| 摘要 |
A cordless cellular or pleated window shade having a head rail, a bottom rail and a pleated shade fabric therebetween uses a conventional spring tensioned roller shade bar for raising and lowering the shade without draw cords. A lead screw permanently affixed to an end cap of the head rail threadingly engages one end of the roller shade bar while the opposite end of the roller shade bar has a movable support locking the spring tensioner of the roller shade bar to the support to permit movement of the roller shade bar within the head rail. Lift cords wrap and unwrap themselves about the roller shade bar so that lowering of the shade tensions the spring which spring tension is then used to raise the pleated or cellular shade. The pitch of the lead screw forces the lift cords to wrap themselves about the shade roller bar in a singular, non-overlying manner while the roller shade bar moves within the head rail thereby assuring consistent alignment of the bottom rail with the head rail at any shade position.
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