US2530186A - Portable spraying apparatus for molten materials - Google Patents

Description

Nov. 14, 1950 E. L. TRIMM ET AL PORTABLE SPRAYING APPARATUS FOR MOL'IEN MATERIALS Filed Oct. 13, 1947.

Fig. 1

.Fig. 2.

2 Sheets-Sheet 1 ERNEST L. TRIMM may; yw m ATTORNEYS.

INVENTORS.

NOV. 14, 1950 TRlMM ETAL 2,530,186

PORTABLE SPRAYING APPARATUS FOR MOLTEN MATERIALS Filed Oct. 13, 1947 2 Sheets-Sheet 2 INVENTORS.

ERNEST L. TRIMM NATHAN Anne ATTORNEYS.

#UNITED- l'sTA Patented Nov. 14, 1950 PORTABLE SPRAYING'APP A Y MOLTEN MATERIALS Ernest L, Trimm and Nathan Arnovv, Norfolk, Va.-

' Application October 13, 1947, Serial No. 779,474

' 4 Claims. (o1. 91 12.2)

This invention relates to an improved portable and self-contained apparatus for spraying lead, and other low-melting point metals, alloys, and plastics, for metallizing, filling in, and/or coating metal surfaces, a primary object of this invention being to provide apparatus of this type which more nearly meets the ideal of small size and compactness, light weight, and good balance, to a degree that the average worker can-operate with greater speed and accuracy, and with less fatigue than heretofore, thereby being able to-clo more and better work in less time.

Another important object of this invention is to provide a device of the characterindicated above,-in which the main weight or bulk of the device, including the reservoir and its contents of molten metal, are vertically aligned above the handle of the device in sucha way that overhanging and unbalanced weight factors are eliminated, whichwould otherwise require counterbalancing either by undesirable additions of counterbalancing weights, which would increase overall weight of the device, or by exertions on the part of the operator other than those involved in lifting or supporting, and directing the spraying action of the device, such that the operators efiiciencywould be substantially reduced.

Another important object of this invention is: to-provide' a device of the character above-indi-' cated which contains constant heat metal melting means operating at an unusually high Working temperature, utilizing any available heating gas'gsuch as illuminating gas oracetylene, and inaddition, built-in means for pre-heating the spraying air before it reaches the spray nozzle so as toeliminate cooling effect at the point of the sp Another important object of this invention isthe provision of a deviceof the character indicated above, which has an unusually large molten metal capacity, inan arrangement which assures a constant spray, and wherein means is provided to prevent slag from passingfrom the molten metal reservoir to the spray nozzle or through the valve mechanism;

Another important object of this invention is the provision of a device of the above indicated character, having a novel compound spray noz zle, involving structure in which the inner molten metal nozzle, when assembled into'the outer air nozzle is perfectly and unavoidably centered therein, and wherein means is provided to trap any slag which may reach the nozzle before the slag can clog the nozzle or be sprayed therefrom.-

A still further important object of this invention is to provide a device of the character indicated above which contains a novel construction and arrangement of moltenmetal shut-off valve mechanism eliminating drip or after run of the molten metal and providing positive and accurate control of the flow of the molten metal from the reservoir to the spray nozzle. Y

A still further important object of this inventionis the provision of a device of the character indicated'above inwhich the molten metal controlling valve and a spray air valve are associated in directly cooperative'relation for simultaneous operation by a single hand lever, whereby the flow of molten metal and of compressed air are properly timed andcoordi'nated.

A still further importantobject of this invention is to provide a device of the character indicated' above having special insulation means precluding'dir'ect transmission of heat between the molten metal reservoir and its heating means, and the handle and valve operating hand lever of the device, thereby assuring a cool handle.

Other important objects and advantageous features of this invention will be apparent from the following description and the drawings thereunto appended, wherein, 'for purposes of illustration and disclosure only, a presently preferred embodiment of this invention is set forth in detail.

In the drawings: i 7

Figure 1' is a left hand side elevation of said embodiment. 7

Figure 2 is a top plan view,

Figure 3 is a vertical central the line 3-3 of Figure 5.

Figure 4 is an enlarged verticallongitudin-al section taken through the spray nozzle.

"Figure 5 is a fore end elevation; V

Figure 6 is a transverse vertical section taken on the line 6 -6 of Figure 3. a

Figure 7 is a horizontal section taken on the line 11 of Figure 3, and,-

Figure 8 is a horizontal section taken on the line 8-8 of Figure 3.

