Abstract: A green ball grinding method includes the step of supplying a green ball between a first surface of a first member and a second surface of a second member constituting a grinding apparatus, and the step of grinding the green ball between the first surface and the second surface while the green ball rotates around its own axis and in orbital motion. In the step of grinding the green ball, the step of causing the green ball grinding to proceed while applying load between the green ball and each of the first surface and the second surface, and the step of modifying the rotation axis of the green ball by reducing the load lower than in the step of causing the green ball grinding to proceed are executed alternately.

Abstract: An apparatus (10) for altering a surface of a bowling ball (14) has a bowing ball holder (12) with a surface altering mechanism (16). The bowling ball holder (12) includes a portion (18) to receive the bowling ball (14). The surface altering mechanism (16) is positioned in the ball receiving portion (18) of the bowling ball holder (12). The surface altering mechanism (16) applies a surface pattern onto the bowing ball (14).

Abstract: This invention relates to an apparatus and method for refurbishing lacrosse balls by using a fast, convenient, automated, entertaining, energy efficient, portable, and modular machine/method of removing a thin layer of rubber from the surface of a used lacrosse ball, by applying even pressure and random rotation of abrasive, one to four cups or rings, utilizing a combination of gravity and/or force of the cups against the surface of the ball, and the introduction of a solvent at various speeds, volume, and concentration, during and after the removal of a thin layer of rubber, to maximize the restoration of the rubber surface.

Abstract: A method and system for resurfacing one or more lacrosse balls is provided. The system includes a container, a rotatable member, and a motor. The container is configured to hold the one or more lacrosse balls. The rotatable member includes an abrasive surface configured to scuff the lacrosse balls while in the container, The motor includes a drive shaft coupled to the rotatable member and configured to facilitate rotation of the rotatable member. With this arrangement, the lacrosse balls are positioned over the abrasive surface such that, upon rotation of the rotatable member the abrasive surface scuffs the lacrosse balls to, thereby, resurface the balls.

Abstract: An apparatus (10) for altering a surface of a bowling ball (14) has a bowing ball holder (12) with a surface altering mechanism (16). The bowling ball holder (12) includes a portion (18) to receive the bowling ball (14). The surface altering mechanism (16) is positioned in the ball receiving portion (18) of the bowling ball holder (12). The surface altering mechanism (16) applies a surface pattern onto the bowing ball (14).

Abstract: A golf ball kit having an abrasive material adapted for imparting enhanced micro surface roughness to an exterior surface of a golf ball. The enhanced micro surface roughening affects the aerodynamic properties of the ball as compared to golf balls having the same set of construction specifications but without enhanced micro surface roughness. The kit includes an instruction device having a plurality of correlations between at least one performance parameter and micro surface roughness for at least a first golf ball.

Abstract: A green ball grinding method includes the step of supplying a green ball between a first surface of a first member and a second surface of a second member constituting a grinding apparatus, and the step of grinding the green ball between the first surface and the second surface while the green ball rotates around its own axis and in orbital motion. In the step of grinding the green ball, the step of causing the green ball grinding to proceed while applying load between the green ball and each of the first surface and the second surface, and the step of modifying the rotation axis of the green ball by reducing the load lower than in the step of causing the green ball grinding to proceed are executed alternately.

Abstract: A lacrosse ball resurfacer is suitable for roughening a surface of a lacrosse ball. The ball resurfacer includes a surfacing element with a concave recess formed thereon. The recess is sized to receive at least a portion of the lacrosse ball and has an abrasive surface disposed thereon.

Abstract: A spherical body polishing apparatus capable of reducing polishing costs includes a rotating disk having a rotating disk polishing surface and a fixed disk having a fixed disk polishing surface opposed to the rotating disk polishing surface. The rotating disk polishing surface is capable of relative rotation while keeping being opposed to the fixed disk polishing surface. The rotating disk polishing surface has a groove portion formed therein and extending circumferentially along the rotation. The rotating disk having the groove portion therein includes an abrasive grain layer having a higher hardness than that of a material ball which is a spherical body and a holding layer formed on the abrasive grain layer and having a lower hardness than that of the abrasive grain layer. The groove portion is formed to penetrate the holding layer in a depth direction and to reach the abrasive grain layer.

