| 摘要 |
The shape of the beams (2-5) is achieved by rolling, and they have a central part. Also involved are two inner body parts running at right-angles to the beams, and two parts running outwards from the body parts. These outer parts are parallel to and displaced from the central part, and there are two outer body parts running at right-angles to the beams, each terminating in an inwardly or outwardly bent part. Each cross beam has its central part directed downwards, and each longitudinal beam has its central part directed upwards, so that the central parts of the beams are located by the side of each other during welding, to ensure a satisfactory weld seam. The longitudinal beams are bent to form feet of a U-shaped formation. |
