| 摘要 |
PURPOSE:To form clearance grooves at both ends of a shank of a work adjacent to the filler radius portions thereof without doing damage to the filler radius portions by employing a belt of abrasive cloth which is pressed by retainer pieces so as to form the clearance grooves. CONSTITUTION:In order to cut clearance grooves, both arms 2 are closed, and an abrasive cloth 7 is pressed into contact with both ends of a shank Wa of a work W by retainer pieces 6 with pressure applied from the backsides of the retainer pieces 6, and then the work W is rotated. Thus, both ends of the shank Wa are ground by the abrasive cloth 7. projections 6a which serve as abutments of the retainer piece 6 against the abrasive cloth 7 can be so thin as to have a width of about 2-3mm and form clearance grooves adjacent to filler radius portions Wb without overlapping them. Even if the side edge of the abrasive cloth 7 rides the filler radius portion Wb, pressing force is not applied so strong at this portion, that the hardened layer Wc produced by cyanide bathing or the like will not be eliminated. |