Abstract: A bowling ball abrader and polisher utilizes cooperative rotational inter-engagement between a cup-shaped abrading an polishing tool and a non-motorized rotating ball holder assembly to obtain even, concentric abrasion patterns on a bowling ball surface. Upon placement of a bowling ball in a ball cradling surface formed in the rotating ball holder, application of the rotating abrading and polishing tool on the surface of the bowling ball causes a corresponding rotation of the bowling ball using the non-motorized rotating ball holder, which enables the outer surface of the bowling ball to be more uniformly abraded and polished.

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 bowling ball surface treatment machine includes a housing and a ball movement guider provided inside the housing for guiding movement of a bowling ball, the ball movement guider having a guider center axis and an inner circumferential surface. A surface treatment disc with a surface treatment is arranged below the ball movement guider for supporting and rotating the bowling ball. The surface treatment disc has a disc center axis deviating from the guider center axis. The machine further includes a disc driving motor for rotating the surface treatment disc about the disc center axis and a controller for allowing the disc driving motor to repeatedly accelerate the surface treatment disc to a target rotation speed, rotate the surface treatment disc in a surface treatment position at the target rotation speed for a predetermined running time and then decelerate the surface treatment disc toward a zero speed.

Abstract: Brut polishing of superhard materials to remove positive asperities by use of pressure and heat.

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 of polishing workpieces in a magnetic float polishing chamber comprising a lower chamber piece and an upper chamber piece which is removably receivable in the lower chamber piece and is connected to a powered spindle for rotating the upper chamber piece in the polishing operation. The method preferably comprises one or more of the steps of (a) geometrically aligning the upper chamber piece with the powered spindle by machining the upper chamber piece in-situ, (b) machining the contact surface of the upper chamber piece in-situ between various polishing runs, and (c) mounting the lower chamber piece in a manner effective for causing the lower piece to automatically self-align coaxially with the upper chamber piece.

Abstract: A cutting cup for a sphere making machine. The cutting cup includes a cylindrical ring having an outer wall, an inner wall, a bottom wall, and a top wall, the top wall having at least one beveled facet angled downwardly from the outer wall to the inner wall. A cutting element is attached to each of the beveled facets. Each of the cutting elements has a cutting edge adapted to at least partially contact a workpiece to be formed into a sphere. A mounting member is attached to the bottom wall of the cylindrical ring for attaching the cutting cup to the spindle of a sphere making machine.

Abstract: A manufacturing process to make a ball valve of the present invention includes the following steps: a) prepare flat circular metallic plates each of which has a rectangular indentation in a circumference; b) mold those plates into bowl shape; c) remove the circular bottom of the bowl shapes to reform a hemi-spherical shape by another mold; d) weld each pair of the hemi-spherical shapes into a spherical shape each of which has a pair of aligned openings and a lateral rectangular through hole; e) trim and grind the uneven connection seam; and f) polish and smooth the outer surface to finished a qualified ball valve which has uniform arc and thickness.

Abstract: An apparatus and process of surface finishing golf balls prior to painting is provided. The apparatus and process make use of nylon loops as a finishing material that is used to abrade the surface of adjacent moving golf balls. Optionally, the abrading process between the nylon loops and the surface of the golf balls may be carried out in the presence of a continuous stream of water. As water is removed from the processing equipment, the removed water carries with it abraded material. The process provides for improved adhesion of the paint to the surface of the golf ball.

Abstract: A system, apparatus and method is disclosed for providing a consistent liquid mixture according to a predetermined recipe for use at a point of use. The apparatus includes a plurality of liquid component reservoirs in which a constant gas pressure is maintained. A plurality of valves are provided, with individual valves connected to an outlet port of each reservoir. An electronic controller controls the valve actuation in a repetitive sequence to discharge predetermined doses of selected liquid components for mixing to form the consistent liquid mixture. A mixing section receives the sequence of doses to mix them together to form the liquid mixture.

Abstract: An apparatus and process of surface finishing golf balls prior to painting is provided. The apparatus and process make use of nylon loops as a finishing material that is used to abrade the surface of adjacent moving golf balls. Optionally, the abrading process between the nylon loops and the surface of the golf balls may be carried out in the presence of a continuous stream of water. As water is removed from the processing equipment, the removed water carries with it abraded material. The process provides for improved adhesion of the paint to the surface of the golf ball.

