A vertical blind has a headrail, a transmission shaft, a plurality of slats located below the headrail with a gap, a driving assembly, a first clutch, a first pushing component, and a light-blocking member configured to be driven by the first pushing component to move from a blocking position coving the gap to a non-blocking position revealing at least a part of the gap. When the transmission shaft is driven to rotate in a first direction, the first pushing component is moved toward the first end of a movable region. When the first pushing component has been moved to the first end of the movable region and the transmission shaft keeps being driven to rotate in the first direction, the first clutch prevents the transmission shaft from further driving the first pushing component, whereby the first pushing component stays at substantially the first end of the movable region.

A covering for an architectural opening has a dual cord operating system. The covering may include a head rail, blind panels depending from the head rail, and an operating system. The operating system may include a housing connected to the head rail, a first drive assembly rotatably mounted within the housing and operable to move the blind panels between an extended configuration and a retracted configuration, and a second drive assembly rotatably mounted within the housing and operable to move the blind panels between a closed configuration and an open configuration.

A tilt-control assembly for use with an operating mechanism of an architectural-structure covering is disclosed. The tilt-control assembly includes a limiter having an external screw thread and a ball operatively associated with the screw threads so that rotation of the limiter moves the ball relative to the limiter. The screw threads may include variable pitch threads. For example, the screw thread may include a middle thread pitch in a middle portion of the screw thread and an end thread pitch adjacent to the ends of the screw thread, the middle thread pitch being smaller than the end thread pitch. In addition, the limiter and/or screw threads may include a variable diameter. The ball may be positioned within a groove including a contoured surface that substantially corresponds to the variable diameter. The ends of the screw thread may include substantially spherically shaped end portions for receiving the ball therein.

A covering for an architectural opening has a dual cord operating system. The covering may include a head rail, blind panels depending from the head rail, and an operating system. The operating system may include a housing connected to the head rail, a first drive assembly rotatably mounted within the housing and operable to move the blind panels between an extended configuration and a retracted configuration, and a second drive assembly rotatably mounted within the housing and operable to move the blind panels between a closed configuration and an open configuration.

A multistate resistance adjusting device for a non-pull cord window blind includes a base, an adjusting unit, and an elastic member. The base has a bottom trough provided on the periphery thereof with positioning grooves. The adjusting unit has a control pin provided with a transmission portion rotatable and vertically movable on the base and a positioning portion provided on the outer peripheral surface of the transmission portion and connected with an adjusting rod. When the positioning portion is engaged with one of the positioning grooves, the control pin is disabled from rotating relative to the base and adjusting the resistance applied on the lift transmission cord. When the control pin is moved upwardly to separate the positioning portion thereof from the positioning groove, the control pin is rotatable relative to the base, and the resistance applied on the lift transmission cord is adjustable through the adjusting rod.

The present invention relates to a lamella blind system comprising at least one lamella element having: a screen body made of a membrane material; a first rotatable mount with a first clamp engaging a first end of the screen body; and a second rotatable mount with a second clamp engaging a second end of the screen body; wherein the screen body is clamped between the first and second rotatable mounts; wherein the screen body is loaded with a pre-determined tension applied in an axial direction parallel to the axis of rotation; and wherein the lamella element is rotatable about an axis of rotation defined by the first and second rotatable mounts; a first support structure supporting the first rotatable mount; a second support structure supporting the second rotatable mount; and a drive mechanism for controlling the rotational position of the at least one lamella element, wherein the drive mechanism is a single-ended drive mechanism acting on only one of the first and second rotatable mounts of the at least one lamella element.

A tilt-control assembly for use with an operating mechanism of an architectural-structure covering is disclosed. The tilt-control assembly includes a limiter having an external screw thread and a ball operatively associated with the screw threads so that rotation of the limiter moves the ball relative to the limiter. The screw threads may include variable pitch threads. For example, the screw thread may include a middle thread pitch in a middle portion of the screw thread and an end thread pitch adjacent to the ends of the screw thread, the middle thread pitch being smaller than the end thread pitch. In addition, the limiter and/or screw threads may include a variable diameter. The ball may be positioned within a groove including a contoured surface that substantially corresponds to the variable diameter. The ends of the screw thread may include substantially spherically shaped end portions for receiving the ball therein.

A covering for an architectural opening has a dual cord operating system. The covering may include a head rail, blind panels depending from the head rail, and an operating system. The operating system may include a housing connected to the head rail, a first drive assembly rotatably mounted within the housing and operable to move the blind panels between an extended configuration and a retracted configuration, and a second drive assembly rotatably mounted within the housing and operable to move the blind panels between a closed configuration and an open configuration.

A light blocking system is disclosed, which is adapted to be used in a vertical blind which includes a headrail, a control mechanism provided in the headrail, and a covering assembly including a plurality of slats. Each of the slats is connected to the control mechanism with an end thereof, and therefore is hung below the headrail. A gap is left between the covering assembly and the headrail. The control mechanism is adapted to turn the slats in situ relative to the headrail, or to move the slats back and forth in a longitudinal direction of the headrail. The light blocking system includes a cover plate provided corresponding to the gap, wherein the cover plate covers the gap when the covering assembly is in a closed state.

A covering for an architectural opening has a dual cord operating system. The covering may include a head rail, blind panels depending from the head rail, and an operating system. The operating system may include a housing connected to the head rail, a first drive assembly rotatably mounted within the housing and operable to move the blind panels between an extended configuration and a retracted configuration, and a second drive assembly rotatably mounted within the housing and operable to move the blind panels between a closed configuration and an open configuration.