Abstract: A method of manufacturing a laid-up, bonded and, cured composite part, includes filling a groove on a facing surface of a tool with a foaming, self-skinning sacrificial material and covering the facing surface of the tool with a caul sheet. The tool is heated to cure the foaming material, filling the groove and forming a hard, smooth surface skin on the foam, flush with the facing surface of the tool. A series of plies are laid-up on the facing surface of the tool to form a tool-side skin, and other components of the part are laid-up on top of the tool-side skin plies. An adhesive/resin matrix is coated on or pre-impregnated into the skin plies and the components for bonding/curing to create a rigid integral assembly of the skin and components. A vacuum bag is applied over the laid-up skin and components and is sealed to peripheral regions of the facing surface of the tool around the laid-up skin and components.

Abstract: An apparatus for machining workpieces includes a feed conveyor which has an alignment station and a discharge conveyor which adjoin a machining zone. Between the feed conveyor and the discharge conveyor, there is a transport device which is disposed at one side of the machining field and which has displaceable work holders which grasp the workpieces at one of their edges. The transport device receives the workpieces at the alignment station at the end of the feed conveyor, conveys them at substantially the same level to the machining station in the machining zone, transfers them there to vacuum work holders on a work rest, and then transports them, after the machining, to the discharge conveyor.

Abstract: A jig for holding an arcuate wood piece is mounted on the table of a molder-planar. The jig has a base which is attached to the table. Mounted for rotation on the base is a clamp holder. A clamp is attached to the clamp holder for holding the arcuate wood piece for rotation with the clamp holder and for engagement with the cutting tool of the molder-planar so as to cut the arcuate wood piece.

Abstract: A curved machining jig for machining a curved workpiece having an arcuate shaped centerline, the curved machining jig comprising a table having a rotatably mounted column extending perpendicular from the table, the column rotating on a first axis perpendicular to the table, an arm attached to and extending from the column, a drive portion on the arm, a tool attachment and a workpiece attachment supported above the table, the curved workpiece removably retained by the workpiece attachment, a machining tool on the tool attachment, a means for moving the drive arm causing the arm to rotate about the column engaging the workpiece and the machining tool to perform a curved machining operation on the workpiece.

Abstract: A machine tool for machining panels, plates and discs, is fitted with a number of workpiece clamping devices (10) that move along a work bench (20) of the machine tool. The machine tool has sensors (8) designed to detect the position of the clamping devices (10), and a unit (2) built into the operating head (15) of the machine tool, which engages the clamping devices (10) to move them to preset positions on the bench (20) by one or more relative movements between the head (15) and the bench (20).

Abstract: The invention relates to a device to machine workpiece edges with variable dimensions using a device for clamping the workpieces and a machining unit, whereby the device according to the invention is characterized by a first clamping bed with a clamping plate for clamping the workpiece surfaces, a second clamping bed with a clamping plate for clamping the workpiece edges hanging over the first clamping bed and means to change the position and the orientation of the first clamping bed relative to the second clamping bed.

Abstract: A mounting assembly that secures a tooling plate to a base plate. The base plate has a mounting aperture which receives a pin that extends from the tooling plate. The pin has a locking aperture located essentially perpendicular to the longitudinal axis of the pin. Located within the mounting aperture is an armature which has a lip that extends into the locking aperture when the tooling plate is placed onto the base plate and the pin is inserted into the mounting aperture. The interlocking armature and pin secure the tooling plate to the base plate. The pin and armature lip have cooperating chamfered cam surfaces that move the lip into the locking aperture when the pin is inserted into the mounting aperture. The assembly includes a spring biased button that can be depressed to move the armature out of the pin so that the tooling plate can be released from the base plate.

Abstract: An improved crank adapter mounts on the end of a milling machine worktable and enables the operator to adjust the worktable lateral position with a forward facing crank. This relieves the need for the operator to reach past the worktable end and manipulate a sidewards facing crank. The crank adapter mechanism includes a bevel gear mounted on the end of the worktable lead screw which engages a second bevel gear driven by a forward facing crank. The crank adapter mechanism can be mounted on either or both ends of the worktable after removal of the existing end plate or end plates.