Abstract: A bowling ball resurfacing device is capable of evenly abrading, machining and furbishing the entire surface of a bowling ball. The resurfacing device includes a housing, first and second rolling wheels which are rotatably provided within the housing in a spaced-apart relationship with each other to hold and support the bottom surface of the bowling ball, a driving motor operatively connected to the first and second rolling wheels for causing the first and second rolling wheels to rotate, a friction contact unit for supporting the bowling ball in cooperation with the first and second rolling wheels and for making frictional contact with the surface of the bowling ball to abrade the bowling ball, and a relative speed regulator for intermittently changing the rotational speed of the second rolling wheel with respect to the first rolling wheel so as to alter the axis of rotation of the bowling ball.

Abstract: An apparatus is provided for polishing balls that comprises a cradle that is supported for rotation about a first axis. The cradle is shaped to support a spherical object and includes a ball spinner positioned and adapted to spin the spherical object in the cradle about a second axis that is oriented at an angle to the first axis. The apparatus also comprises a first drive operably connected to the cradle for rotating the cradle about the first axis at a first speed of rotation, and a second drive connected to the ball spinner to spin the spherical object about the second axis at a second speed of rotation.

Abstract: An apparatus and process of surface finishing golf balls prior to painting is provided. The apparatus and process make use of nylon loops as a finishing material that is used to abrade the surface of adjacent moving golf balls. Optionally, the abrading process between the nylon loops and the surface of the golf balls may be carried out in the presence of a continuous stream of water. As water is removed from the processing equipment, the removed water carries with it abraded material. The process provides for improved adhesion of the paint to the surface of the golf ball.

Abstract: A method for finishing the surface of a rolling contact component, such as a bearing roller element, a bearing ring or a traction drive rolling element, comprises the steps of: carrying out a cutting operation on the surface, subsequently calendering or burnishing the surface by means of a ball comprising a material harder than the bearing component material whereby the maximum calendering or burnishing pressure exerted on the surface is less than 7 Gpa.

Abstract: Silicon balls of single crystal silicon for use in semiconductir circuit substrates or the like, which have been lapped to satisfy necessary requirements and a method of making the same. The silicon ball of single crystal silicon is a lapped ball of single crystal silicon having a sphericity of not greater than 0.08 &mgr;m and also having a residue stress layer of not greater than 5 &mgr;m in a depth from a processing surface thereof on one side in negative and positive directions. The method of making the silicon balls makes use of a pair of lapping tables 2 and 3 supported in face-to-face relation with each other. One or both of the lapping tables 2 and 3 is prepared from finely divided abrasive particles hardened by the use of a resinous bonding material. Workpieces W of single crystal silicon are sandwiched between the lapping tables 2 and 3 and are lapped to provide the lapped balls.

Abstract: A polishing method and apparatus can concurrently establish a stable removal rate, a small step height reduction rate, and reduction of detects on the polished surface for various kinds of polished subjects, while providing less environmental problems and requiring less processing costs. The method for polishing a surface of a semiconductor device wafer comprises first polishing a surface of the semiconductor wafer by a first fixed abrasive polishing method; and finish polishing the polished surface of the semiconductor wafer by a second fixed abrasive polishing method different from the first fixed abrasive polishing method.

Abstract: A bowling ball resurfacing device is capable of evenly abrading, machining and furbishing the entire surface of a bowling ball. The resurfacing device comprises a housing, first and second rolling wheels which are rotatably provided within the housing in a spaced-apart relationship with each other to hold and support the bottom surface of the bowling ball, a driving motor operatively connected to the first and second rolling wheels for causing the first and second rolling wheels to rotate, a friction contact unit for supporting the bowling ball in cooperation with the first and second rolling wheels and for making frictional contact with the surface of the bowling ball to abrade the bowling ball, and a relative speed regulator for intermittently changing the rotational speed of the second rolling wheel with respect to the first rolling wheel so as to alter the axis of rotation of the bowling ball.

Abstract: A compressing machine includes a press unit 12 for compressing a concentrated sludge within a squeezing chamber to provide a briquette B, and a press control means 13 for controlling the press unit 12. The press control means 13 includes a parameter and compressing speed setting means 26, a parameter measuring means 28, and a compressing speed control means 27. The parameter and compressing speed setting means 26 is a means in which a relation between a predetermined parameter that may affect compression performed by the press unit 12, and a compressing speed of the press unit 12. The predetermined parameter may include a coolant temperature, ambient temperature or a coolant content and others. The parameter measuring means 28 is a means for measuring the predetermined parameter.

