| 摘要 |
PURPOSE:To rapidly correct the amount of wear of a brush and keep said brush in a proper position by using a conductive brush for a polishing brush, and bringing said brush into contact with a conductive reference body to electrically detect its position, and lifting up and down said conductive brush with the detected position as a reference. CONSTITUTION:A conductive brush 20 consists of a large number of nonconducting brush stocks 20b and a proper number of equally wear resistant conductive brush stocks 20a and, when this brush 20 has worn, if the lower end of the brush 20 is brought into contact with the surface of a conductive reference body 26 by means of a driving device 5, a circuit is formed via a spring ring 23, a conductor 25, the brush stock 20a, reference body 26 and a conductor 27, enabling a position to be detected by means of a switch 28. And, a screw 3 is rotated by means of the driving device 5, the indication of a lifting up-down quantity measuring device 29 is read with the contact position as a reference, and the amount of a set value is sent. Thereby, the position of the height of the brush 20 with respect to a workpiece is made proper to carry out accurate polishing. |
