ROLLER MECHANISM:
A roller blind mechanism for winding and unwinding a roll able blind, the mechanism comprisinga support element, a drive sprocket which is rotatable mounted on the support element for transmitting rotational movement to a blind supporting member, and a manually-movable elongate flexible drive element which includes a plurality of interlinked tooth-engaging elements, the drive sprocket including a plurality of flexible teeth engagable with the tooth engaging elements of the flexible drive element. A roller blind mechanism as claimed in claim 1, wherein a radial extent of the teeth of the drive sprocket is equal to or greater than a maximum dimension of the tooth-engaging elements of the flexible drive element. A roller blind mechanism as claimed in claim 2, wherein the radial extent is equal to or greater than twice the maximum dimension of the tooth-engaging elements of the flexible drive element. A roller blind mechanism as claimed in claim 1, wherein the teeth of the drive sprocket flex in a circumferential direction of the sprocket.
Advantage
1:Pollution free power generation.
2:Low installation cost.
Disadvantage:
1:Maintenance will be very difficult.
2:Might cause collision