US2456439A - Machine for the manufacture of metal grains - Google Patents

Description

Dec. 14,1948. R MQRANE ET A 2,456,439

Filed March 17, 1945 3 Sheets-Sheet '1 &

Dec. 14,1948. R. MORANE ETAL MACHINE FOR THE MANUFACTURE OF METAL GRAINS Filed March 17, 1945 s Sheet-Sheet 2 KNVENTOR- Dec. 14, 1948. R. MORANE ET AL MACHINE FOR THE MANUFACTURE OF METAL GRAINS Filed March 17, 1945 3 Sheets-Sheet 3 Patented Dec. 14, 1948 MACHINE pong-r1112 MANUFAGTURE or Y. METAL GRAINS toae M-wane Pa and Reser- Mar net,

yillepfnvray, France -S ei 2nLBrbl e L 90. Ar entine Pat nt expi e nu r 1 hopper-whence the lead drops flow out andthen metal grains or pellets of extremely fine nature and particularly grains of non-ferrous metals or alloys. As distinguished from the method and apparatus for the manufacture of shot described and claimed in our co-pending application Ser. No.- 582,938 filed March 15, 1945, the present said apparatus has been specially devised to avoid the aforesaid disadvantages, and to permit the quick and automatic production of metal grains or pellets of well defined uniform size. Whereas in the co-pending application the metal layer in thecup should be relatively thick, in the present invention, on the contrary, the setting of the apparatus must be such as to maintain only a thin layer in the cup.

Another object of the invention is to provide an apparatus as aforesaid wherein the improved result is obtained notably by discharging the molten metal from the melting pot ,in the form of thin streams and by causing them to reach the perforated bottoms of dividing rotary cups as a thin layer, said cups being subjected to impacts while their rotary motion is combined with an oscillatory motion of their feeding chutes to ensure correct distribution of the-molten metal .over their perforated or dividing bottoms.

A further object of they invention is to provide, a new machine made up of a minimum number of simple and rugged parts and lending itself to an automatic actuation whilerequiring a minimum of supervision and labor, said ma chine including a melting pot, a ladle and a plurality-of metal-dividing revoluble cupsfed f m he adle and subie edto the act -o a iolt ns;.svst n-v ".With these and such other objects l oiew; as will incidentallyiappear hereafter, the invention compriseson the .one hand the novel features which-characterize the novel structure Of the machine as ..exemplifiedin theaccompanying diagrammatic drawings forming-a partof the present disclosure;

In the drawings:

-'Fig. 1 is a vertical sectional view of the aprpliance" builtv according .to the invention and adapted-for themanufacture of of. iead alloy.

r Fig. 2 isa plan-view thereof.

Fig. 3 isan elevational view showing how-the distributing ladle .-is mounted on a. depressible contrivance.

Fig. A is a sectional view drawnon-a .larger scale showing the distributing ladle and a cup having-a perforated bottom.

Fig.-'5 is a sectional view drawn on a larger scale showing the valves which control the flow .of molten metal from the pot.

As illustrated in the drawings, the appliance :used for the manufacture of grainsH-or pellets madeof alead alloy, for example an alloy of lead and arsenic such as may be utilized for the prograins or pellets vduction of lead steels i. e. grains of extreme fineness-,-.pri marily comprises a pet I for melting the alloy, the said potbeing heated for-example by a burner :2..or .by'any other means, whether electrically or otherwise. The pot I- may be fitted withia pyrometer enabling the temperature of sthe alloy to be constantly observed.

The pot I is-provided' with a double system ofivalves including afirst valve 3 mounted on a ine second va ve 5 u ded y a m H ion-partly closes the outlet port It for the has. hile all wing a in re m f a avo; stheret sh- The valve 5 i an trai ed ,v-

redzh hi hrece e n th scre leenerniastnee e va ve. the sa d ro fleein in turn controlled by an electromagnet l2 which is excited under conditions that will be hereinafter set forth. This device permits molten metal to be discharged from the pot at I0, either automatically or intermittently.

When being discharged from the melting pot, the metal is guided through a downtake chute I3 into a regulating ladle ll of suitable capacity; This ladle is heated by any appropriatemcans,

for example by a gas range I5 or by an electric or other heater, to a suitable temperature, for example in the example being considered to 450 C.

In contradistinction to what takes place in the manufacture of shot, which manufacture calls cups 25 are internally provided with several sieves 21 made of perforated sheet metal arranged in superimposition, the perforations being located in staggered relation. Such sieves are held down on the bottom of each cup 25 by a steel ring or This driving disk 28 is made of cast iron and is for an important and regular delivery, the abovedescribed device permits the regulating ordistributing ladle M to be fed only with a small quantity of lead just as soon as the metal level in the ladle l4 sinks by a small extent, whereby extremely fine metal grains or pellets Without anylargediameter grains can be obtained.

