An extension ladder includes sub-ladders and cushions. Each sub-ladder includes a rung s connected to two tubes. The tubes of each sub-ladder are telescopically connected to the tubes of an adjacent sub-ladder. Each cushion includes an air bag and a slow-release unit. The air bag includes an open end with a channel. The air bag of each cushion is inserted in a corresponding tube. The slow-release unit is operable to slowly release air from the air bag and includes a restraint and a membrane. The restraint is connected to the open end of the air bag. The membrane includes an aperture and is movable arranged between the restraint and the open end of the air bag, with the aperture in communication with the channel.

An extension ladder includes sub-ladders and cushions. Each sub-ladder includes a rung s connected to two tubes. The tubes of each sub-ladder are telescopically connected to the tubes of an adjacent sub-ladder. Each cushion includes an air bag and a slow-release unit. The air bag includes an open end with a channel. The air bag of each cushion is inserted in a corresponding tube. The slow-release unit is operable to slowly release air from the air bag and includes a restraint and a membrane. The restraint is connected to the open end of the air bag. The membrane includes an aperture and is movable arranged between the restraint and the open end of the air bag, with the aperture in communication with the channel.

An access device is configured to be switched between a stored state in which an access member is stored in a vehicle body and a deployed state in which the access member is deployed. In the stored state, an exterior cover becomes a portion of the an exterior surface of the vehicle body and the access member is stored inside the vehicle body. In the deployed state, the access member extends from the vehicle body toward the a ground surface and the exterior cover is disposed on the a back side of the access member.

A telescopic pipe includes a base pipe having a base inner pipe rotated by external force, and a base outer pipe arranged to receive the base inner pipe; a connecting pipe having a connecting inner pipe coupled to the base inner pipe to be extendable to transfer rotational force, and a connecting outer pipe screw-coupled to the inner circumferential surface of the base outer pipe to be extendable; and a finishing pipe including a finishing inner pipe coupled to the connecting inner pipe to be extendable and to be rotated, and a finishing outer pipe that is interlocked by means of rotation of the finishing inner pipe and is screw-coupled to the inner circumferential surface of the connecting outer-pipe to be extendable, wherein the connecting outer pipe is interlocked by the rotational force of the extended finishing outer pipe and thus is extended and retracted along the base outer pipe.

An extension ladder having a base section having a first base rail and a second base rail in parallel and spaced relationship with the first base rail and rungs attached to and between the first and second base rails. The extension ladder having a fly section having a first fly rail and a second fly rail in parallel and spaced relationship with the first fly rail and rungs attached to and between the first and second fly rails. The fly section in sliding engagement with the base section. The extension ladder having a force applicator attached to the base section and the fly section which offsets some or all weight of the fly section. A method for using an extension ladder. A method for manufacturing an extension ladder.

An extension ladder having a base section having a first base rail and a second base rail in parallel and spaced relationship with the first base rail and rungs attached to and between the first and second base rails. The extension ladder having a fly section having a first fly rail and a second fly rail in parallel and spaced relationship with the first fly rail and rungs attached to and between the first and second fly rails. The fly section in sliding engagement with the base section. The extension ladder having a force applicator attached to the base section and the fly section which offsets some or all weight of the fly section. A method for using an extension ladder. A method for manufacturing an extension ladder.

According to the present invention, a ladder having an adjustable length comprises: a first support including a first outer support and a first inner support inserted into the first outer support; a horizontal foothold for connecting the first supports to each other; a first gear formed at the inner side of the horizontal foothold and having a groove part formed therein; a second gear engaging with the first gear and changing the rotational direction of the first gear; a rotary bar coupled to the second gear; a third gear formed at the end of one side of the rotary bar; a screw bolt having a fourth gear, which engages with the third gear and is formed at the end thereof, formed inside the first inner support, formed in a stick type, and having threads formed on the outer side thereof; and a screw nut in which the screw bolt is formed, and to which the first inner support is coupled at the outer side thereof.

According to the present invention, a ladder having an adjustable length comprises: a first support including a first outer support and a first inner support inserted into the first outer support; a horizontal foothold for connecting the first supports to each other; a first gear formed at the inner side of the horizontal foothold and having a groove part formed therein; a second gear engaging with the first gear and changing the rotational direction of the first gear; a rotary bar coupled to the second gear; a third gear formed at the end of one side of the rotary bar; a screw bolt having a fourth gear, which engages with the third gear and is formed at the end thereof, formed inside the first inner support, formed in a stick type, and having threads formed on the outer side thereof; and a screw nut in which the screw bolt is formed, and to which the first inner support is coupled at the outer side thereof.

A ladder rung accessory assembly includes first and second caps have a respective base that is shaped to cover respective rung openings of a selected rung of an extension ladder to reduce acoustic noise during transport. Each cap includes a guide member that is received in the respective opening to position the attached base. Channels formed through the bases and guide members are shaped to receive a cable tie passing through each cap and the selected rung. The first cap is held against the ladder by a head of the cable tie and the second cap is held against the ladder by an internal pawl locking mechanism of the second cap that ratchets against a toothed tape section of the cable tie.

A ladder rung accessory assembly includes first and second caps have a respective base that is shaped to cover respective rung openings of a selected rung of an extension ladder to reduce acoustic noise during transport. Each cap includes a guide member that is received in the respective opening to position the attached base. Channels formed through the bases and guide members are shaped to receive a cable tie passing through each cap and the selected rung. The first cap is held against the ladder by a head of the cable tie and the second cap is held against the ladder by an internal pawl locking mechanism of the second cap that ratchets against a toothed tape section of the cable tie.