Abstract: A hand-held, chuck-type part holder provides holding means for a machine part. The hand-held part holder may be secondary holding means for a part which itself is then inserted into a primary machine clamp. The chuck uses standard replaceable collets which may be easily interchanged for different size parts. The collet is actuated by a rod which is moved in turn by an air cylinder which is supported by a handle. The part-gripping collet may be actuated by a tilt switch which provides the automatic clamping action of the collet as the operator turns the holder to the vertical position before inserting or removing a part from the end of the collet. Additionally, a fixture mounted to the bed of the processing machine may be used which guides the part holder into alignment with the primary clamp as it is inserted. The fixture includes pivot and slide means which both support and direct the movement of the part holder.

Abstract: In a work support device of a camshaft miller in which a plurality of journal portions (3b) of a work (3) to be machined are supported by a plurality of supporting portions (6), (7) from a lower side and a side reverse to a work milling direction, the work support device is constructed such that supporting surfaces of the supporting portions (6) supporting the work from the lower side thereof are inclined towards the other supporting portions (7) supporting the work from the side reverse to the milling direction and wherein a clamp mechanism (10) having clamp arms (13) for pressing the work from the upper side thereof is disposed above the supporting portions.

Abstract: A cutting and beveling device for simultaneously cutting and beveling a selected work piece. The cutting and beveling device includes a work table and a support assembly secured to the work table. The work table defines a work surface for supporting the work piece. The support assembly supports a router in a manner such that the router is suspended over the work surface and is movable in a linear direction between the ends of the work table. The router receives a bit configured to cut and bevel simultaneously. The work table includes a slotted opening which receives shavings resulting from the cutting and beveling operation. The work table also includes a vacuum system for removing dust and particles resulting from the cutting and beveling operation.

Abstract: An apparatus for forming selected machining functions relative to a workpiece comprising a machine carriage having one or more machining spindles and a work table assembly having a pair of work tables, a shuttle assembly selectively moveable along the table movement axis and a connect/disconnect mechanism associated with each of the work tables for selectively aligning and connecting and disconnecting the work tables relative to the shuttle. The present invention also relates to a work table assembly for use with a machining apparatus.

Abstract: A method and apparatus for automated loading and unloading of a cylinder in an engraver. The method and apparatus permit the engraver to accommodate cylinders of differing geometries, including a range of lengths, diameters and mounting configurations. The engraver includes a headstock and a tailstock which cooperate to rotatably support a cylinder at an engraving station in the engraver. The engraver includes a cylinder handling system having at least one cylinder supporting the cylinder between the headstock and the tailstock during the loading and unloading of the cylinder. The cylinder handling system includes a driver for driving the cylinder support towards and away from the engraving station until the headstock and the tailstock engage and rotatably support the cylinder. Once the cylinder is rotatably supported between the headstock and the tailstock, then the cylinder support is retracted.

Abstract: An improved worktable for cutting and machining operations, and particularly for removing flash from plastic parts, includes a floating work surface. The floating work surface is slidably supported on a lower fixed surface by a cushion of air. Four guides, one on each side of the floating work surface, permit translational movement of the floating surface during deflashing of a plastic part, while inhibiting rotational movement of the surface and part.

Abstract: The tool holder is designed to hold an object rigidly in place, at a strategic location, with the benefits of simplicity of placement and easy removal. There are two basic parts: base assembly and the tool mount assembly that mates with it. A spring loaded, cam activated piston locks the pieces together. A non-locking internal conical taper permits 360 degree rotation. A handle mounted on the side activates the camming mechanism to lock the tool or object rigidly in place, being secured to the tool mounting surface.

Abstract: A method for making a bed for a gantry-style milling machine, where said machine has a routing spindle which said machine is capable of moving in the X, Y and Z directions, and where said machine has means to support a bed, comprising placing material millable by the machine on said support means and planing said material level with the machine.

Abstract: A vise transport for milling machines and comprised of articulated inner and outer lever arms, the inner lever arm received in an adapter socket secured to the milling machine, and the outer lever arm universally carrying a vise support, the articulating axes of the inner and outer lever arms being vertical and parallel and the axes of the vise support being vertical and horizontal for manipulating positions of the vise and its alignment with the milling machine table to which it is mounted, there being an adapter plate for safe attachment of the vice to the vise support.

Abstract: The subject of the present invention is a pallet carrier for machine tools, said carrier being mounted on an NC work table and comprising profiled slideways as well as centering elements and hydraulic clamping members. For thorough cleaning and improved adjustment the invention provides pressure-fluid ducts within the pallet carrier coupled to quick-action connectors in the front of the pallet carrier and leading to spray nozzles which are disposed within the slide faces of the said slideways.

