Патент USA US2133504код для вставки
Oct. 18, 1938. H. R.'F'oR'roN , 2,133,504 ' vMEYI'ALIZING SPRAY ‘GUN FiledOct. 2, 1935 v‘ - v ,INVENTOR. xarald?. fiz'arfarz ' I I v 2,133,504 Patented Oct; _ 18, 1938 UNITED STATES I PATENT OFF-ICE 2,133,504, METALIZING SPRAY GUN Harold it. Foi‘ton, Detroit, Mich. I _ Application October 2, 1935, ‘Serial No. 43,164 5 Claims. This invention relates to portable apparatus for melting, atomizing and spraying metals, hav (01. 91-123) A still further object involves the conduction ing generally as its object the provision of an improved organization of parts adapted to apply 5 in this manner a metallic coating to any suitable protect the \latter by a surrounding ?lm of highly heated gases to assist in maintaining the tem surface/by projection of the molten atomized perature of the nozzle. metal against the work in a pressure-induced A still further aim'of the present invention comprises the provision of improved heating stream. 1 of heated gases from the heating chamber around the crucible and over the nozzle to constantly ‘ . _ ‘ ' t . ' means carried by and located entirely within the Various forms of apparatus for accomplishing these general ends have been known heretofore, and while some have worked satisfactorily for certain‘purposeaall have been subject to short head, together with means for proportioning the heating effect to the rate of delivery of blast air comings, and there has not to my knowledge been stant delivery of a uniform atomized blast of available heretofore a satisfactory small and portable implement, or one of any size manu molten metal is insured. 10 and metal tovbe melted in such manner that con , In the drawings: Figure 1 is a side elevational view of an im- " facturable at low cost yet reliable in operation. It has also been’ considered necessary to utilize ~ proved device incorporating the principles of my ?aming'gases in the projection ‘of the atomized invention. Figure 2 is a sectional view thereof taken sub- . metal, thus rendering impossible the coating of stantiallyon' the line 2—2 of Figure 1 and look 2 “combustible substances. Further, where such ?ame-type projection is employed, a triple nozzle ing in the direction of the arrows. ; .Figure 3 is a longitudinal sectional elevation must be provided, that is, there must simul taneously be fed from as close to a common point vtaken generally on the line 3-3 of Figure 2 and as is practicable, molten metal, air under pressure, 25 and the gases of combustion. This fact has made ' it impossible from a practical standpoint to re duce the size'of the nozzle and apparatus to pro portions allowing ready portability and treat 1~_ment of relatively small work, such as that re 30 ‘quired to be coated) in the field‘, of mechanical dentistry. The present invention aims to over come the mentioned dif?culties, to provide efl‘icient operation without the use of ?ame projection, and in a manner which enables use of a much ’. 35 smaller nozzle assembly, and consequent adapta tion" of the apparatus to manufacture in much looking in the direction of the arrows. > ' Figure 4 is an enlarged detail sectional view of 25' the nozzle portions. - _ ' Figure 5 is a sectional elevation thereof‘itaken substantially as indicated on the line 5--5 of Figure 4 and looking vin the direction ‘ of the arrows. , Figure 6 is an enlarged detail sectional view of one of the gas Jet nozzles. '30 _ Referring now to the drawings, reference char! acter i0 designates a generally cylindrical sheet metal housing, carriedby- a handle l2 and hav ing a back or upper wall and an open lower face in which the nozzle-projecting portions are sup ported. upper or back wall is apertured, as physical proportions, and of such ,size as to enable at H, to Its allow the escape of hot gases. Within the performance of small and ?ne work. A further object is the provision of such ap- _ the casing element is a framework carried there smaller, more easily handled and economical paratus of the gun type, in which melting, of the metal takes place entirely within the gun, and no storage or reservoir of molten metal is provided, the metal being projected immediately upon melt 45 ing and consequently given .no opportunity to unduly oxidize. , by. comprising a generally cylindrical ring ele ment l5 supported within the outer casing by screws I6, and a backing plate I! provided with a ?ue portion 20 arranged to ‘ discharge through the opening ill in the back wall of the casing. 