| 摘要 |
<p>The mould is used in the mfr. of straight lengths of reinforced concrete stairway, providing for rapid adjustment of the dimensions of treads and risers. It uses slidably interconnected tread and riser formers which are attached in pairs to a stepped screw. A stiffened angle iron (3, 4) forms each tread and the succeeding riser, fixed to a secondary angle iron (8) forms a tread overhang whilst fixing to the succeeding tread plate. The connections are made by nuts to studs (14) or bolts (12) which traverse slots (9, 10) in the secondary angle iron. The tread connection also secures a channel section with a laminar tongue (6) at each end. Opposed tongues are linked and pinned (7) to nuts (17) mounted on fixed but rotatable stepped screw (20) operated by a hand wheel.</p> |
