| 摘要 |
The door is suspended from a fixed guide channel (6) by rollers running in the latter's interior. Opening effort is applied to the door by a smooth drive-roller bearing on a friction track (5) fixed along the door top; another such roller applies closing effort. Each roller is integrally connected, coaxially, with a toothed wheel (7) permanently meshed with a toothed driving wheel (2), mounted at a fixed point on the wall above the guide channel and rotated by a geared motor (2), in one direction to close and in the other to open the door. The driven wheels, with the associated rollers, are carried at the ends of a support bar (3), tilting about the driving wheel center. A weak friction coupling with the latter wheel causes the bar to tilt in the appropriate direction when the motor starts, bringing the corresponding drive-roller into contact with the door track. A short inclined toothed rack (9) engages with the driven toothed wheel as the door finally closes, re-aligning the support bar. The friction track is slotted to accept magnetic inserts required for end-of-travel sensors. |