Abstract: A method for machining a pair of shoe pockets for piston in a swash plate type compressor is disclosed. In this method, the shoe pockets are respectively formed on the opposed walls of the slot in the piston of the compressor while conforming to a single imaginary sphere. The method comprises the step of moving a cutter provided with an arc-shaped cutter blade that has a rotation diameter less than the width of the slot. Thereafter, there is performed the step of relatively revolving the cutter with regard to the piston by allowing the central axis of a revolved part to move along a circular orbit within the slot while rotating the cutter, so as to cut the shoe pockets to conform to the single imaginary sphere. Finally, the step of retreating the cutter out of the slot when the cutter completes one round revolution and is returned to its initial position is performed.

Abstract: An apparatus is provided for polishing balls that comprises a cradle that is supported for rotation about a first axis. The cradle is shaped to support a spherical object and includes a ball spinner positioned and adapted to spin the spherical object in the cradle about a second axis that is oriented at an angle to the first axis. The apparatus also comprises a first drive operably connected to the cradle for rotating the cradle about the first axis at a first speed of rotation, and a second drive connected to the ball spinner to spin the spherical object about the second axis at a second speed of rotation.

Abstract: A description is given of an apparatus and a method for grinding a workpiece, in particular a shaft part. According to the method, the workpiece is clamped in place for the grinding working and its geometry is subsequently ground in such a way as to maintain its dimensions and shape. According to the invention, at least part of the surface of the workpiece is precision-worked at least partly at the same time as the grinding. The apparatus according to the invention has a work-spindle headstock and a tailstock for clamping the workpiece in place as well as a grinding unit with a grinding wheel for grinding the workpiece. The grinding unit and workpiece are arranged movably in relation to each other in a controlled manner. The apparatus according to the invention additionally has a precision-working unit, which can be moved according to the geometry of the workpiece in such a way that at least part of the surface of the workpiece is able to undergo precision working.

Abstract: Apparatus and methods for substantial planarization of solder bumps. In one embodiment, an apparatus includes a planarization member engageable with at least some of the plurality of outer surfaces to apply a planarization action on one or more of the outer surfaces to substantially planarize the plurality of outer surfaces, and a securing element to securely position the bumped device during engagement with the planarization member. Through application of “additive” and/or “subtractive” processes, the solder balls are substantially planarized.

Abstract: Apparatus and methods for substantial planarization of solder bumps. In one embodiment, an apparatus includes a planarization member engageable with at least some of the plurality of outer surfaces to apply a planarization action on one or more of the outer surfaces to substantially planarize the plurality of outer surfaces, and a securing element to securely position the bumped device during engagement with the planarization member. Through application of “additive” and/or “subtractive” processes, the solder balls are substantially planarized.

Abstract: A method of forming a mold for forming a resinous domed article which may be employed as a cover of a monitor camera is provided. The mold consists of a female block and a male block. The female block has formed therein a domed mold cavity which includes a hemispherical wall that is just half a sphere and an annular wall extending from an end of the hemispherical wall. The male block has a domed protrusion mating with the domed mold cavity of the female block. The domed protrusion consists of two parts; a hemispherical portion and a cylindrical portion. The hemispherical portion is mechanically joined to the cylindrical portion. This structure allows the surface of the domed protrusion of the male block to be formed smoothly without any irregularities on an interface between the hemispherical portion and the cylindrical portion.

Abstract: Apparatus and methods for substantial planarization of solder bumps. In one embodiment, an apparatus includes a planarization member engageable with at least some of the plurality of outer surfaces to apply a planarization action on one or more of the outer surfaces to substantially planarize the plurality of outer surfaces, and a securing element to securely position the bumped device during engagement with the planarization member. Through application of “additive” and/or “subtractive” processes, the solder balls are substantially planarized.

Abstract: Apparatus and methods for substantial planarization of solder bumps. In one embodiment, an apparatus includes a planarization member engageable with at least some of the plurality of outer surfaces to apply a planarization action on one or more of the outer surfaces to substantially planarize the plurality of outer surfaces, and a securing element to securely position the bumped device during engagement with the planarization member. Through application of “additive” and/or “subtractive” processes, the solder balls are substantially planarized.

