A suspension conveying device according to the present invention includes screw shafts of two suspension line pulling-up/feeding mechanisms in a conveying traveling body 1. The screw shafts have low-speed drive regions, in which feed pitches for driven bodies are small, and high-speed drive regions, in which feed pitches for the driven bodies are large. The screw shafts are installed so that the low-speed drive regions and the high-speed drive regions are disposed mutually oppositely as viewed from the driven bodies when a conveyed object supporter is at one end of an elevation/lowering stroke, and the conveyed object supporter is tilted in a middle of the elevation/lowering stroke when the screw shafts are driven to undergo forward/reverse rotation at a fixed speed by a motor.

A dip coating system having at least one dip-coating tank, which can be filled with a treatment fluid. A conveying system displaces the articles to the dip-coating tank, into the interior of the dip-coating tank, out of the dip-coating tank, and away therefrom. This conveying system has at least one trolley which has a fastening device for the article, which can be rotated around an axis of rotation. The trolley is drawn by at least one driven traction chain extending parallel to its movement direction. A rotating device having at least one sprocket or gear wheel that can be connected to the fastening device in a rotation-locking manner, that is arranged coaxial to the rotational axis of the fastening device, and at least one rotation chain or rotation gear rack, which extends parallel to the movement direction of the trolley, with which the sprocket or gear wheel cams.

An apparatus (1) for the surface treatment of the structure of a vehicle (V) by complete immersion in treatment baths contained in treatment tanks (2) comprises a plurality of trolleys (3) moved in a treatment path (P) by means of driver chain means (4), these trolleys can be selectively hooked in engagement with said chain drive means (4), are supported by opposite support and sliding guides (9) extended along said path (P) and have a portion (12) engaged with cam-slider-coupling with cam elements (11) arranged along said path (P) to determine a complete rotation of said trolleys around an axis of transverse rotation at said treatment tanks (2).