| 摘要 |
The flap is moved by a spindle (4) carrying a gear wheel (1) half way along and with an external screw thread (20) each end, rotated by a pinion (18) driven by a d.c. motor (17). The flap has two hollow sections (8,9) enclosing the gearing, one section (8) carrying the motor and the other section (9) having an extension (10) guiding the spindle, the whole forming a nut and spindle drive, the gear wheel being internally threaded and acting as a nut. This nut carries two stops (2,3) projecting from its periphery and the spindle carries two stops (5,6). One stop (5) is at the end of the spindle and the other (6) is guided by a slot (7) along the spindle. The stops on the nut are smaller than the pitch of the screw thread.
|
