US3734406A - Method and apparatus for producing a flat fan paint spray pattern - Google Patents

Method and apparatus for producing a flat fan paint spray pattern Download PDF

Info

Publication number
US3734406A
US3734406A US00167695A US3734406DA US3734406A US 3734406 A US3734406 A US 3734406A US 00167695 A US00167695 A US 00167695A US 3734406D A US3734406D A US 3734406DA US 3734406 A US3734406 A US 3734406A
Authority
US
United States
Prior art keywords
paint
nozzle
orifice
air
froth
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00167695A
Other languages
English (en)
Inventor
P Runstadler
E Nord
D Hastings
S Rosen
D Scarbrough
F Wilhelm
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nordson Corp
Original Assignee
Nordson Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nordson Corp filed Critical Nordson Corp
Application granted granted Critical
Publication of US3734406A publication Critical patent/US3734406A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
    • B05B7/02—Spray pistols; Apparatus for discharge
    • B05B7/12—Spray pistols; Apparatus for discharge designed to control volume of flow, e.g. with adjustable passages
    • B05B7/1209—Spray pistols; Apparatus for discharge designed to control volume of flow, e.g. with adjustable passages the controlling means for each liquid or other fluent material being manual and interdependent
    • B05B7/1245—A gas valve being opened before a liquid valve
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B1/00—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means
    • B05B1/34—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to influence the nature of flow of the liquid or other fluent material, e.g. to produce swirl
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B1/00—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means
    • B05B1/02—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to produce a jet, spray, or other discharge of particular shape or nature, e.g. in single drops, or having an outlet of particular shape
    • B05B1/04—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to produce a jet, spray, or other discharge of particular shape or nature, e.g. in single drops, or having an outlet of particular shape in flat form, e.g. fan-like, sheet-like
    • B05B1/042—Outlets having two planes of symmetry perpendicular to each other, one of them defining the plane of the jet
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B1/00—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means
    • B05B1/26—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means with means for mechanically breaking-up or deflecting the jet after discharge, e.g. with fixed deflectors; Breaking-up the discharged liquid or other fluent material by impinging jets
    • B05B1/262—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means with means for mechanically breaking-up or deflecting the jet after discharge, e.g. with fixed deflectors; Breaking-up the discharged liquid or other fluent material by impinging jets with fixed deflectors
    • B05B1/265—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means with means for mechanically breaking-up or deflecting the jet after discharge, e.g. with fixed deflectors; Breaking-up the discharged liquid or other fluent material by impinging jets with fixed deflectors the liquid or other fluent material being symmetrically deflected about the axis of the nozzle
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
    • B05B7/24—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas with means, e.g. a container, for supplying liquid or other fluent material to a discharge device
    • B05B7/2489—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas with means, e.g. a container, for supplying liquid or other fluent material to a discharge device an atomising fluid, e.g. a gas, being supplied to the discharge device

