Image Number 2 for United States Patent #4791703.
The present invention relates to a length adjustable center rod structure for a vertical shutter drape. The center rod is located in the inner side of an over-head track, and has two or more sections of telescoped hollow tubes so that the length thereof can be easily adjusted for length variations of the over-head track. The positioning of each hollow tube for the telescoping, is guided by a respective quasi-U-shaped, latitudinal, and straight trough provided on the tube wall. Each trough is also utilized for the reception of a downwardly protruding quasi-U-shaped tongue located on the sleeve axle inner surface sliding elements. When the center rod is rotated, it drives every shutter blade axle of the sliding elements to rotate via their respective sleeve axles.