GB1201912A - Metal ladders - Google Patents

Abstract

1,201,912. Ladders. ALCAN RESEARCH & DEVELOPMENT Ltd. 15 Sept., 1967 [29 Sept., 1966], No. 43663/66. Heading E1S. A ladder comprises extruded aluminium alloy stiles and rungs wherein the stiles are hollow and each have interconnected webs 12 or non-interconnected flanges which extend towards the opposed stile, which webs or flanges are transversely slotted (Figs. 1, 2, not shown) to receive the ends of hollow rectangular, (Fig. 4, not shown) or inverted troughlike rungs (Fig. 3, not shown). The trough-like rungs have T-sectioned flanges 6, 8 (Fig. 3), and may be inserted between the non-interconnected flanges 3 (Fig. 1) with one portion of each flange 8 resting in a slot in the appropriate flange, the rung also being retained by blind rivets 9, (Fig. 5, not shown). The hollow rectangular rungs are slid into two slots at each end, with their side walls 19 lying outside the webs 12, in the embodiment shown, to which they are blind-riveted. The flange 3 (Fig. 6, not shown) may be interconnected at their bases. The upper wall, and if it is present the lower wall, of each rung may be externally serrated. Either rung section may be employed with any of the stile sections.