Patent ID: 7004404
Filing Date: 2006-02-28
Classification: B05B

Abstract:
1. An apparatus for spraying liquid surface treatment material, the apparatus comprising: a liquid inlet for supply of the liquid surface treatment material; a gas inlet for supply of pressurized gas to be mixed with the liquid surface treatment material; an outlet nozzle through which the gas and liquid surface treatment is sprayed; a control needle valve arranged for axial movement on a first axis and adapted to regulate the supply of the liquid surface treatment material to the outlet nozzle; a gas valve operable between an open position and a closed position; a gas chamber communicating with said outlet nozzle and arranged to co-axially surround the control needle valve; and a gas supply passageway connecting the gas inlet and the gas chamber; wherein said gas chamber has a first end portion adjacent the gas supply passageway, the first end portion having a radius of curvature so as to provide gas to the nozzle in a direction substantially parallel to said first axis, wherein the radius of curvature of the internal surface of the first end portion of the gas chamber is at least 1.3 times the diameter of the gas supply passageway.