Abstract: The milling machine lathe attachment is attachable to an existing milling machine so as to eliminate the need for an operator owning both a milling machine and a lathe. It is designed to be mounted to the side of the milling machine and to be used without disturbing a setup in the associated vise. The attachment is also designed to be mounted to the front of a milling machine and allows the programming of the very point of single point tool contact so as to follow whatever contour or steps are desired. This type of cutting is not possible on a lathe with guaranteed accuracy, while on a milling machine it is quite feasible.

Abstract: An improved machining apparatus for machining a workpiece. The machining apparatus includes a base assembly having a base support member and a table support frame non-movably attached to the base support member. A pair of cross members span the upper surface of the table. The table support frame has a longitudinal axis transverse to the cross members and includes a raceway for allowing lateral displacement of the table relative to the base assembly. At least one spindle is mounted on the cross members and can be displaced along the longitudinal axis of the cross members. Flexible retractable covers are mounted on spring-loaded rollers attached to the ends of the table support frame. The machining apparatus further includes a conveyor positioned proximate the base assembly at the lower edge of the table for removing cuttings and debris resulting from the machining of the workpiece.

Abstract: A table extender for a milling machine which includes upper and lower work support members with the lower work support mounted on the table or bed of a milling machine and a pair of shot pins moveably mounted in the lower work support and engageable in openings in the upper work support. The upper work support is moveable on slides relative to the lower work support and a locking handle is provided so as to lock and unlock the shot pins to allow the upper and lower work supports to be moved relative to each other.

Abstract: In the ball screw guide unit of the invention, since a guide rail is formed of a channel bar having a groove, and a ball screw shaft is engaged with a movable member which is reciprocatively movable in the groove along a lengthwise direction of the guide rail, so that the centroid of the guide rail is adjacent to the axis of the ball screw shaft. Therefore, when a pretension is applied to the ball screw shaft, a straightness of the guide rail is not impaired and a feed accuracy of the movable member can be maintained. Further, the guide rial may be provided at its lower and side surfaces with reference surfaces used for adjusting parallelism between the guide rail and the axis of the ball screw shaft, in which case assembly and adjustment of the table can be performed more easily.

Abstract: The present invention is a fixture primarily for use with a machining center. The fixture has a plurality of face plates mounted on an interior casing and moveable jaws exposed on the face plates. Parts to be machined can be placed between the jaws and gripped by the jaws for easy and quick setup of various machining operations. Assemblies for actuating the jaws are described.

Abstract: A method of and apparatus for forming a through bore or recess in a turbine blade, for a lacing wire hole for example, includes a machine capable of approaching the area to be machined in a first direction during which an initial machining operation may take place and them moving in a second direction completing the machining operation. Support means are provided to ensure the blade is held firmly. The method and apparatus permit of accurate machining of blades when they are in an array of blades still secured to the rotor.

Abstract: A device for producing drilled holes with an undercut in facing panels includes a drill bit with a drill head that produces an undercut, and a drilling table for supporting a facing panel in which the drilled holes with an undercut are to be produced and displaceable in a plane of the drilling table. A trunnion projecting from a rotatable base member and engaging a bearing secured to the drilling table is movable between a first position in which the trunnion axis coincides with the axis of rotation of the base member, and a second position in which the trunnion axis is eccentric to the axis of rotation of the base member to effect swiveling of the drilling plate when the rotatable base is driven rotatably.The device has a mechanism for moving the trunnion between the first and second positions including a lever pivotally mounted on the base member, the trunnion being mounted on the lever, and a piston-cylinder drive secured to the base member for pivoting the lever.

Abstract: A machine tool installation comprising a frame, a track along which the frame is movable, a machining head on the frame and movable transversely of the track and workpiece support means, wherein the support means comprises a plurality of modules extending transversely of the track and independently movable along the track, a plurality of columns on each of the modules, each of the columns being independently movable along the modules, a workpiece fixing member at the upper end of each column and which can be moved vertically, and computer control means for controlling all the aforesaid movements in three perpendicular directions to permit the automatic positioning of the fixing members until they occupy the desired positions for supporting and fixing the workpiece during machining.

Abstract: The present invention is a fixture primarily for use with a machining center. The fixture has a plurality of face plates mounted on an interior casing and moveable jaws exposed on the face plates. Parts to be machined can be placed between the jaws and gripped by the jaws for easy and quick setup of various machining operations. Assemblies for actuating the jaws are described.