4 The ?ue may be guarded as by a hat 22 arranged . A further important object is the provision of thereover to protect the user of the implement, whose head, or other portions of whose body might such apparatus in which air is used for projec tion of the molten metal, but cannot cool the at times come close to the ?ue. The hat is shown metal before it leaves or cause congelation there . as swingably attached, so that it may be moved 50 clear of the flue to allow removal of the crucible of in the nozzle. ‘ _ ' Another important object is the provision in and other internal parts; a loose rivet, as 23, such a device of an improved combined crucible serving to pivotally attach the hat to the back wall and nozzle element for the molten metal, which of the casing. In the‘ open front of the casing-and spaced 55 crucible element serves as a conveying tube rather from the ring I5, supported if desired by the than storage element for the molten metal, to gether with improved means for protecting the . same screws I6, is an annular element 25 pro nozzle portion against engagement by the aspirat ing air, and consequent undesired conduction of 60 heat therefrom. vided with a circular feeding channel 21 for com bustible gas, which is burned to provide the heat ‘source. The front of element 25 is provided with 60 ‘‘ 2 2,133,504 a generally frusto-conical depression 29. The freezing of the metal within the nozzle. The _ depression. is closed and thus made to constitute ' base of the crucible and the surface of element an air delivery chamber by a front plate 30. In tegral with element 25 is a forwardly projecting cylindrical central wall 26' which, as best shown in Figure 4, projects‘ into ‘the space within and de?nes the inner periphery of the annular air 25 upon which it rests are not roughened or oth through the hollow handle [2, and discharge into the general effect of the suction, moreover, is erwise specially treated to allow the desired minute‘gas ?ow therearound, but are in my pre ferred construction simply machine ?nished. It may be that the slight ?ow necessary to main feed opening 32, guarding the nozzle 52 'thru ' tain the skin of heated air about the nozzle is possible because of the vibration of the loose which the molten metal is discharged against di crucible due to the action thereupon of the 10 rect engagement by the aspirating air. flames, metal, and air ?ow. It is to be noted that Air and gas delivery tubes 34-35 may be run the air passage 29 and gas passage 21 respective ly, while ‘the metal to be sprayed may also be 15 delivered through thehandle, preferably in rib bon form, as indicated at 31. Driving means for feeding the ribbon may comprise a pair of roll ers 38—-39 in frictional engagement therewith, and one, as'39, drivable by such means as worm v20 and worm wheel ill-4|, the former in turn car ,-"f'ried upon and drivable by flexible shaft 44, which may project from the handle to any suit able source of power, as the electric motor dia grammatically indicated at 45'. The air and gas 25 passages, or at least those portions thereof which project from the handle, are of course preferably ?exible, as is the ribbon 31, and the air and gas supply couplings and the ribbon supply reel or the like (unshown) may be mounted upon the .30 bench- (also unshown), or other support upon which the tool is to be used. It is preferable for the sake of convenience that the tool, if pro— portioned for small work, such as the metalizing operations frequently desirable in mechanical 35 dentistry, be used within a few feet of these con nections and the motor, so that the connecting tubes, shaft and’ ribbon may not be unduly long and cumbersome. A combined metal melting and delivery tube 50, which will for convenience be designated a crucible, is arranged substantially coaxially of and centrally within the casing, the upper end thereof being closed by a plug as 5|, while ‘its ,lower delivery end carries the integral nozzle extension 52 which projects through but is some what smaller than the space within the cylin drical wall 26, as best indicated in Figure 4. The crucible is preferably formed of metal, although it may be ‘of refractory material, but in either event is merely loosely positioned within the cas ing, not tightly secured in place, and provided with an annular pocket 53 surrounding the noz zle portion 52 at its area of connection with the body of the crucible, such pocket being thus con 55 nected to the space between the nozzle 52 and wall 26. The base portion of the crucible sur to maintain the crucible seated, so that although vibration may allow a slight ?ow therebeneath, flaming gases cannot escape. 15 _ The metal ribbon is fed into the side of ‘the crucible through a simple oversized opening 60, and is melted as fast as it enters by the flames from the gas jets 63, which are so focused as to concentrate the hottest portions of their flames 20 upon the wall of the crucible. Six such jets are shown, a pair carried by each of three combined bolts and gas feed’ tubes 65, extended between element 25 and backing vplate l8 and secured to each ‘by suitably threaded coupling portions 66- 25 61, the former providing a gas connection between thesupply chamber 21 and the gas channel 68 in each element 65, while a nut 69 may be se-' cured upon the portion 61 which projects through the backing plate. Each gas nozzle is axially 30 drilled, as at 10, to