| 摘要 |
<p>A blind control unit 10 has a chain sprocket (15, fig 2) rotatable about an axis and a chain guard 16 that is slidable in a radial plane with respect to the axis. It is slidable between an open position where a drive chain 24 may be engaged with the chain sprocket and a closed position where the drive chain is held in place on the sprocket. A latching element (42, fig 2) may releasably hold the chain guard in the closed position.</p> |
