Roller blind with control apparatus

摘要

A control apparatus (100) for positioning and counterbalancing an amount of flexible blind material (110) wound onto or unwound from a rotatable shaft (108) of a windable covering such as a blind. The apparatus includes a main body (102) and a variable torque device, at least partially fitted within the main body, having means of achieving a variable torque to prevent rotation of the shaft (108) due to a variable weight of blind material (110) hanging from the shaft in any position between a wound position and an unwound postion of the blind material defining full travel of the windable covering.