Patent attributes
A roller blind assembly includes a blind roller, a clutch assembly that includes a bracket engagement member, and a pre-torsioned spring assembly that includes a spring. The pre-torsioned spring assembly is positioned in an interior cavity of the blind roller, and exerts a torque proportional to a preset torsion of the spring to promote rotation of the blind roller relative to the bracket engagement member. Rotation of the blind roller relative to the bracket engagement member in a first direction decreases torsion in the spring while rotation of the blind roller relative to the bracket engagement member in a second direction increases torsion in the spring. The pre-torsioned spring assembly is preferably selected from a group of at least two pre-torsioned spring assemblies, each spring assembly having a different spring preset torsion.