Abstract: A stage mechanism includes a feed screw, a fixed stage having a space portion incorporating the feed screw, a movable stage, and a backlash absorbing portion. The feed screw has a first end portion and a second end portion. The stage mechanism further includes a deviation preventing portion preventing the feed screw from deviating in a direction toward the first end portion and a pressing force adjusting portion adjusting the pressing force by which the feed screw is pressed in a direction from the second end portion side to the first end portion. The deviation preventing portion is in contact with a wall of the space portion on the first end portion side. The pressing force adjusting portion is in line contact with and presses the second end portion.

Abstract: Machine tools are provided, including machines tools of large dimension, which include a bench, an upright base, control elements for the translation of the upright base, an upright base position sensor comprising an optical line or linear encoder fixed to the bench, detection elements for detecting the temperature of the optical line and management elements for processing the temperature signals coming from the optical line temperature detection elements and the signals of the upright base translation control elements to determine a correction signal for the upright base translation control elements according to at least one temperature detected along the optical line.

Abstract: A numerical control device has: a program reading unit reading a machining program; an inclined-surface setting unit setting an inclined-surface coordinate system regarding an inclined surface; an indexing-angle generating unit calculating an indexing angle where a tool used for machining of the inclined surface is oriented perpendicular to the inclined surface, and generating a move command. The program reading unit outputs an inclined-surface setting command instructing setting of the inclined-surface coordinate system, an inclined-surface indexing command instructing calculation of the indexing angle, and a tool selection command instructing selection of any of tools respectively having different mounting angles. The inclined-surface setting unit sets the inclined-surface coordinate system according to the inclined-surface setting command.

Abstract: A machine tool 1 includes a turret (4, 104) to which a tool unit 2 is adapted to be radially mounted, a cylindrical turret pivoting driving shaft (5, 105) for transmission of pivoting driving force to the turret (4, 104), a rotary tool driving shaft (8, 108) adapted to be rotated with respect to an indexing axis for transmission of rotation driving force to a tool (7, 107) of a rotary tool unit (2b, 102b) mounted on the turret (4, 104), and a unit pivoting driving shaft (12, 112) adapted to be rotated with respect to the indexing axis independently of the rotary tool driving shaft (8, 108) for transmission of pivoting driving force to the rotary tool unit (2b, 102b) mounted on the turret (4, 104) to change the direction of the rotation axis AX2 of the tool (7, 107). The rotary tool driving shaft and the unit pivoting driving shaft are coaxially arranged inside the turret pivoting driving shaft.

Abstract: In a combination machining lathe, a workpiece holding device holds a workpiece in a manner that permits the workpiece to rotate around an axis parallel to a direction of a horizontal Z axis. A tool post holds a tool that comprises a holder and a bit. The tool held by the tool post is indexed to a position in which the longitudinal axis of the holder is parallel to an X axis direction. The bit of the tool held by the tool post is angled such that a longitudinal axis of the bit is disposed in a position tilted away from the X axis direction closer to a horizontal axis in a plane containing the X axis and the Y axis. A turning operation is performed while the tool and/or the workpiece are moved relative to each other in a direction of the longitudinal axis of the bit.

Abstract: Disclosed is a convergence machining apparatus based on turning in which a rotation center of a work piece to a headstock and a footstock and a slide surface of first and second beds mounted with a reciprocal carriage, the headstock, and the footstock are positioned on the same virtual line when viewed from a direction parallel with a rotation axis of the work piece, thereby preventing an offset error in processing due to a relative displacement between the work piece and a tool installed at the reciprocal carriage.

Abstract: A device for the fine machining of a circumferential workpiece surface arranged eccentrically relative to an axis of a workpiece. The device comprises a pressure mechanism configured to press a fine-machining tool against the circumferential workpiece surface. The device also includes a drive unit configured to drive an active section of the pressure mechanism via a first drive and a second drive. The first drive drives the active section in a movement plane that runs crosswise to the workpiece axis along a first movement trajectory. The second drive drives the active section along a second movement trajectory that is at an angle to the first movement trajectory.

Abstract: Disclosed is a convergence machining apparatus based on turning in which a rotational axis of a work piece fixed by a headstock and a tailstock and a center of a width of a slide surface of a bed on which a reciprocal carriage installed with a tool is transferred while being supported are positioned at the same virtual plane, thereby preventing an offset error according to a relative displacement between the work piece and the tool during processing.

