GB381618A - Extension ladder - Google Patents

Abstract

381,618. Ladders. MAGIRUS AKT.- GES., C. D. and HUMMEL, W. A., 1, Parkstrasse, both in Ulm-on-Danube, Germany. July 14, 1931, No. 20150. Addition to 380,541. [Class 20 (ii).] The side rails of the telescopic ladder described in the parent Specification are modified according to the present invention so that each comprises two hollow bars having a connecting portion which serves as a brace and which extends perpendicularly to the plane of the ladder. According to one construction, each side rail 21, Fig. 1, comprises two bars 22, 23 which are welded to the internal stiffening brace 24. The side rails of each upper section are guided by rollers 30 carried by the side rails of the section below, these rollers being journalled in bearings 31, 34 carried respectively by the side rails and brackets 34<1>. A further guiding means is provided by the overlapping engagement of the flanges 28, 29 of the side rails of adjacent sections. The brackets 341 are secured to extensions 32 of the tubular rings 33, which latter are welded to the side rails. Modified forms of side rails of somewhat similar section are also described. According to further modifications, the side rails are approximately S- or Z-shaped in cross section, one such construction comprising three hollow bars 67, 68, 69, Fig. 13, which are welded together, the part 68 constituting the central bracing. A still further form of side rail is shown in Fig. 15, in which two trapezium-shaped bars are welded to an internal brace. In this construction, the side rails 86 of the upper section are guided by rollers 84 mounted upon a rocking arm 80. This arm is carried by a bracket 81 secured to an extension of the rung 82 of the lower section. Similar rollers 90 mounted on rocking arms 87 are carried by the vertical stanchions 92 of the lower section and engage with an angle-section bar 91 secured to the section above.