Abstract: A p-type thermoelectric material is prepared by mixing and melting at least two members selected from bismuth, tellurium, selenium, antimony, and sulfur to obtain an alloy ingot; grinding the alloy ingot to obtain powder of the allow mass; and hot pressing the powder. At least the hot pressing is carried out in the presence of any one of hexane and solvents represented by CnH2n+1OH or CnH2n+2CO (where n is 1, 2 or 3). A dopant may be used at the step of mixing.

Abstract: A magnetoresistive device having a first pole, a second pole, and a first tapered pole pedestal therebetween and magnetically connected to the second pole. The first tapered pole has a width that increases with increasing distance away from the air bearing surface, ABS. The magnetoresistive device can also include a second tapered pole pedestal magnetically connected to the first pole, and separated from the first tapered pole pedestal by a write gap. The second tapered pole pedestal has a width that increases with increasing distance away from the air bearing surface. A method of the present invention includes defining the trackwidth of a write element by lapping a tapered pole pedestal. More specifically, the trackwidth is given by a known taper angle, a zero throat width, and a throat height, wherein the throat height is controlled precisely by lapping.

Abstract: A process is described for the chemical mechanical machining of semiconductor wafers. A plurality of surfaces are successively subjected to a polishing step, in which they are brought into contact with a polishing device. The polishing device contains a polishing-grain carrier with polishing grains, and the surfaces are moved relative to the polishing device. Material is removed from the surface by the polishing grains, which are fixed in the polishing-grain carrier and may become partially detached from the carrier material during the polishing operation. In each case one or more polishing steps is preceded by a conditioning step for regeneration of the polishing device. The polishing device and a conditioning surface of strong structure are brought into contact with one another and moved relative to one another, with the result that starting states of the polishing-device surface at a beginning of the individual polishing steps are comparable with one another.

Abstract: An appliqué film and paint removal tool includes a central rotating shaft, a spring-loaded locator pin, at least three freely rotating bearings, an arbor, and a collar. The rotating shaft may be centered with the locator pin and pushed down until the bearings touch the surface from which the appliqué or paint material is to be removed. By rotating while touching the mold line contour of the fastener the bearings will cause the appliqué film or paint treatment to separate around the mold line of the fastener. The separated material than can be peeled off and the fastener is accessible. Therefore, the appliqué film or paint treatment can be removed from fasteners without damaging the surface around the fastener. The appliqué film and paint treatment removal tool may be designed to accommodate all fastener diameters and mold line contours.

Abstract: A honing method proposes that using an arbor honing tool a remachining be carried out using the same tool either simultaneously or following onto arbor honing, in which the ratio of the stroke speed to the rotational speed of the tool is significantly increased. This leads to a cross-structure of the honing tracks allowing a better oil holding capacity.

Abstract: A detachable tool body is connected to the mandrel by means of a universal type coupling. The mating end of the drive shaft is constructed with U-shaped element having a pair of arms extending axially towards the tool body. The inner surfaces of the arms form a partially cylindrical seat. A similar U-shaped element having a pair of similar arms is constructed on the tool body with basically a mirror image profile relative to the drive shaft element. In the assembled position the mated arms define an inner bearing chamber (seat) having dual cylindrical surfaces with transverse axes. A barrel is constructed, which is shaped to nest in the seat formed by the mated pair of U-shaped elements and acts as a bearing which allows dual axes of motion. The adjustment rod of the abrasive element adjustment mechanism extends from the drive shaft through a bore in the barrel and into the tool body.

Abstract: A method of forming a recess in a body having a surface of substantially cylindrical form utilises a grinding wheel having a first axis in the form of a drive axis, and a circumferential surface concave to a second axis that is substantially orthogonal to the first axis. The grinding wheel also includes first and second opposing radial surfaces of substantially planar form. At least a portion of the circumferential surface of the grinding wheel is engaged with an outer surface of the body and the grinding wheel is rotated about the drive axis to cause a region of the body to be ground, thereby to define a recess in the body having a periphery including at least two substantially square corners and at least one pair of substantially parallel facing edges. The method is conveniently used to provide an opening or port of at least partially square or rectangular form in a cylindrical body such as a metering valve.

Abstract: A method and apparatus for simultaneously inspecting and grinding roll mills which utilizes a transducer assembly which produces a creeping wave propagation in conjunction with a couplant fluid provider and data acquisition circuit which allows the operator to see the crack and imperfections in on the surface of the mill rolls as they are rotated and to grind them off.

