality of tips (12) extending outwardly from the outer surface. The plurality of tips (12) contact the grinding wheel during the grinding operation, thereby alleviating glazing and heat expansion of the grinding wheel while being dressed. Other preferred embodiments include sandwiching the interrupted cutting surface between two flat grinding surfaces, preferably being made of diamond or Borazon.

Abstract: A tool grinding machine has a machine control unit, which by means of a suitable measuring device, which for instance comprises a tracer (9) and a measuring module, first determines the wobble runout with respect to the ideal receptacle axis (C) of a workpiece receptacle. In the grinding machining of the blank (7) or a workpiece, this wobble runout is taken into account and compensated for; that is, the grinding tools are made to trace a tumbling workpiece in such a way that the workpiece is machined to the exact intended dimensions and concentrically.

Abstract: In one embodiment, a cutting tool assembly used for creating grooves in a microreplication tool is described. The cutting tool assembly includes a mounting structure and multiple diamonds mounted in the mounting structure. For example, first and second tool shanks having first and second diamond tips can be positioned in the mounting structure such that a cutting location of a diamond cutting tip of the first tool shank is a defined distance from a cutting location of a diamond cutting tip of the second tool shank. The defined distance may correspond to an integer number of pitch spacings, and may be accurate to within a tolerance of less than approximately 10 microns.

Abstract: In a method for machining rotation pieces, including at least one working step, and wherein at least one surface of the workpiece which is clamped in the device is subjected to a grinding step, at least one front-sided boring is carried out in the workpiece in the same clamping device used for the grinding step. For example, during a grinding process, the workpiece can be clamped at least at both ends in a clamping apparatus, and for the boring process, the clamping apparatus can be released at least at one end and a chuck for a boring tool can be arranged there, which then performs the desired end-face boring.

Abstract: There is provided a rolling slide member coming in contact with a mating member in a rolling or sliding manner, wherein a plurality of grooves having an inclination of 0 to 30 degree and a groove depth of 0.5 to 15 ?m are formed in a circumferential direction at the time of grinding a contact surface with the mating member. In the contact surface, the axial surface waviness is set to 0.1 or more in the filtered centerline waviness (WCA) and the axial surface roughness is set to 0.7 or more in the ten-point height of roughness profile (Rz) by the grooves 26.

Abstract: It is provided that a grinding method of a rotating workpiece W having a cylindrical part and at least one end face beside the cylindrical part. The grinding wheel 30 has a rotational axis parallel to a rotational axis of the workpiece W and has an external surface 30FM, at least one side surface 30SM and at least one R-part 30KM between the external surface 30FM and the side surface 30DM. The grinding wheel 30 is moved backward in oblique direction to the end face to grind the end face for rough grinding in a process [1]. The grinding wheel is moved forward perpendicular to the rotational axis of the workpiece to grind the end face for finish grinding in a process [2a] and to grind the cylindrical part for rough grinding in a process [2b].

Abstract: The present invention relates to a method for grinding of cam profiles on a camshaft (1), having an inner shaft (5) and an outer shaft (4) arranged coaxially one inside the other and mounted to rotate with respect to one another. The camshaft (1) additionally has first and second cams (2, 3) that can rotate with respect to one another over a limited circumferential angle about the camshaft axis (6), the first cams (2) of which are fixedly connected to the inner shaft (5) and the second cams (3) of which are fixedly connected to the outer shaft (4). It is essential to this invention that during and/or after the grinding operation a fluid is forced under pressure into the outer shaft (4), thereby preventing penetration of grinding dust into the interspace (8) between the first cams (2) and the outer shaft (4) or flushing out any grinding dust that has already penetrated.

Abstract: A glass-ceramic plate, and production methods and apparatuses in relation to the plate. The plate is designed for example to equip a cooktop, and includes, on at least one of its faces, a differentiated surface finish formed in the body of the bare glass-ceramic plate.

