| 摘要 |
PURPOSE:To aim at uniformly polishing a material to be polished, by providing two ultrasonic switches for controlling the sidewise movement of an abrasive material in a polishing device, to control a transverse drive means for automatically moving the abrasive material sidewise. CONSTITUTION:Ultrasonic switches 12, 13 are arranged at a predetermined space in the sidewise direction, corresponding to the movement of a sand paper 3, and therefore, the first ultrasonic switch 12 detects the right limit end of movement of the sand paper while the second ultrasonic switch 12 detects the left limit end thereof. A wood member 2 is moved in its longitudinal direction while the sandpaper 3 is rotated among three rollers 4a through 4c, and simultaneously, the sandpaper 3 is moved sidewise by a sidewise drive means. In this arrangement, when both switches 12, 13 are turned off, the sand papers are moved to the left, and thereafter the second switch 13 is turned on so that the sandpaper 3 is moved to the right. Thus, the sandpaper 3 may uniformly polish the wood member 2. |