Abstract: A method of generating holes in fiber-reinforced metal laminate material is provided, including creating a first bore 18 by passing a cutting element 16 from a first side 24 of the fiber-reinforced metal laminate material 10 to a second side 26, the first bore 18 including first bore sidewalls 19 at least a portion of which includes a taper 28 having a taper diameter 33 and a taper depth 32; passing the cutting element 16 through the first bore 18; moving the cutting element 16 outward of the taper diameter 33; and retracting the cutting element 16 through the first bore 18 to create a second bore 34 having straight second bore sidewalls 36.

Abstract: A method facilitates fabricating a coupling including a first annular coupling member and a second annular coupling member. The method comprises coupling the first coupling member to a machine assembly that includes a plurality of grinding wheels coupled to a tool storage member, machining a plurality of troughs in the first coupling member using at least one of the plurality of grinding wheels, such that at least one projection is defined between adjacent troughs, coupling the second coupling member to the machine assembly, and machining a plurality of troughs in the second coupling member using at least one of the plurality of grinding wheels, such that the second coupling member is configured to rotatably couple to the first coupling member.

Abstract: A pipe renovating method and system in which a pipe is first cleaned and then coated with a suitable coating material. In the cleaning step, pressurized air and particles of abrasive material are pumped into a first end of a pipe while suction is applied to the second end of the pipe via a vacuum pump to improve flow along the entire length of the pipe. The coating material is subsequently pumped in at one end of the cleaned pipe while suction is applied at the other end. In each step, the suction flow rate is higher than the input flow rate, so as to steer the mixture towards the second end. This method can be used to coat and clean different sections of a pipe system, by connecting the input materials successively to different access ports in the system.

Abstract: A laminated wear ring for a chemical mechanical planarization (CMP) apparatus provides improved control of the removal rate of material from the edge of a wafer during a polishing/planarization operation. The laminated wear ring includes a high stiffness stainless steel base and a plastic laminate. The high stiffness stainless steel base avoids flexing of the wear ring during polishing and thus provides control of the flexing of a polish pad against which the wafer surface is pressed. The plastic laminate protects the stainless steel base from attack by the polishing slurry and provides a buffer that protects the stainless steel base from mechanically damaging the wafer and vice versa.

Abstract: A portable precision flange grinder grinds a flange on a duct. The flange has an axis, a radius, and a periphery. A mount mounts the grinder within the duct. The mount attaches to openings at ends of the duct. A grinding wheel grinds a flange on a duct and arranged to rotate along a periphery of the flange. A first linkage translates the grinding wheel along an axis of the flange to bring the grinding wheel laterally in grinding contact with the flange. The first linkage engages with the mount along an axis of the flange. A second linkage translates the grinding wheel along a radius of the flange bringing the grinding wheel radially in grinding contact with the flange. The second linkage attaches to the first linkage. A bearing assembly rotates the grinding wheel about the periphery of the flange. The bearing assembly is attached to the first linkage.

Abstract: The application describes a honing tool for use with a CNC machine. A fluid actuator provides the mechanism for causing radial adjustment of abrasive elements. The actuator consists of a piston and cylinder assembly mounted within the tool and powered by the through the tool cooling fluid of the CNC machine.

Abstract: An end face polishing apparatus has a support member mounted for undergoing rotational movement. A tubular member is mounted on the support member for rotation therewith. The tubular member has a first surface connected to a main surface of the support member and a second surface extending in an axial direction at a first distance from the main surface of the support member. A lapping member is mounted on the support member for rotation therewith. The lapping member has a first surface connected to the main surface of the support member and a second surface extending in the axial direction at a second distance from the main surface of the support member smaller than the first distance.

Abstract: A vehicle wheel has an outboard face which includes a smoothed portion to provide a cosmetic finish to the wheel face. The smoothed portion is formed by pressing a cutting tool having a non-symmetrical tip against the wheel surface as the wheel is rotated.

Abstract: A processing apparatus capable of grinding an arcuate groove (a groove having an arcuate shape in section) of various shapes defined in a work with a good accuracy. A pseudo-elliptic arcuate groove defined in a work is ground by a forming grindstone. The work is moved in a Y-axis direction (vertically on a paper sheet) in a state in which the forming grindstone is supported on a tool table for rotation and is moved in a X-axis direction (a direction perpendicular to the paper sheet) to abut against the arcuate groove, while rotating the work in a direction of an arrow with its axis L matched with an axis C of an indexer. Thus, it is possible to relatively move the forming grindstone to trace the arcuate groove, thereby accurately grinding the arcuate groove.