Abstract: A feeding device includes a tool holder, a cutter, a feeding mechanism and a mounting seat. The cutter is positioned on the tool holder. The mounting seat has at least one guiding portion. The tool holder is engaged with the at least one guiding portion. The feeding mechanism drives the tool holder and the cutter to controllably reciprocate along the at least one gliding portion.

Abstract: A lathe includes a machine support, a work table, a moving device and a feeding device. The work table is rotatably positioned on the machine support for driving a workpiece placed on the work table to rotate. The moving device is movably mounted, slidably on the machine support along a first direction above the work table. The feeding device is slidably positioned on the moving device along a second direction vertical to the first direction, the feeding device includes a cutter. The feeding device drives the cutter backwards and forwards under precise control at high speed along a third orthogonal direction for machining the workpiece.

Abstract: A working machine includes a base, at least one z-axis track mounted on the base, a secondary z-axis track mounted on the base, at least one z-axis saddle mounted on the z-axis track, a secondary z-axis saddle mounted on the secondary z-axis track, at least one x-axis track mounted on the z-axis saddle, at least one x-axis slide mounted on the x-axis track, at least one upright support mounted on the x-axis slide, and at least one y-axis track mounted on the upright support. Thus, the y-axis track is disposed at a vertical state so that the y-axis track is operated exactly and stably to facilitate operation of the working machine and to enhance the working precision and stability of the working machine.

Abstract: The present invention provides a self feeding drill press lathe attachment designed for rotating a workpiece along a horizontal axis to remove material from the workpiece to form it into a desired shape. The drill press lathe attachment comprises a base and a power transfer box along with components commonly found on a lathe, but without a motor. The drill press lathe attachment, or “motorless” lathe, may be mounted directly to the bed of an existing drill press thereby providing an alternative means of achieving turning operations without needing a traditional motor driven lathe.

Abstract: To provide a machine tool capable of preventing even chips in a powder form and coolant from leaking to a feed mechanism side. A slide plate 12 is provided to cover a feed mechanism 16. The slide plate 12 is fixed to a second headstock 6 to move in an axial direction together with the second headstock 6. Between the slide plate 12 and a bed side member, a seal portion 31 is provided. The seal portion 31 has a first slide contact member 20 provided on the slide plate 12 and a second slide contact member 18b which is provided on the bed side member and in slide contact with the first slide contact member 20, and the first and second slide contact members 20 and 18b relatively slide while being in contact with each other.

Abstract: A fast tool arrangement, in particular for lathes for machining optical workpieces, has a carriage, which for linear reciprocating movements is guided in a housing on bearing elements stationary in relation to the housing, and which at its outer end carries a holder for a tool or workpiece and at its inner end is actively connected with a moving coil drive. The carriage has the cross-section of a T-profile with plane-parallel flange and web faces wherein the bearing elements are arranged in pairs on both sides of the profile web and the profile flange.

Abstract: A machine slide tool assembly and a drive mechanism that includes a slide plate slideably mounted on guide members connected between opposed end supports and which slide plate is reciprocally driven by a drive assembly. The drive assembly includes a piston and cylinder arrangement disposed between the opposed end supports wherein a piston is displaceable within the cylinder by fluid pressure alternatively acting on the opposed ends of the piston, and which piston includes a gear wheel rotatably journaled thereto which is disposed in meshing relationship with a gear rack connected to the slide plate whereby the reciprocating motion of the piston is transmitted to the slide plate for enhancing the linear displacement of the slide plate relative to the linear displacement of the piston within its cylinder.

Abstract: A machine tool for achieving a high degree of flexibility during workpiece processing comprises a machine bed with side walls arranged thereon, which respectively comprise a basic body with a front overhanging projection arranged thereon. On the side walls a tool spindle is arranged to be linearly movable by means of slides. Underneath the front overhanging projections a processing space is formed for the workpiece processing, in which a workpiece positioning unit is arranged. The processing space underneath the front overhanging projections is freely accessible, whereby depending on the processing task different workpiece positioning units can be arranged therein.

