Jib arm for ships hull spray cleaner - is horizontally swivelable by actuator acting on double-pivoted linkage between jib and support

摘要

The mechanism is intended for swivelling a crane jib (37) or the like, e.g. such as is used for moving a spray head (7) with high-pressure nozzles (8) directing cleaning jets at the hull surface (12) of a ship in dry dock. The jib crane (37) is swivelable (about a vertical pivot) by at least one actuating cylinder (39) arranged between the arm and a frame (16) of a horizontally movable carriage (59). The cylinder acts on a double-pivoted linkage (38) between frame and arm. The linkage may comprise two members pivoted to frame and arm respectively and to one another whilst the trunnion- mounted actuator is pivoted to the member which is pivoted to the frame. An actuator-linkage assembly may be arranged to either side of the jib arm pivot.