Abstract: A method of reducing the force required to insert an elastomeric seal in a cavity of a metallic member includes tumbling the member in a tumbling machine with media to decrease the surface roughness of the member. Preferably, the tumbling step includes decreasing the surface roughness of the metallic member at least a portion of the member defining an entrance to the cavity. The method is particularly useful for reducing the force required to insert fuel injectors having top O-rings into fuel rail cups.

Abstract: An improved method of manufacturing automotive accessory drive belts or other workpieces of pliant material which have a grooved operative face, a tool having an abrasive ramp configuration for performing said improved method and a method of manufacturing said tool with the abrasive ramp configuration.

Abstract: The present invention provides a method and an apparatus for surface treatment to polish and wash with high accuracy the inner surface of a member having complicated internal configuration. A magnet 23 is arranged on outer side of a member 1, which is made of a nonmagnetic material and for which surface treatment is to be performed on inner surface. Magnetic grains and abrasive grains in slurry state are supplied to inner surface of the member. At least one of the member 1 and the magnet 23 is rotated and are relatively moved in axial direction at the same time.

Abstract: A method is described to prepare shaped steal test-pieces (1) for tensile under corrosion fatigue tests, which provides for contacting a test-piece (1) subject to rotation about its longitudinal axis and, each time, a disk (10) of sand paper, also rotating, the contact being ensured by the own weight of the test-pieces itself.

Abstract: A honing tool assembly adapted to be chucked in a honing machine for reciprocation and rotation, the assembly comprising a diamond-plated tool for honing cylindrical bores in a workpiece, the diamond-plated tool having a spiral pattern on a cylindrical outer surface, a central bore in the tool adapted to receive a tapered rod engageable with a tapered surface on the central tool opening, the tool being provided with a longitudinal slot that allows the outside diameter of the tool to expand as a force is applied to the tapered rod whereby stock is removed from bore walls of the workpiece with precision roundness and concentricity.

Abstract: A method and apparatus for creating a groove in the surface of a collector ring for use in an electrical device. The method and apparatus can be used to create a new groove in the surface of a collector ring having none, or can be used to enhance or re-form an existing groove in the surface of a collector ring. In some embodiments, the groove in the surface of the collector ring is created using a cutting tool that has a cutting action that functions independently from the motion of the collector ring. In other embodiments, a masking material is positioned over a portion of the surface of the collector ring to create a masked portion and an exposed portion of the surface of the collector ring. A groove is then created in the exposed portion of the surface of the collector ring. The masking material is then removed from the surface of the collector ring.

Abstract: A tool for finishing an outside diameter surface of a cylindrical workpiece. The tool includes a rotatable substantially cylindrical member having an inner work-engaging surface adapted for finishing the O.D. surface of the cylindrical workpiece. The inner work-engaging surface includes abrasive particles thereon and defines a bore to receive the workpiece. The substantially cylindrical member includes at least one longitudinal split permitting radial expansion and contraction of at least part of the cylindrical portion for workpiece O.D. finish adjustment. The tool includes a rotable shaft, a plurality of spring loaded work-engaging elements adapted for finishing the O.D. surface of the workpiece. The work engaging elements have abrasive inserts. The plateaued O.D. surface has peaks that are 3-10 times smaller than the valleys.

Abstract: A rotation axis of a work spindle and a rotation axis of a spindle primary-axis portion are rotated relative to each other and feeding of a work-piece to a tool is accordingly adjusted, whereby warpage of the tool in accordance with a change in machining condition is corrected. A revolution volume of the relative rotation is compared and calculated in process based on data entered in advance, a result of measurement by a displacement sensor and information such as a machining position, and controlled in real time until the end of machining. The relative rotation is driven by an actuator such as a piezoelectric element, at a resolution even as fine as in seconds. The data entered in advance can be sequentially updated in accordance with monitoring of a processed product.

Abstract: An internal grinding method for grinding an inner surface of a work having a straight line generatrix shape while performing an in-process inner-diameter size measurement intermittently through oscillation synchronized between a grindstone and a measurer; wherein a circumferential surface of the grindstone is trued into a shape inclined with respect to a moving direction of a X-axis slide table moving forward/backward relative to the work so that normal grinding force when the X-axis slide table moves backward is reduced, while the work is supported with inclination with respect to the moving direction of the X-axis slide table so that the X-axis slide table is oscillated in the moving direction.

