| 摘要 |
PURPOSE: To obtain a strong clamping force without technical complicate structure, by changing an interval of clamping units by an amount equal to an extension of a piezoelectric transfer actuator by the actuator for coupling the units with one another to performs alternate clamping operations of the units. CONSTITUTION: Two clamping units 4a, 4b are engages with a bar 3. The units each has a yoke 5 having two rims 6, 7 and a base 8. A groove 9 is formed between the rims. The base 8 has a portion 10 of small section at a position of boundary arc 11. Two legs 12 are respectively provided at both sides of the arc 11. The legs 12 are fixed to a piezoelectric actuator 13. This actuator 13 can be elongated in a direction of an arrow 14. The actuator 13 can be pressed separately by the elongation due to electric energization. A clamp screw is provided at an extension member 18 of the rim 7, and arranged so as to be regulated with respect to the bar 3. |
