Low-deflection roller shade tube for large openings

A roller tube for a motorized window treatment, the roller tube comprising:

• a first tube comprising aluminum or steel, the first tube having an outer surface and an inner surface, and defining a single cylindrical void delimited by the inner surface, wherein a plurality of splines extend radially from the inner surface into the void, the splines being oriented along a longitudinal axis defined by the first tube;
• and
• a second tube, concentric to the first tube, the second tube comprising carbon fiber additively constructed on an outer surface of the first tube, wherein the second tube comprises a plurality of layers of carbon fiber material including an innermost layer, an outermost layer, and at least two adjacent intermediate layers, wherein the innermost layer is bonded to the first tube, a first intermediate layer of the at least two adjacent intermediate layers is bonded to the innermost layer, a second intermediate layer of the at least two adjacent intermediate layers is bonded to the first intermediate layer, and the outermost layer surrounds the innermost and first and second adjacent intermediate layers, wherein the innermost layer and the outermost layer are each oriented such that fibers of the respective layers have the same alignment relative to the longitudinal axis of the first tube, and wherein fibers of the first and second adjacent intermediate layers have a same alignment, and wherein the alignment of the first and second adjacent intermediate layers is different from the alignment of the innermost layer and the outermost layer.

A method of reducing deflection of a roller tube for a motorized window treatment, the method comprising:

• providing a first tube comprising aluminum or steel, the first tube defining a single cylindrical void delimited by an inner surface of the first tube;
• additively constructing a second tube on an outer surface of the first tube, wherein the second tube is concentric to the first tube and comprises a plurality of layers of carbon fiber material including an innermost layer, an intermediate layer, and an outermost layer, wherein the innermost layer and the outermost layer are each oriented such that fibers of the innermost layer and the outermost layer have the same alignment relative to the longitudinal axis of the first tube;
• and
• curing the carbon fiber;
• and
• wherein the roller tube is configured to be supported only at its distal ends, has a length of at least ten feet along the longitudinal axis of the first tube, and an outer diameter that does not exceed two inches, and wherein a load from a weight of the roller tube and a weight of a covering material affixed to the outermost layer of the second tube causes the roller tube to deflect no more than one eighth of an inch from the longitudinal axis of the first tube.