Abstract: A NC machine tool having a constitution in which a table (15, 115) for placing a work thereon and a spindle (14, 114) for setting a tool are relatively moved by three feed mechanisms (18-20, 118-120), for X-axis, for Y-axis, and for Z-axis, to carry out machining. A preload is applied to all the three feed mechanisms (18-20, 118-120), for X-axis, for Y-axis, and for Z-axis, using a rack-pinion (21, 22, 24, 25, 27, 28, 121, 122, 124, 125, 127, 128), and using two motors (16, 23, 29) for each axis to prevent backlash in the rack-pinion.

Abstract: A NC machine tool having a constitution in which a table (15, 115) for placing a work thereon and a spindle (14, 114) for setting a tool are relatively moved by three feed mechanisms (18-20, 118-120), for X-axis, for Y-axis, and for Z-axis, to carry out machining. A preload is applied to all the three feed mechanisms (18-20, 118-120), for X-axis, for Y-axis, and for Z-axis, using a rack-pinion (21, 22, 24, 25, 27, 28, 121, 122, 124, 125, 127, 128), and using two motors (16, 23, 29) for each axis to prevent backlash in the rack-pinion.

Abstract: A preload control apparatus comprising a bearing 16-19 and at least one coned disc spring 26 for exerting a preload on the bearing, one or some or all of the coned disc spring(s) being at least partly made of a shape memory alloy so that the preload on the bearing can be adjusted with changes in temperature of the coned disc spring(s).

Abstract: A machine tool comprising:a toolholder for holding a tool;a spindle for detachably supporting the toolholder;a spindle support for rotatably supporting the spindle;a drive means for driving the spindle supported on the spindle support;a stop means for preventing the toolholder from rotating relative to the spindle support; anda cutting oil supply means for supplying a cutting oil to the tool via the stop means.

Abstract: A pallet changer includes at least one pallet (4, 14) for holding a workpiece (5, 15); a first guide (41) for guiding the pallet (4, 14); a first support (2) for supporting the first guide (41); a second guide (51) for guiding the pallet (4, 14); a second support (30) for supporting the second guide (51); a first linear motor (40) associated with the first guide (41); a second linear motor (50) associated with the second guide (51). The pallet (4, 14) is made of conductive material so as to serve as a secondary conductor for the first linear motor (40) and the second linear motor (50) for performing changing of the pallet (4, 14) between the first linear motor (40) and the second linear motor (50) along a desired direction (Y).

Abstract: A machine tool comprises: (a) a tool (22); (b) a body (2); (c) a tool supporting means (10) for supporting the tool (22) provided relative to the body (2); (d) a means (4) for supporting a pallet (P) for setting a work (W), the support means (36, 35) being provided relative to the body (2); (e) a first moving means (31, 32, 32a, 33, 34, 37, 39) for moving the means (4) about a center axis (U2) along a first direction (B1, B2); and (f) a second moving means (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) for moving the tool supporting means (10) so as to cause relative motion between the tool supporting means (10) and the means (4) for performing machining operation of the work (W).

Abstract: A manual pallet changer for performing a loading operation and an unloading operation for a pallet between a table of a machine tool and a pallet magazine comprising a clamp for clamping the pallet to the table of the machine tool. The pallet magazine connected to the machine tool by an opening and closing joint, the pallet magazine as a whole being rotatable about a supporting point of the opening and closing joint; and the pallet magazine having first guide rails arranged alone a longitudinal direction of the pallet magazine in two rows; second guide rails arranged along a direction different from the longitudinal direction in two rows; movable guide rails arranged along the longitudinal direction in two rows, the movable guide rails being movable between an upper position and a lower position; and a lift for moving up and down the movable guide rails.

Abstract: A machine tool includes a table (24) movable in a first direction and a second direction for supporting a work holder (H), a work storage magazine (3) for storing a plurality of work holders (H), and a work changer for transferring work holders (H) between the work storage magazine (3) and the table (24). The axis of the work holder (H) supported in the table (24) is directed in a horizontal direction. Each axis of the work holders (H) stored in the work magazine (3) is directed in a vertical direction.

Abstract: A pallet exchanger includes a machine tool table movable along a first axis and a second axis, a mounting arrangement for mounting a plurality of pallets each of which has a workpiece, a support for supporting the mounting arrangement, and a motive device for moving the mounting arrangement relative to the machine tool table along a third axis perpendicular to the first and second axes. The mounting arrangement includes a guide arranged along the first axis, first and second mounting parts, and an intermediate part between the first and second mounting parts. The motive device includes a drive device mounted on the support and an operating device driven by the drive device which moves the mounting arrangement on the support relative to the machine tool table.

Abstract: A preload control apparatus for use in a spindle (12) of a machine tool comprises a bearing (16,17) and a plurality of springs (26a to 26d) for exerting a preload on the bearing (16, 17). Some or all of the springs (26a to 26d) are at least partly made of a shape memory alloy so that the preload on the bearing (16,17) can be adjusted with changes in temperature of the springs (26a to 26d).