As is shown on Fig. 3, the distributing ladle I4 is mounted on a depressible contrivance l6 which is balanced by a counterweight 11; .The rockingaxes may be mounted on bearings so as to increase the sensitivenessof the depressible carrier. The rod l8 which carries the ladlel l has mounted thereon a finger 19 which comes into contact with a switch 20 connected .by a wire 2lto a source of current S and by a wire 22 to the electromagnet l2 which controlsthe valve 5. A further wire 23 interconnects the source of current S and the electromagnet l2. Alternatively the return of the current may be ensured by proper grounding.

The counterweight ll corresponds with the weight of the movable assembly plus the weight of the molten metal. As soon as the ladle I4 is full, the depressible carrier comes into-operation and opens the switch 20, thereby cutting off the exciting current from the electromagnet .I2 and consequently allowing the valve 5 controlled by the said electromagnet to fall back. As soon as the weight of the ladle l4 diminishes, the counterweight ll drives it, allowing the said ladle to go up, while the finger l3 comes into contact with the'switch 20 in the opposite direction, thereby closing it back and reestablishing. the exciting current through the electromagnet and consequently opening the valve 5.

The ladle I4 is provided at its lower end with one or more nozzles 24, the number ofwhich matches that of the dividing cups 25 arranged underneath the ladle 14 (see Figs. 1 and 2), the

said nozzles being preferably made of steel and advantageously having such a conical shape as will permit easy dismantling and accordingly easy cleaning thereof (see particularly Fig. 4). These nozzles have a hole made oncaliber through which, during a. time unit, a quantity of metal may-flow which exactly correspondswith the delivery of each dividing cup 25. As the level of molten lead alloy remains practically constant in the ladle l4, due regard being paid to the relation which prevails between its diameter and its height, the delivery through the nozzles 24 is therefore practically always the same.

Downtake chutes 26 made for example of sheet steel take the molten metal which is ejected from the nozzles 24 into the cups 25. Such cups have a suitable diameter, their bottombeing formed with a large number of holes 'of' suitable sectional area. "In'order to permit extremely fine metal grains or pellets being manufactur'ed;-the

provided at its lower end with a shoe 30 formed integral therewith. This shoe is guided by a pair of rings 3|, 32 arranged on a jolting table 33 to which reference will be made hereafter.

The rings 28 are driven at a suitable speed by means of a pinion 34 which is driven in turn by a, speed-reducing gear 35 including a worm. Such reducing gear is housed in a water tight casing which is secured to a part of the machine not subjected to jolts or vibrations.

The reducing gear 35 is controlled by a hollow shaft 36 driven by a motor 37. Such an assembly permits each cup to be rotated at a suitable speed While imparting to them proper vibratory motion. For the sake of clarity, it may be mentioned that a universal joint, hidden by the uprights supporting ladle I4,- is inserted between reducing gear 35 and shaft 4!.

Such rotary motion as is imparted to the cups may be combined with an oscillatory motion imparted to the downtake chutes 26, in which case the latter should be mounted for pivoting inside a hole provided in a plane member 53 of shaft 50. Such a motion is accomplishedby means of a cam 38 which is in frictional relation with a roller 39 supported by shaft 50. The downtake chutes are urged back by a return spring 51, when the rollers have been driven away through the action of cam 38 on roller 39. Moreover the downtake chutes are heated by means of a gas range 40, thereby preventing the molten alloy from cooling while it flows. Cams 38 may be secured to cups 25 by welding or other suitable means or may be machined integrally thereon.

It will be seen that, owing to the described device, only a very small quantity of molten metal can be supported by the bottom of each cup 25, the said metal being perfectly distributed over the whole area. Moreover, owing to the automatic inflow of metal such as hereinbefore described, the feed is caused to correspond with the delivery of each cup. Even delivery for each 25 is thereby ensured which prevents the formation of such numerous Wastes as might arise from an unduly large or uneven feed.

As there is but a very small quantity of molten metal on the bottom of each cup 25, it is necessary, in order to allow proper flow of the metal through the holes in each cup, and consequently to give the ensuing grains or pellets extreme fineness, that all the cups should be subjected to jolts or impacts of suitable rapidity and proper extent. To that effect, the several cups are mounted on a common frame 33 which may be for example pivoted at M to the machine frame and which has vibrations imparted thereto by means of a rotarycarn 42 operated for example by means of the electric motor 3'! which controls the revolution of the cups or alternatively by any other suitable electrical, mechanical or pneumatic means. This cam may be mounted on roller bearings. The movable assembly 33 is first lifted by this cam and then falls upon wedges 43 the height of which may be adjusted, this permitting the amplitude of the jolts or impacts being regulated.

Considering the small delivery of the cups 25, they are heated (for example to 450 C. in the example being considered) by a gas range 64 or by any other equivalent means.

