Triangular beam for use in construction industry of central-stringer staircase, has stringer exhibiting round or square rectangular form, and walk supports made of sheet steel, where lower part of beam is formed at specific folding angle

摘要

The beam has a stringer for carrying steps of a staircase and made of metal or wood. The stringer exhibits round or square rectangular form, and the beam exhibits a triangular form, where a lower part of the beam is formed at a folding angle of 90 degree. The staircase exhibits a slope of 45 degree, and the beam is made of sheet steel, where a length of the beam is 3 mm according to a length of the staircase. Folds of the beam are formed as walk supports that are made of a triangular cut.