Abstract: An elevator installed in an elevator shaft has a cage, a counterweight, hoist cables suspending the cage and the counterweight, and a driving unit disposed outside a space in which the cage moves vertically in the elevator shaft, and provided with drive sheaves around which the hoist cables are wound to move the cage and the counterweight in the elevator shaft by the driving unit. The hoist cables are wound around the drive sheaves and sheaves supported on the cage and the counterweight in two-to-one roping arrangement such that the driving unit is at a level below the ceiling of the cage as located at its uppermost position. The cage-side sheaves are disposed at four positions on the lower portion of the cage respectively and symmetrically with respect to a center of gravity of the cage in a top plan view.

Abstract: An elevator installed in an elevator shaft has a cage, a counterweight, hoist cables suspending the cage and the counterweight, and a driving unit disposed outside a space in which the cage moves vertically in the elevator shaft, and provided with drive sheaves around which the hoist cables are wound to move the cage and the counterweight in the elevator shaft by the driving unit. The hoist cables are wound around the drive sheaves and sheaves supported on the cage and the counterweight in two-to-one roping arrangement such that the driving unit is at a level below the ceiling of the cage as located at its uppermost position. The cage-side sheaves are disposed at four positions on the lower portion of the cage respectively and symmetrically with respect to a center of gravity of the cage in a top plan view.

Abstract: A slip frequency type driving control apparatus includes a detector for detecting an input current and an input voltage to an induction motor, a calculating unit for calculating a rotor flux and a torque current of the induction motor, a neural network for outputting an excitation current command value and a slip frequency command value, and a vector control unit for performing vector control for the induction motor. The neural network receives a rotor flux command value, a torque current command value, a calculated rotor flux value, and a calculated torque current value, performs learning on the basis of a back-propagation law using signals output in correspondence with these inputs, and outputs an excitation current command value and a slip frequency command value.

Abstract: A positioning mechanism for wafers put in a container, wherein a notch is formed on the periphery of the wafer. The positioning mechanism includes a drive roller coupled to a drive source, an arm member, a first end thereof being fixed and a second end having a protrusion. The arm is elastically movable in the direction of the wafer surface, and the protrusion has a shape corresponding to the notch of the wafer. A transmission roller is supported between the first and second ends of the arm member. The axes of the drive roller and transmission roller are in the vicinity of the wafer so that the transmission roller is driven by the drive roller while the protrusion contacts with the periphery of the wafer outside the notch region. The transmission roller loses contact with the drive roller when the protrusion is engaged with the wafer notch.

Abstract: A wafer positioning apparatus includes at least first, second and third optical position detectors for detecting a circumference portion of a wafer. The first to third optical position detectors are arranged on a circumference of a circle having a diameter identical to that of the wafer. A transportation robot is used for holding the wafer and moving the held wafer with respect to the first to third optical position detectors. A control circuit controls the transportation robot in accordance with output signals of the first to third optical position detectors so that all of the first to third optical position detectors detect the circumference portion of the wafer at the same time.