Abstract: In one aspect of the present invention, an outer diameter (O.D.) centerless grinding machine for use in grinding a diamond workpiece has a grinding wheel positioned parallel to a regulating wheel which is adapted to press a cylindrical workpiece into the grinding wheel as the regulating wheel rotates. Electronic equipment may be adapted to adjust a pressure of the regulating wheel against the grinding wheel. Also, a carrier may be adapted to house the workpiece, the carrier being attached to a translation mechanism adapted to move the carrier between the wheels such that the workpiece is in contact with both wheels.

Abstract: A method of grinding the outer circumferential surface of a workpiece 5 formed of a hard and brittle material into a predetermined shape using a grinding wheel while rotating the workpiece 5 is disclosed. The method includes plunge grinding the workpiece 5 at an arbitrary portion (plunge ground portion 21) in the longitudinal direction of the workpiece 5 by causing the grinding wheel to come in contact with the workpiece 5 in a direction which intersects a rotational axis 8 of the workpiece 5, and traverse grinding the workpiece 5 toward the plunge ground portion 21 by moving the grinding wheel relative to the workpiece 5 in a direction parallel to the rotational axis 8 of the workpiece 5. This allows the outer circumferential surface of the workpiece made of a hard and brittle material, such as a honeycomb structure used for a DPF, to be ground into a predetermined shape in a short time, and prevents occurrence of chipping during grinding.

Abstract: A railway grinding system is capable of grinding a frog, another switch, or another railway section of interest in situ over a precisely defined path that is unaffected by the geometry of the railway section to be ground. The system includes a frame providing the reference path and a grinding machine movable along the reference path. The grinding tool preferably has at least four degrees of freedom with respect to the reference frame. Versatility can be further enhanced by permitting one grinding tool, such as a cup grinder configured to grind a generally horizontal surface of the railway, to be replaced with another grinding tool, such as a flange grinder configured to grind a generally vertical surface of the railway. The frog grinder can perform either single-event reconditioning grinding or periodic maintenance grinding.

Abstract: Synthetic shingles are made and treated, such that upper surfaces thereof that are to be weather-exposed in the installed condition, are scuffed, abraded, or scraped in such a manner that different visual appearances occur between abraded zones and unabraded (or lesser abraded) depressions, to enhance the natural-appearing materials that the synthetic shingles are designed to resemble. The shingles and the abrading medium have motion relative to each other. The abrading medium may take on various forms, such as a roller, a brush, a pad, etc. Some portions of the upper surface of the shingle remain unabraded, preferably being those portions that are depressed relative to higher portions of the shingle. The shingle may be of a single layer construction, or a multi-layer laminate.

Abstract: The invention relates to a grinding method and to a cylindrical grinding machine, in which a sintered hard metal round rod is completely pushed through a chuck of a workpiece spindle head, said chuck having chuck jaws. Two backrest seats are ground on the freely projecting end area of the round rod, and two backrests are then placed on the round rod in directions. The resulting secure support of the end area enables a front cone to be ground with a high level of precision with regard to the concentricity at the end of the round rod facing the quill of a tailstock. A multiple grinding wheel, which is comprised of two differently designed individual wheels that directly rest against one another in an axial manner, serves to grind the front cone and is advanced toward the round rod in the X-direction. The multiple grinding wheel is mounted in a grinding spindle. The individual wheels have different grinding areas.

Abstract: A centerless grinder for grinding an elongated workpiece includes a grinding wheel having a working surface with a plurality of raised areas extending circumferentially around at least a portion of the working surface. A platform is provided having an elongated top surface for supporting the workpiece substantially adjacent to the working surface of the grinding wheel and a front surface with a plurality of lateral grooves for receiving the raised areas on the working surface of the grinding wheel such that movement of the platform toward the working surface into a working area adjacent to the grinding wheel enables the raised areas to pass into the lateral grooves and grind the workpiece.

Abstract: In a method for machining rotation pieces, including at least one working step, and wherein at least one surface of the workpiece which is clamped in the device is subjected to a grinding step, at least one front-sided boring is carried out in the workpiece in the same clamping device used for the grinding step. For example, during a grinding process, the workpiece can be clamped at least at both ends in a clamping apparatus, and for the boring process, the clamping apparatus can be released at least at one end and a chuck for a boring tool can be arranged there, which then performs the desired end-face boring.

