US Patent 11339608 Adjustable spring system and method for roller blinds

A method for altering the spring constant (k) of a torsion spring for a roller blind, the method including (i) locating a dampener at a predetermined length along a longitudinal axis of the torsion spring, and (ii) tightening an end of the torsion spring against the dampener to increase the spring constant. Further disclosed is a roller blind system having a cylinder, a fabric attached to the cylinder for winding and unwinding from said cylinder, a torsion spring and a damper moveable along the longitudinal axis of the spring.