Abstract: A chuck (1) for a tool which is attached to a clamped part (8) of the main unit (2) of the chuck, wherein a retainer (3) for holding a large number of needle rollers (32) around the clamped part and a clamping sleeve (5) are rotated to clamp and fix the tool in the attached state. The retainer is composed of four separate retainer parts (4a to 4d), and the separate retainer parts have a movement adjusting mechanism that allows the separate retainer parts to move to appropriate clamping positions. Movement of the separate retainer part located closest to the tip end of the retainer is limited.

Abstract: A microcomputer system is provided with a subroutine function. The microcomputer system includes a first timer, a first shifting unit, a second timer and a second shifting unit. The first timer operates to measure an actual execution time of a subroutine. The first shifting unit operates to sense that the measured execution time of the subroutine reaches a predetermined time, to the subroutine if sensed and shift the subroutine to the main routine. The second timer operates to measure an actual execution time of a main routine. The second shifting unit operates to sense that the measured execution time of the main routine reaches a predetermined time, to interrupt the main routine if sensed, and shift the main routine to the subroutine.

Abstract: A servomotor control device including a drive pulse generating circuit for generating a pulse signal having a frequency corresponding to an actual frequency of a servomotor, and arithmetic operation unit for outputting a control signal on the basis of the pulse signal for control of the servomotor. The arithmetic operation unit generates the control signal by implementing an extrapolation correction on the basis of preestimated variation of a frequency of the servomotor due to a time delay between a moment when the pulse signal is generated and a moment when the control signal is applied to the servomotor.