Patent ID: 8556059

Claim:
A roller blind clutch assembly for controlling the raising and lowering of a roller blind, the clutch assembly comprising: a roller tube mount coaxially and rotatably mounted to a barrel; a clutch member coaxially and rotatably mounted to the barrel between the roller tube mount and the barrel, said clutch member having a first window formed between a first and a second edge of the clutch member; a torsion locking spring having an outside diameter, said torsion locking spring being coaxially mounted to the barrel between the barrel and the clutch member, the torsion locking spring having opposite first and second ends projecting into the first window such that the first and second ends of the torsion locking spring are both between the first and second edges of the clutch member; the roller tube mount having an extension portion configured to extend into the first window, the extension portion having opposite first and second shoulders, the extension dimensioned such that the first and second shoulders both fit between the first and second ends of the torsion locking spring within the first window, and the extension portion having a concave face extending between the first and second shoulders, said concave face having a circular diameter less than the outside diameter of the torsion locking spring to form a gap between the extension and the torsion locking spring.