| 摘要 |
<p>The floor joist is partic. for house construction, and is formed by two U-sections (1, 2) spaced apart and with their arms facing away from each other. They are joined together by a bar or tube zigzagging (3) between their bases, and a wooden beam is fitted inside one or both U-sections. The zigzag bar or tube can be welded to the U-section base at its bends, and if a bar is used it can be of round section. The design allows a much greater gap to be spanned than with a plain wooden joist, while a wooden floor is still easily nailed to it.</p> |
