Spring system for roller blinds

摘要

A roller blind including a roller of having a roller length and a roller outer diameter, a fabric attached to said roller for winding and unwinding from said roller. The fabric has a fabric length, a fabric weight, a fabric height, and fabric thickness. The blind includes a bottom bar having a bottom bar weight, and at least one spring operatively connected to the roller to drivingly rotate the roller in at least one direction of rotation. The spring is selected according to a Protocol such that it's length ensures that it drives the roller with a constant operating force.

主权项

1. A roller blind comprising
a roller; a fabric attached to the roller for winding about and unwinding from the roller; a stationary shaft extending inside the roller; at least one helically wound torsion spring arranged about the stationary shaft and operatively connected to the roller to drivingly rotate the roller in at least one direction of rotation; and an electric motor coupled to an end of the stationary shaft for drivingly rotating the roller in combination with the at least one spring, the motor having an output shaft on an end of the motor remote from the stationary shaft.