Definitions

  • ABSTRACT A method and apparatus for spraying a coating material such as paint, in a flat fan pattern.
  • a stream of paint under a relatively low pressure is caused to flow in an annular film.
  • Streams of gas at a slightly higher pressure are directed against the paint film so that the gas is sheared into microbubbles which are entrained in the paint stream to form a froth.
  • the froth flows through a chamber in which the bubbles disperse uniformly in the paint and is then discharged through a narrow slit nozzle effective to give it a fan shape.
  • the froth is released to atmospheric pressure, the microbubbles of air expand rapidly and rupture, causing the paint to disintegrate into finely atomized drops.
  • the apparatus includes a cooperating orifice plate and collar which define a thin annular paint flow channel; and a plurality of air in'ection channels which intersect the paint flow channel! A1r is introduced through these channels and is directed against the paint film.
  • the nozzle includes a hemispherical endwise portion provided with an elongated discharge slot.
  • a protuberance or ball is disposed within the nozzle and deflects the froth so that the froth passes through a relatively narrow passageway between the ball and nozzle.
  • a modified gun includes a conventional airless flat fan orifice; and does not utilize an internal ball.
  • This invention relates to a method and apparatus for spraying coating materials, such as paints, lacquers, and the like, and is particularly directed to a novel method and apparatus for obtaining a flat fan or narrow elongated (as opposed to conical) paint spray pattern.
  • coating materials such as paints, lacquers, and the like
  • This invention relates to a method and apparatus for spraying coating materials, such as paints, lacquers, and the like, and is particularly directed to a novel method and apparatus for obtaining a flat fan or narrow elongated (as opposed to conical) paint spray pattern.
  • coating materials such as paints, lacquers, and the like
  • a stream of paint is extruded from a nozzle and is blasted by a stream of air under a high pressure. This high pressure air stream functions to break the rod of paint into particles. These particles are then subjected to secondary air streams which function to shape the paint spray into a flat fan-like configuration.
  • a second known technique involves the formation of two conical sprays of paint. These conical sprays are directed against one another forwardly of the gun so that they interact to form a flat fan-like pattern.
  • a third commonly used method in commercial practice is so-called airless spraying in which paint is forced through an orifice at a relatively high pressure, for example, a pressure of the order of 300-3000 pounds per square inch.
  • the orifree is of a special configuration including a small size aperture with the face of the nozzle surrounding the orifice being provided with a narrow elliptical, tapered recess to impart a fan-like pattern to the atomized paint.
  • each of these methods of forming a flat paint fan has one or more inherent disadvantages.
  • the disadvantages is the fact that the fan-shaped paint patterns cannot be controlled precisely to provide a uniform pattern of the desired configuration.
  • the pattern produced by an airless gun tends to have heavy tails which result in the irregular deposition of relatively large-sized droplets at the ends of the fan pattern.
  • the impinging cones or secondary air stream approach it is not feasible to produce a uni form fan having feathered endwise portions.
  • the conventional air spraying method also has the recognized disadvantage that it requires a large mass of high velocity air.
  • This high velocity air along with the air flow which it induces, results in an objectionable wastage of paint.
  • an appreciable portion of the paint spray is carried past the workpiece even when an electrostatic charge is applied to the paint.
  • Other portions of the paint spray are wasted because the high kinetic energy present in the air causes the paint to bounce back or rebound from the surface being coated.
  • this type of conventional air spray painting presents a substantial problem of ventilation.
  • more than one gun is operated at a time so that it is not uncommon for a paint spray installation to be provided with a large capacity ventilation system capable of capturing paint particles entrained in a large mass of high-speed air, for example, capture velocities of 150 feet per minute.
  • this air carries a substantial amount of entrained paint which has been oversprayed or has rebounded, various types of filters or water curtains are required to minimize atmospheric pollution.
  • Airless paint spray systems also require relatively expensive equipment including pumps and related components for maintaining the paint under high pressure. Moreover, in many airless applications it is necessary or desirable to provide a heater for elevating the paint temperature to improve its application properties. All of this adds to the initial cost of the system as well as 0 the cost of its operation.
  • the principal object of the present invention is to provide a completely new and different method of forming a flat spray of paint and similar coating materials.
  • the present method and apparatus utilize a small quantity of air of the order of one-tenth that required in previous commercial air-paint spray systems so that the problem of paint rebound and overspray is very largely eliminated.
  • the present method utilizes in part certain aspects of the method of spraying disclosed in the copending application of Peter W. Runstadler, Jr., Eric T. Nord, Donald R. Hastings, Don R. Scarbrough, and Frederick R. Wilhelm, for Method And Apparatus For Spraying Ser. No. 167,701 filed on even date herewith.
  • the paint pattern is comprised of minute particles of remarkably uniform size. These particles are distributed throughout the pattern in an extremely uniform manner. There are no tails or localized areas of paint concentration in the pattern.
  • the pattern is particularly advantageous since its ends are feathered, i.e., are less dense.
  • the present system can be operated from conventional shop air and does not require any special compressor for providing high pressure air as required in conventional air spraying systems.
  • the present system utilize a high pressure paint pump or associated equipment as employed in conventional airless spraying systems.
  • the paint is not only finely and uniformly atomized, but it is projected at an optimum velocity for coating purposes, for example, a velocity of 200 feet per minute at a distance of 10 inches from the gun. While this velocity is sufficiently high to cause the paint to be projected in the desired direction toward the object to be coated and to adhere to the object upon impingement, neither the velocity nor amount of air is high enough to cause more than a minimal amount of overspray or rebound.
  • the use of the present painting apparatus and method not only minimizes paint wastage, but also greatly simplifies ventilation and filtering requirements.
  • the present paint spraying method is predicated upon the concept of injecting minute air bubbles under pressure into a confined stream of paint under a pressure of from 30-100 psi to form a frothin which the paints remains the continuous phase, passing. the froth through a chamber within which the bubbles become substantially uniformly dispersed throughout the liquid, and thereafter expelling the froth through a nozzle orifice effective to impart a flat fan configuration to the resultant spray which is formed as the froth enters the atmosphere and the entrained air bubbles explode, breaking up the paint into a uniform spray of minute droplets.
  • the paint atomizing section of the spray unit includes members configurated to form the paint stream into a thin annular film.