provide gas connection with the passage 68, while air ports 'Il through the sides of the nozzles supply air in suitable quan titles to the larger mixing and discharge ori?ce 12, these parts being proportioned in accordance with the gassupply, and, as stated above, to focus the hottest part of the ?ame upon the cru cible. The stem of each nozzle 63 may extend far enough into passage 68 to partly close the connection between it and the nozzle opening, thereby serving as a pressure reducing or meter ing ori?ce, which, particularly inthe case of the nozzle nearer the supply chamber 21, equalizes the gas supply pressure. The air supply for the burners enters the casing through the space 15 45 between element 25 and ring l5. ‘ It will be seen that in event it is desired to remove the crucible it is merely necessary to swing hat 22 clear of the ?ue and remove the cru cible therethrough, since it merely rests in place. 50 I have found that a tool constructed in the man ner described, and substantially in the propor— tions shown, functions more satisfactorily than any similar device of which I am aware, and par ticularly embodies satisfactory‘ operation in a much smaller construction, but it is necessary that rounding the pocket 53, and which rests upon the aspirating power of the air blast equal or ex the top wall of element 25, is not so ?nished as to ceed the rate of metal delivery, and that the heat tightly conform to and seal itself against such ' ing also be rapid enough to melt the metal as fast as it is delivered. The heating of the cruci wall, as a result of which when, during opera tion, the aspirating air blast reduces the pressure ble near the nozzle end is also important in main in front of the nozzle assembly with respect to taining the‘ temperature of the metal and the , the pressure within the casing, a certain amount of the air and/or heated gases within the casing 65 may leak between the base of the crucible and element 25, into the‘pocket 53, and out around the nozzle 52, such air being highly heated by its contact with the. crucible and forming a skin -of heated gases surrounding the nozzle and pre— 70 venting undue absorption of heat therefrom by the colder wall 26, thus assisting in maintaining the temperature of the nozzle, which effect is also aided by the shortness-of the nozzle and its in tegrality with the crucible. These factors fa 75 cilitate ready heat conduction and guard against nozzle. ' > It is also not possible, in accordance with my experience, to make the gun function properly, 65 and to prevent clogging in the nozzle, if the cru cible is tightly secured. The proportioning of the nozzle with respect to the air discharge and pressure, the rate of metal delivery and the heat, must of course be fixed, but once satisfactorily 70 set no adjustments are necessary. It is best, if constant pressure air supply is not available, to utilize a controlling valve in the air line adapted to maintain the pressure reasonably constant. The drawings accompanying this disclosure are, N 3 2,133,504 excepting as to'the enlarged views, substantially of full size and proper proportions, although the limits of drafting ability will not enable accu rate showing of the proportions of the nozzle and jet openings, which must be ?xed with accuracy. 3. In a portable metalizing device, a casing hav ing an opening therein, a combined metal fusing and conducting element within the casing having an inlet opening near one end thereof and an out These can be readily ?xed by the designing en let nozzle portion connected to its other end and extending through the opening in the casing, ' gineervhowever, although it may be of further help to set forth that in connection with such a means for feeding metal in strip form substan tool, utilizing a metallic ribbon oi’ tin-lead mix 10 ture, similar in composition to ordinary solder, and an air pressure of 35 pounds, the air dis charge should be approximately 2l/gycubic feet per minute. A blast projection is then secured at the nozzle at a rate approximating 20,000 feet 15 per minute. Due to the protection of the metal against loss of heat up to the very instant of its discharge, and the apparent tendency of each tialiy continuously through the inlet opening and into said element, means. for heating other‘ por tions of said element, an atomizing jet ori?ce ad 10 jacent the nozzle and discharging in the same gen~ eral direction for aspirating and projecting the metal, a wall between said nozzle and blast jet ori?ce for shielding the nozzle against direct impingement by the atomizing blast, said wall 16 also providing a restricted passage between the interior of the casing and the nozzle to enable atomized particle to shield itself with a protecting ' the heating of the latter by means of hot gases skin of heated air which remains stagnant de— from the interior of the casing, and means ap 20 spite the propagation of the particle, the blast will