The herein illustrated embodiment of the invention comprises in general (a) a vertical pistol-grip handle through which heating gas and air blast conduits extend and on which is section taken on mounted valve means controlling the flow of metal and air to the nozzle; (b) combined heat insulating means and molten spray metal pot or reservoir shielding and supporting means consisting of air spaced and contact insulated plates mounted upon the upper end of, the handle; (c) the melting'pot or reservoir assembly mounted upon and airspaced above said plates and consisting of a melting pot and its cover, a special air and molten metal spray nozzle, a special valve for admitting molten metal to the nozzle, means for trapping slag in the pot and in the nozzle, and an air chamber connected by conduits to the air valve and to said nozzle, for preheating and stabilizing the air on its way to the nozzle.

Except for the spray nozzle, the valve parts,

the conduit connectors or couplings, and-the assembling studs and the like, which are preferably of cast or spun brass, the component parts of the device are preferably of cast aluminum in order to gain the advantages of light weight, adequate strength, and relatively low-heat transmission between the parts.

Referring in detail to the drawings, the nu-- meral 9 generally designates the pistol grip handle of the device of relatively uniform oval cross section having a slight forward inclination with respect to the perpendicular and terminating at its upper end in a generally horizontal portion ID, the major portion of which projects rearwardly, as indicated at II, to a point just rearward of the lower end of the pistol grip, where said portion II has an upstanding transverse V- shaped foot I2. At the forward end of the portion I is a forward projection including an upset foot I3 of relatively flat forwardly elongated form. These feet are provided to support thereabove the superjacent structure hereinafter described.

As shown in Figure 3, the forward part of the handle 9 is formed with a forwardly inclined very tical bore I4 through which the heating gas blowpipe I5 extends to emerge at the top of the handle at a point just rearward of the front foot I3. The blowpipe is mounted in concentrically spaced relation in the bore I4 by an ordinary perforated plug I6 threaded into the lower end of the bore and having air admitting passages II communicating with its gas passage I8. A coupling 29 may be used to connect to the plug I6 a gas shut-off hand valve 2I which in turn is connected to a suitable source of illuminating or heating gas, including acetylene (not shown).

Spaced rearwardly from the blowpipe bore I4 in the handle 9 is the compressed air or blast conduit 22 whose lower end is equipped with an adapter 23 threaded therein and arranged for connection to a suitable air blast hose (not shown). The upper part of the air conduit 22 curves upwardly and rearwardly to connect with the inlet and outlet parts 24 and 25, respectively, of the air blast control valve 26, which is preferably mounted on the right hand side of the upper portion I 0 of the handle. Above this valve the uppermost portion of the air conduit 22 opens through the top of the rearfoot I2 as indicated at 21.

The air control valve 26 comprises a body 28 suitably fixed to the side of the handle portion III, which includes, as shown in Figure 8, the axially spaced non-communicating bores 29 and 30 opening through opposite ends of said body. A gland 3| threaded in the outer end of the bore 30 bears against a packing 32 for the valve stem or rod 33 which projects through and beyond the gland 3| in one direction, and through a conforming body bore 34 in the opposite direction into the bore 29 where it has fixed thereto a conforming cylindrical valve element 35 having a conical face 36 for cooperation with a reduced valve seat 31 at the forward end of the bore 29.

The air intake part 24, mentioned above communicates with the aperture of the valve seat 31, while the outlet port 25 communicates with the bore 29 at a point spaced rearwardly from the normal seated or closed position of the valve element shown in Figure 8. Threaded in and closing the rear end of the bore 29 and acting as an abutment for the helical valve closing spring 38 interposed between itand the valve element 35 is the hollow stud 39.

The air valve is actuated open by pressure exerted upon the forward end of the stem 33 by a lateral ear 49 on the hand lever or trigger 4I,

when the latter is compressed rearwardly toward the forward side of the handle 9 by the operator. A helical spring 42 is circumposed upon the valve stem 33 and expands between the gland 3| and the ear to return the lever 4| forwardly to starting or initial position when released so that the spring 38 can immediately, but independently, return the valve 35 to its initial or closed position.

The hand lever or trigger 4I comprises a depending Y-shaped member whose arms 43 are positioned at opposite sides of the forward foot I3 and pivoted on a pivot pin 44 transvers-ing the rear part of said foot. The valve operating ear 49 is on the right hand arm 43. The lower or standard portion 45 of the hand lever is vertically concaved and traversely rounded to accommodate the hand of the operator, and its forwardly curved lower end 46 is adapted to be arrested in rearward movement by engagement with a stop 41 projecting forwardly from the handle 9, in the extreme rearward compression of the lever. The left hand arm 43 has a rearward extension 48, to the rear end of which is operatively connected the lower end of the molten metal valve operating mechanism hereinafter described.