Abstract: An on-line roll grinding method for a work roll, which can decrease an overshoot, by which the pressing load of a rotating grinding wheel on a work roll exceeds a set grinding pressing load, is provided. This method is an on-line grinding method for a work roll, adapted to press a rotating grinding wheel (3a) having elasticity against a work roll (1) of a rolling mill to grind the work roll, wherein when the pressing load of the rotating grinding wheel (3a) reaches a set load F, which has been set beforehand, after the rotating grinding wheel (3a) contacts the work roll (1), the forward velocity of the rotating grinding wheel (3a) is reduced to decrease an overshoot by which the pressing load of the rotating grinding wheel (3a) on the work roll (1) exceeds a set grinding pressing load F0.

Abstract: A composite contact wheel, grinding assemblies comprising the same, and methods of abrading cylindrical workpieces using coated abrasive belts.

Abstract: The present invention relates to a method for grinding of cam profiles on a camshaft (1), having an inner shaft (5) and an outer shaft (4) arranged coaxially one inside the other and mounted to rotate with respect to one another. The camshaft (1) additionally has first and second cams (2, 3) that can rotate with respect to one another over a limited circumferential angle about the camshaft axis (6), the first cams (2) of which are fixedly connected to the inner shaft (5) and the second cams (3) of which are fixedly connected to the outer shaft (4). It is essential to this invention that during and/or after the grinding operation a fluid is forced under pressure into the outer shaft (4), thereby preventing penetration of grinding dust into the interspace (8) between the first cams (2) and the outer shaft (4) or flushing out any grinding dust that has already penetrated.

Abstract: During centerless cylindrical grinding, attention must be paid to the fact that the workpiece (3) is placed in a very specific position between the grinding wheel (1), the regulating wheel (2) and the support guide (4). The optimal position of the workpiece (3) initially set cannot be maintained as a result of the progression of the grinding process and the changes caused by said process in the diameter and contour of the workpiece (3). The invention provides a solution to said problem, whereby height adjustment and/or the oblique position of the support guide (4) are automatically modified in accordance with the progression of the grinding process and during said grinding process with the purpose of achieving operationally optimal readjustment. The progression of the grinding process can be detected using measuring techniques, e.g. by measuring the diameter of the workpiece (3) or its deviation from roundness and using said measurement as output variable for adjusting the support guide (4).

Abstract: A centerless grinding apparatus (10) includes an outer diameter surface grinding wheel (11) for grinding the outer diameter surface of a work (1) of a substantially cylindrical shape, a regulating wheel (12) for supporting the outer diameter surface of the work (1) in conjunction with the outer diameter surface grinding wheel (11) and an end surface grinding wheel (21) for grinding the end surface of the work (1). The end surface grinding wheel (21) grinds the end surface of the work (1) while the outer diameter surface grinding wheel (11) grinds the outer diameter surface of the work (1) in a state that the work (1) is disposed between the outer diameter surface grinding wheel (11) and the regulating wheel (12).

Abstract: A curable emulsion comprises: an oil phase comprising blocked polyisocyanate and curative; and an aqueous phase comprising at least partially neutralized crosslinked copolymer of monomers comprising at least one free-radically polymerizable carboxylic acid and at least one of an alkyl or alkaryl (meth)acrylate. In some embodiments, the curable emulsion further comprises nonionic surfactant. Methods of making the curable emulsions and their use in the manufacture of abrasive articles are also disclosed.

Abstract: A metal ring with smaller stress concentration is manufactured, and the manufacture and maintenance of a rolling roller for transferring a mesh-shaped unevenness to the metal ring is facilitated. A mesh-like unevenness 8 is formed to the surface of an inner circumference rolling roller 6. This unevenness 8 is formed by rotating the inner circumference rolling roller 6 at a predetermined speed, and moving a grinder 9 back and forth in the axial direction of the inner circumference rolling roller 6 while biasing the grinder toward the surface of the roller 6 with predetermined force. The grain size of the grinder is between #270 and #1000. When the inner circumferential surface of the metal ring 1 is rolled using the inner circumference rolling roller 6, a mesh-like unevenness 2 is transferred onto the metal ring 1.

