Abstract: Provided is an endless operation cord that is easy to replace. The present invention provides an operation cord including: a main cord having one and the other ends; a first coupling part disposed at the one end; and a second coupling part disposed at the other end. The first and second coupling parts can be coupled together directly or via a coupling member and can be coupled or uncoupled by means of a relative rotation between the adjacent coupling parts or between the adjacent coupling parts and coupling member or a relative movement in a direction other than a length direction of the main cord between the adjacent coupling parts or between the adjacent coupling parts and coupling member.

Abstract: Provided is an endless operation cord that is easy to replace. The present invention provides an operation cord including: a main cord having one and the other ends; a first coupling part disposed at the one end; and a second coupling part disposed at the other end. The first and second coupling parts can be coupled together directly or via a coupling member and can be coupled or uncoupled by means of a relative rotation between the adjacent coupling parts or between the adjacent coupling parts and coupling member or a relative movement in a direction other than a length direction of the main cord between the adjacent coupling parts or between the adjacent coupling parts and coupling member.

Abstract: An improved winding apparatus for a roller blind is disclosed. The winding apparatus includes a clutch mechanism provided between the winding roller and the cord pulley for transmitting rotation of the pulley to rotation of the winding roller. The clutch mechanism is arranged to prevent the urging mechanism from rotating the winding roller when the cord is not handled. It also allows the pulley to rotate a predetermined angle in a screen lifting direction when the cord is operated to lift the screen. At this point, the urging mechanism is permitted to rotate the winding roller in the screen lifting direction. Additionally, when the pulley is rotated by the cord in a screen lowering direction the pulley is first allowed to rotate freely for a predetermined angle. Thereafter, the screen lowering motion of the cord is transmitted through said pulley to said winding roller to lower the screen.