학술논문
Electrostatic spray coating gun
Document Type
Patent
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Source
Subject
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Abstract
An electrostatic spray coating gun for applying coating materials which have high to moderately high electrical voltage electrical system, improved hydraulic seals, and is adaptable to apply porcelain enamel coatings in slurry form. The gun has a flexible and resilient electrode in the form of an elongated coil spring. This form of electrode substantially eliminates the likelihood of scratching or puncturing the skin of an operator or repairman, and allows the electrode to return to its proper orientation after being bumped, while exhibiting proper paint charging characteristics for use in electrostatic spray coating. The electrode is positioned forward of a flat-fan spray nozzle and is displaced from the axis of the spray by means of an extension assembly which can be angularly displaced about the axis of the spray. The gun further incorporates improved packingless bellows sealing between an opening into the coating conduit in the barrel of the gun and a control rod for a needle valve in the conduit. Novel static seals allow the use of a bellows in the form of a non-machined extruded fluorinated hydrocarbon commonly known as TFE Teflon. The packingless seals, properly designed flow passages, the position of the charging electrode, and wear resistant to be used not only for the electrostatic spraying of the common electrically conductive coating materials, but also for abrasive coating materials, such as glazes, in slurry form.