Abstract: A method and apparatus for shaping the radial surface of a roller or other cylindrically shaped part in a single cycle. The preferred embodiment forms a crown geometry on one roller at a time using a CNC system to control a grinding surface in three axes. The grinding surface is controlled in two linear orthogonal directions (x and y) and around a circular axis (c) through corresponding stepper motors. In addition, the axial pressure applied by the grinding surface of the radial surface of the roller is controlled by an air pressure programmable regulator acting through a pneumatic cylinder. These four individually controlled, precise degrees of motion of the grinding surface, operating with a single rotating roller, permits extremely accurate crown shaping. The shaping is, in fact, so precisely controlled and so accurate that only one “cycle” of the grinding surface against the roller is required to achieve the desired crown profile.

Abstract: A method and a device for grinding a machine part that has two shaft elements, a machine part axis and a large diameter central element having a side surface which is embodied in the form of a flat truncated cone. The machine part is clamped between centers and is movable in a direction of the machine part axis. The side surface is ground by a cylindrical outer contour of a first grinding wheel such that the cutting speed is constant across the entire axial dimension of the first grinding wheel which is mounted on a grinding spindle along with a second, narrower grinding. The second grinding wheel is positioned to grind the shaft element by swiveling the spindle using two pivots that are located perpendicular to each other and by displacing the grinding spindle perpendicular to the machine part axis with the machine part remaining in the same clamped position.

Abstract: The invention relates to a method and to a device for producing molds for toothed belts. A grinding wheel (9) that has a profiled periphery is used instead of a milling cutter to provide the circumference of a roller-shaped blank (4) with the matrix of a desired tooth contour of a toothed belt. The circumferential profile of the grinding wheel (9) is trimmed using a CNC-controlled diamond trimming pin (11) or alternatively with a profiling diamond (19).

Abstract: A high smoothness grinding process for obtaining a highly smooth surface of a metal material member. The process includes grinding an outer peripheral surface of a cylindrical or generally cylindrical metal material member by using a super abrasive grain grinding wheel in a condition in which a value [a peripheral speed of the grinding wheel/a peripheral speed of the metal material member] is not larger than 100, the grinding serving as a main grinding step.

Abstract: A stepping motor stator stack and rotor stack finishing method whereby the burrs remaining on the small tooth surfaces of the stacks can be eliminated and prevented from lodging in the spaces between laminations of a plurality of stacked steel plates, without causing dulling of these small teeth. After abrasive finishing is carried out, a high pressure liquid jet spray nozzle is introduced into the central cylindrical cavity of a stator stack, and while the nozzle is moved along the central axis of the central cylindrical cavity and rotated relatively centered on the central axis of the central cylindrical cavity, the high pressure liquid jet is sprayed from the jet orifices striking the small tooth surfaces of the stator stack facing the central cylindrical cavity so as to remove the burrs remaining on the small tooth surfaces.

Abstract: In a grinding machine, a generally cylindrical workpiece having at least first and second grinding areas is ground by use of a grinding wheel supported by a wheel head. The first grinding area is first ground such that power consumed by the grinding machine is maintained at a first level. After completion of grinding for the first grinding area, the grinding wheel is indexed to the second grinding area by moving the wheel head such that the power consumed by the grinding machine is maintained at a second level higher than the first level. After completion of the indexing operation, the second grinding area is ground in the same manner as the first grinding area.

Abstract: An apparatus may include a stand, a tire mount supported by the stand and releasably attachable to a tire, a tire rasp, and a tire rasp mount attachable to the tire rasp. The tire rasp mount includes a pair of handles. A four bar support pivotally attaches the tire rasp mount to the stand using hime joints. A motor operably rotates the tire and the tire rasp in opposite directions. An operator can manually move the tire rasp into contact with the tire and apply pressure between the tire rasp and the tire to texturize tread surfaces of the tire. A method is also disclosed which includes forming slices and grooves into the tread surfaces of the tire while maintaining the thickness of the tread. The slices and grooves may extend circumferentially around portions of the tread surfaces of the tire, and about 1/32-inch to about 1/16-inch deep.