Abstract: A table for securing a pallet supporting a workpiece to a machine tool, the table having a spindle movable in a vertical direction. When the spindle ascends, the clamp arms move outward thereby to enable the clamp pawl to clamp the pallet at a clamping position, and when the spindle descends, the clamp arms are withdrawn to release the pallet from clamp.

Abstract: The machining system (10) disclosed here is particularly well-suited for automatically machining flat parts from individual sheets of aluminum. The system (10) includes a machining table defined by a pair of spaced-apart, parallely-extending table beams (18, 20). Clamping rails (192) mounted to each beam (18, 20) grip opposite side edges of an individual sheet (11) of aluminum, in a manner such that the sheet spans the distance between the beams (18, 20). The clamp rails are driven linearly relative to the beams, in order to move the sheet back and forth therebetween. Upper and lower carriage beams (14, 16) also extend transversely across the table beams (18, 20), one above the sheet (11), and the other below. The upper carriage beam (14) carries both a spindle carriage (28) and an upper clamp carriage (30). The spindle carriage (28) moves a cutting tool back and forth sideways relative to the sheet (11), and vertically up and down, for cutting parts from the sheet (11).

Abstract: A tooling plate having a plurality of columns of holes can be quickly and easily configured as a jig. Every second column contains threaded holes and the other columns contain unthreaded holes for reception of alignment pins. Alignment pins can be inserted into these unthreaded holes to produce a jig suitable for aligning a workpiece. The threaded holes are utilized by clamps that hold the workpiece rigidly in place and by an alignment bar that can be used to align the workpiece along any desired direction parallel to a front face of the tooling plate.

Abstract: An apparatus and method are provided for finishing the fabrication of venetian blinds at or near a point of purchase. The blinds are shipped to the point of purchase in a partially completed condition wherein the slats of the blinds have registered apertures formed in spaced relationship to one end of each slat, but with the opposed end being free of such apertures. An interlacing support and a pull cord are mounted to the ends of the slats having the apertures formed therein. The overall length of the slats exceeds the width of the window for which the blinds are intended. Apertures are then cut into the blinds at a selected distance from the trimmed ends. The blinds are completed by appropriately mounting a second interlacing support and pull cord in proximity to the trimmed ends of the blind.

Abstract: A pin for use in a chuck for clamping a discoid portion of a workpiece, the chuck including a base, at least to fixed clamps secured on a front end surface of the base, a movable clamp adjacent to the front end surface of the base and the pin secured to the front end surface of the base. The pin is adapted to fit in a hole formed in a discoid when the discoid is mounted on the chuck wherein the hole has a larger diameter than the pin. The pin has generally rhombic transversed section with a long diagonal and a short diagonal. The pin is truncated by a predetermined amount at each end along the long diagonal to allow the workpiece to move a limited distance relative to the pin along a line formed by the short diagonal. The limited distance may be a function of an initial clearance between the discoid portion and the chuck or a function or a variation between the diameter of the discoid portion and its design diameter, or a function of both.

Abstract: This invention relates to a machine tool having a table for mounting a workpiece. The body of a machine tool is equipped with a table for mounting a workpiece. The table is further equipped with a rotary table. When performing turning operations of the workpiece, the workpiece is mounted on the rotary table. On the other hand, when performing other operations, except for the turning operation, the workpiece is mounted on the non-rotary table. In addition, if desired, the workpiece can be mounted on both the table and the rotary table for performing other operations.

Abstract: A first table (1) slidable leftwards and rightwards of a gear finishing machine and a second table (2) slidable forwards and rearwards of the machine are disposed in an overlapped relationship such that one of the tables is mounted on the top of the other table. Of these tables, the upper table is guided by a horizontal guide member (3) which is adapted to be rotated to any desired angular position and to be clamped at such position. A feed motor (5) drives the first table to slide.For sliding the table assembly along a diagonal direction, the angular position of the guide member is adjusted so that it extends along such direction.A horizontal stability of the table assembly is secured without employing a conventional parallel link mechanism. The table assembly is driven to slide so as to pass the center of machine so that an accuracy of gear finishing is assured.

