| 摘要 |
PURPOSE:To facilitate fine adjustment by screwing a propelling lever onto a feed screw shaft and adjusting the interval between the pulley parts by driving said propelling lever. CONSTITUTION:One pulley part 1B is fixed onto a propelling lever 8, which is screwed onto a feeding screw shaft 7 and connected to an electric motor 12 through gears 9, 10 and 11. Therefore, when the propelling lever 8 is driven, it advances and retreats in the axial direction on the feed screw shaft 7, and the interval between the pulleys 1 can be adjusted finely and stably. |
