Patent Application
20070190263
This application relates to a method and apparatus for providing a coating on the interior surface of a non-cylindrical part, such as a faucet spout.
Electrophoretic coatings (e-coat) are known in the prior art, and are utilized with surfaces that will come into contact with fluids such as potable water. The coatings are intended to prevent leaching of metals from the surfaces of the component as the fluid passes through the components. This is especially true of components containing copper and lead.
Typically, the coatings have been applied in large baths. The coating material is put into the bath, and an anode/cathode creates a charge to cause the coatings to adhere to the surface of the metal component. Faucets would desirably have this coating, however, the use of the bath is undesirably complicated. Also, interior surfaces are not always adequately coated by such a bath.
It is also known to put the anode/cathode within the interior of the component, and coat only the interior of the component. However, known methods have typically been utilized for cylindrically shaped parts, such as cans. The known apparatus for coating a cylindrical part has utilized a relatively rigid anode extending along an axis parallel to the cylindrical part.
Thus, the coating of the inner surface of a faucet spout, or other non-cylindrical parts, has proven challenging. Moreover, faucet spouts, and potentially other components, have outer coatings for appearance purposes. As an example, a faucet spout may have a chrome plating on its outer surface. It may be desirable to have this plating put onto the faucet spout prior to the e-coat being applied. In such a situation, it would be necessary to keep the e-coat material from contacting any of the chrome-plated surfaces.
For all of these reasons, a method of simply coating the interior surfaces of non-cylindrical components is desirable.
In a disclosed embodiment of this invention, an anode has a non-linear shape. In disclosed embodiments, the anode is actually flexible such that it can bend to conform to the non-cylindrical shape of a component to be coated. In one embodiment, an electrode is received within the interior of a plastic tube, and the plastic tube has holes to allow the coating material to contact the electrode. As disclosed, a charge is applied once the electrode is inserted within the component, and such that the electrode is the anode. The component may be a faucet spout. In the disclosed embodiment, the component is grounded such that it provides a cathode. It should be understood that the component could be made the anode, and provided with a positive charge, and the grounded cathode be the electrode that is moved into the interior of the component to be coated. In fact, the internal electrode can be the anode or the cathode as needed, depending on the paint system used.
In various other embodiments, a plurality of cylindrical tube sections with spaced beads, spherical beads or bead-like members, which are non-conductive, may be utilized to surround the electrode and prevent contact with the conductive vessel being coated. In this embodiment, the cylindrical balls will be in point contact with the interior surface of the component. It is desirable to minimize contact between the electrode and cover assembly, and the interior surface to be coated. Each contact point is potentially a location where there would be no coating.
In another embodiment, the plastic tube is formed as a helical wrap around the electrode. Gaps between the wraps allow the coating to contact the electrode during charging.
In other features, the apparatus that holds the component, may be turned during the coating process. This will cause any entrapped air bubbles to shift, such that the location of the air bubbles will change and the entire surface will be coated.
In yet another embodiment, the electrode may be moved within the component during coating. This movement will ensure that any location of contact between the electrode and cover assembly and the interior surface will change such that no point within the interior surface will be in contact with the electrode and its cover during the entire coating process. This will ensure that the entire surface should be adequately coated.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
An apparatus 20 for coating the interior of a component such as a faucet spout 22 is shown in
An anode and protective covering assembly 26 is inserted within the interior of the faucet spout 22. Clamps 28 hold the faucet spout on the apparatus 20. Insert plug 30 is inserted at one end of the spout, and may have a drain 32 to a paint (e-coat) tank, and another drain 34 to a rinse tank. Another component 36 is positioned at the other end of the spout. A paint supply line 38 and a rinse supply line 40 may be placed at that end. These fluids flow within a housing component 42 including a seal 44. Paint is inserted into the faucet spout while the anode assembly 26 is within the spout. A charge is placed on the anode and the coating will occur. It is believed helpful for the paint to continue to flow during this process. Once the coating is complete, a rinse may flow within the faucet spout. The rinse may occur prior to the e-coat curing. While not shown, it is preferred that both the paint and rinse include a pump for moving the fluids through the faucet spout 22, and that the pumps pull the respective liquids from the tanks to which the lines 32 and 34 return. That is, the fluids are preferably flowing in a closed loop.
Air bubbles 122 may be within the faucet spout when the coating occurs. As known, the air bubbles will typically migrate to the vertically highest location. Thus, at some point during the component coating, the apparatus 20 is preferably moved to rotate about a pivot point P. As an example, a rotated position is shown at 120. In this rotated position, the air bubbles 122 were moved to a new point 222. If there was any area that was not coated due to the original location of the air bubbles 122, the new location of the air bubbles 222 will ensure that prior location will be coated.
The anode and protective sleeve assembly 126 is shown in
Although preferred embodiments of this invention have been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.
