US 2233304 A
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Description (OCR text may contain errors)
Patented Feb. 25, 1941 APARATUS FOR DEPOSITING FLUENT MATERIALS Pun-ling Allen Bleakley, St. Louis, Mo., assignor,
by mesne assignments, to The Bleakley CorPO- ration, Toledo, Ohio, a corporation of Delaware Application September 16, 1936, Serial No. 100,987
This invention relates to a molten metal spray apparatus, and has particular reference to a means for introducing into the pencil of finely divided molten metal which issues from the metal spray apparatus a uent material, preferably in the form of a powder for impregnation oi' the deposited metal when it hardens, for coactionwith the molten metal either mechanically or chemically while it is still in the molten state, for acting upon the surface upon which the molten metal is to be deposited in such a way as to effect a thermal bond between the deposited metal and the surface, and for other purposes.
Attempts have been made heretofore to impregnate or mix solid metallic or non-metallic particles with molten metal for various purposes. For example, in the manufacture of anti-friction bearings ofthe graphite-impregnated type, it has been attempted to blow by means of a current of air or the like, powdered graphite into a stream of molten metal in such a way that when the metal hardens it f orms a matrix for the graphite. These attempts have not been successful, largely because the metal is not sufficiently finely-divided or atomized before the graphite is introduced therein, with the result that while the hardened metal contains a small proportion of graphite, the graphite is not uniformly distributed 30 throughout the metal but occurs in relatively large irregular patches, so that the graphite 1s not adequately available for uniform lubrication of the bearing during operation. Attempts have also been made to mix powdered metals or the like with a flame or pencil of molten metal for the purpose of melting the powdered metal or causing it to combine chemically or mechanically with the molten metal, but these attempts have not been successful, largely because the powdered metal has not been introduced at the proper point in the flame or in the pencil of molten metal, and in the latter case, because the molten metal has not been sufficiently iinely divided for intimate mixture with the -powdered metal or 45 other material.
In accordance with the present invention, a molten metal spray apparatus is provided, preferably of the general type disclosed in copending application Serial No. 756,076, iiled December 5,
50 1934, whereby the iluent material, whether liquid or powdered metal, non-metal, or mixtures of metal and non-metal, is introduced into the llame and pencil of either molten metal or other material melted in the metal spray apparatus at a 55 point 'beyond the melting chamber.
More specifically, in the apparatus of the aforesaid copending application, on which the iiuent material distributor is preferably an attachment, .the material to be initially molten minute particles by means of a .tubular envelope of a gas, which preferably contains a component rendering the gas inert or 4deoxidizing it where it initially contains oxygen, or which contains a iiuid material specifically reacting or combining chemically with the molten material. I'he attachment for connecting the metal spray apparatus of the form described into the apparatus of this invention is mounted over the restricted discharge oriii-ce for introducing into the pencil of molten material within the gaseous envelope the iiuent'material under pressure from a reser- 20 voir, which is either placed under pressure to force the fluent material therefrom and through the gaseous envelope into the pencil, or is so arranged that the fluent material is abstracted therefrom with an aspirating action by means ,25
of a current of gas under pressure for forcing the iiuent material through the gaseous envelope into the pencil of molten material for intimate commingling therewith. c
It will be seen that with the apparatus of the 30 present invention, fluent extraneous material, either liquid or powder, may be eiectively and intimately mixed with the iinely-divided molten material in such a Way that when .the material hardens, the initially fluent material is either uniformly distributed throughout thehardened material, or is intimately mixed therewith if it is ofthe nature producing a chemical action or a solution with the molten material.
For a more complete understanding of the invention, reference may Ibe had to the accompanying drawing, in which:
Figure 1 is a side elevation of the apparatus of this invention;
Fig. 2 is an enlarged axial section through the 45 spray head of the apparatus, showing the arrangement of the fluent material distribution;
and r Fig. 3 is an enlarged fragmentary section of the lower portion of the uent material reservoir, showing the iiuent material injector.
