A retractable barrier system for inhibiting access to designated private and public areas both indoors and outdoors, including by way of example but not limitation, retail and warehouse aisles and the like, includes a flexible screen retractable and extensible from a rotatable rod coupled to a mounting member, the mounting member having an attachment mechanism for coupling with a receiving member, wherein a winding mechanism is coupled to the rotatable rod for retractably receiving and extending the flexible screen, the flexible screen is comprised of material having a sufficient modulus of elasticity to promote substantially smooth retractably receiving thereof and may further include tapering between ends thereof, and the winding mechanism may include a guide member having a surface of sufficient diameter oriented substantially perpendicular to the flexible screen to guide the flexible screen upon retractably receiving the screen.

A slat system having a slat hanging with slats and a shifting apparatus for shifting the slats. The slats are intercoupled and movable from a closed position, in which broad faces of the slats are substantially flush in a plane and narrow faces of adjacent slats face one another, into an open position, in which the broad faces of the slats are parallel to one another but not parallel to an opening and closing direction, using the shifting apparatus to shift the slats in the opening and closing direction. The shifting apparatus has a pulling means coupled at one end to the slat hanging. The slat system has a first sheave mounted so as to be rotatable about an axis in two directions, to which sheave the other end of the pulling means is fastened, and a locking means to block the sheave from rotating in the open position.

A slat system having a slat hanging with slats and a shifting apparatus for shifting the slats. The slats are intercoupled and movable from a closed position, in which broad faces of the slats are substantially flush in a plane and narrow faces of adjacent slats face one another, into an open position, in which the broad faces of the slats are parallel to one another but not parallel to an opening and closing direction, using the shifting apparatus to shift the slats in the opening and closing direction. The shifting apparatus has a pulling means coupled at one end to the slat hanging. The slat system has a first sheave mounted so as to be rotatable about an axis in two directions, to which sheave the other end of the pulling means is fastened, and a locking means to block the sheave from rotating in the open position.

A cover for covering an opening defined in a surface, the opening defined between a first edge and a second edge, and defining an opening width therebetween, shorter than a length of the opening, the cover having a cover width and configured to be supported, in use, at the first edge and the second edge of the opening when the cover width is parallel to the opening width, wherein the cover width is adjustable from a first cover width to a second cover width, and wherein the cover is configured to maintain the cover width at the second cover width, in use.

A balance system used with a door of a cupboard comprises a transmission shaft, a first pulley on the transmission shaft, and a balance component. The first pulley is connected to a door belt, one end of the door belt is secured to the first pulley, and the other end of the belt is connected to the door. The balance component comprises a balancing member, a balancing belt and a second pulley on the transmission shaft. One end of the balancing belt is connected to the second pulley, and the other end of the balancing belt is connected to the balancing member, such that the balancing member is hung on the second pulley. The first pulley and the second pulley rotate synchronously, and the door belt and the balancing belt are wound oppositely. With the balance system, a small driving force can open/close the door.

An extendable arm structure includes: an upper extendable arm and a lower extendable arm which extend parallel in a same direction; and a vertical coupling member that couples the upper and lower extendable arms. Each of the extendable arms includes a plurality of X-shaped cross units each formed by pivotally coupling two rigid members via a middle coupling shaft, and two end coupling shafts that pivotally couple ends of adjacent ones of the cross units. The extendable arm structure further includes: a planar member that closes, in a planar fashion, a space between the rigid member of the upper extendable arm and the rigid member of the lower extendable arm which extends parallel to the rigid member of the upper extendable arm in a same direction.

An extendable arm structure includes: an upper extendable arm and a lower extendable arm which extend parallel in a same direction; and a vertical coupling member that couples the upper and lower extendable arms. Each of the extendable arms includes a plurality of X-shaped cross units each formed by pivotally coupling two rigid members via a middle coupling shaft, and two end coupling shafts that pivotally couple ends of adjacent ones of the cross units. The extendable arm structure further includes: a planar member that closes, in a planar fashion, a space between the rigid member of the upper extendable arm and the rigid member of the lower extendable arm which extends parallel to the rigid member of the upper extendable arm in a same direction.

An improved barrel bolt assembly and extensible gate comprising the same wherein the assembly includes a washer having at least one inward or outward projection annularly disposed about an internal periphery thereof, a fastener having a head portion and a shank portion extending therefrom, and a barrel having a head portion and a boss portion extending therefrom, wherein the boss portion is operative to receive the fastener shank portion and the barrel boss portion further includes at least one inward or outward projection annularly and complementarily disposed and formed with respect to the inner periphery of the washer, to receive and mate with the washer, whereby the washer and barrel interlock to prevent rotational movement with respect to each other.

A retractable barrier system for inhibiting access to designated private and public areas both indoors and outdoors, including by way of example but not limitation, retail and warehouse aisles and the like, includes a flexible screen retractable and extensible from a rotatable rod coupled to a mounting member, the mounting member having an attachment mechanism for coupling with a receiving member, wherein a winding mechanism is coupled to the rotatable rod for retractably receiving and extending the flexible screen, the flexible screen is comprised of material having a sufficient modulus of elasticity to promote substantially smooth retractably receiving thereof and may further include tapering between ends thereof, and the winding mechanism may include a guide member having a surface of sufficient diameter oriented substantially perpendicular to the flexible screen to guide the flexible screen upon retractably receiving the screen.

An improved barrel bolt assembly and extensible gate comprising the same wherein the assembly includes a washer having at least one inward or outward projection annularly disposed about an internal periphery thereof, a fastener having a head portion and a shank portion extending therefrom, and a barrel having a head portion and a boss portion extending therefrom, wherein the boss portion is operative to receive the fastener shank portion and the barrel boss portion further includes at least one inward or outward projection annularly and complementarily disposed and formed with respect to the inner periphery of the washer, to receive and mate with the washer, whereby the washer and barrel interlock to prevent rotational movement with respect to each other.