Abstract: A system and method for polishing spherical shaped devices is disclosed. The system includes a carrier and an enclosure. The carrier has two projections so that when a device is placed between the projections, it contacts the carrier at two contact points. The enclosure matingly engages with the carrier so that it also contacts each device at two contact points. A movement system, such as a motor, provides relative movement between the carrier and the enclosure so that the four contact points polish each device. Also, the relative movement moves each device so that the device's entire outer surface is polished by the apparatus.

Abstract: A machine for lapping bowling balls and, thus, re-rounding, smoothing, and cleaning the balls. The machine is comprised of three concave abrasion blocks with drive motors, adjustable mounting brackets attached to an adjustable support table, a catch basin with filter to separate suspended solids from liquids, and a pump and fluid delivery tube to deliver flushing and/or cleaning liquids. The abrasion blocks are comprised of resilient concave blocks with abrasive sanding disks. The positions of all three abrasion blocks are preferably simultaneously and equally adjusted by small adjustments to the position of a top table relative to the stand that holds the pivotal motor mounts. Ramps on the rotatable table cooperate with the mounts to slightly pivot the motor mounts inward and outward from the ball, changing the orientation and distance of the abrasive blocks relative to each other and, hence, to the ball.

Abstract: A ball grinding machine for grinding ceramic bearing balls and the method thereto employing a non-rotating upper circular plate and a rotating lower circular plate to perform precision grinding of ceramic balls. The grinding mechanism according to the present invention comprises two or more separate concentric fixed rings, adjacent annular recesses into the lower surface of the upper circular plate, and corresponding two or more concentric hydraulic pressure rings inserted into said recesses, each with a slanted bottom surface towards the adjacent fixed ring for supplying pressure to the ceramic bearing balls on top of the lower circular plate at a sloped angle. The inner surface of the fixed ring, the slanted bottom surface of the pressure ring, and the grinding surface of a diamond grinding wheel installed on top of the rotating lower circular plate together form a grinding track.

Abstract: A molded golf ball having burrs in a region of its surface is ground using a grinding head having an abrasive surface of a sufficient width or diameter to cover the burr-bearing region of the golf ball surface and a drive mechanism for driving the grinding head. The drive mechanism is actuated to drive the grinding head to bring and force the abrasive surface against the burr-bearing region of the golf ball surface for grinding away the burrs. The point of time when the drive mechanism experiences a load change beyond the predetermined value is detected by a control unit to deliver a signal representing the substantial completion of grinding, in response to which the grinding step is terminated.

Abstract: A golf ball buffing apparatus includes a holder for holding a golf ball and an assembly for buffing the surface of the golf ball. The buffing assembly mounted for motion toward and away from the golf ball includes a rotating shaft; a buffing head affixed to one end of the rotating shaft and having a buffing face shaped in substantial conformity with the surface of the golf ball; and a guide assembly having a plurality of following faces that are disposed radially outward from the buffing head and substantially coincide with the extended shape of the buffing face. The buffing head and the guide assembly are movable together in the axial direction of the shaft. The apparatus can efficiently buff only selected portions on the surface of the golf ball where burrs are formed.

Abstract: A method for manufacturing a golf ball, wherein a grinding tool and a ball to be ground are rotated so that their adjacent points move toward opposite directions. A grinding face of the grinding tool is arranged to be Japanese Industrial Standard grain size #80 to 300. The ball is rotated at 100 to 600 mm/s and the grinding tool is rotated at 2400 to 6900 mm/s, and relative velocity of the grinding tool and the ball is 2500 to 7500 mm/s. Flash formed on a parting line of the ball is thereby removed by the grinding face of the rotating grinding tool.

Abstract: A spherical body grinding and polishing apparatus comprises: a rotary shaft having a spiral path groove in the outer cylindrical surface along which spherical bodies to be processed are moved, the rotary shaft being vertically movable and rotatable; and a housing having grinding and polishing surfaces on which the spherical surfaces of the spherical bodies moving along the path groove are slid. When spherical bodies such as silicon spherical bodies are supplied to the apparatus, the spherical bodies are rolled and moved along the spiral path groove formed in the outer cylindrical surface of the rotary shaft while sliding on the inner surface of the housing, so that the outer surfaces of the spherical bodies are ground and polished until the spherical bodies become high in sphericity.