Referring to the drawing, numeral I0 generally designates the metal spray apparatus disclosed in the aforementioned application and includes a base Il', preferably pivoted or otherwise 55 mounted on a suitable support I2. for movement relatively to the surface being sprayed, and carrying the wire feed mechanism-housing 'I3 and the Wire feed motor I4. Secured to the housing 5 I3 is a hollow bracket I5 through which the wire is advanced to the spray head I8supported by the bracket I5 and shown in enlarged section in Fig. 2.
The wire I1 of metal or other material to be 10 molten is advanced by the wire feed mechanism through the spr'ay head I6 into the melting chamber I8 having the nozzle I9 forming the restricted discharge orifice 20. The combustible gas for heating the melting chamber I8, such as a mixture of acetylene and oxygen. is supplied thereto through passages 2| from a suitable mixing device 22 to' which the individual gases are supplied by means not shown. The molten metal or other material is finely-'divided and conveyed out of the melting chamber I 8 to the surface 23 of deposit by a tubular envelope of compressed gas supplied throughpassages 24 from connected annular chambers 25 to which the gas is supplied 'by pipe 26.
25 As described in the aforementioned application, the tubular envelope gas may 'be air, which is preferably rendered inert by having mixed therewith an auxiliary gas, such as hydrogen, acetylene, or the like, for deoxidizing it. Alternatively, the auxiliary gas may be an active gas for reducing or reacting with the molten material, as described in said application. This auxiliary gas is supplied to annular chambers l25 through metering port 21 from pipe 28. A portion of the envelope air is bled'through metering port 29 into passages 38, which lead it into the melting chamber I8, where the air serves as secondary combustion-supporting air. While the arrangement described is preferred, it may be modified to suit requirements.
Threaded on nozzle I9 as shown in Fig. 2, or otherwise mounted at the discharge orice 20 is a dished disc 3| which forms with the inclined outer surface of nozzle I9 an annular depression.
Screwed or otherwise secured to the disc 3I and forming therewith the annular chamber 32 is a nozzle pl-ate or ring 33 having central opening 34 encircled by the flange 35 and aligned with discharge orifice 20 of nozzle I9. Opening 34 is larger in diameter than the end of nozzle I 9, so that an annular pasage 36 leading from chamber 32 is formed.
Discharging into chamber 32 near the periphery thereof is a pipe 31 supplied with fluent material from reservoir 38 in quantity regulatable by needle valve 39 adjustably threaded through the cover 43. The iluent material in reservoir 38 is preferably aspirated therefrom into pipe 31 by an air blast through injector 4I, supplied by pipe 42 controlled by valve 43 from source pipe 44, in turn controlled by shut-off valve 45. Preferably connected to pipe 42 between valves 43 and 45 is a branch pipe 46 leading to the upper portion of the reservoir 38 above the iluent material therein and controlled by valve 41, so that,
if required, pressure may be applied to the material from above.
In operation, assuming that it is desired to mix a uent dry material, such as powdered graphite, with a metal, such as babbit, for the purpose of depositing a self-lubricating bearing material on the surface 23, the wire I1 is of babbit and the graphite is charged into reservoir 38. The metal spray apparatus I il is then placed in 75 operation to spray a pencil of finely-divided molten babbit through orice 23 by means of the tubular gaseous conveying envelope. The air valves 43 and 4 5 are opened and the resulting action of Injector 4I causes the graphite to be blown under pressure through pipe 31 into an- 5 nular chamber 32, from which it is uniformly distributed through annular passage 36 into the molten metal pencil, the pressureof .the graphite blast being suilicient to penetrate the tubular gaseous envelope, so that the graphite intimately l0 and uniformly commingles with the nely-divided molten material. The mixture of graphite and babbit is deposited on surface 23 and when the babbit hardens, it forms a matrix for the uniformly dispersed graphite therein. Y l5 The supply of fluent material is preferably. regulated jointly by theair blast and by needle valve 39. Where pressure on the fluent material is desired instead of or in addition to the aspirating action, the valve 41 is opened and properly 20 manipulated. Where only aspiration is employed the reservoir cover 40 is provided with an air leak. The inlet from pipe 31 may be arranged tangentially in chamber 32 to impart a whirl to the graphite.
