US2644717A

US2644717A - Spray device for liquids, thermoplastics, molten metal, or the like

Info

Publication number: US2644717A
Application number: US158448A
Authority: US
Inventors: Kopperschmidt Wilhelm
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-11-11
Filing date: 1950-04-27
Publication date: 1953-07-07
Anticipated expiration: 1970-07-07

Description

July 7, 1953 w. KoPPERscHMlDT SPRAY DEVICE FOR LIQUIDS'. THERMOPLASTICS, IIOLTEN METAL 0R THE LIKE Filled April 27, J1,950

Patented .ulvy 7, 14953 y y oFI-ICE l 2,644,711lv l SPR-AY DEVICE Foa LIVQuIDs', THERMO- PLASTICS, MoL'rEN OR THE "Wilhe'ImKopperschmidt, Haxnhmg,.ermany ApiicationfAprii 27, 19515,;seia1No.,158,448'

' 'In Germany' November I1', 1949 The present inventionl relates A'to `spray guns preferably of the ,type for hot-spraying yof such coating materials as paints, lacquers, synthetics, thermoplastics, molten metals,y and other corrosion-resistant or insulating materials.

The primary object ofthis-invention is to provide vsuch a spray device inwhichV the spray medi-um Iis continuously adjustably ejected by -high hydraulic self-pressure from a spray chamber through an exchangeable nozzle having a round, at, slotted, oro'ther profile-shaped orice and after ejection is'passed -tl'rroughr mechanical dispersing means arranged-within al` protective jet hood. The-nozzle of the device, tapering offv conically from the Yspra'y-'chambe'r toward its orifice, serves as seat for faconcntrically guided and axially slidable valve needle-with 'correspond-ingly shaped tip cross-section. The protective hood extending from lthe mouth ofthe nozzle either diverges funnel-like or extendstubular4 for a certain distance anddiverges'then;

The provision of mechanica-l dispersing and atomizing means is another object of Vthis invention comprising one or more screens, screenliker'walls, baiiie plates, louvers radially arranged fins, or the like arranged suitably in the path of the issuing spray within the Vjet hood; whereby undissolvable particles, abrasives or veryviscous or sticky materials are additionallydispersedduring spraying and so are' transferred into a uni-1 form protective coating. v

'Spray guns of conventionalconstruction, serving to hot-spray 'lacquers, thermoplastics, or other corrosion-resistant spray mediums by application of compressed airl Aor other gase's'under high tension have'the disadvantage that the large quantities of gases necessary to achieve atomization of the spray mediumyimpingeuponthe su-r'- face to be coated with such an impact thata considerable portion of the material sprayed rebounds from the surface and is carried into the surrounding atmosphere by thegexp'anding gases, forming a ne spray fog in spray booth and work room, impairing health of workmen, and even creating explosive gases. To remove such'gases, requires inconvenient suction'and e'xhaus'tjequipment in thev spray room which is 'also expensive in vinstallation and operation;4 yAnother drawback is that if suchv equipment is inadequate,v other sur-` faces Within the work rooms are loaded and soiled with spray medium. Furthermore, acontinuous change-over of the surrounding atmospheric-air by eiicient exhaust equipment, especially during theA coldseason, Yrepresent-sal considerable andexpensive Aburden-on the hea-ting plantbyexhaust- 18' Claims. (Cl.` 3299-1-48 6) ing large amounts of heated air. High-pressure not-spray apparatus at present in use, having self-contained electric drives and working with pressures of Afrom 3000 toGGO lbs. per sq. in.,v are generally `of complicatedv design, diflicult to handle inconvenient, and in continuous usage therefor'e tiresome tothe opera-tor. Especially, when it is required vto spray' large quantities of material and considerable surface areas with thermoplastics; such known spraying apparatus become completely inadequate. When spraying materia-ls-Awhich tend to form* strings, such as, for

example, thermopl-as-tics, bitumen etc.,with compressed Aair or' gases, the rela`.-tivel'y slow Vissu-ing hotspray-material particles are subjected' to the Acooling effect of the gases, emerging with considerable higher velocity, a-nd are apt to draw strings -of considerable length, chilling on the surrounding air, -and giving thev so-called Woolformation effect'. Under such conditions the surface to` be ni'shedA recel es a very irregular and-spotty'coating.

