Stringer connection for rectangular hollow section ladder rung - uses winged W=section shoe which clips into window and latches onto inserted rung end

摘要

The interlocking connection secures a rung (3) to the stringer (2) of a ladder, both members being of a rectangular hollow section or similar, and the connection utilising a rung end shoe (4) to combine wedge and spring clip retaining effects. A rectangular window (W) in the longeron wall locates the shoe which is of a winged (6) 'W' section, right angled triangular rib (5) cooperating with each wing (6) to provide a groove locating a window edge. The major faces of the rung have a longitudinal groove of shallow rectangular section and traversed by a transverse slot (8) adjacent to the rung end, the side having curtailed ribs (9) defining a spigot. Once the shoe is positioned in the longeron the rung end is slid into place transverse right angled triangular ribs (7) on the internal shoe walls locking into the rung slots (8) to secure the assembly.