A door operator comprises a rotary shaft, a chain disk for rotating the rotary shaft, and a locking mechanism for locking the rotary shaft. The locking mechanism comprises a bidirectional rotary block, a plurality of push pins and anti-rotation posts. When the chain disk rotates, the push pins urge the bidirectional rotary block to rotate the rotary shaft, and when the rotary shaft rotates, the of anti-rotation posts lock the bidirectional rotary block, and preclude the rotary shaft from rotating.

The present disclosure includes a retrofitted door brake. The retrofitted door brake may, in various embodiments, comprise a hub comprising a cylindrical central axle, a plurality of projections extending radially away from an outer circumference of the central axle, and/or a cam comprising a plurality of pins that hold the projections away from a channel wall of a brake housing. The pins may be configured to break away from the cam to release the projections into contact with the channel wall, and the pins may be fitted with a cover, such that the pins are capable of withstanding abrasion and wear. The cover may comprise a cylinder having an axially running aperture, and/or a beveled edge that shaves a layer of the outer surface from one of the plurality of pins as it is fitted over the pin.

A cord wrapping mechanism converts linear motion to circular motion for use in coverings for architectural openings. The cord is guided onto a spool.

A control structure for a window covering includes a base, a revolving wheel having an axial post, a restriction means including a bushing fitting around the axial post, a transmission member provided on a side of the bushing, and at least one pawl connected to the axial post. The revolving wheel is connected to the base. The restriction means has at least one cutting groove. The transmission member has at least one abutting portion on an inner wall thereof. The pawl is pivotable within a width of the cutting groove. When the revolving wheel is rotated forward, an end of the pawl passes through the cutting groove to mesh with the abutting portion. When the revolving wheel is rotated backward, the pawl disengages from the abutting portion, and the transmission member is rotatable relative to the revolving wheel. Whereby, it could prevent generating noise while operating the window covering.

A mechanical multiple torque damping device includes a support module, a spindle coupling sleeve and a damping cylinder. The support module includes a mounting seat, a tubular support axle extending from the mounting seat, a friction ring sleeved on the support axle, and a screw shaft extending through the support axle. The spindle coupling sleeve is rotatably sleeved on the support axle to support a horizontal spindle. The damping cylinder is axially displaceable along the screw shaft relative to the friction ring during rotation with the horizontal spindle. A cylinder body of the cylinder has inner frictional surface sections in frictional contact with the friction ring to generate multiple frictional torques to the horizontal spindle.

A window covering is provided according to the present application, to achieve automatic extending or retracting of a window covering curtain. The window covering includes: a rotating shaft for extending and retracting control, a wound sheet spring and a cord winding box. The extending and retracting of the window covering curtain is achieved by winding the curtain pull cord via the cord winding box, and the force transmission between the wound sheet spring and the cord winding box is achieved by gear transmission. A spring wound sheet is provided inside the wound sheet spring. One proper wound sheet spring is chosen according to the weight of the window covering curtain to allow the window covering curtain to maintain a balance state of force without under the effect of an external force, to fix the extending or retracting state of the window covering curtain.

A door includes a door leaf (1) with a vertical running direction and a drive (7) for opening and closing the door. A braking device (8) is provided, and this is configured such that the door leaf (1) cannot be moved in the closure direction solely by a weight force thereof, but only with the assistance of the drive (7).

A fenestration assembly includes a sash, a frame surrounding the sash, and at least one screen assembly mounted in at least one of: the top portion and the bottom portion. The frame includes a top portion, a bottom portion, and two jambs forming first slots extending lengthwise along at least a portion of the jamb. The first slots each include a screen edge retention feature. The screen assembly includes a roller assembly substantially hidden from view, a screen material attached to the roller assembly, and a plurality of raised features. Edges of the screen material extend into the first slots. The raised features are attached to each of the edges of the screen material. The raised features are configured to engage the screen edge retention features and retain each of the edges of the screen material at least partially within the first slot of each of the two jambs.

A window covering system comprises a shell, a weight member, a covering material positioned between the shell and the weight member, a control device. The covering material comprises at least one ladder, multiple slats corresponding to the at least one ladder, and at least one lifting cord, wherein the lifting cord is connected between the shell and the weight member. The control device comprises a driving module, a releasing module, and an operation module that are connected to each other. The ladder is connected to the operation module, and the lifting cord is connected to the driving module, such that the operation module drives the ladder to tilt the slats, at the same time, the releasing module is driven by the operation module to remove restriction to the driving module, hence descending the weight member.

A cord wrapping mechanism converts linear motion to circular motion for use in coverings for architectural openings. The cord is guided onto a spool.