| 摘要 |
PURPOSE:To simultaneously mold the connecting portion of a strip and a stair by extrusion molding a tread and a riser and by producing a stair in which nuts are buried at both end portions of through holes installed at the front and rear of the tread. CONSTITUTION:A flat-plate tread 1 and upright riser 2 are extrusion molded, and a stair 3 whose cross section has protruding portions 4, 5 is produced. Through holes 6, 6 are installed in the protruding portions 4, 5 in parallel to the front edge of stair 3, and a cylindrical nut 7, 7 is inserted and fixed to each end of the through hole 6, 6. The stair 3 is installed to a strip 9 by inserting a bolt 10 and screwing it into the cylindrical nut 7 for tightening. Thus, a stairway is constructed in such a manner. This enables mass production of stairs 3 which have uniform quality and good surface property. This method also can firmly fix the stairs to the strip. |
