| 摘要 |
<p>PROBLEM TO BE SOLVED: To easily install a stair, by providing a pair of right and left open strings formed of a plurality of stages of horizontal strips and vertical strips having a rise height and connecting the horizontal strips stepwise. SOLUTION: A steel plate with standard dimensions is cut by a laser to form a bamboo whisk-shape in which horizontal strips 12a and vertical strips 12b vertically arranged from one end of the horizontal strips are continuously connected, to form open strings 1a, 1b. The installation holes 14 of both ends of these open strings 1a, 1b and the holes 15 of the bracket in a steel frame are fastened with bolts to fix the strings to a building steel frame. Then, temporary treads 2a are placed on the horizontal strip 12a so that the threads of hook bolts 13 fixed to four holes 13a of the horizontal strip 12a can be inserted in the through holes 21a, 25a of temporary tread 2a and fastened with nuts 22 and fix the tread 2a and install a temporary stair. In this way, stepwise girders going up to the upper floor straight can be obtained by only bolting the upper and lower ends of the open strings 1a, 1b to the building side and hence, a stair can be easily installed.</p> |
