| 摘要 |
PROBLEM TO BE SOLVED: To provide an indoor staircase capable of ensuring an attractive appearance and sufficient tread fitting strength.SOLUTION: The present invention relates to an indoor staircase in which a tread 3 is supported by a bridgeboard 2 through a tread fixture 4. An assembly groove 26 is formed at a fitting position of the tread fixture 4 on an upper surface of the bridgeboard 2. The tread fixture 4 comprises: a tread backing plate 5, which is roughly horizontally placed; and an inside downward piece 61 and an outside downward piece 65, which extend downward from the tread backing plate 5 and face each other. The tread backing plate 5 is fixed on an underside of the tread 3 through a tread fastening tool 11. The inside downward piece 61 is placed along an inside surface 23 of the bridgeboard 2, while the inside downward piece 61 is fixed on the inside surface 23 of the bridgeboard 2 through a beam fixing tool 13 with the outside downward piece 65 inserted into the assembly groove 26. |