Abstract: A five axis motion controlled ultra-precision machine tool is provided in which major portions are composed as a structure completely symmetric about the machining point and errors due to thermal displacement can be minimized. A pair of Y axis guide members (41,41) are secured to the top face of a base (i) at both sides of an X axis slider (3) interposed therebetween for X direction so as to movably guide Y axis sliders (4,4) in horizontal Y direction perpendicular to X axis. Y axis linear motors (42,42) and the Y axis guide members (41,41) are disposed substantially at the center of mass of the Y axis sliders (4,4) respectively, so that the Y axis sliders (4,4) can be driven in Y direction with vibration and errors in alignment minimized.

Abstract: The present invention provides a lathe which accumulates a reduced amount of chips on a slide member serving as a tool holder mounting base and which enables a reduction in the forward-backward dimension of the entire lathe. A lathe includes a spindle 2 that rotatably supports a workpiece and processing means 4 located in front of the spindle 2. The lathe moves one or both of the spindle 2 and the processing means 4 forward and backward to execute machining on the workpiece. The processing means 4 includes a tool 40, a tool holder 41 that supports the tool 40, and a slide member 42 which is slidable in a lateral direction and which supports the tool holder 41. The slide member 42 has an inclined surface 42c that is positioned lower as the inclined surface 42c approaches the spindle 2 and on which the tool holder 41 is mounted and supported.

Abstract: A turning machine is provided for machining a workpiece with respect to a longitudinal axis (14) of the machine. The machine comprises a base (2), a headstock (10) and a tailstock (12) supported by the base for mounting respective ends of the workpiece (8) such that it is rotatable about said longitudinal axis, and a carriage (4) for carrying a tool (24) to engage with the io workpiece. The carriage is moveable parallel to said longitudinal axis along two guideways on the base, wherein the guideways are located in use on either side of and spaced horizontally from said longitudinal axis. The machine configuration seeks to reduce roll and/or pitch errors occurring as the carriage moves along the workpiece.

Abstract: A machine for machining optical workpieces, is equipped with a workpiece spindle, by which the workpiece can be rotatably driven about a workpiece rotation axis, and with a first fast-tool assembly, by which a turning cutter is movable in the direction of the workpiece and away from it. The workpiece spindle and the first fast-tool assembly are also movable relative to each other in a direction transverse to the workpiece rotation axis. Provided adjacent to and preferably in parallel configuration with the first fast-tool assembly is a second fast-tool assembly with a graver which has its end that faces the workpiece being essentially punctiform. The graver is movable by the second fast-tool assembly, in the direction of the workpiece and away from it, so that a marking of any geometry can be produced on the latter in the same span.

Abstract: In order to provide a machine tool with at least one movable slide, which has a plurality of holders for tools and/or workpieces, and which can be corrected in a simple manner, the at least one slide has a plurality of separate subslides and the relative position of the subslides in relation to one another is adjustable in a securable manner.

Abstract: A lathe exhibits a vertically positioned, motor-driven work spindle on whose lower end are positioned workpiece clamps, an initial compound slide system (19) by means of which the work spindle can move vertically in the Z1 direction and horizontally in the X1 direction, at least one initial stationary tool holder (22), and at least one second tool holder (46) which can execute an advancing action in at least one direction during the machining process. The advancing movement of the second tool holder (46) is independent of the control of the first compound slide system (19). The second tool holder (46) can be moved in controlled fashion along two axes by a second compound slide system (28, 30, 32, 34).

Abstract: The present invention provides an improved machine tool, comprising a machine frame, a support arranged on the machine frame and having a first receiving means for the workpiece or the tool. A cross slide system is arranged on the machine frame and has a second receiving means for the tool or the workpiece which can be moved by the cross slide system in a movement zone of a cross slide movement surface. The cross slide system may comprise two slide elements, one of which is supported on the machine frame and the other bears the second receiving means, such that the slide elements are guided so as to be movable on one another by a single two-dimensional guide means which is movable in the direction of both cross slide movement axes. The guide means determines the precision of the guidance of the second receiving means parallel to the cross slide movement surface.

Abstract: In order to use moved masses which are as small as possible in a machine tool, in particular for the rotary machining of workpieces, comprising a machine frame, a tool carrier, a workpiece carrier, it is proposed to provide a parallel kinematic arrangement, which has three parallelogram guides connected in an articulated manner at one end to a receiving means for one of the carriers and at the other end to a slide and an N/C-controlled linear drive for each slide and by which the carrier arranged on the receiving means is movable relative to the machine frame in a three-dimensional movement space.

