拨盘的结构如图所示:盘座2固定在车床主轴上(以止口d定位),爪座4与盘座可相对转动,而相对转动范围由限位钢球6控制。卡爪1用卡爪轴5固定在爪座4上,允许绕卡爪轴转动,卡爪的尾槽插进固定于盘座的拨销3上。在自由状态下,由于弹簧7的拉力作用使爪座顺时针方向转动,三只卡爪便自动松 The structure of the dial is as shown in the figure: the disk base 2 is fixed on the lathe spindle (positioned at the stop d), the claw base 4 and the disk base can rotate relative to each other, and the relative rotation range is controlled by the limit ball 6. The claw 1 is fixed on the claw base 4 by the claw shaft 5 to allow rotation about the claw shaft, and the tail groove of the claw is inserted into the pin 3 fixed on the base. In the free state, due to the pulling force of the spring 7 causes the claw base to rotate clockwise, the three claws are automatically loose