  • Air injection channels are provided for directing air against portions of the film whereupon the air is sheared by the film into a series of pressurized microbubbles which are entrained in the film.
  • the resultant froth is passed through a cham ber which is configurated to provide a partial pressure drop within the froth prior to the time the froth exits through a fan-shaping nozzle.
  • the nozzle orifice is in the form of an elongated slot in a hemispherical dome.
  • the interior of the dome provides a chamber which houses a protuberance, having at least a segment of spherical surface concentric in a vertical plane with the interior wall of the dome and forming therewith a relatively thin curved passageway into which the froth is deflected and through which it flows prior to its emergence from the orifice.
  • this construction provides a flat spray pattern having uniformly fine particle size and even distribution.
  • the ends of the pattern are feathered so that deposited patterns can be overlapped to form a uniform surface coating.
  • the present invention also contemplates a modified embodiment of simpler construction for use where feathered fan edges and extreme uniformity of spray pattern are not required.
  • This modified construction is like that just described except that no internal protuberance or ball is provided within the nozzle, and instead of a plain slot the orifice is shaped in the configuration conventionally used for airless spray. It was surprisingly determined that this nozzle provides a flat fan when spraying paint at the present low pressures in view of the fact that when paint as used in conventional airless spraying is passed through such a nozzle at these low pressures, no useful atomization whatsoever occurs.
  • FIG. 1 is a partial vertical sectional view through one form of a spray gun constructed in accordance with the principles of the present invention.
  • FIG. 2 is an enlarged vertical cross-sectional view through the nozzle end of the gun. 1
  • FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 2.
  • FIG. 4 is an enlarged cross-sectional view taken along line 44 of FIG. 2.
  • FIG. 5 is a perspective view of the collar member.
  • FIG. 6 is a perspective viewof the orifice plate member.
  • FIG. 7 is an end view of the nozzle.
  • FIG. 8 is a cross-sectional view similar to FIG. 4 of a modified form of gun.
  • FIG. 9 is an end view of the nozzle of the modified form of gun shown in FIG. 8.
  • FIG. 10 is a perspective view of the modified form of orifice plate utilized in the gun of FIG. 8.
  • FIG. 1 illustrates a typical spray gun 10 adapted to utilize the paint spray atomizing means of the present invention.
  • spray gun 10 could be used to apply a decorative or protective coating to a product, such as a refrigerator, automobile part, furniture, containers, or the like.
  • the coating materials to be sprayed include not only paints, but also enamels, lacquers, stains, varnishes, emulsions, waxes, adhesives and the like.
  • the word paint is used in a very generic sense to encompass all of these various types of coating materials.
  • spray gun 10 is merely exemplary and the atomizing means of this invention can be incorporated in many different types of guns.
  • spray gun 10 is a hand-held, non-electrostatic gun.
  • the present atomizing means can be incorporated advantageously in non-hand-held automatic guns of the general type shown in .luvinall U.S. Pat. No. 3,169,883.
  • spray gun 10 is not shown as being provided with any paint charging means
  • the present atomizing means can be used advantageously in connection with electrostatic spray guns having any suitable means for applying a charge to the paint spray.
  • One generally suitable form of paint charging device is shown in Juvinall et al. U.S. Pat. No. 3,169,882.
  • spray gun 10 includes a body portion 11, a handle portion 12, and a spray head portion 13 mounted on the forward end of a barrel portion 14 and having a nozzle 15 mounted at its forward end.
  • the handle portion 12 of the gun is provided with a suitable fitting 16 for coupling the gun to an air line, for example, a shop air line under a pressure of 50 psig.
  • the barrel portion 14 is provided with a paint inlet conduit 17. This conduit is adapted to be connected to a paint spray line by means of any suitable coupling.
  • the paint spray line is normally fed with paint which is pumped under pressure from a paint spray tank, or alternatively, is fed from a pressurized tank.
  • the paint pressure at the gun is relatively low and is preferably in the range of from 30 to I00 psi. This pressure is preferably regulated, or made constant, in any suitable manner.
  • Valve member 23 is carried by a stem 25 which extends forwardly from the handle into engagement with a pad 26 formed on the rear surface of trigger 18.
  • Valve 23 is spring-urged to its closed position by means of a compression spring 27 disposed within chamber 22. This spring, acting through stem 25, is likewise effective to urge the trigger to its forwardmost position.
  • Tapered sleeve member 28 which forms a seat for valve 23, is provided with a plurality of radial passageways 30 effective, when valve 23 is unseated, to interconnect chamber 22 and, hence, air inlet conduit 21 with a passageway 31.
  • This passageway in turn communicates through a bore 32 to elongated passageway 33. Air moves forwardly along this passageway through an orifice 34 controlled by a needle valve 35.
  • the needle valve threadably engages body 11 and is adapted to be held in its adjusted position by a conventional lock nut arrangement.
  • Orifice 34 communicates with a bore 36 and annular groove 37.
  • Annular groove 37 in turn communicates with a plurality of longitudinal passageways 38 terminating in an enlarged chamber 40.
  • air is supplied from this chamber to the atomizing section of the gun through air injection slots 41 formed in collar member 42.
  • Trigger member 18 also is effective to control the flow of paint to the atomizing means. More particularly, as is best shown in FIGS. 1 and 2, paint enters the gun through paint conduit 17. Paint flows from this conduit forwardly through a passageway 43 surrounding valve stem 44.
  • the valve stem is provided with a tapered end 45 adapted to seal against seat 46 formed in fluid tip member 47.
  • Valve stem 44 extends rearwardly through a suitable packing member 48 carried by the barrel and through an enlarged opening formed in trigger member 18.
  • the valve stem carries a sleeve member 50 which is slidably mounted in the gun body 11.
  • Sleeve 50 has a head member 51 formed adjacent to its forward end and disposed for abutment with a pad 52 formed on the rear surface of the trigger.
  • This section comprises an orifice plate member 54 best shown in FIGS. 5 and 6.
  • the orifice plate member 54 includes a disc-like base portion 55 having three bores 56 formed therein.
  • a cylindrical projection 57 extends forwardly of the base.
  • This projection carries a forwardly extending support rod 58 having a ball-like protuberance 60 formed on the outer or free end thereof.
  • protuberance 60 includes a hemispherical outer surface 60a and a frustoconical section 60b joining section 60a with the support rod.
  • the orifice plate is mounted in the gun with the rear face 61 of base member 55 in abutment with the forward face 62 of the tip member 47.
  • a recess 49 is formed in rear face 61 surrounding the port 53 in the tip member and interconnecting that port with bores 56.
  • the orifice plate member 54 is partially telescopically received within a rearwardly extending flange 63 of collar member 42.
  • Collar member 42 includes a transverse wall 64 having a central bore 65 of slightly larger diameter than the diameter of cylindrical projection 57. This bore is at least partially in registry with bores 56 and together with the outer periphery of projection 57 defines an annular film-forming flow channel 68. Preferably this channel is between 0.005 inch and 0.050 inch in thickness.