Abstract: Organic bonded abrasive tools, having controlled microstructures, comprise a relatively low volume percentage of abrasive grain and a relatively low hardness grade, but are characterized by the excellent mechanical strength and efficient grinding performance of much harder grade, lower porosity tools, especially in versatile grinding processes, such as centerless grinding. A method for centerless grinding with these tools is provided. Methods for making the abrasive tools utilizing agglomerated abrasive grain are described.

Abstract: A molded brush segment having a plurality of integrally molded bristles extending from a generally planar center portion. The brush segment is molded from a moldable polymer, such as a thermoplastic elastomer, and has a plurality of abrasive particles present in at least the bristles of the brush segment.

Abstract: The present invention relates to a grinding apparatus for grinding an out-of-round trunnion tire for a rotating kiln. The present invention is mounted on a trunnion roller such that a tracking wheel and a grinder are in tangent with the out-of-round trunnion tire. The mounting bracket supports a means for angling the grinder so that it is in tangent with the out-of-round tire and making it round. The grinder is part of a grinder head assembly which is mounted on the angling means. The grinder head assembly includes the grinder, a housing and a drive mechanism. The drive mechanism includes a motor which drives the grinder wheel so that it grinds the trunnion tire back into round.

Abstract: A grinding method comprises steps of simultaneously grinding plural grinding portions of a workpiece by plural grinding wheels T1, T2 moved individually each other, and terminating said grinding by a predetermined grinding wheel T1 prior to a termination of said grinding by the other grinding wheel T2. Whereby, a content of the grinding by each grinding wheel T1, T2 can be same. A grinding condition in each grinding by each grinding wheel T1, T2 can be changed in accordance with a measuring result of the grinding portion in the grinding.

Abstract: In centerless grinding there are the in-feed and the through-feed scheme, each having their respective advantages and disadvantages. When a work being machined by centerless grinding has plural portions being machined, those portions can be distinguished as portions being machined suitable for in-feed and portions being machined suitable for through-feed. Then, the present invention, using the same centerless machine, performs through-feed grinding in the first half of the process, then automatically switches from that and performs in-feed grinding in the latter half of the process. Thus, in a single piece of work being machined, sites suited to through-feed grinding are subjected to through-feed grinding, and sites suited to in-feed grinding are subjected to in-feed grinding. Not only so, but it is unnecessary to alter the setup between the first half of the process and the latter half of the process, wherefore centerless grinding can be performed very efficiently.

Abstract: For the machining of a workpiece (18) rotating about a workpiece axis, a first abrasive tool (20), which rotates about a first tool axis, and the workpiece (18) are advanced towards one another, in order to machine a first workpiece face in a first abrasive operation. Further, a second abrasive tool (54), which rotates about a second tool axis (56), is advanced towards the workpiece (18), in order to machine a second workpiece face in a second abrasive operation. The two workpiece faces are designed rotationally symmetrically with respect to the workpiece axis and are arranged adjacently to one another in such a way that a sharp, burr-free, circular transition edge is formed between them. The two abrasive operations are controlled in such a way that they are terminated at the same time.

Abstract: A method and apparatus for a circular grinding of a workpiece having first and second workpiece faces which are rotationally symmetrical with respect to the workpiece axis and which form a circular transition edge between them are provided. The workpiece rotating about its axis and a grinding wheel rotating about a grinding-wheel axis are advanced towards one another. During grinding, an auxiliary abrasive tool, which rotates about an auxiliary-tool axis and has a plane abrasive surface arranged at right angles to the auxiliary-tool axis, is pressed against the workpiece in such a way that the abrasive surface is arranged in a tangential plane to the second workpiece face and touches the second workpiece face along a contact line. The plane abrasive surface projects in the direction of the contact line away from the second workpiece face beyond the transition edge.