Patent ID: 9114520
Filing Date: 2015-08-25
Classification: B24B,B25F

Abstract:
1. A power tool comprising: a driving motor configured to output any number of output rotations; a spindle equipped with a front tool; a continuously variable transmission mechanism configured to seamlessly shift the number of the output rotations from the driving motor in any ratio and output the shifted number of the output rotations to the spindle; a rotational speed of the spindle changed by both the shifted number of the output rotations of the driving motor and a changed ratio of the continuously variable transmission mechanism; a low speed section of the spindle; and a high speed section of the spindle, wherein the rotational speed of the spindle in the high speed section is higher than the rotational speed of the spindle in the low speed section, reduction by the continuously variable transmission mechanism has priority over reduction of the driving motor when the rotational speed of the spindle is reduced in the high speed section, and the output rotations of the driving motor reduce the rotational speed of the spindle in the low speed section.