Telescopic tubular steel scaffold - uses reduced diameter sleeved head on outer tube with enlarged foot on inner tube to prevent axial separation

摘要

The height adjustable tubular steel support has the top edge of the outer tube (1) being bent inward (1a) so that the internal diameter (D1) is reduced to a value (DIa) nominally exceeding the external dia (D2) of the inner tube (2). Similarly the foot of the inner tube is enlarged until its external diameter (D2a) is nominally less than the internal diameter of the outer tube. A sleeve (3) is fixed to the head of the outer tube and may have an external screw thread fixed to the outer sleeve by a weld run (4) located by the channel formed by the inwardly bent lip (1a), and may stand proud of the outer sleeve by a fraction (La) of its length (L).