US Patent 7726673 Cast trailing arm assembly for trailer suspension

A trailing arm assembly for a suspension includes first and second axle wraps. The first and second axle wraps are welded to each other to substantially surround an outer perimeter of an axle member. The first axle wrap is then welded to one side of the axle member at a first weld area and the second axle wrap is welded to an opposite side of the axle member at a second weld area. The first axle wrap includes a spring seat and the second axle wrap includes an arm body with a bushing receiver portion at one arm end. A bushing tube attached to the bushing receiver portion. The first weld area comprises a single window weld and the second weld area comprises first and second window welds that are positioned on opposing sides of the arm body.