Abstract: A wood lathe includes an axial moving unit with a movable seat, which is sleeved movably on a driving rod and a guide rod that are parallel to each other. A driving gear is disposed rotatably on the movable seat, and engages a gear-engaging member of the driving rod. When an actuator member is rotated, the gear rotates synchronously therewith so as to move the movable seat on the driving rod. A sample bar and a bar blank are held on a bed of the lathe. A blade is carried on the movable seat for cutting the bar blank. A tracing unit is disposed on the movable seat so that a groove pattern on the sample bar is traced mechanically and is duplicated on the bar blank.

Abstract: The invention provides a clamping device for machine tools capable of preventing the occurrence of impressions. In a clamping device for machine tools, a tailstock (movable carriage) is provided on a top face of a fixed bed and the tailstock is positioned and fixed with respect to the fixed bed. The tailstock is supported by linear-motion bearings (guides) which are disposed between the tailstock and the fixed bed. Blocks are slidably engaged with rails extending in the travel direction with rollers interposed between them. Further, a recess portion extending in the travel direction is formed in the top surface of the fixed bed. A cylinder mechanism is arranged so that left and right inner walls in the recess portion are pressed by a pair of pistons provided on the undersurface of a headstock.

Abstract: A lathe adapted to trim and true the circumference of a rotating cylindrical surface comprising an axially forward plate with a central aperture and a plurality of radially interior and radially exterior apertures, an axial rearward plate with a plurality of radially interior and radially exterior apertures; fixed cylindrical spacers fixedly coupling the forward and the rearward plates, a plurality of threaded cylindrical spindles rotatably supported with respect to the forward and rearward plates with a planetary gear secured with respect to each spindle, a rotatable advancement assembly formed with a rotatable plate and a forwardly facing cylindrical periphery and a tracking ring in meshing contact with the planetary gears whereby rotation of the rotatable plate with respect to the rearward plate will rotate the tracking ring to rotate the planetary gears and the threaded cylindrical spindles, a carriage having two parallel threaded bores in meshing relationship with the threads of spindles for axial moveme

Abstract: A machine tool, such a lathe, is described that includes a machine base and four base columns supporting a horizontal roof-shaped upper section. Horizontally guided Y-carriages and Z-carriages are suspended from an underside of the upper section. A horizontal working spindle is suspended from the Z-carriages. An X-carriage is arranged and vertically guided on the lower section of the machine stand.

Abstract: A method and related structure for operating an engine lathe comprising performing the desired lathe operation by automatically translating the tailstock toward a workpiece and automatically stopping said translation at predetermined distances.

Abstract: In a machine tool having a worktable feed mechanism of the type that a worktable is moved in a horizontal direction relative to a tool spindle along a pair of guideways in parallel with the horizontal direction, there is provided a cutting chips collection space formed between the pair of guideways fixed to a base. A pair of ball screws are arranged outside of the cutting chips collection space for moving the worktable relative to the tool spindle in the horizontal direction. The cutting chips and coolant generated by contacting a tool with a workpiece drop into the cutting chips collection space directly without being heaped onto a cover mechanism of the worktable feed mechanism.

Abstract: An apparatus for machining both inside and outside of a hollow workpiece (16) to impart thereto inner and outer curved surfaces that are contoured to be non-circular is disclosed. It includes workpiece supports (10, 11) that clamp the workpiece oriented substantially vertically from its opposite upper and lower sides to support it rotatably about its axis extending substantially vertically. A C-axis drive (18) acts on the workpiece supports to rotate the workpiece about that workpiece axis. The workpiece supports are driven by a Z-axis drive to move the workpiece in a direction of that workpiece axis. Also included are an exterior machining unit (24) having a cutting tool (26) arranged to be movable in a direction of X-axis that is orthogonal to the workpiece axis, and an interior machining unit (25) having a cutting tool (33) arranged to be movable in a direction of U-axis that is parallel to the X-axis.

Abstract: A portable single-point beveling tool includes a tool housing, an associated tool drive mechanism and a base member which is rotatably supported on the housing for rotary motion about a rotation axis and arranged to be rotated by the tool drive mechanism. The base member has a portion which extends in a generally radial direction with respect to the rotation axis. The base member carries a cutting tool holder assembly, which includes a cutting tool holder. The base member also carries a cutting tool feed assembly, which is arranged to simultaneously drive the cutting tool holder assembly in a linear radial direction and the cutting tool holder in a linear axial direction with respect to the rotation axis. Rotary motion of the base member actuates the cutting tool feed assembly to drive the cutting tool holder assembly and the cutting tool holder.

