The preset invention relates to a gate with a crash-down prevention mechanism, comprising a gate panel which can be opened and closed by the rotation of a gate panel drive, a motor which is coupled to the gate panel drive, and a braking assembly with which opening and/or closing the gate panel can be decelerated, and a first measuring device for determining at least one movement parameter of the gate panel. In order to improve such a gate to the extent that a crash down of the gate can be reliably detected, and a braking assembly which brakes the gate quickly and avoids damage to the gate is triggered just as reliably, it is proposed to provide a second measuring device for determining at least one movement parameter of the motor, and a comparator which compares the measured movement parameters of the gate panel and the motor and triggers the braking assembly when the measured movement parameters of the gate panel and the motor fall outside of a defined relationship to each other.

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 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 blind lifting control module includes a transmitting wheel, an anti-backward unit and a driving unit disposed to a supporting unit. The transmitting wheel for connecting a blind reeled horizontal axle has a wheel ratchet portion meshable with a corresponding reel ratchet portion of a driving reel of the driving unit. The anti-backward unit has a torsion spring operable and deformable relative to the transmitting wheel. A pull cord is reeled on the driving reel and has a free end passing through a thrust member and a hindering member, and is pulled to shift the torsion spring to a released state to permit lowering of a blind. The thrust member is turned by pulling of the pull cord to thrust the driving reel to mesh with the transmitting wheel for lifting the blind.

A blind lifting control module includes a transmitting wheel, an anti-backward unit and a driving unit disposed to a supporting unit. The transmitting wheel for connecting a blind reeled horizontal axle has a wheel ratchet portion meshable with a corresponding reel ratchet portion of a driving reel of the driving unit. The anti-backward unit has a torsion spring operable and deformable relative to the transmitting wheel. A pull cord is reeled on the driving reel and has a free end passing through a thrust member and a hindering member, and is pulled to shift the torsion spring to a released state to permit lowering of a blind. The thrust member is turned by pulling of the pull cord to thrust the driving reel to mesh with the transmitting wheel for lifting the blind.

The present invention relates to a door descent preventing apparatus, and more particularly a door descent preventing apparatus mounted to a shaft installed at an inlet or an outlet of a chamber in a vertical direction in order to prevent descent of a door configured to be moved upwards and downwards along the shaft, the door descent preventing apparatus including a plurality of support bars, an upper fixing unit configured to connect upper ends of the support bars to each other, the upper fixing unit including a first upper fixing piece having a semicircular arc shape and a second upper fixing piece having a semicircular arc shape, and a lower fixing unit configured to connect lower ends of the support bars to each other, the lower fixing unit including a first lower fixing piece having a semicircular arc shape and a second lower fixing piece having a semicircular arc shape.

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 cam. The retrofitted door brake cam 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 cam. The retrofitted door brake cam 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.