Mounted directly upon the feet I2 and I3 of the handle 9 are the similar inverted saddlelike metal plates 49 and 58, which are of generally rectangular shape with rounded corners. The rearward part of the lower plate 49 seats conformably in the aperture of the V-shaped rear foot I2 and is fixed in place by studs or pins 5I traversing the divergent sides of the foot. The forward part of the lower plate 49 rests coextensively upon the forward foot I3 and is fixed thereto by a stud 52 threaded downwardly thereinto through the plate, as shown in Figure 3. So fixed in placethe lower plate 49 is airspaced from the handle 9 to the extent of the length and vertical depth of the space 53 between the feet I2 and I3 and the upper portion II] of the handle 9.

The upper plate coextensively overlies the lower plate 49. but is spaced upwardly therefrom to provide the airspaces 54 on the opposite sides of a central, longitudinally extending insulation strip or block 55 which is positioned between the plates along their middle in order to achieve the desired parallel airspacing thereof, in conjunction with small isolated pieces 56 of insulation spaced at opposite sides of the strip 55 near the forward ends of the plates, and rearwardly positioned transverse insulation strip 51. The island pieces 56 are traversed by assembling studs 58 which are threaded upwardly through the lower plate 49 into the upper plate 59. Other assembling studs 59 are similarly threaded through the rear portions of the plates and traverse the rear transverse insulation strip 57.

When assembled the rear transverse strip 51 and adjacent portions of the upper and lower plates together provide a, continuation 68 of the airblast passage 22, with whose upper termination 2'! the continuation 60 registers, as shown in Figure 3. The upper end of the gas blowpipe projects above the forward part of the upper plate 50 through openings provided throughthe plates.

The vertically and transversely arranged flat cylindrical casing 62 of the air chamber 6| has a longitudinally elongated foot 63 depending from the bottom thereof and secured in place along the middle of the upper plate 50 immediately above the rear spacing strip 51 by studs 64 threaded upwardly through the plates and into the foot 63 on opposite sdies of the strip 51. The open side of the casing 62 faces rearwardly and is closed by a removable disk cover 65 secured by studs 66 traversing circumferentially spaced pairs of lugs 61. The foot 63 is vertically traversed by a continuance 68 of the air blast passage continuance 60 with which its lower end is registered, with an apertured gasket 69 placed to seal theconnectio-n, and whose upper end opens into the casing 62, beneath a spirally produced bafiie 18 provided therein to cause the incoming air to take a spiral whirling path around the casing 62 and thereby be stabilized in motion and preheated by the heat resident in the chamber 6| by reason of the'proximity of the chamber 6| to and its contact with the metal melting and containing reservoir H, which is positioned immediately forwardly of and is partially supported by the casing 62 of the air chamber 6 l.

The metal reservoir ll comprises a heavy, relatively shallow cylindrical cup-like casting 12, and a removable cover 13. The cups heavy thick bottom has its greatest thickness or depth where the underside of the bottom declines forwardly and downwardly longitudinally of the device, as indicated at 14, to a point 15 located immediately above the blowpipe I5, whose flame is directed against this forward point of greatest thickness, which is also. closest to the spray nozzle 16 which ismounted on the forward part of the bottom of the cup. At opposite sides of the forward point 15 of the bulge 14 diagonal spacing sleeves H are arranged between laterally outward points of the upperplate 50 and the reservoir to support the forwardend of the reservoir in airspaced rela-.

tionto the upper plate,and assembling studs 18 passv upwardly through the upper plate and through the sleeves and thread into the bulge M. I The rear end of the reservoir is flattened as indicated at 19 to conformably engage and be supported by the forward side of the air chamber 1 l, to which it isrigidly connected by a hollow bolt 80 threaded into the reservoir and passing through an opening in the air chamber wall, and having a clamping nut 8| operating against an interposed washer or gasket 82.

The metal containing space 83 of the reservoir is plain cylindrical, with a slag screen 84 spaced above its bottom 85 to prevent egress of slag from the space 83. The space 83 is covered by the domed cover 13 seating outside a ridge 8'! on the upper end of the reservoir, and removably held in place by screws 88 passing through paired peripheral lugs 89. The center of the cover 13 is provided with a hanging hook 98, by means of which the device may be conveniently hung up when not in use or when the device is being heated up for use, thereby correctly supporting the device under these conditions and leaving the operator free for other tasks as well as eliminating the need for special or improvised equipment for correctly supporting the device under s'ueh condi tions. 9

To the rear of the hook 9|] the cover is thick-- ened at 86 and formed with a circular filling open= ing 9| having a flaredupper portion 92 facilitat= ing accurate dropping or pouring of material into the reservoir H with the cover in place.