Abstract: An apparatus for servicing and repairing cues including a collet mounted to a rotation member and having a collet body defining a passage including a generally conical surface, at least two collet jaws formed of a flexible resilient material and slidably disposed within the passage to define arcuate gaps with the surface, and an adjuster for slidably moving the collet jaws to flexibly bear against a cue inserted through the collet. A cutter feed includes a mounting to a bed proximate to a headstock for movement parallel to the bed. A cue tip shaper mounted to the cutter feed and having a rotatable arm for shaping a cue tip to a preselected curvature. A flexible resilient sleeve rotationally mounted to a support for holding a cue by frictional contact. A pivot mount for mounting a motor to the bed in a first position proximate to the support and pivotable to a second position proximate to the headstock. A pincers press mounted for sliding movement along a guide way to pinch and smooth wrap on a cue.

Abstract: In order to improve a lathe, in particular, a multiple-spindle lathe, comprising at least one workpiece spindle arranged on a machine frame and rotatable about a spindle axis, this workpiece spindle projecting with its front end into an operating area, and a tool slide with a longitudinal slide element guided for displacement in Z-direction parallel to the spindle axis in a longitudinal guide means located outside the operating area and arranged on a slide stand of the machine frame and with a cross slide arranged in the operating area and displaceable in X-direction transversely to the spindle axis in relation to the longitudinal slide element, this cross slide being guided on a cross slide guide means arranged at a front end of the longitudinal slide element and movable by means of a cross feed gear, such that the tool slide as a whole is constructed in as space-saving a manner as possible and, in particular, requires little space in the operating area in order to create the possibility of using several too

Abstract: A shield slide mechanism for moving the cutting tool of a clamshell lathe is provided. By shielding the mechanism, metal chips created during the cutting process are precluded from jamming the mechanism and preventing the controlled movement of the cutting tool. The tool block slide assembly incorporates a cam lever actuated feed screw operating through a unidirectional roller clutch rather than a conventional star wheel to provide a more controlled movement of the tool block slide.

Abstract: A lathe for producing an aspherical surface on an optical lens blank has a horizontal base, and a spindle is arranged for disposition in a preselected adjusted position on the base to rotatably mount the optical lens blank about a first preselected axis. A support is arranged on the base for pivotal movement about a second preselected axis. The support includes a roller cam follower rotatable about a third preselected axis and having a cylindric cam follower surface, a cutting tool disposed in a preselected adjusted position on the support for forming the aspherical surface on the optical lens blank, and a fluid pressure motor conjointly urging the roller cam follower and the cutting tool in a direction generally perpendicular to the third preselected axis.

Abstract: A portable machine tool comprises a main spindle and a machine body that is rotatable relative to the main spindle. A take-off shaft is mounted in the machine body and is rotatable relative to the machine body, and a rocker arm is rotatable about the axis of the take-off shaft. A cam and follower mechanism converts rotation of the machine body to reciprocating rotation of the rocker arm, and a releasable clutch mechanism that is effective between the rocker arm and the take-off shaft can be switched between a first state in which it converts reciprocating rotation of the rocker arm to unidirectional rotation of the take-off shaft and a second state in which reciprocating rotation of the rocker arm has no effect on the take-off shaft.

Abstract: A lathe includes an auxiliary transverse table at an opposite side to a transverse table. The auxiliary transverse table includes an auxiliary tool carrying an abrasive on one end thereof positioned at the opposite side to a machining tool of the transverse table. A workpiece is machined in a high straightness degree since the auxiliary tool of the auxiliary transverse table supports the workpiece on the opposite side to the tool of the transverse table which performs machining the workpiece. In addition, the machining time period as well as the number of machining processes on the workpiece can be reduced since the abrasive on one end of the auxiliary tool gives final touches to the workpiece during machining.

