A closure cover and an extension ladder are provided. The closure cover includes an upper closure plate, a lower closure plate, and two airtight sheets, the upper closure plate and the lower closure plate are fixedly connected by a connector, the upper closure plate and the lower closure plate are each provided with ventilation holes, the airtight sheets are fixed to a surface of the upper closure plate facing away from the lower closure plate and a surface of the lower closure plate facing away from the upper closure plate, respectively, and the airtight sheets are capable of controlling the closing and opening of the ventilation holes.

A telescopically extendable and collapsible ladder assembly includes multiple collapsible ladder sections provided with an air damper at the bottom end of tubular stile members. The air dampers provide retardation of gravity induced velocity of the collapsible ladder sections upon collapse of the ladder sections. Multiple air dampers include a throttle valve securing device, for cooperating with a throttle valve of the air damper when the collapsible ladder section is in the collapsed position, to secure the throttle valve in its throttle position and/or an obturator device. The obturator device includes a first obturator member and a second obturator member where the first obturator member and the second obturator member are configured to, when the collapsible ladder section is in the collapsed position, in combination provide additional throttling.

A telescopically extendable and collapsible ladder assembly includes a top ladder section, a bottom ladder section, and one or more intermediate ladder sections. The assembly may include sliding automatic release actuators, having a slanted actuating surface for interaction with actuator surfaces of spacers provided at each end of a rung of an adjacent ladder section, such that, when a rung is moved towards the rung of an adjacent lower ladder section, the activation surfaces of the spacers push the release actuators into an unlocking position and subsequently position the rung at an anti-finger pinching distance. The top rung of the bottom ladder section may be provided with a centrally arranged grip element that forms a housing for manually operable release actuators provided at the bottom side of the rung.

A collapsible ladder includes two vertical stiles with rungs disposed therebetween. Each stile is formed by a plurality of telescopically collapsible columns. Each collapsible column has a bottom opening, an inner wall and a cover to cover the bottom opening. The cover has a small cylindrical portion and a large cylindrical portion with a peripheral surface located under the small cylindrical portion. The small cylindrical portion is inserted into the bottom opening of a column The large cylindrical portion is exposed outside of the column and inserted inside of a next lower column. A sealing ring is disposed inside a annular groove and touches the inner wall of the next lower column when the stile is extending or collapsing. One or more air ducts are provided in the cover. A first air opening iarranged above the large cylindrical portion in correspondence with an opening in a lower wall part of the column.

A collapsible ladder (10) is disclosed having rungs secured to telescopically collapsible stile sections and at least one stabiliser bar secured to the foot of the ladder, the (or each) stabiliser bar (12a, 12b) being displaceable between a storage position in which the bar lies, at least predominantly, between the two stiles and a deployed position in which the bar widens the footprint of the ladder to improve the lateral stability of the ladder. A rod (20) is connected to extend downwardly from the uppermost stile section of the ladder and a catch mechanism (30) is provided at the foot of the ladder to engage the lower end of the rod to prevent the ladder from being extended. The catch mechanism (30) is operable by the (or a) stabiliser bar to release the rod and permit the ladder to be extended only when the stabiliser bar is in the deployed position.

A buffer guiding structure for an extension tube comprises an inner tube, an outer tube, and a buffer member. The inner tube is slidably sleeved into the outer tube. The buffer member is provided at an end surface of one end of the inner tube. An edge of the buffer member engages with an outer edge of the inner tube and abuts against an inner wall of the outer tube, such that when the inner tube extends outwardly, the buffer member is scrolled downwards to reduce a friction force, and when the inner tube retracts inwardly, the buffer member remains slidably abutting against the inner wall of the outer tube, thereby realizing buffer function. The buffer guiding structure for an extension tube has a simple structure and good buffing performance, and can protect hands from being clamped.

A stretchable ladder, having inner leg bar and outer leg bar, the side edge of the outer leg bar forming an opening. The outer leg bar is sleeved on the inner leg bar, with the inner leg bar and the outer leg bar being relatively slidable. The ladder has a lock structure for locking the inner leg bar and for preventing the inner leg bar from separating from the outer leg bar. The lock structure is disposed at the outer leg bar, and is hookable to the inner leg bar, so as to make the inner leg bar embedded in the outer leg bar.

Embodiments include a telescoping ladder with a plurality of columns and rungs. The ladder can have a plurality of locking assemblies for locking adjacent columns to a rung thereby restricting relative sliding motion between adjacent columns. The locking assembly can have a locking button positionable against the rung front surface and rotatable with respect thereto between a locked position and an unlocked position. The locking assembly can have a locking pin positioned within the rung and slidable between an extended position and a retracted position along a locking pin axis generally perpendicular to the rotational axis. The locking assembly can have a connector pin extending in a direction parallel to the rotational axis, for connecting the locking button to the locking pin such that rotation of the locking button about the rotational axis slides the locking pin about the locking pin axis.

A rung for use in a ladder section of a collapsible ladder (1) is provided. The collapsible ladder comprises several ladder sections (5, 5a-5j), where each ladder section comprises two ladder tubes (10, 12) arranged parallel to each other and interconnected by the rung (20) to form the respective ladder section, and where each ladder tube (10, 12) is telescopically inserted into a ladder tube (10, 12) of a lower ladder section to form the collapsible ladder (1), the rung (20) comprising a main section (22), a first bracket section (24a) and a second bracket section (24b), wherein the first and second bracket sections (24a, 24b) are arranged at each end of the rung (20) to receive the respective ladder tube (10, 12). The rung (20) is characterized in that the main section (22) and the first and second bracket sections (24a, 24b) are provided as an integrated unit.

A ladder tube (10, 12) for use in a ladder section of a collapsible ladder (1) is provided. The collapsible ladder comprises several ladder sections (5, 5a-5j), where each ladder section comprises two ladder tubes (10, 12) arranged parallel to each other and interconnected by a rung (20) to form the respective ladder section, and where each ladder tube (10, 12) is telescopically inserted into a ladder tube (10, 12) of a lower section to form the collapsible ladder (1). The ladder tube (10, 12) is characterized in that it has a cross-sectional shape comprising at least one straight section (16) which at each end is connected at an angle larger than 90 degrees to at least one additional section (18) of the cross-sectional shape.