Abstract: An apparatus for precision linear positioning of material along a frame, having carrier means for carrying the material juxtaposed above the frame, means for linearly moving the carrier means along the frame having a plurality of pneumatic cylinders each having an extendable and rectractable piston, the cylinders connected to each other in a series and including a first end pneumatic cylinder attached to the frame and a last end pneumatic cylinder attached to the carrier means, such that the carrier means is moved by the amount of the cumulative extension and retraction of the pistons, stopping means associated with each the pneumatic cylinder for limiting the extension of each the piston, and means for providing a controllable amount of air to each pneumatic cylinder to selectively control extension and retraction of each piston.

Abstract: A machine tool table for supporting a workpiece beneath a cutting tool during operations requiring that the cutting tool pass completely through the workpiece and into the table.

Abstract: A table exchanging device for a wood working machine wherein workpieces of wood can be individually attracted and fixed by a sucking action by vacuum and such sucking action can be maintained also while the slide tables are slidably moved. The device comprises a pair of hollow slide tables having air sucking holes formed in upper walls thereof, a hollow bracket provided in a pneumatically communicating relationship on each slide table, and a hollow tubular shaft provided on each of a pair of left and right beds of the wood working machine and connected to a blower or a vacuum pump. A first hollow arm is supported for horizontal pivotal motion on each hollow bracket and pneumatically communicated with the follow bracket at their mutually connecting location. A second hollow arm is supported for horizontal pivotal motion on each hollow tubular shaft and pneumatically communicated with the hollow tubular shaft at their mutually connection location.

Abstract: A chuck for clamping a discoid portion of a work piece includes a base, at least two fixed clamps secured on a front end surface of the base, a movable clamp adjacent to the front end surface of the base and a pin secured to the front end surface of the base. The pin is adapted to fit in a hole formed in the discoid when the discoid is mounted on the chuck wherein the hole has a larger diameter than the pin. Furthermore, the pin is positioned radially inwardly of the movable clamp toward the chuck center and oriented so that the two fixed clamps are equiangularly spaced about and equidistantly spaced from the pin. As a result, the discoid may move relative to the pin and toward the two fixed clamps, without rotation thereof. Accordingly, the centroidal axis of the discoid may be aligned with the rotational axis of the chuck so that precision machining may be achieved.

Abstract: A glasses frame carrier for a reproducing machine, of the type comprising a base plate (1), two parallel strips (8, 9) slidably mounted on the base plate are relatively movable toward and away from each other, and a device for centering the glasses frame between the two strips. The strips are respectively fixed to opposed parallel portions of a cable (16) forming a loop around two spaced-apart pulleys, one pulley (14) constituting a cable-driving element (16) and including a braking device (21, 23, 24) which is adjustable and constituted by an elastic element (23) which biases the pulley (14) in contact with a friction element (21).

Abstract: A tool or workpiece holder retention mechanism which engagably retains the holder retention portion of the holder by creating a clamping force which draws the holder retention portion into a cooperatively formed area between two retaining jaws. Two abutting surfaces, one on the holder and one on the abutting surface on the retention mechanism housing, have formed thereon cooperatively engagable surfaces at least one of which is generally spirally formed, which meshedly engage to self-center the tool holder. Preferably the cooperatively engagable surfaces are in the form of mating spiral gear teeth specifically the jaws and the holder retention portion are constructed and actuated so as to be radially freely floatable to avoid interference with the self-centering function of the mating spiral surfaces.

Abstract: The herein proposed invention relates to mechanical engineering. The essence of the invention resides in the fact that a contrivance for setting the table position includes two disks provided with drives for moving the table in a horizontal plane and disposed eccentrically one above the other as to be free to rotate about their pivot pins, the upper disk being rotatably mounted with respect to the pivot pin of the lower disk. The pivot pin of the lower disk mounts one device for reading the length of table movement in a horizontal plane along one of the coordinate axes, and a pin is fixed in position on the upper disk a distance from its axis equal to the amount of eccentricity between the pivot pins, the pin being movably associated with the table so as to carry another device for reading the length of table movement in a horizontal plane along the other of the coordinate axes.

Abstract: In an actuator, a carriage coupled to an item to be displaced with a translatory movement comprises a follower element which defines contact surfaces engaged against the flanks of the thread of a micrometric screw. The contact surfaces co-operate with the thread of the screw only over a small angular portion thereof. The follower element of the carriage is held on the thread of the screw by resilient thrust means acting on the carriage so as to urge it pivotally about an axis (X--X) which is parallel to its direction of translatory movement, being prevented from moving in all the other degrees of freedom. The actuator is especially adapted for use in translator devices in which the level of precision is of the order of a micrometer.