  • each of the slots is 0. l 3 inch wide and 0.015 inch deep as measured from the forward face of transverse wall 64.
  • the diameter of projection 57 is equal to 0.120 inch while the diameter of collar opening 65 is O.l60 inch so that the annular film-forming channel 68 is 0.020 inch in width.
  • the length of projection 57 as measured from the front face of disc member 55 is 0.125 inch as compared to a thickness of 0.109 inch of transverse wall 64.
  • the projection extends completely through opening 65 in the orifice plate and extends forwardly thereof by approximately 0.016 inch.
  • this projection can terminate flush with the forward face of wall 64 or even slightly behind it if desired.
  • the forward face of the collar member 42 abuts circular base section 72 of nozzle member 15.
  • This nozzle member is centered with respect to collar member 42 by engagement of the periphery of base section 72 with the inner wall of forwardly extending flange 71 of the collar member.
  • the rear face 73 of the nozzle base 72 engages the four quadrantal pad-like portions 74 formed on the forward face 64 of the collar member in the areas between the cross channels 70.
  • the base of the nozzle member cooperates with the collar to form four radial air injection channels interconnecting chamber 40 with annular paint flow passage 68.
  • Nozzle member 15 further includes a forwardly extending cylindrical bore, or passage, 75 which in a preferred embodiment is 0.160 inch in diameter and approximately 0.36 inch long.
  • the nozzle member protrudes forwardly through a central opening 76 in retaining nut 77.
  • the outer end of the nozzle is domed or generally hemispherical in shape (as is best shown in FIGS. 2 and 7) and includes a generally rectangular slot 78 disposed along a diameter of the dome.
  • the two ends 80 of the slot are angulated so as to lie generally along radii of the periphery of the dome. The radial disposition of these edges greatly enhances the feathered configuration of the spray pattern.
  • the seat includes a angle having its apex at the center of the dome.
  • the innermost edges of the slot are spaced apart a distance less than the maximum diameter of ball 60 which in the preferred embodiment is 0.140 inch.
  • the hemispherical portion of the ball is generally concentric on a vertical section with the inner wall 81 of the dome. The ball and dome thus form a hemispherical flow space approximately 0.010 inch in thickness.
  • the nozzle member 15, collar 42 and orifice plate 54 are held in stacked relationship against one another and against tip member 47 by the retaining nut 77.
  • the forward end of this nut is provided with a recessed shoulder 82 which abuts an annular shoulder 83 formed on the forward portion of nozzle base member 72.
  • the opposite end of the retaining nut is provided with internal threads as at 84 for engagement with a threaded cylindrical extension 85 on barrel member 14.
  • the spray gun is operated in accordance with the process parameters for spraying paint set forth in the above-identified application of Peter W. Runstadler, Jr., Eric T. Nord, Donald R. Hastings, Donald R. Scarbrough and Frederick R. Wilhelm, for Method and Apparatus for Spraying. More particularly, in the operation of the present spray gun, paint under a pressure of from 30-100 psig flows past open needle valve 44 through distributor recess 49 formed in the rear face of orifice plate 54 and through bores 56 in the orifice plate into the annular flow channel 68 formed between projection 57 and the surrounding spaced wall of the collar member.
  • Air under pressure, flows past the end of needle valve 35 through passageways 36 and 38 into chamber 40 and, hence, radially inwardly along four channels formed by cross slots 70.
  • the pressure of the air line is regulated by needle valve 35 so that the pressure of the air where it intersects the paint film is slightly greater, e.g., 2 psi greater, than the paint pressure at that area.
  • Air emerging from the inner ends of slots 70 intersects the annular film of paint and is sheared off in the form of a myriad of entrained microbubbles in the paint.
  • the paint with the entrained air bubbles, then moves forwardly as a froth through chamber 75. In this space the bubbles and paint are mixed so that the bubbles are uniformly distributed throughout the paint.
  • there is a pressure drop from annular flow channel 68 to nozzle opening 78 it is believed that the bubbles also expand somewhat during their path of travel toward the nozzle opening.
  • the paint and bubbles Prior to the time that the paint and bubbles emerge from nozzle opening 78, they are deflected outwardly in their path by protuberance 60 toward the inner wall 81 of the dome portion of the nozzle.
  • the froth consisting of the paint as a continuous phase and the entrained air bubbles, passes outwardly in the space between the ball and dome and emerges from slot 78.
  • the air bubbles in the froth expand rapidly causing the froth to be broken up into a spray of minute droplets believed to be of the order of from to 100 microns in diameter.
  • the forward velocity of these particles 10 inches from the nozzle in a preferred embodiment, has been found to be of the order of 200 feet per minute which is ideal for spray painting.
  • the spray is projected from the nozzle in a flat fan pattern which is characterized by a uniform distribution of uniformly-sized particles.
  • the pattern is particularly desirable since it has feathered edges which facilitate the application of overlapping patterns to a workpiece.
  • the spray contains a relatively small quantity of air, for example, the mass ratio of air-to-paint is in the range of 0.1 to 1.6.
  • the ball-like protuberance 60 The highly advantageous results obtained from the use of the ball-like protuberance 60 are to some extent explainable only as an empirical discovery. However, it is believed that these results are due in part to the fact that the ball performs one or more of the following functions. In the first place, the ball prevents straight lineal flow from the froth-forming area to the orifice. Rather, the ball restricts the area behind the orifice and forces the froth to flow outwardly, i.e., in a transverse direction prior to the time that it reaches the orifice.
  • the ball defines the inner wall of a passage, which wall is disposed to contact those portions of the paint film which have previously flowed along the inner wall of channel 68 and, hence, tend to have less air bubbles entrained therein than the portions of the film which flowed along the outer edge of the channel 68 directly adjacent to the ends of the air injection channels 70. Because of the geometric relationship of the ball to the nozzle opening, these inner portions of froth containing less air, tend to flow adjacent to the ball, and are then forced to flow across the outer portions of froth in the nozzle area before they are emitted from the nozzle. This results in a more homogeneous mixture of the froth exiting from the nozzle and, again, results in a greater uniformity of the final bubble size and distribution.
  • the ball and surrounding wall of the nozzle force the froth to flow through a confined area so that the bubbles in the froth are compacted to further increase the homogeneity of the froth, resulting in a greater uniformity of the final bubble size and distribution.
  • orifice plate member 154 includes a disc-like base portion 155 having three bores 156 formed therein.
  • the orifice plate further includes a cylindrical projection 157 which extends forwardly from the center portion of the base.
  • the projection does not carry a support rod or ball.
  • the projection 157 is of a length such that it terminates even with the forward wall of the collar member. However, the forward end of this projection can extend beyond this forward wall in the manner of projection 57 or can terminate slightly behind the wall if desired.
