| 摘要 |
PURPOSE:To control an aperture easily and exactly, by alternately turning 2 concentric frames for controlling a sector, as to an aperture mechanism of a microscope, etc. CONSTITUTION:A frame 3 turns through a pinion 7 turned electrically, a click spring 5 formed as one body with the frame 3 moves, and the aperture opening becomes large. Subsequently, a frame 1 turns with a pin 1b of the frame 1 being concentrical with the frame 3, through a slot 3b of the frame 3. As a result, a gear 1d of the frame 1, which has not been engaged with the pinion by a non- tooth part 1d' is engaged with the pinion 7, and as for a gear 3d of the frame 3, its engagement with the pinion is detached by a non-tooth pard 3d'. As a result, the frame 3 stops, the frame 1 provided with a click spring 4 turns, and the aperture is closed gradually from the maximum opening. By turning in one direction by alternate turning of said 2 concentric frames, the aperture is controlled easily and exactly. |
