Abstract:
A ladder including a first stringer and a second stringer spaced transverse from each other is provided. Each of the first and second stringers defines a channel and includes a plurality of crosspieces disposed in the channels of the first and second stringers. A plurality of rungs are spaced along and coupled between the first and second stringers. Each of the rungs has a horizontal portion and a vertical portion extending from the first stringer to the second stringer. A plurality of ribs are spaced along and coupled between the horizontal and vertical portions of the rungs.
Abstract:
A frictional weld joint couples first and second body portions of an article together. The frictional weld joint comprises a first bead extending from the first body portion of the article and a second bead extending from the second body portion of the article. The second bead has an interior stem and an exterior stem space from the interior stem defining a cavity therebetween. The first and second beads are placed in contact with each other with the centerline of the second bead offset from the centerline of the first bead. A force is applied to either the first or second body portions to generate friction between the first and second beads to plastically displace the first and second beads. The force is removed for fusing the first and second beads together to couple together the first and the second body portions of the article.
Abstract:
A frictional weld joint couples first and second body portions of an article together. The frictional weld joint comprises a first bead extending from the first body portion of the article and a second bead extending from the second body portion of the article. The second bead has an interior stem and an exterior stem space from the interior stem defining a cavity therebetween. The first and second beads are placed in contact with each other with the centerline of the second bead offset from the centerline of the first bead. A force is applied to either the first or second body portions to generate friction between the first and second beads to plastically displace the first and second beads. The force is removed for fusing the first and second beads together to couple together the first and the second body portions of the article.