a paint sprayer is disposed substantially on the axis of an almost closed loop formed by a transporter . its axis of rotation is aligned so that the area in which the sheet of atomized paint it produces intersects the cylinder defined by the axes of the objects to be painted lies in an area contained between but reaching as far as circles delimiting the part - cyclindrical surface over which the objects move . an annular nozzle connected to a source of pressurized gas is disposed behind a rotating bowl of the sprayer so that an annular gas jet is directed onto the initial part of the thin sheet of atomized paint . the pressure of the gas fed to this nozzle is modulated periodically so that the aforementioned intersection area reaches the delimiting circles alternately and periodically .