Abstract: The application describes a honing tool for use with a CNC machine. A fluid actuator provides the mechanism for causing radial adjustment of abrasive elements. The actuator consists of a piston and cylinder assembly mounted within the tool and powered by the through the tool cooling fluid of the CNC machine.

Abstract: A retaining ring is configured for use with an apparatus for polishing a substrate. The substrate has upper and lower faces and a perimeter. The apparatus has a movable polishing pad with an upper polishing surface for contacting and polishing the lower face of the substrate. The retaining ring has a retaining face for engaging and retaining the substrate against lateral movement and a bottom face for contacting the polishing surface of the polishing pad. The bottom face of the retaining ring extends downward from an inner portion adjacent the retaining face to a lowermost portion radially outboard of the retaining face.

Abstract: A pipeline cleaning and renovating method of the present invention comprises introduction of abrasive particulates by pressurized air through the pipelines to remove the incrustation adhering to the inner surface of the pipelines. Water or other liquids are introduced into the pipelines to generate or increase a moisture content in a flow of the pressurized air. The air flow through the pipelines is controlled to induce a substantially helical flow pattern such that a substantial amount of abrasive particulates are driven by the air flow to move along the inner surface of the pipeline in order to efficiently remove the incrustation. After the pipelines are cleaned, a coating material is added into the pipelines and driven by the air flow in the substantially helical flow pattern to provide an even coating film on the cleaned inner surface of the pipelines. This method can be broadly applied to various types of pipelines and various diameters of the pipelines from 13 mm to 300 mm.

Abstract: A device for honing blind bores in parts, a blind bore including a cylindrical bore open at one end and closed adjacent to the opposite end including a honing mandrel for mounting on a honing machine that produces rotation thereof, the mandrel having a cylindrical honing portion adjacent one end which portion and the adjacent portion of the mandrel have spaced axially extending slot therethrough to enable the honing portion of the mandrel to expand and contract in size, the honing portion having a portion adjacent to the end thereof which is somewhat larger than the rest of the honing portion when the honing portion is expanded for honing in the blind hole, the end portions of the mandrel between the spaced slots being elastically expandable from a retracted position which is less than the diameter of the surface to be honed to enable insertion therein to a more expanded condition wherein the diameter of the honing portion at the largest point is the diameter at which the mandrel will hone the blind hole.

Abstract: A method of cleaning gas turbine compressors using crushed, solid, sublimable material, such as dry ice, which can be used in during low temperature conditions, poses no risk of ice formation, clogging cooling hole passages, or degrading the emissions from the turbine.

Abstract: Honing devices configured for use with a source of pressurized fluid. The honing device includes a honing body with a base extending along an longitudinal axis. The base may include a distal end and a proximal end adapted for fluid communication with a source of pressurized fluid. The honing body further includes a plurality of leaves with a first end attached to the distal end of the base and a second end spaced from the distal end. The outer surface of at least one of the plurality of leaves includes an abrasive work engaging surface. Pressurized fluid may encourage the second end of at least one of the plurality of leaves to move away from the longitudinal axis in order to hone the interior surface of the workpiece. Methods of honing the interior surface of a bore hole are also provided.

Abstract: An inner surface 16a of a torque transmitting disc of a toroidal type continuously variable transmission can be finish-worked without also enhancing accuracy of a cylindrical surface as an outer peripheral surface of the disc. The inner surface is finish-worked with super finish while urging a working surface of a grindstone against the inner surface. In this case, roller shoes are rollingly contacted with the inner surface to prevent the disc from being radially displaced under force from the working surface.

Abstract: A reamer with adjustable expansion/contraction and a bore finishing machine comprising the reamer. The reamer has a rotation shaft that is externally operable and a grinding section. The grinding section is cylindrically shaped, and has a plurality of axially-extending slits in its peripheral wall and a tapered inner surface. The rotation shaft is connected via threaded sections to a sliding shaft, which is in turn connected to a diameter expansion member consisting of a tapered cone fitted into the tapered inner surface of the grinding section. When the rotation shaft is operated to rotate, the rotational motion is converted into linear motion of the slide shaft due to a guide pin and a guide hole. The linear motion moves the diameter expansion member back and forth inside the grinding section, thereby contracting/expanding the outer diameter of the grinding section mechanically and precisely. The bore finishing machine has a hollow main rotation spindle, and a rotation spindle inside the same.

