Abstract: In an elevating mechanism 14 where an elevating mechanism 17 carried so as to rise and fall along a fixed surface 16 is moved up and down through a suspension member 18, a braking mechanism 18 is born by the elevating mechanism 17 so as to pivot vertically. A tensile spring 32 is provided on the braking mechanism 31, for pivotally urging it to the direction close to the fixed surface 16, while the suspension member 18 is connected to the braking mechanism 31, for pulling the braking mechanism 31 in the direction apart from the fixed surface 16 due to the weight of the elevating mechanism 17, in opposition to the tensile spring 32. When the suspension member 18 is cut off, then the braking mechanism 31 comes into contact with and digs into the fixed surface 16 by action of the tensile spring 32, so that the elevating mechanism 17 can be stopped from falling.

Abstract: The machine tool includes a column that can be moved back and forth. The column supports a spindle which is adapted to hold a tool for machining a workpiece at an end thereof. A worktable located in front of the column which is adapted to hold the workpiece. A back cover is located behind the column to prevent swarf of the workpiece from being scattered into a space behind the column. The back cover is arranged to move back and forth integrally with the column.

Abstract: The machine tool includes a column that can be moved back and forth. The column supports a spindle which is adapted to hold a tool for machining a workpiece at an end thereof. A worktable located in front of the column which is adapted to hold the workpiece. A back cover is located behind the column to prevent swarf of the workpiece from being scattered into a space behind the column. The back cover is arranged to move back and forth integrally with the column.

Abstract: In an elevating mechanism 14 where an elevating mechanism 17 carried so as to rise and fall along a fixed surface 16 is moved up and down through a suspension member 18, a braking mechanism 18 is born by the elevating mechanism 17 so as to pivot vertically. A tensile spring 32 is provided on the braking mechanism 31, for pivotally urging it to the direction close to the fixed surface 16, while the suspension member 18 is connected to the braking mechanism 31, for pulling the braking mechanism 31 in the direction apart from the fixed surface 16 due to the weight of the elevating mechanism 17, in opposition to the tensile spring 32. When the suspension member 18 is cut off, then the braking mechanism 31 comes into contact with and digs into the fixed surface 16 by action of the tensile spring 32, so that the elevating mechanism 17 can be stopped from falling.

Abstract: A steel has a tensile strength of 850 to 1700 MPa, a yield ratio of at most 80%, and a penetration border energy ratio of at least 2.0 relative to the penetration border energy of a reference steel JIS SS400 (corresponding to ASTM A36) of the same thickness. The steel can be produced by first effecting a heat treatment 1 on an unstable austenitic steel; then effecting, at least once, one or more or any combination of the heat treatment 1 and a heat treatment 2 on the steel; and then finally effecting the heat treatment 2 on the steel. Heat treatment 1 heats the unstable austenitic steel to at least the Ac3 transformation temperature and then water-cools the steel to a temperature below 350° C. Heat treatment 2 heats the steel to a temperature between Ac3 and Ac1 transformation temperatures and then water-cools the steel to a temperature below 350° C.

Abstract: A steel has a tensile strength of 850 to 1700 MPa, a yield ratio of at most 80%, and a penetration border energy ratio of at least 2.0 relative to the penetration border energy of a reference steel JIS SS400 (corresponding to ASTM A36) of the same thickness. The steel can be produced by first effecting a heat treatment 1 on an unstable austenitic steel; then effecting, at least once, one or more or any combination of the heat treatment 1 and a heat treatment 2 on the steel; and then finally effecting the heat treatment 2 on the steel. Heat treatment 1 heats the unstable austenitic steel to at least the Ac3 transformation temperature and then water-cools the steel to a temperature below 350° C. Heat treatment 2 heats the steel to a temperature between Ac3 and Ac1 transformation temperatures and then water-cools the steel to a temperature below 350° C.

Abstract: In an elevating mechanism 14 where an elevating mechanism 17 carried so as to rise and fall along a fixed surface 16 is moved up and down through a suspension member 18, a braking mechanism 18 is born by the elevating mechanism 17 so as to pivot vertically. A tensile spring 32 is provided on the braking mechanism 31, for pivotally urging it to the direction close to the fixed surface 16, while the suspension member 18 is connected to the braking mechanism 31, for pulling the braking mechanism 31 in the direction apart from the fixed surface 16 due to the weight of the elevating mechanism 17, in opposition to the tensile spring 32. When the suspension member 18 is cut off, then the braking mechanism 31 comes into contact with and digs into the fixed surface 16 by action of the tensile spring 32, so that the elevating mechanism 17 can be stopped from falling.

Abstract: A proximal end of a coolant nozzle is inserted into a large-diameter portion provided at an end of a shaft's coolant passage. The coolant nozzle is urged toward the distal end thereof, by a coil spring, and is prevented from coming out, by a stopper screw. Provided at the distal end face of the coolant nozzle is an O-ring, as a sealing member, that contacts to the periphery of an opening to a coolant passage of a tool holder. The O-ring may be easily replaced because the O-ring can be removed together with the coolant nozzle after the removal of the stopper screw.

