A door curtain anti-dropping device for a rolling door is provided. The device comprises a worm shaft connected to the output shaft of the door operator, and a drive shaft comprising a limiting disc with through holes. The worm wheel having receiving slots is fixed on the drive shaft to mesh with the worm. The driven wheel is disposed adjacent to the limiting disc. Baffle plates designed to cover the through holes and receiving slots extend from the driven wheel. Plural latching pins stored with spring potential energy are compressed by the baffle plates and retained in the through holes and receiving slots. When the worm wheel is excessively worn and dislocated from the driven wheel, the baffle plates are moved to allow the latching pins to spring out and insert into the notches of the front cover, thereby lock the worm wheel and prevent the winding shaft from rotating.

A door curtain anti-dropping device for a rolling door is provided. The device comprises a worm shaft connected to the output shaft of the door operator, and a drive shaft comprising a limiting disc with through holes. The worm wheel having receiving slots is fixed on the drive shaft to mesh with the worm. The driven wheel is disposed adjacent to the limiting disc. Baffle plates designed to cover the through holes and receiving slots extend from the driven wheel. Plural latching pins stored with spring potential energy are compressed by the baffle plates and retained in the through holes and receiving slots. When the worm wheel is excessively worn and dislocated from the driven wheel, the baffle plates are moved to allow the latching pins to spring out and insert into the notches of the front cover, thereby lock the worm wheel and prevent the winding shaft from rotating.

A door curtain anti-dropping falling device for a rolling door is provided. The device comprises a worm connected to the output shaft of the door operator, a drive shaft driving the winding shaft, a worm wheel having plural oblique elongated grooves and fixedly mounted on the drive shaft and meshes with the worm, a driven wheel having plural oblique elongated holes and is driven by the worm to move synchronously with the worm wheel, a limiting disk for restricting the driven wheel from moving axially, and plural latching pins extending through the elongated holes and received in the elongated slots. Under the normal operation of the door operator, the latching pins are retained in the center positions of the elongated holes and grooves. When the worm wheel are excessively worn and dislocated from the driven wheel, the latching pins lock the worm wheel and stop the winding shaft from rotating.

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.

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.

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 safety device for a window shade system comprising a shade tube having a first end mounted to a first bracket 100 and a second end mounted to a second bracket. The system also includes a first plurality of catchpins 110 mounted to the first bracket, wherein the first plurality of catchpins 110 are mounted below the first end of the shade tube. In response to the first end of the shade tube disengaging from the first bracket, the first plurality of catchpins 110 catch the first end of the shade tube and prevent the first end of the shade tube from further falling.

A safety device for a window shade system comprising a shade tube having a first end mounted to a first bracket 100 and a second end mounted to a second bracket. The system also includes a first plurality of catchpins 110 mounted to the first bracket, wherein the first plurality of catchpins 110 are mounted below the first end of the shade tube. In response to the first end of the shade tube disengaging from the first bracket, the first plurality of catchpins 110 catch the first end of the shade tube and prevent the first end of the shade tube from further falling.

In one aspect, a power assist module for covering for an architectural structure may include a spring and a spring shaft extending through the spring. Additionally, the power assist module may include a threaded shaft member coupled to the spring shaft and a follower member rotationally coupled to the threaded shaft member such that the follower member is moved axially along the threaded shaft member as the follower member is rotated relative to the threaded shaft member.