| 摘要 |
<p>A window blind comprising a head rail, a bottom rail and a window covering extending between and operatively connected to the head rail and bottom rail. At least one lift cord extends between the bottom rail and the head rail. A spring motor operatively coupled to the lift cord applies an upward force on the bottom rail toward the head rail. A one way brake prohibits the bottom rail from moving toward the head rail but permits the bottom rail to be moved away from the head rail by an operator. <IMAGE></p> |
