GB455542A - Stairs - Google Patents

Abstract

455,542. Staircases. MACDONALD, J. P., 228, Gloucester Street, Ottawa, Canada. Jan. 29, 1936, No. 2668. Convention date, March 16, 1935. [Class 20 (iv)] A staircase comprises a plurality of metal treads and risers adjustably connected together, each tread 1 having a flange 21 in engagement with a face of the adjacent lower riser 2, and each riser 2 having a flange 3 along its bottom edge in engagement with the upper face of the adjacent lower tread 1. The flange 21 of the tread 1 is secured by bolts 14 to the riser 2, and the flange 3 of the riser 2 is secured by bolts 4A to the tread 1. The relative positions of the risers and treads may be adjusted by providing slots 18, Fig. 2, in the risers 2, and slots 20, Fig. 4, in the treads 1 for the bolts 14, 4A respectively. The vertical faces of the risers 2 may be serrated or corrugated adjacent the slots 18 as shown at 19, Fig. 2, and the flange 21 of the tread 1 may be similarly formed to provide an interlock between these parts. Instead of providing slots 18, 20 in the risers and treads, the metal may be stamped to provide disc portions, any one of which may be knocked out to provide an aperture for the connecting bolt. The tread 1 is provided with a nosing formation above the flange 21. The vertical edges of the risers may be formed with flanges 7 which may be screwed to the stringers B. The treads may be formed with side flanges 5 which may be bent upwardly or downwardly for attachment to the stringers by screws. Downwardly-turned flanges 9 may also be formed at the sides of the tread beneath the nosing for attachment to the stringers. Each tread may be supported by a member 17 having a vertical flange 23, which is perforated to receive the bolt 14, and a horizontal flange 22 having a slot for engaging the bolt 4A. An angle 15 may be secured by the bolts 4A below each tread. A downwardly-turned flange 16 may be provided along the inner edge of each tread. The stringers may be of wood or metal, or they may be metal-covered. In certain cases, only one stringer need be provided, and only certain of the treads and risers need be secured to the stringer or stringers.