  • the orifice plate is provided with a rear face 161 which abuts forward face 62 of tip member 47.
  • a recess 149 is formed in rear face 161 surrounding the port 53 in the tip member. This recess provides fluid communication between port 53 and bores 156.
  • a collar member 42 is disposed forwardly of orifice plate 154 and includes a rearwardly extending flange 63 which surrounds and telescopically receives the orifice plate.
  • collar member 42 includes a transverse wall 64 having a central bore 65 of slightly larger diameter than the diameter of cylindrical projection 157.
  • the clearance between the wall of the bore and the projection is preferably of the order of 0.005 inch to 0.050 inch in width.
  • Two diametral cross slots 41 are milled in-the forward face of the collar member at right angles to one another in the same manner shown in FIG. 5. As explained previously, these slots extend to the periphery of the collar member and in the preferred embodiment are 0.13 inch wide and 0.015 inch deep as measured from the forward face of wall 64.
  • the forward face of collar member 42 abuts the circular base section 172 of the nozzle member 115.
  • This nozzle member is centered with respect to collar member 42 by engagement of the periphery of base section 172 with the inner wall of forwardly extending flange 71 formed on the collar member.
  • the rear face 173 of the nozzle engages the four approximately quadrantal pad-like portions 74 (see FIG. formed on the forward face 64 of the collar member in the areas between the cross channels 41.
  • the base 172 of the nozzle member 115 defines one wall of the four radial air injection channels constituted by slots 41 in the collar member.
  • nozzle member 115 includes a slightly tapered internal passageway 175. This passageway terminates in a rounded end portion 179.
  • An orifice 180 extends across the end of the nozzle member. This orifice is of the type conventionally used in airless spray equipment to provide a flat fan spray. Specifically, the orifice includes a small center aperture with the surrounding walls of the nozzle member being tapered inwardly and cut in a generally narrow elliptical-shaped opening.
  • the operation of the modified form of nozzle is the same as that of the preferred nozzle, except that the froth formed by the impingement of air upon the paint flows directly through chamber 175 to the nozzle opening and isnot deflected outwardly by any ball member.
  • the froth Upon its emission from nozzle 180 the froth explodes and forms a spray having a fan-shaped pattern of minute paint spray droplets.
  • This pattern has substantially the same air-to-paint mass ratio as that obtained from a nozzle of the preferred type.
  • the forward velocity of the spray is substantially the same.
  • the paint spray particles are not distributed quiteas uniformly hroughout the pattern and the pattern lacks the desirable feathered edges described above.
  • a paint spray gun for spraying a flat fan spray
  • said gun having an air conduit and a paint conduit
  • froth forming means including means communicating with said paint conduit and defining a film-forming channel for said paint, said channel having opposed walls, means communicating with said air conduit and including an opening in one of said walls for injecting bubbles of air from said air conduit into the paint film formed in said film-forming channel to form a froth, a nozzle member having an orifice,
  • the nozzle orifice being configurated to cause the paint spray to form a flat fan pattern.
  • the paint spray gun of claim 2 further comprising a protuberance disposed within said nozzle behind said orifice.
  • a paint spray gun for spraying a flat fan spray, said gun comprising a body portion,
  • said orifice plate having one face disposed toward said tip member and having a projection extending outwardly from the opposite side thereof
  • a collar member having a central opening receiving said projection to define an annular film-forming channel
  • said orifice plate having a bore extending therethrough to place said film-forming channel in fluid communication with the paint discharge port of said tip
  • said collar member having an inwardly extending air injection channel in communication with said air conduit for injecting bubbles of air into a film of paint in said channel to produce a froth
  • a nozzle having a narrow elongated orifice therein and an internal passageway therethrough in fluid communication with said film-forming chamber
  • a protuberance disposed within said nozzle intermediate said orifice and said film-forming channel, whereby when'the froth is discharged from the nozzle orifice the air bubbles expand to break up the paint into a spray of fine particles, said spray having a flat fan pattern.
  • a paint spray gun for spraying a flat fan spray, said gun comprising a body portion,
  • said orifice plate including a transverse base portion having a rear face in engagement with said tip portion, a cylindrical projection extending forwardly of said base portion,
  • a collar member including a rearwardly extending flange embracing the periphery of said orifice base, and a transverse wall having a central opening receiving said projection to define an annular filmforming chamber
  • the orifice plate having a bore extending therethrough to place said film-forming channel in fluid communication with the paint discharge opening of said tip
  • said collar member including a forwardly projecting peripheral flange, the forward face of the transverse wall or the collar member having an inwardly projecting slot formed therein and communicating with said central opening, said slot also extending outwardly through said forwardly projecting flange,
  • a nozzle member having a base in abutment with the forward face of said collar member and overlying said slot to define an air injection channel
  • said nozzle member base being telescopically received within said forwardly extending flange
  • said nozzle member providing an internal passage and including a nozzle orifice, whereby when air is injected into said film of paint a froth is formed which flows outwardly through the space in said nozzle and when the froth is discharged from the nozzle orifice the air bubbles expand to break up the paint in a spray of fine particles, the nozzle orifice being configurated to spray paint to form a flat fan pattern.
  • the paint spray gun of claim 10 further comprising a retaining nut surrounding said tip, orifice plate, collar, and base of said nozzle member, said retaining nut defining an air chamber interconnecting the air conduit and said air injection channel.
  • a method of forming a flat fan paint spray comprising the steps of injecting a plurality of microbubbles of air into a stream of paint to form a froth, the air and paint being intermixed as to have a mass ratio of air-to-paint of from 0.1 to 1.6,
  • a method of forming a flat paint spray comprising the steps of forming a thin film of paint
  • a paint spray gun for spraying a flat fan spray comprising:
  • said orifice plate having one face disposed toward said paint discharge opening and having a projection extending outwardly from the opposite side thereof,
  • said inwardly extending air injection channel in communication with said air conduit for injecting bubbles of air into a film of paint in said channel to produce a froth
  • a nozzle having a narrow elongated orifice therein and an internal passageway therethrough in fluid communication with said film-forming chamber
  • a protuberance disposed within said nozzle intermediate said orifice and said film-forming channel, whereby when the froth is discharged from the nozzle orifice the air bubbles expand to break up the paint into a spray of fine particles, said spray having a flat fan pattern.