Abstract: This invention relates to a pallet changer suitable for use with a machine tool. When exchanging pallets, the pallet changer employs a drive means 3 for driving a table 2, and a transfer means 12 comprising a chain 66 and sprockets 64, 65. The transfer means 12 is driven by the drive means 3, and the pallet 4 is moved in the same direction as the table 2.

Abstract: This invention relates to a machine tool which can do multiple operations such as drilling and turning operations on a workpiece once the workpiece is attached onto the workhead, thereby obtaining time savings in loading the workpiece and maintaining quality in the operations. According to this invention, a workhead (4) has a spindle (16). The toolhead (5) has a spindle (42). A first indexing means (6) indexes the direction of the axis of the spindle (42). A second indexing means (8) indexes the spindle (16) in the first direction (A). A first stopping means (9) stops rotation of the spindle (16) when necessary. A second stopping means (11) stops rotation of the spindle (42) when necessary. A first driving means (7) and a second driving means j(10) rotate, respectively, the spindle (16) and the spindle (42). Driving systems (12, 13) are designed to move the workhead (4) and the toolhead (5) relative to each other in a three dimensional manner.

Abstract: A pallet magazine for setting a plurality of pallets including a column and a plurality of swing units mounted on the column. A turntable as driven about a horizontal axis and including a plurality of rails for receiving the pallet. An indexing member securing the turntable at a desired position.

Abstract: This invention relates to an apparatus and method for sensing a thrust load applied to a spindle of a machine tool. The object of the invention is to generate a signal representing the thrust load alone, exclusive of other forces such as frictional resistance within the spindlehead feeder, etc. so as to accurately measure the thrust load. According, to one disclosed embodiment, a first pressure sensor is arranged between a thrust bearing supporting the spindle and a surface on the spindle support and a second pressure sensor is arranged between a second surface on the spindle support and the machine tool frame. Each of the pressure sensors may be, for example, a piezo-electric film pressure sensor.

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 machine tool has a machine tool body (3), a spindle (1) having a supporting portion (2) and being rotatably supported by the machine tool body (3), and a tool holder (5) having an inserting portion (6) attached to the supporting portion (2). A coating layer (10) made of a hard material including titanium is provided on the supporting portion (2) of the spindle (1) and/or the inserting portion (6) of the tool holder (5).

Abstract: This invention relates to a pallet changer suitable for use with a machine tool. When exchanging pallets, the pallet changer employs a drive means 3 for driving a table 2, and a transfer means 12 comprising a chain 66 and sprockets 64, 65. The transfer means 12 is driven by the drive means 3, and the pallet 4 is moved in the same direction as the table 2.

Abstract: A pallet changer includes a support, a table movable on the support along one direction, a plurality of pallets for holding a workpiece, a drive mechanism for moving the table, a transfer device for moving the pallet along the one direction relative to the table. The transfer device comprises a pinion shaft rotatably mounted on the table, the pinion shaft having sprockets at opposite ends thereof and a pinion at an intermediate portion thereof, a rack member movably mounted on the support, a rack displacing member mounted on the support for moving the rack member between a first position wherein the rack member can engage the pinion and a second position wherein the rack member can disengage the pinion, counter sprockets rotatably mounted on the table each cooperating with the sprocket of the pinion shaft, chains each placed between the sprocket and the counter sprocket, and an engaging mechanism for detachably engaging the chains and the pallet.

Abstract: A machine tool has a machine tool body, a spindle attached to the machine tool body for holding a tool, a bed provided on the machine tool body, and a table located on the bed for supporting a workpiece at a desired position and orientation so that the workpiece can be machined by the tool. The machine tool further includes a workpiece station for storing workpieces and a workpiece changer for moving the workpieces between the workpiece station and the table. The workpiece station is an endless conveyor having a series of setting openings located at regular intervals. Each workpiece is supported by a workpiece holder, and each of the workpiece holders are detachably set in one of the setting openings. A spring within each setting opening holds the workpiece holders.

Abstract: A pallet changer for a machine tool comprising:(a) a work station comprising a plurality of members which form holes for a plurality of pallets each having a workpiece, the members being arranged at predetermined intervals in an endless chain manner such that one of the members can be positioned at a predetermined position;(b) a table for the machine tool for mounting one of the pallets; and(c) a pallet transferor positioned between the workstation and the machine tool to exchange one of the pallets positioned at the predetermined position for the pallet mounted in the table, the pallet transferor comprising,(1) a first mover arranged to be movable in a first direction parallel to the arrangement direction of the pallets positioned in the predetermined position,(2) a swinger mounted with respect to the first mover, the swinger being rotatable at a predetermined angle,(3) a second mover for moving the swinger along a second direction perpendicular to the first direction,(4) a rotator operably arranged with the