The present `invention has a further object to provide means toA overcome some or all of the above enumerated shortcomings and to'provide a relatively simple; generally applicable,v and adjustable-spray'- device for most A,diversified spray mediums which assures trouble-free operation and uniform ejection even of spray mediums having' very unfavorable spraying qualities. An important featureA of the present device is that it vnot considerably fumigates the atmosphere of th'e'vjspray room and' that therefore exhausting equipment need not be installed.

Other features and' advantages of the present invention Wijllbecome `appa/rentA from the following' detailed' description taken in. connection with the'ac'companying' drawings showing diagrammatically apreferred embodiment of the invention` and in which:

' "Eigflii's a` longitudinal section of a spray device, wherei'n the upper half Vindicates a form irrwhichno mechanical dispersing means are interposed inthepath of thespray jet issuing from the nozzle; andthe Vlower half indicates the mechanical dispersirig4 means as interposed in the jet path' according to thepresentV invention; and v FigZ isa section on the line 2-2 of Fig. 1 throughl the/spray" chamber with valve needle adjustifngfmeans.

f jQnthedrawing.; theA same'A numerals refer to the samepa-rts throughout and the device shown consists'Orlapressure-proof'housing I with a cylind'rical"bore'formingV a spray chamber 2 which i'sada-ptedto receive and guide a valve need1e-3,v

8 with perforations to allow free passage of spray medium. Collars 8 guide needle 3 concentrically in relation to nozzle 6 in its axial movement Within chamber 2. Nozzle 6, having a chamfered face 9, is tightly screwed against sealing surface 4 within housing I providing a pressure-tight closure of chamber 2 at this point. A short shaft I0 enters through cylindrical housing Wall tangentially into spray chamber 2, said shaft having projections or cams Il fixed in spaced relation to its inside end which engage the collars 8 of needle 3 (see also Fig, 2). The outside extension of shaft IB carries a trigger I2 by means of which needle 3, extending with its tapered and pointed portion I4 into a correspondingly shaped seat in nozzle 3, may be'raised off its seat against the resilient action of a vspring I3 or the like, and the effective opening of the spray vorifice may so be changed as required. In closed position of the device, spring I3 presses the tapered portion I4 of needle 3 against its seat in nozzle 6 whereby pressure-tight closure of spray chamber 2 is assured. The tapered seat in nozzle 6 is adjoined toward the outside, by a round, flat, slotted, or otherwise shaped ejection orifice or mouth-piece I5.

A spray medium supply line I1 connects to a supply opening I6 in housing I leading radially into spray chamber 2 through which hot spray medium is fed into said chamber under high selfpressure. A jacket line 20, surrounding line I1, carries hot oil, hot gases, or other heating means, to keep the spray medium in line I 1 from chilling and congealing. A return line 43 through which spray medium not ejected through nozzle 6 may ow back, is connected to another passage 42, leading also radially into spray chamber 2 but angularly displaced against passage I6. This line is also heated by heating means within jacket line 44 for the same reason as line I1. yJacket line has connection to a radial opening I8 which is axially spaced in relation to passage I6 and joins an axial passage I9 leading into an annular deep groove 2| which in Yturn has connections with a number ofpassages 22 arranged in spaced relation within'the circumferential portion .of housing I around spray chamber 2. Said passages have substantially axial or helical direction and join with vtheir other end a chamber 23 at the rear end of housing I from where a line. 24 establishes connection with jacket line 44; thelatter connection not being indicated on the drawing.

