PURPOSE: To facilitate frame assembling by providing each beam with a hole for fitting a connecting rod, and forming the shape of this hole by two passing portions, one portion being slightly larger than the outer diameter of rod and the other being slightly smaller than the outer diameter of the same.

CONSTITUTION: To perform frame assembling, first beams 1 are arranged in parallel, and fixed to each other by a panel 2 fastened by a hook 3. Each beam 1 has a hole 4 composed of upper and lower portions 4a and 4b, the diameter of the upper portion 4a being slightly larger than the outer diameter of a rod 5, and the lower portion 4b being slightly smaller than the outer diameter of the same. The rod 5 is first inserted through the upper portion 4a of the hole 4, put through all the beams 1, and then pressed down to the lower portion 4b by a hammer. At this time, the rod 5 is passed in a narrow portion between the upper and lower portions 4a and 4b, but the rod 5 is passed therethrough by the elasticity of a tubular shape. Thus, a frame is assembled without any skills.