PIVOTAL JOINTS AND LOCKING MECHANISMS THEREFOR

摘要

A lockable pivot joint for connecting elements such as main legs (10, 12) and bracing legs (16, 18) of a ladder and which may be mounted within a rung (14) comprises a shaft (32) rotationally fixed to one of the elements (16) e.g. by splining (at 40) and having locking means (28) adapted to make locking engagement with means (30) on another element (12) on axial displacement of the shaft, e.g. against a biassing spring (44) and caused by a screw engagement (at 34). The locking means (28, 30) may be friction surfaces eg with radial striations.