arrive at and adhere to the work in an homo geneously fused coating, even though projected purtenant said ?rst mentioned opening to pre 20 vent escape of flame through said passage. through a considerable distance. The tool is ordinarily used in the horizontal position in which 4. In a device of the character described, a housing having a heating chamber and an open ing therein, a “combined metal fusing and con 25 it is shown, but functions satisfactorily when ducting element in the heating chamber, a nozzle tilted as much as forty-?ve degrees. While it will be apparent that the illustrated embodiments of my inventionherein disclosed are well calculated to adequately ful?ll the ob 30 jects and advantages primarily stated, it is to be understood that the invention is susceptible to variation, modi?cation and change within the spirit and scope 'of the subjoined claims. What I claim is: 35 1. Means for spraying atomized molten metal comprising a housing incorporating a metal re ceiving crucible, heating ‘means, therefor and a discharge nozzle for melted metal directly con nected to and integral with the receiving means, connected to' said element and discharging out side the chamber through said opening, means for delivering metal to said element substantially continuously, means for heating said element to melt the metal therein at a rate at least as fast as 30 that at which it is delivered thereto, aspirating means including a jet surrounding the nozzle for discharging a gaseous projecting agent and draw ing the molten metal from the crucible through the nozzle to form an atomized blast thereof, the 86 aspirating power of the jet being at least as great » I as the rate of melting and delivery of the metal, said surrounding jet being spaced from the nozzle by a separate wall concentric with but spaced 40 means for maintaining the nozzle in a heated ' from the nozzle, the jet being arranged to draw condition, a blast discharge nozzle surrounding heated gases through the space between said wall the metal discharge nozzle and arranged when in operation to aspirate the molten metal from the first mentioned nozzle and atomize and project 45 such metal, said ?rst mentioned nozzle project ing loosely through the blast discharge nozzle, and the crucible being free to move with respect to the housing. 2. In a device of the character ‘described, a 50 housing having a heating chamber therein and an opening connecting the same with the exte rior, a combined metal fusing and conducting element within and smaller than the heating and nozzle to maintain the temperature of the nozzle, said element and nozzle constituting an assembly rested loosely in said housing and against said opening, and means for heating the 45 nozzle without allowing ?ame projection. 5. In a device of the character described, a housing having a heating chamber and an open ing therein, a combined metal fusing and con ducting element in the heating chamber, a nozzle connected to said element and discharging out side the chamber through said opening, means for delivering metal to said element substantially continuously, means for heating said element to chamber, a metal discharge nozzle portion car 65 ried by and connected to the interior of said ele- - melt the metal therein'at a rate at least as fast ment and projecting through but smaller than as that at which it is delivered thereto, aspirating .55 the. opening in the housing, means within the means ‘including a jet surrounding the nozzle for heating chamber for heating said element, means discharging a gaseous projecting agent and draw including a projection jet appurtenant the open ing the molten metal from the crucible through ing and adapted to discharge a projecting ?uid under pressure to reduce the pressure at the mouth of the nozzle and induce molten metal within said element to flow therefrom, and means for feeding metal to said element, said element and nozzle being fitted loosely enough in the opening to allow a slight ?ow of heated gases from within the chamber through the space‘be tween the nozzle and opening, to maintain in a highly heated condition the metal within the 70 nozzle while preventing ?ame projection‘, said heating means, metal fusing and conducting ele ment, nozzle and projection jet being so propor tioned as to discharge the metal as‘fast as it is melted. the nozzle to form an atomized blast thereof, the aspirating power of the jet being at least as great as the rate of melting and delivery of the metal, said surrounding jet being spaced from the noz zle, and the nozzle being relatively short and con stituting a unitary assembly with said element and resting loosely in said housing and against 65 said opening, whereby e?icient heat conduction may take place between the element and nozzle, and whereby heated air may escape around the nozzle but escape of ?ame is inhibited, whereby 70 the nozzle is heated by the'escaping air. l HAROLD R. HORTON.