| 摘要 |
The present invention in accordance with an aspect to achieve the purpose includes a pair of side boards formed on both sides; a plurality of rotation members fixed between the side boards in a horizontal direction; and a tread-board which is installed to be crossed between the rotation member and includes a plurality of horizontal boards, vertical boards, and bending parts formed in a single member. The rotation members are arranged in the bending parts of the tread-board to be able to rotate to disperse impact applied to the horizontal boards into the tread-board. The tread-board is included as a single member which is integrally formed and moves in one unit. Therefore, the present invention may offset the impact and reduce vibration applied to the stair. |
