Patent attributes
In one aspect, a spring assist module for a covering includes a torsion spring that is selected according to a protocol such that the torsion spring drives a driven part of the covering with a constant operating force. In another aspect, a roller blind includes a roller and a torsion spring operatively coupled to the roller, with the torsion spring having a spring characteristic(s) selected according to a protocol that matches the spring characteristic(s) to a torque curve associated with the roller blind to drive the roller with a constant operating force. In a further aspect, a method for selecting a spring for use within a roller blind includes determining a parameter(s) of the roller blind, determining a torque curve for the roller blind based at least partially on the parameter(s), and selecting a spring characteristic for a torsion spring of the roller blind that matches the torque curve.