| 摘要 |
PURPOSE: A stage for a ladder is provided to prevent transformation of the stage shape by increasing the strength. CONSTITUTION: A stage for a ladder comprises an upper plate(10), an edge part(20), and a support bar. The edge part comprises a front edge part(21) and a side edge part(22). A protrusion(24) is combined in support bar and formed on the side edge part. A concave groove(25) for reinforcing the intensity is formed on the edge parts. The concave groove is formed in order to pass back and forth through the protrusion.
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