| 摘要 |
<p>The assembly has a connecting structure (7) engaging a baseplate. There is a rotary knob structure (2), an elongated rotatable platform (3) and a set of three gearwheels (4) meshed together. The gearwheels are all the same size. The central gearwheel (41) is directly connected to the rotary knob and is mounted over a hole (311) in the rotatable platform. The left gearwheel (42) and right gearwheel (43) are diametrically opposed and rotate in the same directions and move with the rotatable platform as it turns. There is a damping cover (6) over the gearwheels.</p> |
