Abstract: A lathe includes a spindle rotatable on a spindle axis, a tool post to which a tool is attachable, an X1-axis ball screw extended in an X1-axis direction perpendicular to the spindle axis and capable of moving the tool post in the X1-axis direction, and an X1-axis support bearing provided on an end of the X1-axis ball screw with respect to the X1-axis direction to restrict movement of the X1-axis ball screw in the X1-axis direction. The tool post is provided with an X1-axis ball screw nut engaged with the X1-axis ball screw. The X1-axis ball screw nut is movable in the X1-axis direction according to rotation of the X1-axis ball screw. The direction that the X1-axis ball screw nut approaches the X1-axis support bearing faces the same direction as the direction that the tool cuts into the workpiece.

Abstract: A lathe includes a spindle rotatable on a spindle axis, a tool post to which a tool is attachable, an X1-axis ball screw extended in an X1-axis direction perpendicular to the spindle axis and capable of moving the tool post in the X1-axis direction, and an X1-axis support bearing provided on an end of the X1-axis ball screw with respect to the X1-axis direction to restrict movement of the X1-axis ball screw in the X1-axis direction. The tool post is provided with an X1-axis ball screw nut engaged with the X1-axis ball screw. The X1-axis ball screw nut is movable in the X1-axis direction according to rotation of the X1-axis ball screw. The direction that the X1-axis ball screw nut approaches the X1-axis support bearing faces the same direction as the direction that the tool cuts into the workpiece.

Abstract: Component deformation or damage is prevented. A shutter device which moves in conjunction with momement of a moving unit in a predetermined direction comprises a first shutter which moves in the predetermined direction inconjunction with movement of the moving unit to cover part of an opening and a second shutter arranged between an end of the opening and the first shutter to expand and contract in the predetermined direction in conjunction with momement of the moving unit. The second shutter comprises a plurality of shutter plates overlapping each other, each of which having a first plate whose longitudinal direction is along the predetermined direction and a second plate whose longitudinal direction is along a perpendicular direction to the first plate. The second plate is provided with a coupling unit which couples the overlapping shutter plates in a manner that they can move in the predetermined direction relative to each other.

Abstract: In a packet transfer system, a transmission-side relay device extracts and integrates data included in a packet transmitted from a transmission device to obtain a packet data stream, extracts data from the packet data stream to obtain a data block, encodes the data block with an error correction code to generate redundant data as a redundant block, generates an error correction data stream obtained by integrating the data block and the redundant block, and packetizes the error correction data stream and transmits the packetized error correction data stream. A reception-side relay device restores missing data using redundant data included in the received data in a case in which there is missing data. The system enables packet transmission and reception to be efficiently performed even in a high loss rate environment.

Abstract: An object of the present invention is to enable packet transmission and reception to be efficiently performed even in a high loss rate environment. In a packet transfer system according to the present invention, a transmission-side relay device 20 extracts and integrates data included in a packet transmitted from a transmission device 10 to obtain a packet data stream, extracts data from the packet data stream to obtain a data block, encodes the data block with an error correction code to generate redundant data as a redundant block, generates an error correction data stream obtained by integrating the data block and the redundant block, and packetizes the error correction data stream and transmits the packetized error correction data stream, and a reception-side relay device 30 restores missing data using redundant data included in the received data in a case in which there is missing data.