Landscapes

  • Nozzles (AREA)
US00167695A 1971-07-30 1971-07-30 Method and apparatus for producing a flat fan paint spray pattern Expired - Lifetime US3734406A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US16769571A 1971-07-30 1971-07-30

Publications (1)

Publication Number Publication Date
US3734406A true US3734406A (en) 1973-05-22

Family

ID=22608428

Family Applications (1)

Application Number Title Priority Date Filing Date
US00167695A Expired - Lifetime US3734406A (en) 1971-07-30 1971-07-30 Method and apparatus for producing a flat fan paint spray pattern

Country Status (12)

Country Link
US (1) US3734406A (enrdf_load_stackoverflow)
JP (1) JPS5322086B2 (enrdf_load_stackoverflow)
AU (1) AU464866B2 (enrdf_load_stackoverflow)
BE (1) BE786903A (enrdf_load_stackoverflow)
CA (1) CA984234A (enrdf_load_stackoverflow)
DE (1) DE2236042C3 (enrdf_load_stackoverflow)
ES (1) ES405203A1 (enrdf_load_stackoverflow)
FR (1) FR2149158A5 (enrdf_load_stackoverflow)
GB (1) GB1404983A (enrdf_load_stackoverflow)
IT (1) IT961728B (enrdf_load_stackoverflow)
NL (1) NL7210336A (enrdf_load_stackoverflow)
SE (1) SE394965B (enrdf_load_stackoverflow)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4396529A (en) * 1978-11-13 1983-08-02 Nordson Corporation Method and apparatus for producing a foam from a viscous liquid
GB2119288A (en) * 1982-05-03 1983-11-16 Binks Mfg Co Air spray gun
US4603813A (en) * 1984-06-29 1986-08-05 Insta-Foam Products, Inc. Double back spray nozzle
US4925101A (en) * 1988-08-26 1990-05-15 Nordson Corporation Wax spray gun and nozzle
US5171613A (en) * 1990-09-21 1992-12-15 Union Carbide Chemicals & Plastics Technology Corporation Apparatus and methods for application of coatings with supercritical fluids as diluents by spraying from an orifice
ES2070717A2 (es) * 1993-03-11 1995-06-01 Sagola Sa Pistola aerografica perfeccionada de reducida presion.
US20040031860A1 (en) * 2002-08-19 2004-02-19 Micheli Paul R. Spray gun with improved pre-atomization fluid mixing and breakup
US20040046040A1 (en) * 2002-08-19 2004-03-11 Micheli Paul R. Spray gun with improved atomization
US20040169093A1 (en) * 2003-02-28 2004-09-02 Strong Christopher L. One-piece fluid nozzle
US20040256493A1 (en) * 2002-10-08 2004-12-23 Turnbull Clifford W. Modular spray gun apparatus and methods
WO2005049145A1 (en) * 2003-10-22 2005-06-02 Trade Associates, Inc. Modular spray gun apparatus and methods
US20060000928A1 (en) * 2004-06-30 2006-01-05 Micheli Paul R Fluid atomizing system and method
US20060065760A1 (en) * 2004-09-28 2006-03-30 Micheli Paul R Turbo spray nozzle and spray coating device incorporating same
US20060214027A1 (en) * 2004-06-30 2006-09-28 Micheli Paul R Fluid atomizing system and method
US20070040047A1 (en) * 2005-08-19 2007-02-22 William Gentry Riley Airbrush with external chucking nut
USD540431S1 (en) 2005-09-06 2007-04-10 Trade Associates, Inc. Spray gun trigger
US20070221762A1 (en) * 2006-03-24 2007-09-27 Micheli Paul R Spray device having removable hard coated tip
US20080017734A1 (en) * 2006-07-10 2008-01-24 Micheli Paul R System and method of uniform spray coating
USD562435S1 (en) 2005-09-06 2008-02-19 Trade Associates, Inc. Spray gun trigger
US20100078499A1 (en) * 2008-10-01 2010-04-01 Wagner Spray Tech Corporation Nozzle for fluid delivery system