The drops of molten alloy which flow through the perforated bottom of the cups fall from an appropriate height, are cooled into solid form and are collected in a receiving container 45 made of sheet metal and accommodated in a pit, the said container being filled with water for completing the cooling of the metal grains. The whole assembly comprising the distributing ladle M and the cups 25 also the jolting system may revolve about an axis 46 (see particularly Fig. 2) the frame carrier comprising castors 47, 47' which can roll on corresponding runways 48, 48'. This permits the receiving container 45 to be taken away at any suitable time or at the end of the day by means of any suitable form of tackle or by any other method and the manufactured product to be laid into the chute leading for example to a drying apparatus.

It will be understood from the foregoing that, owing to the hereinbefore described organization and manufacturing process, it is possible to manufacture such extremely fine metal grains or pellets as will be suitable for several uses and particularly to the production of lead steels.

Obviously the invention is not limited to this use and the apparatus which has just been described may be used with advantage for the manufacture of miscellaneous metal grains or pellets made from metals or alloys of different categories.

It is also obvious that the hereinbefore described apparatus as shown in the drawings was given merely by way of example and that modifications might be introduced into its constructional details without departing from the scope of the invention.

What is claimed is:

1. An apparatus for manufacturing metal grains and particularly grains of non-ferrous metals or alloys, comprising a pot of molten metal, a metal-distributing ladle, a conduit provided at said pot for feeding said ladle, rotatable cups with sieve bottoms for dividing said metal into grain, said ladle having detachable nozzles the openings of which are calibrated to the openings in the cups to give uniform discharge from the cups, each nozzle having a chute for feeding said cups; a drive for imparting to said cups a rotational motion at uniform speed and jolts at certain intervals of time and means for adjusting the extent of the jolts.

2. An apparatus for manufacturing metal grains and particularly grains of non-ferrous metal or alloys, comprising a pot for molten metal, a metal distributing ladle, a conduit provided at said pot for feeding said ladle, rotatable cups with sieve bottoms for dividing said metal into grain, said ladle having nozzles and a chute for each nozzle for feeding said cups; said ladle and said cups carried by a structural unit; said unit also carrying means for heating said chutes and said ladle, a drive likewise carried on said structural unit for imparting to said cups a rotational motion at uniform speed and an oscillatory motion to said chutes, and means con- 6 nected to said drive for imparting jolts to said cups at certain intervals of time with means for adjusting the extent of the jolts.

3. The combination with an apparatus for manufacturing metal grains and particularly grains of non-ferrous metal or alloys comprising a pot for molten metal, a metal distributing ladle, a conduit provided at said pot for feeding said ladle, an assembly of cups with sieve bottoms for dividing said metal into grain, said ladle having nozzles and a chute for each nozzle for feeding said cups and driving means for imparting to said cups a rotational motion at uniform speed and an oscillatory motion to said chutes, of a frame common to and supporting said cup assembly, cam means adapted to be driven by said drive and to impart impacts to said frame and cup assembly, and means for regulating the extent of said impacts.

4. An apparatus for manufacturing metal grains and particularly grains of non-ferrous metals or alloys, comprising a pot for molten metal, a metal-distributing ladle, a conduit provided at said pot for feeding said ladle, rotatable cups with sieve bottoms for dividing said metal into grain, said ladle having nozzles and a chute for each nozzle for feeding said cups, said conduit having associated therewith a set of double valves for controlling the passage through said conduit, said set consisting of a primary valve adapted to permit a rapid closing of said conduit, and a secondary valve adapted to throttle said passage of the conduit to let the metal flow in a thin stream.

5. An apparatus as set forth in claim 4 wherein a depressible counterweighed carrier is provided supporting said ladle, furthermore switch means operable responsive to the depression of said carrier with said ladle and adapted to control said secondary valve.

6. An apparatus as set forth in claim 4 wherein said secondary valve is provided with an electromagnet and adapted to be operated thereby, and wherein a depressible counterweighed carrier is provided supporting said ladle, furthermore switch means operable responsive to the depression of said carrier with ladle and adapted to control said electromagnet.

7. An apparatus as set forth in claim 4 wherein said structural unit caries a depressible counterweighed carrier supporting said ladle furthermore switch means operable responsive to the depression of said carrier with ladle; said conduit having passage controlling means associated with said switch means and adapted to be controlled thereby.

ROGER MORANE. ROGER MARTINE'I.

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

UNITED STATES PATENTS Number Name Date 194,271 Shiver Aug. 14, 1877 228,481 Shiver June 8, 1880 253,764 Reddy Feb. 14, 1882 826,099 Gilman July 17, 1906 857,756 Reddy June 25, 1907 1,647,194 Poindexter Nov. 1, 1927 1,762,693 Linebarger June 10, 1930 1,866,682 Temmen July 12, 1932 2,224,424 Bullock Dec. 10, 1940 2,287,029 Dowdell June 23, 1942

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