Abstract: A closed-type cassette is mounted on a cassette stand disposed in a working region at a position corresponding to an opening formed in a wall separating the working region from a loading region. When the cassette is mounted on the cassette stand, a detecting device gives a signal to that effect to a controller. Then, the controller closes a valve to interrupt nitrogen gas supply into the loading region. A lid of the cassette is opened 20 to 30 sec after the interruption of nitrogen gas supply into the loading region and, then, nitrogen gas supply is resumed. The pressure difference between the loading region and the interior of the cassette is decreased by interrupting nitrogen gas supply into the loading region, so that the lid can be easily opened.

Abstract: A proximal end of a coolant nozzle is inserted into a large-diameter portion provided at an end of a shaft's coolant passage. The coolant nozzle is urged toward the distal end thereof, by a coil spring, and is prevented from coming out, by a stopper screw. Provided at the distal end face of the coolant nozzle is an O-ring, as a sealing member, that contacts to the periphery of an opening to a coolant passage of a tool holder. The O-ring may be easily replaced because the O-ring can be removed together with the coolant nozzle after the removal of the stopper screw.

Abstract: A wafer treatment apparatus is divided into a working zone (S1) and a loading zone (S2) by a wall (2). A closed wafer cassette(3) has a cassette body 31 having a bottom wall provided witha normally closed valve (5). A vent pipe (51) has one end part projecting from a cassette table (6) disposed in the working zone (S1) and the other end part opening into the loading zone (S2). When the cassette (3) is placed on the cassette table (6), the vent pipe (51) wedges through an incision formed in the valve (5) into the wafer cassette (3) to enable the interior of the cassette (3) to communicate with the loading zone (S2). Consequently, the pressure difference between the interior of the cassette (3) and the loading zone (S2) is reduced to naught.

Abstract: In an elevating mechanism 14 where an elevating body 17 carried so as to rise and fall along a fixed surface 16 is moved up and down through a suspension member 18, a braking body 18 is born by the elevating body 17 so as to pivot vertically. A tensile spring 32 is provided on the braking body 31, for pivotally urging it to the direction close to the fixed surface 16, while the suspension member 18 is connected to the braking body 31, for pulling the braking body 31 in the direction apart from the fixed surface 16 due to the weight of the elevating body 17, in opposition to the tensile spring 32. When the suspension member 18 is cut off, then the braking body 31 comes into contact with and digs into the fixed surface 16 by action of the tensile spring 32, so that the elevating body 17 can be stopped from falling.

Abstract: In an elevating mechanism 14 where an elevating body 17 carried so as to rise and fall along a fixed surface 16 is moved up and down through a suspension member 18, a braking body 18 is born by the elevating body 17 so as to pivot vertically. A tensile spring 32 is provided on the braking body 31, for pivotally urging it to the direction close to the fixed surface 16, while the suspension member 18 is connected to the braking body 31, for pulling the braking body 31 in the direction apart from the fixed surface 16 due to the weight of the elevating body 17, in opposition to the tensile spring 32. When the suspension member 18 is cut off, then the braking body 31 comes into contact with and digs into the fixed surface 16 by action of the tensile spring 32, so that the elevating body 17 can be stopped from falling.

Abstract: A closed-type cassette is mounted on a cassette stand disposed in a working region at a position corresponding to an opening formed in a wall separating the working region from a loading region. When the cassette is mounted on the cassette stand, a detecting device gives a signal to that effect to a controller. Then, the controller closes a valve to interrupt nitrogen gas supply into the loading region. A lid of the cassette is opened 20 to 30 sec after the interruption of nitrogen gas supply into the loading region and, then, nitrogen gas supply is resumed. The pressure difference between the loading region and the interior of the cassette is decreased by interrupting nitrogen gas supply into the loading region, so that the lid can be easily opened.

Abstract: Semiconductor wafers are transferred from a closed type cassette into a wafer boat. First, the lowermost five wafers of 13 wafers held in the cassette are simultaneously transferred by five arms from the cassette into the uppermost part of the wafer boat. Then, the lowermost three wafers among the wafers left in the cassette are simultaneously transferred by the upper three arms from the cassette into the boat immediately under the five wafers previously transferred. Further, the uppermost five wafers left in the cassette are simultaneously transferred by the five arms from the cassette into the boat immediately under the eight wafers previously transferred.

Abstract: An NC machine surrounded by a housing provided with a door on a front surface of the housing so that a workpiece may be loaded into the housing and unloaded therefrom when the door is in an open condition. An articulated robot, for replacing the workpiece, is provided so as to be laterally movable along an opening and closing direction of the door. Such a laterally movable function of the articulated robot permits a hand of the robot to grip a desired one of the workpieces arranged in lateral and longitudinal directions on a stock table. The articulated robot is provided with a sensor for detecting a dog provided on the door and an air cylinder for connecting the robot to the door when the dog is detected by the sensor. Accordingly, after the robot is connected to the door by the air cylinder, the door can be opened and closed by the lateral movement of the articulated robot.

Abstract: There is provided a low-temperature service nickel steel plate with excellent weld toughness. This steel plate consists essentially of not less than 0.03% of C, 0.02 to 0.22% of Si, 0.05 to 0.47% of Mn, not more than 0.005% of P, not more than 0.005% of S, 7.5 to 12.0% of Ni, 0.01 to 0.10% of Al, and the remaining of Fe, where the following relations stand 3.5%.ltoreq.(8Si+9Mn).ltoreq.5.1% and 123C+(8Si+9Mn).ltoreq.10.9%.