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, 5 a - 5 j ), 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.
1. A ladder tube for use in a ladder section of a collapsible ladder that includes several ladder sections, where each ladder section has two ladder tubes arranged parallel to each other and interconnected by a rung, and where each ladder tube is telescopically inserted into a ladder tube of a lower ladder section, wherein the ladder tube has a cross-sectional shape comprising:
only one straight section;
a first additional section connected to a first end of the straight section at an angle larger than 90 degrees;
a second additional section connected to a second end of the straight section at an angle larger than 90 degrees;
a third additional section connected to the first additional section;
a fourth additional section connected to the second additional section; and
a fifth additional section interconnecting the third and the fourth additional sections;
wherein the first, the second, the third, the fourth, and the fifth additional sections have convex shapes.
2. The ladder tube according to claim 1 , wherein the ladder tube is at least partly hollow.
3. A collapsible ladder comprising:
several ladder sections, each ladder section including
two ladder tubes arranged parallel to each other, and
a rung interconnecting the two ladder tubes;
wherein each ladder tube is telescopically inserted into a ladder tube of a lower section; and
wherein each ladder tube has a cross-sectional shape including
only one straight section,
a first additional section connected to a first end of the straight section at an angle larger than 90 degrees,
a second additional section connected to a second end of the straight section at an angle larger than 90 degrees,
a third additional section connected to the first additional section,
a fourth additional section connected to the second additional section, and
a fifth additional section interconnecting the third and the fourth additional sections;
wherein the first, the second, the third, the fourth, and the fifth additional sections have convex shapes.
4. The collapsible ladder according to claim 3 , wherein the rung of each ladder section comprises:
a main section;
a first bracket section arranged at a first end of the main section, and having an opening with the same shape as the cross-sectional shape of each ladder tube of the ladder section; and
a second bracket section arranged at a second end of the main section, and having an opening with the same shape as the cross-sectional shape of each ladder tube of the ladder section.
5. A collapsible stepladder comprising:
a first ladder leg; and
a second ladder leg hinge coupled to the first ladder leg;
wherein each ladder leg includes at least three ladder sections, each ladder section including
two ladder tubes arranged parallel to each other, and
a rung interconnecting the two ladder tubes;
wherein each ladder tube is telescopically inserted into the ladder tube of a lower ladder section; and
wherein each ladder tube has a cross-sectional shape including
only one straight section,
a first additional section connected to a first end of the straight section at an angle larger than 90 degrees,
a second additional section connected to a second end of the straight section at an angle larger than 90 degrees,
a third additional section connected to the first additional section,
a fourth additional section connected to the second additional section, and
a fifth additional section interconnecting the third and the fourth additional sections;
wherein the first, the second, the third, the fourth, and the fifth additional sections have convex shapes.