Abstract: A chemical mechanical polishing apparatus has a rotatable platen, a polishing sheet that is wider than the substrate extending between two reels, a drive mechanism to advance the polishing sheet, and a chucking mechanism to intermittently secure the polishing sheet to the platen. The platen can have a platen base that is adaptable to receive either a circular platen top or a rectangular platen top.

Abstract: Methods of cutting pipe and removing contaminants from surfaces of pipe (40) and fittings (37, 38, and 39) that connect pipe (40) by soldering. During the cleaning and cutting of the pipe (40), contaminants are removed by way of a pipe cleaning abrasive (24) that is connected to the cleaning and cutting device. Rotating the device around the axis of the pipe (40) cleans and cuts the pipe until severed. Fittings (37, 38, and 39) are cleaned by a streamlined fittings cleaning abrasives (31, 32 and 33) located on the cleaning and cutting device. A fitting (37, 38, or 39) is placed over the fittings cleaning abrasives (31 or 32 and 33) and pushed so that the fittings cleaning abrasive (31,32 or 33) enters the fitting of the proper diameter (37, 38, or 39) removing the contaminants. The pipe cleaning abrasive (24) and the fittings cleaning abrasives (31, 32, and 33) may be replaceable. The cleaned surfaces of pipe (24) and fittings (37, 38, and 39) are ready to continue soldering process.

Abstract: A method and apparatus are disclosed for abrading the inner surface at the intersection region of a branch outlet with the wall of a body having a passageway. Using abrasive flow machining, it is possible to abrade the intersection region to provide a smooth transition between the wall and the branch outlet.

Abstract: The pipe end burnishing tool has a tool shank with an axis of rotation, a first end adapted to be clamped to drill chuck, a second end, and a stop surface on the second end. A cup member is driven by the tool shank and axially moveable along the axis of rotation. An inside member is also driven by the shank and axially movable along the axis of rotation. A cup spring urges the cup toward the stop surface. An inside member spring urges the inside member away from the first end and also urges the cup member toward the first end. Conical burnishing surfaces on the cup and the inside member cooperate to burnish pipe ends. These burnishing surfaces float in line with the ends of pipes.

Abstract: A honing method proposes that using an arbor honing tool a remachining be carried out using the same tool either simultaneously or following onto arbor honing, in which the ratio of the stroke speed to the rotational speed of the tool is significantly increased. This leads to a cross-structure of the honing tracks allowing a better oil holding capacity.

Abstract: There are disclosed a method for producing an optical fiber base material ingot comprising depositing a soot on a starting core member, and subjecting the soot to dehydration, vitrification by sintering, and then cylindrical grinding, wherein the cylindrical grinding is performed while a core portion central axis is brought into line with a rotation axis of cylindrical grinding machine, and an optical fiber base material ingot produced by the method. According to the present invention, there are provided an optical fiber base material ingot having excellent ingot roundness and excellent core portion eccentricity, and a production method capable of producing the optical fiber base material ingot in a short period of time.

Abstract: Machine for machining an envelope surface of a cylindrical work piece includes a tubular cylindrical housing with a longitudinal axis and having an inner space extending from a first end of the housing, and with an axis offset from the housing axis, a shaft angularly displaceable in the inner space and provided with a recess, and a motor in the recess. A spindle is coupled to the motor and carries a first rotatable tool, a rotatable outer casing encloses the housing, and a lid is arranged for co-rotation with the casing and extends radially over the first end of housing with the lid having a central through opening with the peripheral surface. A second rotated tool is disposed on the peripheral surface, and a support device is adapted to hold the work piece between the tools. The shaft is arranged to cause the first tool to effect radial displacement relative to the second rotated tool.

Abstract: A method for the production of medical fittings, in particular dental fittings, is proposed. A workpiece (1), from which the fitting is produced, has material removed from it by machining with a tool (7). The tool (7) and the workpiece (1) execute a relative movement with respect to each other along a fixed trajectory. The instantaneous loading of the tool is used to control the speed of this relative movement. In order to avoid the load peaks which occur here, and to ensure a more uniform control, it is proposed that the expected loading of the tool along the trajectory is also calculated and is used to control the speed.

