| 摘要 |
A carrier for a louver of a vertical venetian blind is disclosed for supporting a louver for rotation about its vertical axis and for transport along the headrail, which carrier includes a drive mechanism for rotating the louver about its vertical axis. The drive mechanism is disclosed as including a worm and a gear arrangement with a slip clutch disposed between the worm and the drive shaft. In one embodiment, the slip clutch comprises a slotted sleeve mounted on the drive shaft inside the hub of the worm, which sleeve has lugs positioned to engage a stop on the gear to effect the opening of its slot and reduction of its frictional contact with the drive shaft. In second embodiment, the worm itself frictionally engages about the guide shaft and has a slot along its length with the ends of the slot receiving wedge-like cams integral with rings loosely mounted on the drive shaft. Upon one carrier striking an adjacent carrier, the wedge-like cams widen the slot in the worm hub, thus reducing its frictional engagement with the drive shaft. |
