Spray coating device for electrically conductive coating liquids
AssigneeRansburg Corporation
InventorsAdolf H. Sonnleitner, Karl H. Bergmann
Life of this patent
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Abstract
A spray coating device includes a ring (14) surrounding a spray device (4) radially spaced and supporting at least one electrode (28). Gas flowing across the ring (14) and electrode transmits electrical charges from the electrodes to particles of atomized coating material, downstream from a spray head (6) of the spray device (4). The electrical charging of the coating material is considerably increased thereby.
Claims33
An electrode assembly for an atomizer, the atomizer including an atomizer axis along which material dispensed by the atomizer migrates toward an article to be coated thereby, a plane generally perpendicular to the atomizer axis, the location from which material to be atomized by the atomizer is dispensed lying generally in the plane, and the material dispensed by the atomizer being projected generally along the axis in a first direction away from a first side of the plane, the electrode assembly comprising an electrode holder defining a plane curve, a plurality of electrodes, the electrode holder holding the electrodes in spaced orientation to each other, the electrode holder including first and second surfaces inclined toward each other in the first direction toward the plane, means defining first openings therein on a side thereof facing in the first direction from a second side the plane opposite the first side thereof toward the plane, the first openings being spaced along the electrode holder, means providing a second opening or second openings in the electrode holder to direct a second stream or second streams of a gas or mixture of gases at superatmospheric pressure across the first surface, means providing a third opening or third openings in the electrode holder to direct a third stream or third streams of a gas or mixture of gases at superatmospheric pressure across the second surface, the second and third streams of a gas or mixture of gases encountering each other in the vicinity of the first openings, means for fixing the electrodes to the electrode holder with the electrodes extending into the first openings, means for supporting the electrode holder on the second side of the plane adjacent the atomizer with the electrodes extending in the first direction toward the plane and for substantially insulating the electrodes electrically from the atomizer, an electrostatic potential supply, means for coupling the electrodes to the electrostatic potential supply, and the electrode holder including means for feeding a gas or mixture of gases at low superatmospheric pressure to the first openings.
An electrode assembly for an atomizer, the atomizer including an atomizer axis along which material dispensed by the atomizer migrates toward an article to be coated thereby, a plane generally perpendicular to the atomizer axis, the location from which material to be atomized by the atomizer is dispensed lying generally in the plane, and the material dispensed by the atomizer being projected generally along the axis in a first direction away from a first side of the plane, the electrode assembly comprising an electrode holder defining a plane curve, a plurality of electrodes, the electrode holder including means for holding the electrodes in spaced orientation to each other, means for supporting the electrode holder on the second side of the plane adjacent the atomizer with the electrodes extending in the first direction toward the plane, means for coupling the electrodes to an electrostatic potential supply, means for substantially insulting the electrodes electrically from the atomizer, the electrode holder including first and second surfaces inclined toward each other in the first direction toward the plane, means providing a first opening or first openings in the electrode holder to direct a first streams or first streams of a gas or mixture of gases at superatmospheric pressure across the first surface, means providing a second opening or second openings in the electrode holder to direct a second stream or second streams of a gas or mixture of gases at superatmospheric pressure across the second surface, the first and second streams of a gas or mixture of gases encountering each other in the vicinity of the electrodes.
Spray coating apparatus with a spray device (4) featuring a spray head (6) which sprays the coating material through a spray cloud area (8) located downstream from it on the article to be coated, with an electroded arrangement (12) surrounding the spray device (4) while radially spaced from it and featuring at least one electrode (28) which is located upstream outside the spray cloud area (8) and serves the electrostatic charging of the atomized coating material, with a ring (14) supporting the electrodes (28), upstream outside the spray cloud area (8), a first gas channel (52, 78) in the ring (14), characterized in that at least a second gas channel (56, 66) is provided which passes the gas across outside surfaces (60, 68) of the ring (14) to its downstream end (16) facing toward the spray cloud area (8) of the atomizer (4), and in that the ring (14) has through the outside surfaces (60, 68) and the downstream end (16) a cross-sectional size which diminishes downstream, due to which the gas of the second gas channel (56, 66) is upon leaving the outside surfaces (60, 68), downstream from the end (16), mixed with the gas from the first gas channel (52) and flows together with this gas into the spray cloud area (8).
Dependencies are inferred from the claim text.