CORDLESS RETRACTABLE ROLLER SHADE FOR WINDOW COVERINGS

摘要

A cordless retractable shade including an operating system for the shade that varies a biasing force of a spring to counterbalance the shade. The bottom rail of a retractable shade can be raised or lowered, and due to the operating system remains in any selected position of the covering between fully extended and fully retracted, without the use of operating cords. The system includes a method of negating and reversing the spring bias effect at a strategic position whereby the flexible vanes of the shade can be adjusted between open and closed.

主权项

1. A shade comprising:
a rotatable roller; a shade material attached to said roller for retraction or extension of said shade material; a non-rotatable shaft positioned at least partially within said roller; and a first connection member mounted on said non-rotatable shaft and keyed to said roller such that rotation of said roller translates said first connection member along a length of said non-rotatable shaft; wherein:
at an extended position of said shade material from said roller, mechanical interference between said first connection member and said shaft restricts movement of said roller in a retraction direction to restrict retraction of said shade material; androtation of said roller to retract said shade material disengages the mechanical interference between said first connection member and said shaft.