ANORDINATION FOR ALTERNATIVE AV AND ROOTABLE STRAOL AV HET GAS.

摘要

A device for producing a travelling jet of hot gas which travels in a direction transverse to the axis of the jet, partcularly for use in apparatus for erecting cartons wherein a heat activatable adhesive coating has to be heated at a particular location or locations while the cartons are conveyed continuously through the apparatus, comprises a fixed outer tube (25) formed with a longitudinally extending gas outlet or series of outlets (26, 38) and a rotatable inner tube (27) fitting closely with the outer tube and formed with a helical gas passage (28) communicating with its interior. Hot gas is supplied to the interior of the inner tube (27) which is rotated so that the point of coincidence of the helical gas passage with the outlet apertures moves longitudinally along the outer tube (25) so as to cause the hot gas jet to travel along the tube accordingly. In modifications, the rotatable tube may be the outer tube, or both tubes may be rotated.