The lower forward end of the reservoir casting 12 is provided in line with the bulge 14 with a conical opening 92 accommodating the spray nozzle 16 hereinafter described. The conical opening 92 is arranged on a horizontal axis and at its tip opens into the forward end of the axially aligned molten metal conduit 93 whose rearward end communicates with the outlet opening 94 of the valve seat 95 on the lower end of the tubular valve body 96 of the molten metal valve mechanism, hereinafter described. The lower side of the conical opening 92 communicates with the forward, upturned end 91a of the forwardly declining airblast conduit 98a, which is formed through the reservoir bulge l4 and whose rearward end communicates with the bore of the hollowbolt 89, and thereby with the interior of the air chamber 6|. Itis obvious from this arrangement that spraying air passing through the chamber 6| and through the most highly heatedpart of the molten metal reservoir H, which is the bulge 14 and its hot spot 15, will be heated to a very high temperature, in this case substantially 1500 F. at which temperature the device is usually operated, so that there can be no cold air effects at the tip of the spray nozzle I6.

The molten metal valve mechanism comprises the cylindrical valve body 96 having its lower end threaded into the bottom 0f the reservoir space 83 at a point forward of the center of said space, with its hereinabove described valve seat opening 94 opening into the molten metal conduit 93 leading to the spray nozzle 16. The valve body 96 rises through the screen 84 to about the level of the top of the reservoir cup and has metal in-' letting holes 91 below the screen 84 to permit only slag screened molten metal or plastic material, as the case may be, to enter the interior of the valve body from the space 83.

A valve plunger 98 slides through the top ofthe valve body 96 and has a pointed lower end for cooperation with-the valve seat 95. The plunger acts to cut off the entry of molten metal into the valve body by occluding the holes 91 in advance of reaching closing relation to the valve seat 95, so that the slug of molten metal ahead of the plunger is not augmented by any drip from the holes 91 but is forcibly ejected through the open-- ing 94 into the nozzle feeding passage 93 as the plunger approaches its seat. This action also operates to prevent accumulation in the valve or the passages of any significant amounts of molten metal which might interfere with accurate and full valve action, and reduces to a minimum the amount ,of metal or plastic therein required to be returned to a fluid state from a cooled solid stateto permit operation of the mechanism and freeing The lower end of'the' connecting rod 99, which passes loosely through openings I03 provided in the plates 49 and 50, is operatively connected with the rear end of the hand lever arm 48 by a porcelain or equivalent heat insulating material link I04, which is pivotally connected to the connecting rod and hand lever arm, so that when the hand lever M is compressed rearwardly against the handle 9 the connecting rod 99, and hence the plunger 98 will be elevated, and molten metal permitted to flow continuously from the reservoir space 83 to the nozzle 76, as long as the hand lever is compressed or as long as the supply of molten metal in the space 83 lasts.

The same compression of the hand lever 9 pushes the air blast control valve stem 33 rearwardly so that a continuous blast of air flows to the spray nozzle I6 concurrently with the flow of molten metalto the spray nozzle I6, this spraying air, as heretofore pointed out, being highly heated by its passage through the device on its way to the spray nozzle. The melting temperature of the device is controlled by the choice of heating gas and by manipulation Of the gas valve 2i for adjusting the flame of the blowpipe I5.

The special spraying nozzle I6, which seats in the conical opening 92 in the lower forward end of the molten metal reservoir, comprises a preferably brass body, composed, as shown in Figure 4, of an outer member I05 and an inner member I06. The outer member I05 comprises a frustro-conical tip I01 formed with an axial bore I08 having a slight rearward flare, terminating midway of the tip in an enlarged cylindrical bore I09. A minor forward portion of the bore I09 is plain but the remainder thereof, which extends through the outer nozzle member I05 through its rear end, is internally threaded, as indicated at II to receive and assemble the inner nozzle member I05.

Behind the tip I01 the outer nozzle member I has an externally threaded axial portion III of substantially reduced diameter which is adapted to mount the nozzle in the opening 92 by engagement with the threads II 2 provided in the outer end of said openings. Behind the threaded portion III the outer nozzle member has a smooth cylindrical portion II3 of reduced diameter, followed by a portion I I4 tapered to conformably fit the tapered walls of the conical opening 92. Opening through the rear face of the shoulder II5 defined by the portions III and H3 at circumferentially spaced intervals, are the rear ends of relatively small air passages I I6. The air passages IlS converge forwardly toward the axis of the nozzle and their forward ends open through the sidewalls of the smooth enlarged bore portion I09 just to the rear of the rear end of the smaller flaring bore portion I 08.

