Abstract: A hard carbon film (15) is formed directly or through an intermediate layer for enhancing adhesion over an inner surface (11b) of a guide bush (11) for holding a workpiece (51) rotatably and axially slidable on an automatic lathe at a position near a cutting tool, to be in sliding contact with the workpiece (51) or directly or through an intermediate layer for enhancing adhesion on the surface of a superhard lining fixed to the inner surface (11b) The guide bush (11) has remarkably enhanced durability and prevents damaging the workpiece (51) and seizing that makes a machining operation impossible even when the guide bush (11) is used for an extended period of time and when the automatic lathe operates for heavy machining.

Abstract: A hard carbon film (15) is formed directly or through an intermediate layer for enhancing adhesion over an inner surface (11b) of a guide bush (11) for holding a workpiece (51) rotatably and axially slidable on an automatic lathe at a position near a cutting tool, to be in sliding contact with the workpiece (51) or directly or through an intermediate layer for enhancing adhesion on the surface of a superhard lining fixed to the inner surface (11b). The guide bush (11) has remarkably enhanced durability and prevents damaging the workpiece (51) and seizing that makes a machining operation impossible even when the guide bush (11) is used for an extended period of time and when the automatic lathe operates for heavy machining.

Abstract: A rotary grinding machine comprising a grinding wheel supported by a column on a bed, a work table rotatably supported on the bed and carrying thereon a workpiece to be ground, a fluid passage holder located in a circumferential groove formed in the work table and having fluid pressure pockets connected to a fluid pressure source. The work table is inclined with respect to the grinding wheel when the pressurized fluid is selectively fed to the pressure pockets in a predetermined direction. The control method of the grinding machine is also disclosed.

Abstract: A rotary table unit having a stationary base element and a table element rotatably mounted on the stationary base element is provided with hydrostatic and hydrodynamic bearing guides forming a composite bearing guide mechanism for enabling smooth and stable rotation of the table element under application of local load to the table element. The rotary table unit is also provided with a main drive motor for rotating the table element and an auxiliary drive motor for supplementing a drive force of the main drive motor in response to a change in load applied to the table element.

Abstract: A table mechanism comprising two hydrostatically coupled tables, a main table and an auxiliary table, in which after clamping the main table, the gaps in the hydrostatically coupling portions of the tables are adjusted so as to position the auxiliary table precisely.

Abstract: A hydrostatic pressure XY table comprising first and second sliding tables mounted on a bed. The two sliding tables are driven perpendicularly to each other by separate motors through a first lead screw supported on the bed and a second lead screw supported on the first sliding table. The bed has a first trapezoidal groove and the first sliding table has a second trapezoidal groove running perpendicular to the first trapezoidal groove. The first sliding table is engaged with the first trapezoidal groove and the second sliding table is engaged with the second trapezoidal groove. Four hydrostatic pressure guides are provided in the bed, to engage with engaging surfaces of the first sliding table. Four hydrostatic pressure guides are also provided in the first sliding table to engage with engaging surfaces of the second sliding table. A plurality of fluid pressure lines are provided for supplying hydrostatic pressure to the engaging surfaces of the first and second sliding tables.

Abstract: A system for correcting the position of a spindle of a processing machine, in which the spindle is rotatably mounted by hydrostatic bearings in a table on a bed and has an axial hole. A reflector is provided in the hole at a tip end portion, an interferometer is provided adjacent the other end of the spindle opposite the reflector, and a laser unit is provided for emitting a laser beam to the reflector and receiving the reflected laser beam through the interferometer and for producing an output signal dependent on the position of the tip end portion. The output signal is compared with a reference value and the spindle is shifted in accordance with the comparison so as to correct the displacement of the tip end of the spindle caused by thermal expansion.

Abstract: A grinding machine comprising a tool mounting head which is movable vertically between a pair of guide columns on which guide surfaces are provided for guiding the head. A plurality of workpieces are mounted on corresponding holding jigs which are mounted by means enabling them to be tilted, and measurement means such as X-ray or optical means are provided to sense the orientation of a workpiece being machined, with signals from the measurement means controlling the tilting of the corresponding holding jig. Jigs are mounted on a rotary table rotatably mounted on a workpiece slide which can be traversed below a grinding tool.

Abstract: A machine tool elevating and guiding apparatus comprising a tool mounting head which is movable vertically between a pair of guide columns. Guide surfaces on the guide columns are positioned closely adjacent to guided surfaces on the tool mounting head and a flow of pressurized fluid is passed at a fixed pressure between the guide and guided surfaces, such as to eliminate tilting of the tool mounting head. At least one guide surface serves as a reference surface, with a thin film of pressurized lubricating oil being formed between this and an adacent guided surface. The tool mounting head is mounted on an elevating feed screw, with means provided whereby the weight of the head is supported independently of that screw, so that a very high degree of precision in vertical positioning of the tool mounting head is attained.