Annular groove 2l is covered by a flat ring25. All passages serve to permit circulation of heating medium around the spray chamber so as to keep its content hot. Outside threads 26 are cut around the front portion of housing I onto which a protective jet hood 21, 28 is screwed. This jet hood has, a cylindrical portion 28 joined by a funnel-like portion 21 and is preferably used in connection with additional mechanical dispersing means indicated at 3i and to be described later. The protective jethood is preferably provided with thermo-insulated heating meansv arranged within the hood Walls when the de- 4 vice is intended to spray thermoplastic materials. Suitably spaced around the hood wall are one or more circular pipes 29 into which hot or burnable gas may be introduced through a supply line 3U. The circular pipes 29 have suitable perforations directed toward the inside of the funnel-like hood or towardthe/.frontopening so the gas issuing fromv said perforations, eitherV burning or only hot, may impinge upon the surface being coated or upon the issuingspray, to affect the spraying process beneficially in vsome Vway. VIf conditions require, it is also possible to introduce cold or heated protective gases,

through line 30 and circular pipes Y29 with their perforations, into hood 21, 28 and so, if applying hot gases for example, prevent string-forming tendencies of the spray medium. The same means may serve furthermore, to protect issuing and dispersing spray medium against coolingdown or other disturbing influences by enveloping the spray in protective warm or hot gases.

This invention provides that certain spray mediums, which are not sufficiently dispersed when issuing from the nozzle, may be subsequently dispersed and atomized by mechanical means within the protective hood, 28. These vdispersing means may comprise one or more screens, screen-like walls, louvers, baffle plates, radial fins or the like suitably arranged within said hood. Spray medium, ejected from the nozzle through a suitable orifice in a circular or flat jet with a self-pressure of about lbs. per sq. in., is hurled with high velocity against such screens or baille plates, :whereby a very intensive dispersion and atomization is eiected. The mechanical dispersing means 3I are preferably removable and exchangeable, and for certain applications also heatable. It is also advisable to provide means for tilting, so that adjustment in relation to the direction of the issuing jet is possible and so a position may be selected which in each instance effects most favorably a certain spray medium applied and suits the prevailing conditions best. Kind of screen, mash of wire, size of bale plates, and other factors have to be properly chosen to obtain best spraying results.

As may be seen in Fig, 2, shaft Ill enters with its extremity 32 into a socket hole 33 in housing IV where it is rotatably conned and resiliently urged toward the left as viewed on the drawing, by spring 39. At its other extremity, located out' side housing I, shaft I0 carries manipulating means such asa trigger I2` The portion of shaft I0, passing through the wall of housing I, is surrounded by a bushing 34 which is screwed into the housing with threads 35 and tightly sealed by a packing ring 36. Bushing 34 is of such a size that all parts secured torshaft II) inside the housing may be removed with said shaft when bushing 34 is unscrewed. An inner sealing between shaft I0 and bushing y34 is obtained by radial sealing surface 38 on bushing 34 and an annular collar 31 tightly tted on the shaft yand resiliently urged against surface 33 by spring 39, which presses the surfaces firmly together. Additional sealingvbetween shaft I0 and bushing 34 is provided in form of a stuffingbox with packing 4I) and cap-nut 4I on the outside of the housing. The cams II, operatively engaging the annular collars 8 on valve needle 3, are so shaped that in one position of shaft I0,

needle 3 with its collars 8 may be axially removed toward the nozzle end.

Spray nozzle 6 (see Fig. 1) may have a slottedY o r oblong orifice whose width may be continug ously changed by an. eccentric arrangement. and adjusting screw or other suitable vmeans (not shown). Spray vchamber 2 may be keptat uniform workingv temperatures by circulating spray medium, hot gases or hot-oil'l through the .passages around the spray chamber, or by electric heating means.

The mechanical dieper-sing and .atomizing means 3l in the path of the issuingspray may have concave, .convex corrugated, or othersuitable configuration; or they may be tilted in some manner vto favorably inuence dispersion into an exceedingly Ifine spray.. -They'may be heated when .spraying thermoplastics, 'bitumen or the like 'to prevent .clogging-.of their .perforations.

