A top-down bottom-up window covering has a headrail, a middle rail, a bottom rail, a lifting control structure installed at the headrail, and a covering structure installed between the middle rail and the bottom rail. The lifting control structure controls a first rotating shaft and a second rotating shaft to respectively receive or release a first cord and a second cord. The first cord drives the middle rail to move, and the second cord drives the bottom rail to move. A one-way clutch and a pre-stress unit are further provided at the headrail. When the bottom rail pushes the middle rail to move upward, the one-way clutch breaks a link between the first rotating shaft and the lifting control structure. Consequently, a driving force generated by the pre-stress unit immediately drives the first rotating shaft to receive the first cord to keep the first cord taut.

An opening/closing direction restriction mechanism for a manual shutter device and an opening/closing direction restriction mechanism for a suspended sliding door device This opening/closing direction restriction mechanism is provided with: a flange fixedly mounted on a fixed shaft; a bracket which is loosely fitted to the fixed shaft and can be integrally rotated with a winding member; and a two-way clutch which can be switched between a reverse rotation inhibited state in which the revolution of a planetary external gear along a winding direction of the winding member is allowed and the revolution of the planetary external gear along an unwinding direction is inhibited, and a forward rotation inhibited state in which the revolution of the planetary external gear along the winding direction of the winding member is inhibited and the revolution of the planetary external gear along the unwinding direction is allowed.

A method for altering the spring constant (k) of a torsion spring for a roller blind, the method including (i) locating a dampener at a predetermined length along a longitudinal axis of the torsion spring, and (ii) tightening an end of the torsion spring against the dampener to increase the spring constant. Further disclosed is a roller blind system having a cylinder, a fabric attached to the cylinder for winding and unwinding from said cylinder, a torsion spring and a damper moveable along the longitudinal axis of the spring.

A method for altering the spring constant (k) of a torsion spring for a roller blind, the method including (i) locating a dampener at a predetermined length along a longitudinal axis of the torsion spring, and (ii) tightening an end of the torsion spring against the dampener to increase the spring constant. Further disclosed is a roller blind system having a cylinder, a fabric attached to the cylinder for winding and unwinding from said cylinder, a torsion spring and a damper moveable along the longitudinal axis of the spring.

The present disclosure concerns cable-covering tube assembly for a roller blind actuation cable, comprising a first cable-covering tube defining a cable-receiving cavity; and at least one tube connector extending at least partially in the cable-receiving cavity and comprising a cable-mounting portion couplable to the free end portion of the roller blind actuation cable; and a coupling portion couplable to the coupling portion of a similar tube connector. It also concerns a cable-covering tube system and a roller blind actuation assembly comprising first and second roller blind-operating systems having each a driving assembly and a unidirectional angular coupler, and a biasing member operatively coupling the driving assemblies and extending between their respective unidirectional angular couplers

The present invention provides a cordless blind apparatus that can be conveniently operated without a cord. The cordless blind apparatus includes: a roller that is fitted on a rotary shaft; a screen that is wound or unwound on the roller; a weight that is connected to the lower end of the screen and applies torque in a first direction in which the screen is unwound from the roller by the gravity; an elastic member that applies torque in a second direction in which the screen is wound, by applying elastic force to the roller; and a friction stopper assembly that generates friction force on the roller.

A position-fixing system includes a pole, a guiding member adjacent to the pole, and a movable member fitting around the pole. The pole is immovable relative to a window covering. The guiding member includes a principal axis parallel to an extension axis of the pole, and includes a retaining face substantially extending in the direction of the principal axis, but non-coplanar with it. The movable member corresponds to the retaining face. The movements of the movable member and the guiding member are related to that of a shaft of the window covering. When the window covering is being operated, the movable member is driven to rotate around the pole, and moves along the pole and the guiding member. Due to the retaining face, the movable member keeps contacting the pole to create a friction therebetween. Therefore, the position of a covering material of the window covering can be precisely fixed.

A position-fixing system includes a pole, a guiding member adjacent to the pole, and a movable member fitting around the pole. The pole is immovable relative to a window covering. The guiding member includes a principal axis parallel to an extension axis of the pole, and includes a retaining face substantially extending in the direction of the principal axis, but non-coplanar with it. The movable member corresponds to the retaining face. The movements of the movable member and the guiding member are related to that of a shaft of the window covering. When the window covering is being operated, the movable member is driven to rotate around the pole, and moves along the pole and the guiding member. Due to the retaining face, the movable member keeps contacting the pole to create a friction therebetween. Therefore, the position of a covering material of the window covering can be precisely fixed.

A roller shade assembly includes a roller tube including a first end opposite a second end, the roller tube defining an opening longitudinally extending between the first and second ends, and an idler assembly partially received by the opening at the first end, the idler assembly including an idler housing, a plunger received by the idler housing, and a biasing member configured to apply a biasing force onto the plunger, wherein the plunger is configured to slide relative to the idler housing, and the plunger is configured to selectively engage a bracket member.

A non-return mechanism for a motor of an electric curtain is provided which comprises a motor and a gearbox that are successively connected; the output end of the gearbox is connected with a non-return component; the non-return component comprises a flange, an output shaft and a non-return block, the output end of the gearbox is provided with an output bracket; the output bracket is in unidirectional drive fit with one end of the output shaft toward the gearbox and they fit within the accommodating cavity; the output shaft and the non-return block, together with the unidirectional drive fit with the output bracket, a non-return force is effectively generated to steadily maintain the curtain at the required position when the motor stops without damaging the gearbox and the motor as the output shaft reversely drives the gearbox and the motor under the effect of an external force or gravity.