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2924174C2 (de) * 1979-06-15 1984-04-19 Heinrich Bühnen KG Maschinenfabrik, Im- und Export, 2800 Bremen Verfahren und Düse eines Gerätes zum Aufbringen eines Klebers auf ein Substrat
JPS5792762A (en) * 1980-11-29 1982-06-09 Matsushita Electric Works Ltd Pressure contact terminal
GB2157591B (en) * 1984-04-19 1987-11-25 Spraying Systems Co Air-assisted spray nozzle
GB8905835D0 (en) * 1989-03-14 1989-04-26 British Petroleum Co Plc Spray nozzle
JPH0352830U (enrdf_load_stackoverflow) * 1989-09-25 1991-05-22
WO1993013829A1 (de) * 1992-01-17 1993-07-22 Inter Airspray Sweden Ab Schaumsprühvorrichtung
ITTO20140135U1 (it) * 2014-11-04 2016-05-04 Ghelco S R L Pistola per verniciatura
CN109433444A (zh) * 2018-12-24 2019-03-08 宁波协华汽车配件制造有限公司 一种汽车塑料配件表面喷涂设备及其喷涂工艺

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB190619740A (en) * 1906-09-05 1907-03-21 Niederrheinische Glashuettenge An Improved Liquid Fuel Burner.
US1075947A (en) * 1910-10-20 1913-10-14 John Schurs Oil-burner.
FR474904A (fr) * 1913-07-12 1915-03-26 Anton Victor Lipinski Perfectionnements apportés à la pulvérisation des liquides et, notamment à celle des liquides peu fluides
US1500178A (en) * 1920-06-22 1924-07-08 Murdoch Mfg And Supply Company Bubbler head for drinking fountains
US2041482A (en) * 1930-07-19 1936-05-19 Jens A Paasche Air painting device
US2214035A (en) * 1937-08-17 1940-09-10 Vilbiss Co Spray head
US2297497A (en) * 1939-12-09 1942-09-29 Popoff Mintscho Spraying process and apparatus
US2351372A (en) * 1942-08-22 1944-06-13 Clay M Snyder Oil burner
US2522928A (en) * 1947-11-18 1950-09-19 Monarch Mfg Works Inc Spraying nozzle
US2530206A (en) * 1942-10-31 1950-11-14 Colorator Ab Spray gun
GB1031287A (en) * 1963-07-17 1966-06-02 Rotolift Mfg Co Ltd Improvements in or relating to nozzle devices
US3567116A (en) * 1968-12-18 1971-03-02 Minnesota Mining & Mfg Atomizing method and apparatus

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB190619740A (en) * 1906-09-05 1907-03-21 Niederrheinische Glashuettenge An Improved Liquid Fuel Burner.
US1075947A (en) * 1910-10-20 1913-10-14 John Schurs Oil-burner.
FR474904A (fr) * 1913-07-12 1915-03-26 Anton Victor Lipinski Perfectionnements apportés à la pulvérisation des liquides et, notamment à celle des liquides peu fluides
US1500178A (en) * 1920-06-22 1924-07-08 Murdoch Mfg And Supply Company Bubbler head for drinking fountains
US2041482A (en) * 1930-07-19 1936-05-19 Jens A Paasche Air painting device
US2214035A (en) * 1937-08-17 1940-09-10 Vilbiss Co Spray head
US2297497A (en) * 1939-12-09 1942-09-29 Popoff Mintscho Spraying process and apparatus
US2351372A (en) * 1942-08-22 1944-06-13 Clay M Snyder Oil burner
US2530206A (en) * 1942-10-31 1950-11-14 Colorator Ab Spray gun
US2522928A (en) * 1947-11-18 1950-09-19 Monarch Mfg Works Inc Spraying nozzle
GB1031287A (en) * 1963-07-17 1966-06-02 Rotolift Mfg Co Ltd Improvements in or relating to nozzle devices
US3567116A (en) * 1968-12-18 1971-03-02 Minnesota Mining & Mfg Atomizing method and apparatus