Abstract: The present invention provides a method and an apparatus for surface treatment to polish and wash with high accuracy the inner surface of a member having complicated internal configuration.

Abstract: The present invention is directed to improved apparatus' for dislodging and abrading cryolite encrustations from carbon anodes spent during aluminum smelting. Both the plow blade and flailing elements of the present invention are constructed and arranged to substantially conform to the shape of the spent carbon butts to facilitate rapid and efficient cleaning of the spent carbon anodes' surfaces. Systems and methods employing the substantially V-shaped plow blade extension and dual directional rotating flailing assemblies are also disclosed.

Abstract: A processing apparatus capable of grinding an arcuate groove (a groove having an arcuate shape in section) of various shapes defined in a work with a good accuracy. A pseudo-elliptic arcuate groove defined in a work is ground by a forming grindstone. The work is moved in a Y-axis direction (vertically on a paper sheet) in a state in which the forming grindstone is supported on a tool table for rotation and is moved in a X-axis direction (a direction perpendicular to the paper sheet) to abut against the arcuate groove, while rotating the work in a direction of an arrow with its axis L matched with an axis C of an indexer. Thus, it is possible to relatively move the forming grindstone to trace the arcuate groove, thereby accurately grinding the arcuate groove.

Abstract: A semiconductor substrate processing system for polishing a substrate that generally includes a platen and a web of polishing material disposed thereon. Embodiments of the system include a disposable cartridge for housing the web of polishing material, a shield member disposed proximate the web for preventing contamination of the unused portion of the web, a fluid delivery for fixing and freeing the web from the platen, apparatus for controlling the lateral movement of the web, and an apparatus for providing more linear feet of polishing material per height of a roll.

Abstract: A method of grinding the bore of a rotary spindle, the bore having a taper, to true the bore while the spindle rotates about a spindle axis, the steps that include providing a support attachable to a base associated with the spindle; providing an angled slide on the support, the slide being movable endwise relative to the spindle and at a predetermined angle to the spindle axis, that angle corresponding to the spindle bore taper; providing a rotary grinder on the angled slide to be movable endwise therewith while the grinder rotates, bodily adjusting the spindle to bring the spindle bore into position to be ground by a grinder as the grinder is moved on the angled slide relative to the bore, and as the spindle rotates; and operating the grinder to grind the tapered bore as the spindle is rotated and as the angled slide is moved endwise, at a predetermined angle.

Abstract: A combination grinding machine grinds a plurality of axially arranged portions of a workpiece by use of a grinding wheel supported rotatably on a first wheel head and a superfinishing wheel supported rotatably on a second wheel head. A numerical control unit controls feed units for the first and second wheel heads in order to move the first and second wheel heads independently of each other in the axial direction of the workpiece and in the direction perpendicular to the axial direction, such that each of the axially arranged portions is ground by the grinding wheel, and simultaneously with this, another ground portion is superfinished by the superfinishing wheel.

Abstract: A pipe electropolishing system (10, 10a) for in place polishing of a pipe (28) has provision for detecting the instant position of a cathode (14) within the pipe (28) such as cable marks (52) and cable mark sensor (50), an infrared camera (60), heat sensing crayon marks (64), thermisters (66), and capacitance sensors (68), used individually or in combination. According to the inventive in place electropolishing method (80) when it is determined that the cathode is in a nonuniform portion (70) of the pipe (28), then increased polishing action is provided as by increasing the voltage using a variable power supply (30a) and/or by slowing down the progress of the cathode (14) using a variable speed cable puller (18).

Abstract: A grinder pressing device, wherein either the bottom part of a cylinder main body (10) of an air cylinder (1) in a vertical posture or a piston rod (11) is fixed to a fixed plate (2) and the other one is fixed to a movable plate (3) disposed under the fixed plate (2), either a guide table (G2) or a guide (G1) is mounted on the movable table (3) and the other one is mounted on the outer peripheral surface of the cylinder main body (20) and the guide plate (G2) is guided on the guide (G1) in a vertical direction under the rolling frictional condition through balls and, in the air cylinder (1), a coefficient of friction between the outer peripheral walls of a piston (12) and the piston rod (11) and the structural wall of the cylinder main body (10) is set lower by a metal seal so as to support the piston rod (11) by a ball bush movably in forward and backward directions over an extensive distance, a grinder (G) being mounted on the movable plate (3) and air pressures in upper and lower cylinder chambers (13 and