In order to prevent pre-cooling of the molten spraying material by the uent material blast, a combustible, such as acetylene, hydrogen, or the like, may be mixed with the air from pipe' 44 so as to ignite as it mixes with the flame is- 30 suing from nozzle I9.
Metallic, as well as non-metallic, fluent-materials may be supplied in this way to be mixed or otherwise combined with the molten material, or the fluent material may be a liquid, such as a 35 molten material, heavy oils, tars or waxes, and the like, for effecting combinations of dissimilar materials of practically any kinds that will remain in miscible state under the conditions of operation of the apparatus. For example, pow- 40 `dered metals and metallic compounds, such as metallic aluminum, aluminum oxide, ferro-silicon, and the like, may be initially sprayed with or without molten metal to serve as a iluxing agent for preparing the surface to be sprayed in 45 order to secure a good bond between it and the molten material. Thus, after the uxing materials have been employed to treat the surface to be sprayed, their supply is shut olf and the molten material then deposited alone. 50
Also, alloys of aluminum and steel provided by spraying the former in powdered form or alloys or mixtures of other metals may be effected in the same manner. Molten lead or other material may be supplied from the reservoir for mix- 55 ture with finely-divided molten copper or other metal in the sprayed pencil for making copper'- f lead bearings or the like, the pressure and speed of the conveying envelope largely preventing volatilization of the lead or low melting material 60 mixed with a high melting material. Other advantages of the new apparatus are apparent.
It will be seen that with the arrangement of the present invention, each fine particle of the molten or heat-softened material is kept separate 65 uniform subdivision of the heat-softened and fluent particles this intimate and uniform mixture is maintained to the place of deposit.
1. In apparatus of the class described, the combination of a first nozzle, means forming a passageway for reception of a rod to be melted in said first nozzle, means for directing a gaseous stream therethrough to melt said rod and spray the molten material through said rst nozzle, a peripheral chamber around said first nozzle providing an annular passage disposed entirely in the radial plane of the outlet of said rst nozzle, a second nozzle extending from the outer periphery of said passage forwardly from said first nozzle and concentric therewith, and means forl supplying finely divided solid material to said chamber for introduction into said stream through said passage.
2. In combination with a molten metal spray apparatus having a nozzle provided with a single discharge orifice, a passageway for receiving a metal rod to be melted, at least one passageway for supplying a combustible gas and a chamber wherein the gas is burned to melt said rod in said nozzle and spray the molten metal through said orifice, a chamber surrounding said nozzle for supplying finely dividedA solid material for i mixture with the metal spray issuing therefrom,
and a second nozzle on said chamber concentric with said first nozzle and forming with the latter an annular passage around the orifice of said first nozzle through which said material is admitted into the spray, the inlet end of saidl second nozzle being positioned substantially in the radial plane of the end of said first nozzle, whereby said passage is positioned substantially in said plane. 3. In combination with a molten metal spray apparatus having a nozzle provided with a single discharge orifice, apassageway forreceivinga metal rod to be melted, at least one passageway for supplying a combustible gas and a chamber wherein the gas is burned to melt said rod in said nozzle and spray the molten metal through said orifice, a chamber surrounding said nozzle for supplying finely divided solid material for mixture with the metal spray issuing therefrom, said chamber being formed by the exterior surface of said nozzle and an enclosing wall having an interior Surface lying substantially in the plane of the end of the nozzle and an opening surrounding said nozzle and providing with the exterior surface thereof an annular passage lying substantially in the radial plane of the end of the nozzle orifice, and a second nozzle projecting forwardly from said wall concentrically with said iirst nozzle.
PURIJNG ALLEN BLEAKLEY.