It is advisable to provide spray chamber housing I withthermoinsulated.handles which .in `addition .are protected by .suitable shielding` against radiant heat of spray medium and heating means. The handles vth .shieldsarexpreferably universally adjustable and vtiltable in any direction in relation to the body of the spray device, so the .operator is protected from the heat in all possible positions in which the Adevice may be applied when spraying surfaces dicultV of ac.- cess or overhead surfaces.

In hot-.spraying certain vspray mediums, it may suffice to apply back ilowing spray medium4 for heating or heat maintaining of the material in the feed line Il. The material return line 43 is not used in such cases but theV excessive material supplied into chamber 2 is fed .back through jacket line 20. Heating medium, if such should be additionally required to effect temperature anni@ rise within chamber 2, is in such cases fed and returned through another double line. Heating and heat maintaining o one medium by another may also be accomplished in such a manner that they medium to be heated flows inthe Ajacket .line and the heating medium in the inner line.

Handling and operation of the device is as follows: The valve needle 3, which is axially and concentrically guidedwithin cylindrical spray chamber 2, presses under inuence of spring I3 with its tapered pointed .portion I4 against its seat in vnozzle 5, thereby closing spray orificel5 tightly. As soon asl by manipulation of trigger I2, shaft Ii) and its cams II, coacting with annular collarsS on needle 3, are somewhat rotated against the tension of spring I3 needle 3 is lifted oE its seat and nozzle orifice I5 is opened. Spray medium, maintained under high pressure Within spray chamber 2, issues with high velocity through the opening so created. When working with easily dispersa'ble spray mediums such as lacquer, paint, or the like, an arrangement without any mechanical dispersing means is sufcient. Such mediums issue from the nozzle in a circular, flat, cone-shaped, or fan-shaped jet, depending Ion the shape of the orifice.. and leX pand into a fine spray. By proper manipulation of trigger I2 the spray jet can continuously be adjusted or be interrupted at any time. u

When spraying inconsistent, tough or abrasives containing spray mediums, as, bitumen for example, it is advisable to apply additional mechanical dispersing and Yatomizing means as indicated at 3l. More than one screen of ,properly selected wire mash may be -arrangedfaxially behind each other. It is at the same time advisable to provide for adjustable arrangement of screens orbale plates so thed-istance from nozzle 6 and their inclnationin relation tothe spray Jet may be easily Changed@ slit, terrine @adir tions *andi achieve adaptability .to .various lspray' mediums. VTo. prevent clogging of. screens .or baffle-plates. with vcongealing material, '-.i'tV is fad'- visa'ble to provide for heating them additionally .by hot air, vhot oil, or-electrically. .when hot-spraying thermoplastics or .the like.v The spray vmedium is fed through heatable hoses underhy.- .draulic self-pressure ofv aboutfli. .to 5500.1bs. per sq. in. into: .spray ch-amberi! which .is-pressure-tightly .closed .until vvalve needle 3..is1;re traetedby manipulation of trigger I2... Y. ,A fr.

The'hexagon headlof nozzle 6 permits. a ready removal and exchange ofnozzle -6 by application of .asocket-wrench.V With nozzle 6 removed and shaft Lliwithcamsll in a suitable position,'va-lve 4needles may be axially removed and. exchanged. .Sprayehamber l2xcan. then .becleaned without difficulty. Control shaft I0. with cams II can Ybe readily taken out .as a unit with. bushing 34.7by unscrewing the latter. 'Features of easy disassembling and cleaning are very essential .in a spray device, especially .whenv itis necessary'to .change from .one spraymedium tdanothervery Y orten. 'Easily detachable fastening means for jet hood .221, 28 and screens. or baille platesY 3| .Pforcleaning and exchange, .are other advantages of the prese-nt lspray device. The 'provision of .thermo-insulated handles with adjustablev shields facilitates use of the present spray device even under rsuch radverse condition `as -high working temperature yof the spray medium and prevents annoyance to the operator from` the heat radiated by the device. Thus, it represents no problem-to hot-spray ceilings, inside walls of containers, and other surfaces .difficult of access..