Abstract: A machine for cutting slices from a cylindrical workpiece such as a log of pressure sensitive tape. The machine has a machine frame and a mandrel on the frame for holding and rotating the cylindrical workpiece. A disc shaped cutting blade is mounted on a carriage and is movable to cut the workpiece into material slices. The carriage is movable to shift the cutting blade to locations along the mandrel at which the workpiece is cut into slices. A drive mechanism is connected to the carriage assembly for moving the carriage assembly along the mandrel. That drive mechanism has a drive handle which can be manually gripped to disengage a drive rack and pinion and so enable movement of the carriage assembly in either direction along the mandrel. A one-way clutch mechanism connects the handle to the pinion so that rotation of the handle in alternate directions incrementally moves the carriage assembly in one direction only along the mandrel.

Abstract: A lathe with a machine bed, a main spindle stock for a motor driven main spindle fixed to the machine bed, a tail stock moveable in the direction of the main spindle axis, and a cross table including a longitudinal table moveable in the direction of the main spindle axis and a transverse table transversely moveable relative to the longitudinal table, with the longitudinal table being operable by a rotatable longitudinal lead screw and with the transverse table being operable by a rotatably drivable transverse lead screw. The longitudinal lead screw and the transverse lead screw are each provided with a hand wheel, which hand wheel is rigidly connected with a driving wheel couplable to an associated drive motor. The drive motors are controllable by a data processor.

Abstract: In order to improve a machine tool comprising at least one hydraulic drive for working motion or rapid motion operation connected via a supply pipe to a high-pressure network supplied by a high-pressure pump so that the drives can be operated with high pressure for working motion and to a substantial degree with low pressure for rapid motion, it is proposed that a low-pressure network supplied by a low-pressure pump be provided for operating the drive for rapid motion, that a flow-limiting member be arranged between the high-pressure network and the supply pipe for bringing about a pressure drop in the supply pipe during the rapid motion by limiting the flow of a hydraulic medium under high pressure and for maintaining the high pressure to a substantial degree during the working motion, and that the low-pressure network be connected to the supply pipe via a check valve which is open on account of the pressure drop during the rapid motion and closed during the working motion.

Abstract: There is provided a high-production machining device having first and second spindles rotatably mounted on a headstock. A carriage is slidably mounted on the machine bed, and in a preferred embodiment a first drive assembly is provided for sliding the carriage across the upper face of the bed along a transverse axis thereof. First and second slides are slidably mounted on the carriage for movement in a direction normal to the transverse axis, with the first and second slides each adapted to carry a machine tool and each being attached to a common second drive assembly for moving the slides in that normal direction. A linear sensor monitors the positions of the first and second slides relative one another, and an independent compensating assembly is provided for adjusting the position of one of the slides relative the other in the normal direction, whereby positions of the first and second slides in the normal direction can be effectively independently controlled.

Abstract: A machine tool has a housing normally rotated about a housing axis and a part that is axially movable relative to the housing to adjust the tool. An adjustment apparatus for the tool has a drive having a rotary drive output, a differential transmission having a rotary input connected to the drive output and a pair of transmission outputs. This transmission includes a reverser for rotation of one of the transmission outputs opposite that of the other transmission output. Respective wheels coupled to the transmission outputs are rotatable coaxially on the tool housing and respective screws are rotationally coupled to the wheels, axially fixed on the tool housing, and both threaded in the movable part of the machine tool. According to this invention one of the screws is of opposite hand to the other screw.

Abstract: An automatic threading device, applicable to engine lathes or turret lathes, operating with a single point tool traveling parallel to the longitudinal axis of the lathe in a series of passes, generating the thread on a workpiece by synchronizing the travel of the device with the turning of the lathe, as in ordinary lathe threading, but in fully automatic sequences, reducing threading time to a few percent of that of conventional methods. A wide range of diameters, lengths, and thread pitches can be accommodated by one device. Except for a drive screw which provides longitudinal movement of the tool, all operating functions are pneumatically controlled. The device may be adapted for either temporary or semi-permanent attachment to a lathe.

Abstract: A hand operated machine tool for machining a groove about a cylinder bore of an engine block having a body portion adapted to be secured in place within a cylinder bore of an engine block, and having a laterally extending rotating arm provided with a cutting tool for machining the groove as the arm is rotated. In one form of the invention, the arm is provided with a lever which is pivoted at one end to the arm and having its other end disposed in engagement with a threaded handle connected to the free end of the rotatable arm. A fulcrum pin is interposed intermediate the ends of the lever whereby relative rotation of the handle and arm causes the arm and the cutting tool to be progressively advanced toward the engine block to perform the cutting operation as the arm is rotated.