| 摘要 |
PURPOSE:To eliminate an angle error and the wear of the points of contact by providing a first and a second roller on both ends of a lever respectively and setting the ratio between the diameters of said rollers to be equal to the ratio between the distances between the axes of said rollers and a rotary shaft. CONSTITUTION:Rollers 3', 4' are provided on both ends of a lever 1 which is rotatable around a shaft 2, and the ratio between the diameters of the rollers 3', 4' is determined to be A:B in the figure. Thereby when a movable piece 6 is moved from the outside, a movable piece 5 is moved by a quantity increased at a strictly equal ratio to the leverage, enabling an accurate increasing action to be carried out. Thereby an angle error can be completely removed. Furthermore, since the points of contact with the movable pieces 5, 6 are rotatable rollers, the wear of the points of contact can be prevented.
|