Abstract: Using a newly developed composite ceramics material suited for balls of ball-point pens, a method of manufacturing composite ceramics balls for ball-point pens that have affinity for both oil-based ink and water-based ink is provided. In this method, the composite ceramics, whose main components are mullite (3Al.sub.2 O.sub.3 .multidot.2SiO.sub.2) and zirconia (ZrO.sub.2) at the ratio of 50-95% to 5-50% by weight, is polished into mirror-finished balls and then chemical processing or physical processing is performed on the ball surfaces to form indentations in the ball surfaces. The chemical processing is preferably an etching using hydrofluoric acid, and the degree of indentations can be controlled by changing the concentration of hydrofluoric acid and the duration of etching.

Abstract: A sphere polisher capable of making uniform conditions under which balls are polished is provided. The inner and outer polishing circuits are defined by the grooves 23 provided on the rotative disc 10 and the fixed disc 20. The storage conveyor 50 is provided with an outer ball guiding passage 55 and an inner ball guiding passage 56. The ball supply chute 57 is provided with the inner chute portion 57a connecting the inner polishing circuits with the outer ball guiding passage 55, and the outer chute portion 57b connecting the outer polishing circuits with the inner ball guiding passage 56. The ball discharge chute 58 is provided with the inner discharge chute portion 58a connecting the inner polishing circuits with the inner ball guiding passage 56, and the outer discharge chute portion 58b connecting the outer polishing circuits with the outer ball guiding passage 57.

Abstract: In a sphere polishing machine, workpiece balls in a ball passageways which are formed by guide grooves 5 formed in a stationary board 2 and guide grooves 1a formed in a rotary board 1 are moved along the ball passageways while being rotated by the rotary board 1, whereby the portion of the workpiece ball which is brought into contact with the guide groove 1a of the stationary board 1 in accordance with the inclination of the axis of rotation of the workpiece ball, is polished. On each of the ball passageways, a plurality of predetermined positions are selected at predetermined intervals, and relief grooves 6a, 6b and 6c are formed in guide groove portions of the stationary board which correspond the predetermined positions so that, when each of the workpiece balls passes through each of the predetermined positions, the inclination of the axis of rotation thereof is changed.

Abstract: A ball polishing method includes the steps of rotating one of two plates through use of a rotating mechanism while balls are sandwiched between the plates, pressing one of the two plates against the other plate via a guide slide mechanism for guiding one of the two plates to the other plate by means of a pressing mechanism, and polishing the balls while the pressing force is regulated through use of a pressing force control mechanism. The method is further provided with rotary support means for supporting the rotating mechanism and guide support means for supporting the guide slide mechanism, and at least one of them utilizes hydrostatics. By virtue of this method, a machining pressure can be controlled with a high degree of accuracy, and the accuracy of polishing of balls can be improved.

Abstract: A tool quill for carrying out superfinish polishing of a fuel injector needle tip to insure proper sealing of a fuel injector has a universal joint which allows tilting of a polishing stone during the finishing operation to accommodate slight positioning errors between the stone and needle tip and their axes of rotation. Slight tilting movements occur against an elastic straightening force exerted on the universal joint to insure constant polishing pressure, which in turn insures accurate shaping of the polished tip surface.

Abstract: A method of working a workpiece with an apparatus comprising the steps of holding the workpiece by a holding means, rotating the held workpiece by a rotational means in a direction of a tool to match a rotational axis line of the workpiece with a rotation axis line of the tool, matching a vertical axis of the holding means holding the workpiece with an intersection of a swingable rotation axis line of a means for swingably rotating the tool and the tool rotation axis line, and holding the workpiece above the tool and the working the workpiece by exerting work pressure on the workpiece.

Abstract: A method for grinding a surface of a golf ball and removing the thin outer layer thereof, wherein grinding tools arranged on three axes on a plane which axes radiate from a definite point at intervals of 120.degree. between one another are used. Each of the grinding tools possesses a circular grinding face which gradually spreads toward the end and contacts a surface of a golf ball. The grinding tools turn on the respective axes toward the same direction at the same speed keeping the same distance from the definite point.