Abstract: A method of cutting out components from aluminum sheets utilizes a routing tool. The sheet is held firmly in position by vacuum on a vacuum table during the cutting operation with the aid of a film of for example plastics material adhered to the back of the sheet, the routing tool being arranged to cut through the sheet but only partially to penetrate the film.

Abstract: The present invention is an improvement in a machine tool having a pedestal, a vertical column fixedly mounted on the pedestal, a workhead mounted on the column, an elevating mechanism for elevating the workhead along the column, and a worktable provided the pedestal. The workhead carries a spindle, a motor for driving the spindle, a reduction gear and a longitudinal feed gear. According to the present invention, another worktable is provided at a different height from the first worktable and at a position displaced by at least 90 degrees from the first worktable with respect to the column. This considerably reduces the restrictions on the size of a workpiece which can be worked by the machine tool.

Abstract: A vertical machining center, which comprises a pallet clamp unit and a pallet conveyor unit arranged along the front face of the bed. A saddle is provided on the upper surface of the bed, with the saddle being slidable along the X axis. A column is provided on the top surface of the saddle, with the column being slidable along the Y axis. A headstock is provided on the front face of the column, with the headstock being vertically slidable. A tool magazine and an automatic tool exchange device are both arranged alongside the bed, and a numerical control unit is provided for numerically controlling the saddle, the column, the headstock, the pallet clamp unit, the pallet conveyor, the tool magazine and the automatic tool exchange device.

Abstract: An engine block reboring system for main bearings in which the block is mounted on a pair of rails extending laterally on a workbed and is rebored by a tool driven by a right-angle drive extension on a vertical boring machine after the position of the block has been adjusted so that the vertical axis of the boring machine spindle and the desired reboring axis are in the same vertical plane, and the proper height for the tool is set for reference, so that the bearings can be rebored by manipulating the spindle vertically and horizontally in said vertical plane with respect to the height reference. Apparatus is provided for initially properly aligning the block and keeping it in aligned position during the reboring operation.

Abstract: The invention provides work piece support apparatus for supporting resilient sheet material during a machining operation, e.g., routing, in which the support apparatus includes hydrostatic clamping means comprising perforated support pads positioned each side of the resilient material and connected to a fluid supply. By this arrangement a fluid layer under relatively high pressure is interposed between each pad and the adjacent region of sheet material which is thus fluid pressure supported in the immediate vicinity of the routing tool throughout the machining process. The invention beneficially provides a routing machine including the work piece support apparatus in which the work piece is positioned in a generally vertical plane and the routing tool is mounted about a generally horizontal axis.

Abstract: Apparatus for gripping panels or stacks of panels during cutting thereof, comprising a series of identical mechanical grippers grouped side by side in battery formation. The grippers are each formed by two vertically superposed levers (1, 6) acting along a vertical plane, interconnected at a common fulcrum point (7) and urged in the closing direction by a spring (9) and in the opening direction by a centralized mechanical system comprising a shaft (10) which cooperates transversely with the upper levers (6), which is supported by the same structure as the grippers and which may be selectively raised and lowered by one central motion unit (13).

Abstract: A retaining member which bridges the interface in a workpiece being machined is described. The retaining members are designed as a bridge, it being possible for one end portion of this bridge to be fixed on the waste piece (11) and the other end portion of this bridge to be fixed on the remaining piece. The respective retaining members may be connected to the workpiece parts utilizing magnetic force or a partial vacuum, by soldering, adhesion, hard soldering, welding, screwing, riveting, clamping or by using double-sided adhesive tape. With the aid of such an apparatus, the parts of a workpiece to be separated from each other may be held in their original position long enough for the cutting operation to be completed.

Abstract: A machine tool bolster includes a horizontal fixture support plate and a pressure-operable clamp device is vertically shiftably mounted to the underside of the plate and includes a clamp insert holder extending axially into a circular hole provided in the plate. A fixture is mounted to a locating plate provided with a receptacle adapted to receive the clamp insert holder when the clamp device is raised relative to the plate. A rod is connected to a piston of the clamp device and extends vertically through the holder. The upper end of the rod is conically shaped and acts against complementary shaped clamp inserts radially slidably mounted in the holder to shift them outwardly against a conically flared portion of the locating plate receptacle so as to clamp the fixture to the bolster.