Rail for an architectural covering

1. A movable rail for a covering for an architectural opening, the movable rail comprising:

an elongated rail member comprising:

opposing first and second ends defining a length of said rail member in a lengthwise direction of said rail member;

opposing front and rear longitudinal edges defining a width of said rail member in a widthwise direction of said rail member that is smaller than said length;

a bridge member connected between said front and rear longitudinal edges in the widthwise direction;

a channel formed along at least a portion of said length of said rail member, said channel including a central channel portion and first and second channel portions separated from each other by said central channel portion;

first and second longitudinal ridges extending from said bridge member within said channel; and

first and second longitudinally-extending, opposing edge portions defining an opening of said channel that is positioned opposite said bridge member in a transverse direction of said rail member, the transverse direction extending perpendicular to the widthwise direction;

wherein said first and second opposed edge portions are spaced apart across said channel in the transverse direction from said first and second ridges to at least partially define said first and second channel portions of said channel relative to said central portion of said channel; and

wherein the front longitudinal edge extends in the widthwise direction a first widthwise distance beyond the first channel portion and the rear longitudinal edge extends in the widthwise direction a second widthwise distance beyond the second channel portion to define a point of maximum width of the elongated rail member in the widthwise direction, the first widthwise distance being greater than a first width of the first channel portion in the widthwise direction and the second widthwise distance being greater than a second width of the second channel portion in the widthwise direction, the point of maximum width arranged: (1) in a common horizontal plane with the first and second channel portions; and (2) between the bridge member and the opening in the transverse direction.

2. The movable rail of claim 1 , wherein said first and second channel portions define first and second parallel paths extending in the lengthwise direction along said channel.

3. The movable rail of claim 1 , wherein each of said first and second channel portions is substantially C-shaped in cross-section.

4. The movable rail of claim 1 , wherein said rail member is operable to be inserted within a cell of a shade, the shade comprising a cellular structure.

5. The movable rail of claim 1 , further comprising a shade material in which said rail member is inserted.

6. The movable rail of claim 4 , wherein said rail member includes a shape that substantially matches a shape of said cell.

7. The movable rail of claim 6 , wherein said cellular structure comprises a honeycomb structure and said shape of said rail member substantially matches the shape of said honeycomb structure.

8. The movable rail of claim 1 , further comprising an adjustment device positioned at least partially within said channel and adjacent one of said first and second ends of said rail member.

9. The movable rail of claim 1 , wherein said front and rear longitudinal edges include a material thickness greater than a material thickness of said bridge member to provide additional weight to said elongated rail member.

10. The movable rail of claim 8 , wherein said adjustment device is configured to adjust an effective length of at least one lift cord coupled to said adjustment device.

11. The movable rail of claim 8 , wherein:

said adjustment device includes a first adjustment mechanism and a second adjustment mechanism;

said first adjustment mechanism extends in the lengthwise direction within said first channel portion and said second adjustment mechanism extends in the lengthwise direction within said second channel portion.

12. The movable rail of claim 11 . wherein said first adjustment mechanism is separated from said second adjustment mechanism within said channel.

13. The movable rail of claim 11 , wherein said first and second channel portions are configured to support said first and second adjustment mechanisms, respectively, relative to said central channel portion for separate movement along at least a. portion of the said rail member.

14. The movable rail of claim 11 , wherein each of said first and second adjustment mechanisms is separately rotatable relative to said channel about a respective axis extending parallel to the lengthwise direction.