GB404193A - Improvements in or relating to the construction of staircases - Google Patents

Abstract

404,193. Staircases. NORRIS, F. A., 11, St. Andrew's Hill, London. May 15, 1933, No. 14053. [Class 20 (iv).] A metal staircase is provided with the string- ors 10 formed of flat metal plates connected by angle-irons 14, 15 which are U-shaped in plan, as shown in Figs. 1 and 2, and extend between the stringers, each angle-iron being disposed at the junction between the front edge of one tread 11 and the upper edge of the adjacent riser 12. Each tread 11 is unitary with the riser 12 next above it and is of flat form. The side arms 14 of the angle-irons are secured by rivets or bolts 16 to the stringers 10, and the treads and risers are secured by bolts 17, 17a to the horizontal and vertical flanges respectively of the angle-irons. A supplementary tread 18 may be pre-cast or cast in position, and a channel-shaped nosing 19, Fig. 1, may be secured in position by the bolts 17a which connect the riser 12 to the corresponding angle-iron. An additional nosing 21 may be secured to the nosing 19 and the corresponding angle-iron, as shown in Fig. 4. A pre-formed tread 18 of artificial stone, wood, marble &c. may be rivetted or bolted to the tread plate 11 and, if desired, the lower portion of the riser may be curved to accommodate the end of such tread, as shown at 12a in Fig. 5. Angle-irons may be secured to the lower edges of the stringers to serve as a key for plaster applied to the underface of the staircase. Bannisters 22 and newels 23 may be arranged as shown in Fig. 1.