.As shown in Figure 3, the reduced smooth portion I I3 is by its proportioning and position, spaced from the sidewall of the conical opening 92, in such a way as to define an annular air space I", into the bottom of which the forward end 91a of the air blast conduit 98a opens to supply the passages I I6 with air under pressure.

The inner nozzle member I06 comprises an externally threaded portion II8' terminating at its rear end in a disk head H9 of somewhat larger diameter. Beyond the threaded portion H8 and beginning at the rear end of the smooth bore portion I09 the inner member I00 has a forwardly tapering needlelike nose i2-3 reaching almost to the-forward end of thenozzletip ml, the nose or needleIZIl being concentrically spaced from 8 the bore portions through which it extends. The inner nozzle member I06 is longitudinally adjustable within the outer member I05 to adjust the spray of molten metal and air as required.

The disk head H9 is proportioned and positioned to engage the sidewalls of the conical opening 92 near the entrance thereinto of the molten metal passage 93, and thereby define a substantially conical slag trap into whose lower part below the level of the passage 93, any slag coming through the passage 93 with the molten metal can subside and be trapped out of the flowing metal and thereby prevented from going on through the axial spray passage I2I provided through the inner nozzle member I06. As shown in Figure 4, this passage I2I is gradually forwardly tapered, so that its greatest diameter is at the rear end thereof and its smallest diameter at the forward end of the needle part I 20, whereby a slight but advantageous ram effect is obtained.

It will be obvious that the reservoir 'II may be initially charged with fusible metal or plastic material through the opening 9|, and that thereafter as the metal or plastic is exhausted from the reservoir in service, the reservoir may be recharged through the opening 9i while in use and without pausing for removal of the cover I3.

It will be understood that any change or changes in the construction and relative arrangement and oomposition of the component parts may be made within the scope of the.ap-' pended claims, without departure from the invention.

We claim:

l. A device for spraying molten metal, including an upwardly-extending handle, an operating lever mounted upon the exterior of said handle, a molten metal reservoir above said handle, heating means for applying molten metal heat to said reservoir, said means being above said handle, radiant and conducted heat shielding means for the hand of an operator grasping said handle and lever, said shielding means including a horizontally-disposed lower plate having substantially vertically-disposed outer edges and an upper horizontally-disposed plate having substantially vertically-disposed outer edges, said upper plate being spaced above the lower plate, with an air space between said plates, means carrying said lower plate upon the upper end of said handle, means mounting said upper plate upon said lower plate, the vertical planes of said edges of said plates being outwardly of said handle and lever, means mounting said reservoir upon and above said upper plate and within the vertical planes of said edges of said upper plate, means mounting said heating means upon and above said upper plate and within the vertical planes of said edges of said upper plate, a spraying nozzle mounted on a forward part of said reservoir, said nozzle being provided with molten metal passage means and with air blast passage means, molten metal conduit means leading from said reservoir to said nozzle molten metal passage means, air blast conduit means leading to said nozzle air blast passage means, and combined valve means comprising valving components biasing the conduits of said molten metal and airblast conduit means, and means operatively connecting said components together and to said operating lever.

2. A device according to claim 1 in which said means mounting said upper plate upon said lower plate includes a traverse strip disposed between and in face contact with said plates, said strip has an upwardly-extending opening therethrough; said plates have aligning openings, axially aligning with said first-named opening; and said air blast conduit means includes the walls of said openings.

3. A device according to claim 1 in which said plates have side edge portions and curve upwardly at said side edge portions so as to extend outwardly of the lower areas of the sides of said reservoir and heating means.

4. A device according to claim 1 in which said plates have side edge portions and curve upwardly at said side edge portions so as to extend outwardly of the lower areas of the sides of said reservoir and heating means, and the means carrying said lower plate upon said handle includes spaced apart feet extending upwardly and outwardly from said handle with said lower 10 plate cradled upon said feet and spaced above said handle whereby an air space exists between said handle and said lower plate.

ERNEST L. TRIMM. NATHAN ARNOW.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,934,891 Taylor Nov. 14, 1933 2,058,653 Albertson Oct. 27, 1936 2,125,764 Benoit Aug. 2, 1938 2,190,153 Holmes Feb. 13, 19 0 2,252,942 Mourer Aug. 19, 1941 2,397,165 Shepard Mar. 26, 1946

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