While the invention has been'described with reference toA a particular embodiment `thereof it will be understood that changes in arrangement and construction-of parts. be made without cleparting from the spirit and scope of this 'invention. 1 9 A VXZV'hatIclaiInis.:Y Y'. Y f l. `A spray deviceof the character describedrincluding .a pressure-resisting '.spray. chamber, a spray nozzle in oneendwall of said spray chamber, a. protective .jet hood on said end wall and surrounding said. spray nozzle,vmechanical jetdis- .persingimeans Within said hood, an inlet .passage for spray medium to said spray chamber, a valve needle axially slidable within said sprayfcha-mber, ya control shaft with attachedY actuating means, means on `said valve :needle engagingsaid actuating means, a removable bushing surroundingsaid control shaftl at the point of its penetration through the chamber wall', anannular sealing surface on said bushingand a-sealing surface in saidchamber wall coacting with-said annular sealing surface, said bus-hing b-eingof suchl ajsize`V thatY said control shaft with attached y,actuating means can be with-drawn after removal. of said bushing. y Y

2. A spray device as `speciied inclaim 1, in which` said removable bushing, surrounding said control shaft, is provided with .astuing-box for additional sealing between bushing and shaft. g i 3. In a spray device -ofthe charac-ter described, a pressure-resisting spray chamber, an inletpassage for :spray medium, a spray nozzle inserted4 in one wall ofsaid spray chamber having an ejection orifice, a valve needle axiallyslidable within said spray chamber, actuatingv mea-ns for axial .move-v mentof said valve needle,a jet :hoo-d detachably securedY Yto said spray chamber andfproje'cting funnel-like from .the wall :into which saidspray nozzle isinserted and surrounding the latter, and

7 mechanical spray dispersing means inside of said hood and in the path of the issuing spray, jet, said mechanical spray 4dispersing means being adjustable in the direction of the issuing jet.v

4. A spray device as specied in claim 3, in which said mechanical spray dispersing means is heatable, and detachably secured to the jet hood.

5. `In a spray device of the character described, a pressure-resisting spray chamber,y an inlet passage for spray medium, ya spray nozzle inserted in one Wall of said spray chamber, a valve needle axially slidable Within said spray chamber, actuating means for operatively sliding said valve needle in relation to said spray nozzle thereby opening or closing said nozzle, and passages for heating means in the Walls of said spray chamber.

6. A spray device as `specified in -claim 5 in which said heating medium passages run substantially parallel to the axis of said valve needle and said spray chamber and are spaced-apart around the circumference of said chamber, and annular passages at both ends of said chamber in communication with sai-d passages and connected one to the inlet and the other to an outlet passage.

7. In a spray device of the character described, a pressure-resisting spray chamber, an inlet passage for spray medium, an outlet passage for spray medium, a spray nozzle inserted in one Wall of said chamber, a valve needle axially slidable Within said chamber, actuating means for. operatively moving said valve needle, a protective jet hood detachably secured to said chamber, and heating means for said inlet and outlet passages and the connecting lines, said heating means forming part of the connection between said inlet and outlet.

8. A spray device as specified in claim 7, further characterized in that said heating means comprise jackets surrounding the inlet and outlet passages and lines.

9. In a spray device for hot and cold liquids, thermoplastics, and molten metal,' a pressureresisting housing, a pressure chamber within said housing, means for feeding spray medium under high pressure into said chamber, a spray nozzle in the wall of said chamber, a protective jet hood adjoining said housing around said spray nozzle, mechanical dispersing means in said hood, and means for regulating the opening in said spray nozzle.

l0. A spray device as specified in claim 9, said nozzle regulating means comprising a needle valve, a stem on said valve needle, guiding means forsaid stem, and means for moving said stem longitudinally, said stem being located entirely Within said pressure chamber.

