| 摘要 |
PURPOSE:To make it possible to obtain large clamping force by utilizing a speed reducing ratio resulting from the difference between the number of the teeth of gears by providing a chuck body with the first and second internal gears whose tooth numbers are different from each other at the outer periphery and pivotally supporting a planet gear meshing with both of the internal gears at a carrier. CONSTITUTION:The first and second internal gears 17 and 18 are rotatably arranged at the outer periphery of the rear section of a chuck body 11 with their internal teeth 19 and 12 arranged in parallel and with the head sides of the internal gears is mutually overlapping relation and extend to the outer periphery of a screw ring 15. The numbers of the internal teeth 19 and 20 are different from each other. The work of clamping force resulting from the contact of a tool 34 with a chuck jaw 12 generates the relative rotation between the internal teeth 19 of the internal gear 17 and a planet gear 21 resulting in the rotation of the planet gear 21. This rotate the internal gear 18, and rotation speed is much reduced due to the difference between the numbers of the teeth of the internal gears, which rotates the screw ring 15 with big torque in a clamping direction. The tool 34 can be, therefore, clamped and fixed with big torque. |
