| 摘要 |
PURPOSE:To facilitate the manufacture of the title chuck and reduce the cost, by a method wherein a plurality of pawls are contacted to one surface of an annular piezoelectric oscillating piece while the pawls are pushed by a pushing member. CONSTITUTION:An ultrasonic chuck is constituted of a plurality of pawls 4-7, contacting with one surface of an annular piezoelectric oscillating piece 1 and arranged so that the tip ends 4a-7a thereof are faced to the direction of the center of the oscillating piece while the aft ends 4b-7b are provided with springs 8-11 to pull the pawls 4-7 outwardly at all times. In order to contact the pawls 4-7 with the piezoelectric oscillating piece 1 strongly, the pawls 4-7 are pushed by an annular pushing member 12. According to this constitution, a travelling wave is generated in the oscillating piece 1 whereby a member to be worked, which penetrates through the hole of the oscillating piece 1, may be fixed when an AC field is impressed on said oscillating piece 1 in the direction of the thickness or the diameter of the same. |