11. A spray device as specified -in claim 1, including bearings and guiding means for both ends of said control shaft, and resilient means urging said control shaft axially against said annular sealing surface of said bushing.

12. A spray device as specified in claim 1,' in which the actuating means attached to said control shaft and engaging said valve needle are so shaped as to release said valve needle inV one angular position of said control shaft.

13. A spray device of the character described, including a pressure-resistant sp-ray chamber, a spray medium supply connection, a spray nozzle detachably and pressure-tightly joined to -said spray chamber, a valve needle axially slidable and completely enclosed within said spray chamber for cooperation with said spray nozzle, actuating means for said valve needle, and means on said valve needle engaging said actuating means, said 8? detachable spray nozzle upon removal leaving an opening in the front end of said spray chamber large enough to permit removal therethrough ofA saidvalve needle with its means for engaging said actuating means.

14. A spray device as set forth in claim 13, in which said actuating means include a control shaft mounted transversely of said valve needle Within said spray chamber and extending through the Wall thereof so as to be operable from the outside.

15. In a spray device of the character described, a pressure-resistant spray chamber, an inlet passage for spray medium, a spray nozzle inserted in one Wall of saidY spray chamber, a valveneedle axially slidable Within said spray chamber, a control shaft, actuating means for said valve needle on said control shaft, means on said valve needle engaging said actuating means, a jet hood detachably secured to said spray chamber and projecting. from the Wall into which said spray nozzle is inserted, mechanical 'spray dispersing' means within said hood in the path of the issuing jet, and said hood expanding substantially funnel-like outwards from said spray dispersing means.

16. In a spray device of the character described, a pressure-resistant spray chamber, an inlet passage for spray medium, a spray nozzle inserted in one Wall of said spray chamber, a valve needle axially slidable within said spray chamber, a control shaft, actuating means for said Valve needle on said control shaft, means on said valve needle engaging said actuating means, a jet hood detachably secured to said spray chamber and projecting from the wall into which said spray nozzle is inserted, heating means in said jet hood, mechanical spray dispersing means Within said hood in the path of the issuing jet, and said hood expanding substantially funnel-like outwardsfrom said spray dispersing means.

17. In a spray device of` the character described, a 'pressure-resistant spray chamber, an inlet passage for spray medium, a spray nozzle insertedin one wall of said spray chamber, a valve needle axially slidable Within said spray chamber, a control shaft, actuating means for said Valve needle on said control shaft, means on said valve needle engaging said actuating means, a jet hood deta-chably secured to said spray chamber and projecting from the Wall into which said spray nozzle is inserted, mechanical spray dispersing means within said hood in the path of the issuing jet, said hood Vexpanding substantially funnel-like outwards from said spray dispersing means, and suitable pipe lines in said jet hood having perforations for the purpose of ejecting pressure gas or flames into said hood.

18. In a spray device of the character described, a pressure-resistant spray chamber, an inlet'passage for spray medium, a spray nozzle inserted in one wall of said spray chamber, a valvel needle axially slidable within said spray chamber, a control shaft, actuating means for said valve needle on saidcontrol shaft, means on said valve needle engaging said actuating means, a jet hood detachably secured to said spray chamber and projecting from the wall into which said spray nozzle is inserted, mechanical spray dispersing means Within said hood in the path of 'the issuing jet,said hood expandingl substantially funnel-like outwards'from said spray dispersing means, suitable pipe lines inr said jet hood having perforations for the purpose of ejecting pressure gas or flamesv into said hood, and said perforations in said pipes being arranged so as to cause the ejected gases to form a gaseous protective jacket against atmosphere influence around the issuing spray jet.

WILHELM KOPPERSCHMIDT.

Y References Cited inthe le of this patent UNITED STATES PATENTS Number Name Date Kovanda et al. Sept. 13, 1927 Hammers Oct. 20, 1931 Krantzberger Oct. 27, 1931 Gellner et al. July 6, 1937 Number Number 10 483,517 879,971 553,099 87,109