| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a spiral ladder and spiral stairs using the spiral ladder easily built up with simple constitution with a small number of components, and easily usable also for temporary work. <P>SOLUTION: The spiral ladder includes a post formed with a plurality of groove parts of substantially inverted T-shape cross section on the side face of a cylindrical body in the length direction of the cylinder; protrusions of cross-sectional shape corresponding to the groove parts and having a predetermined length; and simple stepboard parts of substantially fan-shaped plate shape formed to be right-angled to the length direction of the post and connected with the protrusions. The spiral ladder further includes stepboard fixtures for inserting protrusions in the groove parts from one end of the post to fix the simple stepboard parts into the optional positions of the side face of the post. A plurality of stepboard fixtures are fixed so as to be spirally arranged around the post to build up the spiral ladder. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