Cited By (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4396529A (en) * 1978-11-13 1983-08-02 Nordson Corporation Method and apparatus for producing a foam from a viscous liquid
GB2119288A (en) * 1982-05-03 1983-11-16 Binks Mfg Co Air spray gun
US4603813A (en) * 1984-06-29 1986-08-05 Insta-Foam Products, Inc. Double back spray nozzle
US4925101A (en) * 1988-08-26 1990-05-15 Nordson Corporation Wax spray gun and nozzle
US5171613A (en) * 1990-09-21 1992-12-15 Union Carbide Chemicals & Plastics Technology Corporation Apparatus and methods for application of coatings with supercritical fluids as diluents by spraying from an orifice
ES2070717A2 (es) * 1993-03-11 1995-06-01 Sagola Sa Pistola aerografica perfeccionada de reducida presion.
US8640976B2 (en) 2002-08-19 2014-02-04 Paul R. Micheli Spray gun having mechanism for internally swirling and breaking up a fluid
US20040046040A1 (en) * 2002-08-19 2004-03-11 Micheli Paul R. Spray gun with improved atomization
US7762476B2 (en) 2002-08-19 2010-07-27 Illinois Tool Works Inc. Spray gun with improved atomization
US20080048055A1 (en) * 2002-08-19 2008-02-28 Illinois Tool Works Inc. Spray gun having mechanism for internally swirling and breaking up a fluid
US6808122B2 (en) * 2002-08-19 2004-10-26 Illinois Tool Works, Inc. Spray gun with improved pre-atomization fluid mixing and breakup
US7311271B2 (en) 2002-08-19 2007-12-25 Illinois Tool Works Inc. Spray gun having mechanism for internally swirling and breaking up a fluid
US20040262416A1 (en) * 2002-08-19 2004-12-30 Micheli Paul R. Spray gun having mechanism for internally swirling and breaking up a fluid
US20050006498A1 (en) * 2002-08-19 2005-01-13 Micheli Paul R. Spray gun with improved pre-atomization fluid mixing and breakup
US7028916B2 (en) * 2002-08-19 2006-04-18 Illinois Tool Works Inc. Spray gun with improved pre-atomization fluid mixing and breakup
US20040031860A1 (en) * 2002-08-19 2004-02-19 Micheli Paul R. Spray gun with improved pre-atomization fluid mixing and breakup
US20040256493A1 (en) * 2002-10-08 2004-12-23 Turnbull Clifford W. Modular spray gun apparatus and methods
US7246759B2 (en) 2002-10-08 2007-07-24 Trade Associates, Inc. Modular spray gun apparatus and methods
US6935577B2 (en) 2003-02-28 2005-08-30 Illinois Tool Works Inc. One-piece fluid nozzle
US20050150981A1 (en) * 2003-02-28 2005-07-14 Strong Christopher L. One-piece fluid nozzle
US20040195369A1 (en) * 2003-02-28 2004-10-07 Strong Christopher L. One-piece fluid nozzle
US7497387B2 (en) 2003-02-28 2009-03-03 Illinois Tool Works Inc. One-piece fluid nozzle
US20040169093A1 (en) * 2003-02-28 2004-09-02 Strong Christopher L. One-piece fluid nozzle
WO2005049145A1 (en) * 2003-10-22 2005-06-02 Trade Associates, Inc. Modular spray gun apparatus and methods
US20060000928A1 (en) * 2004-06-30 2006-01-05 Micheli Paul R Fluid atomizing system and method
US7926733B2 (en) 2004-06-30 2011-04-19 Illinois Tool Works Inc. Fluid atomizing system and method
US7883026B2 (en) 2004-06-30 2011-02-08 Illinois Tool Works Inc. Fluid atomizing system and method
US7992808B2 (en) 2004-06-30 2011-08-09 Illinois Tool Works Inc. Fluid atomizing system and method
US20060214027A1 (en) * 2004-06-30 2006-09-28 Micheli Paul R Fluid atomizing system and method
US20060065760A1 (en) * 2004-09-28 2006-03-30 Micheli Paul R Turbo spray nozzle and spray coating device incorporating same
US7568635B2 (en) 2004-09-28 2009-08-04 Illinois Tool Works Inc. Turbo spray nozzle and spray coating device incorporating same
US20070040047A1 (en) * 2005-08-19 2007-02-22 William Gentry Riley Airbrush with external chucking nut
USD562435S1 (en) 2005-09-06 2008-02-19 Trade Associates, Inc. Spray gun trigger
USD540431S1 (en) 2005-09-06 2007-04-10 Trade Associates, Inc. Spray gun trigger
US20070221762A1 (en) * 2006-03-24 2007-09-27 Micheli Paul R Spray device having removable hard coated tip
US8684281B2 (en) 2006-03-24 2014-04-01 Finishing Brands Holdings Inc. Spray device having removable hard coated tip
US20080017734A1 (en) * 2006-07-10 2008-01-24 Micheli Paul R System and method of uniform spray coating
US20100078499A1 (en) * 2008-10-01 2010-04-01 Wagner Spray Tech Corporation Nozzle for fluid delivery system

Also Published As

Publication number Publication date
NL7210336A (enrdf_load_stackoverflow) 1973-02-01
AU464866B2 (en) 1975-09-11
DE2236042B2 (de) 1978-09-21
JPS4825035A (enrdf_load_stackoverflow) 1973-04-02
GB1404983A (en) 1975-09-03
BE786903A (fr) 1972-11-16
SE394965B (sv) 1977-07-25
DE2236042C3 (de) 1979-05-10
CA984234A (en) 1976-02-24
DE2236042A1 (de) 1973-02-08
AU4372772A (en) 1974-01-03
FR2149158A5 (enrdf_load_stackoverflow) 1973-03-23
ES405203A1 (es) 1975-07-16
IT961728B (it) 1973-12-10
JPS5322086B2 (enrdf_load_stackoverflow) 1978-07-06

Similar Documents

Publication Publication Date Title
US3734406A (en) Method and apparatus for producing a flat fan paint spray pattern
CA2132039C (en) Suction feed nozzle assembly for hvlp spray gun
US3764069A (en) Method and apparatus for spraying
US5209405A (en) Baffle for hvlp paint spray gun
US5344078A (en) Nozzle assembly for HVLP spray gun
US5152460A (en) Spray gun nozzle head
US5074466A (en) Fluid valve stem for air spray gun
US5271564A (en) Spray gun extension
US5165605A (en) Low pressure air atomizing spray gun
US4713257A (en) Spraying method and device for applying a film to a workpiece
US5180104A (en) Hydraulically assisted high volume low pressure air spray gun
US4502629A (en) Nozzle assembly for electrostatic spray guns
KR102646878B1 (ko) 사전-분무화 협폭부를 구비한 스프레이 노즐, 상기 스프레이 노즐을 포함하는 스프레이 헤드 및 스프레이 장치
GB1587898A (en) Method of and apparatus for pneumatically spraying liquid products
US3887135A (en) Gas-atomizing nozzle by spirally rotating gas stream
US3635400A (en) Paint spraying method and apparatus
EP0381072B1 (en) High volume low pressure air spray gun
EP0411830B1 (en) Low pressure air atomizing spray gun
JP2558243Y2 (ja) 内部混合式エアスプレーガン
JPS6212429Y2 (enrdf_load_stackoverflow)
JPS635141B2 (enrdf_load_stackoverflow)
JPS635148B2 (enrdf_load_stackoverflow)
KR19980062641U (ko) 저비산 페인트 스프레이건
JPH0716633B2 (ja) ２液用スプレーガン
JPH0360753A (ja) 低圧微粒化スプレーガン