Fluid sprinkling – spraying – and diffusing – With means fusing solid spray material at discharge means
Reexamination Certificate
2002-02-25
2004-06-01
Hwu, Davis (Department: 3752)
Fluid sprinkling, spraying, and diffusing
With means fusing solid spray material at discharge means
C239S080000, C239S081000, C239S083000, C239S525000, C239S526000, C239S290000
Reexamination Certificate
active
06742719
ABSTRACT:
BACKGROUND OF THE INVENTION
The concept of metalizing or electroplating a surface has been known for years and has proven useful in protecting metal surfaces from corrosion. Buildings, railroad cars, bridges and all kinds of industrial equipment are subject to damage from the elements and the resulting corrosion can shorten the life expectancy of metal surfaces considerably. By providing a protective metal coating on the surface of these types of equipment, corrosion can be inhibited and many more years of use for the structure or apparatus can be achieved.
The present invention relates to means for metalizing various surfaces with a thin layer of a metal for protection against corrosion and the elements and means for carrying out the metalizing process. More specifically, the present invention relates to electric arc spray metalizing devices in which a pair of metal wire tips are brought close to each other at an intersection point within a spray gun component of the device. Each of the metal wires is electrified and an electric arc is created between the wire tips which melts the wire tips. A jet stream of air or another gas is focused at the intersection or arcing point, and the air then atomizes the molten metal at the wire tips and blows the molten particles into a spray stream that eventually deposits the atomized particles onto the substrate. The type of wire used is dependent upon the type of substrate to be coated and the thickness desired. The metalized coating protects the substrate from various external factors.
The procedure generally followed in arc spray metalizing is to first sandblast the surface to be treated in order to prepare it for coating. This, together with the creation of airborne metallic particles from the spray metalizing procedure itself creates a considerable amount of dust, grit and other airborne particles in the working environment. These can become attracted to the charged wires through differences in polarity and can clog both the housing where the wire spools are kept as well as the hollow cables through which the wire is directed to the spray gun. Due to the electrical nature of the process, the operator is also susceptible to electric shock and unless the arc/atomization process is carried out with a symmetrical spray stream, uneven metal deposition may occur on the substrate surface.
U.S. Pat. No. 4,720,044 to Stemwedel teaches an electric arc spray metalizing apparatus in which wire feed drive means are enclosed in a pressurized housing which shields the drive mechanism and other interior elements from the dusty environment. The wires are guided to the atomization point by hollow wire cables and these also carry the electric charge necessary for atomization. The '044 patent to Stemwedel provides a good insight into standard electric arc spray metalization apparatus and is hereby incorporated by reference.
U.S. Pat. No. 4,078,097 to Miller also teaches a metallic coating process wherein the metalizing spray is conducted through two frustoconical sleeves. An orifice plate is contained thereon in the housing and is contained within the pathway of the metal spray. The spray is propelled by a jet air stream that passes through small holes in the two sleeves and the orifice plate. The spray is propelled through the sleeves and orifice plate with such force that the particles adhere to the substrate upon impact.
U.S. Pat. No. 3,818,175 to Essers et. al. teaches and discloses a welding torch comprised of a housing with a contact tube through which the welding wire and electric current are fed to the handle of a gun. The electrode tip is comprised of a metal such as tungsten that has a high melting point and high resistance to dentition.
U.S. Pat. No. 3,546,415 to Morantz teaches an electric spray metalizing device in which a pair of wires are advanced to an arc-forming station, the molten wires being atomized by a gas jet forcing the particles away from the station. The metalizing spray gun has a novel wire feed means whereby the wires are automatically retracted away from the arc a predetermined distance when the metalizing process is turned off. This enables the wires to become properly positioned once the process is re-initiated.
U.S. Pat. No. 3,062,451 to Keshane et. al, U.S. Pat. No. 1,940,814 to Saeger and U.S. Pat. No. 2,876,330 to Reinhardt all disclose known embodiments of electric arc metalizing spray guns in which two wires are fed to a particular point where an electric charge melts the wires and a jet stream atomizes the molten metal into particles. Electric current is fed through or in association with the tubes that carry the wire feeds. Both the electric currents and the two wire leads meet at the atomization intersection and are melted and blown by a jet stream of air that also intersects at the point and forces the molten metal particles in a direction towards the surface to be metalized.
Whereas performance by the devices known in the art might be considered satisfactory, there are many problems inherent in the devices and the processes by which they are employed. Wire feed tubes and the wire drum housing units have been known to clog with dust and grit from the workplace, causing malfunctions. The known devices are not truly capable of uniformly depositing large surfaces areas of metalization. The present invention provides a solution to this end by using greater electrical energy in order to sustain a higher energy arc for consuming larger diameter wires. These large electrical energy requirements must be transferred and contained safely within the system in order to be effective and none of the prior art devices demonstrate an ability to provide such power. Use of greater voltages increases the risk of electrical shock and the devices known in the art even do not properly protect the operator from the lower voltages utilized therein.
The present invention improves upon the electric arc metalizing devices known in the art by making substantial changes to some of the basic components comprising said devices. More specifically, the present invention comprises an improved electric arc metalizing gun wherein a greater amount of electricity may be utilized in order to melt larger diameter wire cables which can then be atomized and dispersed onto the surface area to be coated so as to provide a uniformly coated surface of greater thickness and/or area. The present invention further includes improvements to the wire feed tubes, wire drives, housing and welding leads so that e.g. the greater electrical energy is safely disposed and evenly generated to the arc. The present invention provides easier electric arc metalizing operation through the elimination of clogging problems by protecting the interior components from the intrusion of dust and dirt particles. Other improvements allow for quicker, easier service of the machines all of which result in greater operating efficiency as will be seen in the more detailed description that follows. The improved design is also capable of being powered by an AC inverter which disperses the electricity evenly on both negative and positive legs for improved and more consistent arc. AC power is inherently more dangerous than DC and existing technology cannot utilize AC power. Use of AC power is not even suggested by the prior art.
SUMMARY OF THE INVENTION
An improved electric arc metalizing device allows for the controlled dispersion of atomized metallic particles that covers greater, more uniform surface areas of the subject to be coated. The welding leads and wire feed cables are preferably all encased in a rubberized housing that prevents electric shock and crossover and thereby allows for higher levels of electric energy to be transferred through the conductive wires. Preferably, the electric cable runs completely through the welding lead itself so that a greater charge may be used to melt wire of greater diameters. A preferred more streamlined air block of the gun channels and directs the forced air flow in a more concentrated elliptical pattern that provides a more evenly dispersed an
Midgett Philip Mike
Tudor Carl Frazer
Hwu Davis
International Metalizing & Coatings, Inc.
Young & Thompson
LandOfFree
Twin wire electric arc metalizing device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Twin wire electric arc metalizing device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Twin wire electric arc metalizing device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3339395