| 摘要 |
<p>PROBLEM TO BE SOLVED: To simplify construction by fitting an intermediate support member on the end part or the side surface of a wall, and providing the intermediate support member with a bearing metal fitting where the wraparound inside end part of a tread in the wraparound part is placed and stopped. SOLUTION: Support plates 2a, 2b formed by thick board material, the upper ends of which are formed like a staircase, are fixed to both side surfaces 1a, 1b of a wall 1, and an intermediate support member 3 formed by a thick board material, the upper end of which is formed like a staircase, is fixed to the end face 1c of the wall 1. Bearing metal fittings 4a, 4b having an inverted-L shaped section are fixed to the side surfaces of the support plates 2a, 2b in such a manner that the upper ends are flush with the top surface of each step of the support plates 2a, 2b, and rectangular tread is placed and fixed on the bearing metals 4a, 4b. Further, bearing metal fittings 7a-7e are radially installed like a cantilever on the side surfaces of the intermediate support member 3 in such a manner as to be flush with each step part, and the end of the tread is placed and fixed on the bearing metal fittings 7a-7c. Accordingly, the tread can be supported with satisfactory strength.</p> |
