US Patent 10961777 Ladder tube for a collapsible ladder

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.