US1759269A - Fbebebick c - Google Patents

Description

y 0- F. c. MORRISON 1,759,269

APPARATUS FOR CASTING MOLTEN METAL OR OTHER FLUENT 0R SEMI-'FLUENT MATERIAL Filed Feb. s, 1928 A 77% EYE 4 WITNESS Patented May 20, 1930 aar ' rnnnnn ox o. Monnrson, or SYRACUSE, new Year:

I AP PARATUS FOR CASTING 'llZETAL OR OTHER, FLUENT OR SEMIFLUENT i MATERIAL Application filed February 6, 192 8. Serial No. 252,371.

This invention relates to a method of and apparatus for casting molten metal or other fluent or semi-fluent material irrespective of its temperature into all cavity parts of a mold 50f simple or intricate structure so-that all parts of the casting will be of maximum uniform density without the use of extraneous vpressure.

In casting molten metals in sand molds and '10 also in permanent'molds it is customary to pour the metal from .suitable ladles into the mold at approximately the level of the inlet or sprue hole resulting in a more or less coarse grained casting and in some instances more or less imperfections or deformations due to the trapping of air in the smaller parts of the mold. r I 1 Furthermore, it is well-known that these sand molds are not adapted for producing intricate castings having relatively small intaglio. or relief parts due primarily to the lack of sufficient pressure behind the inflowing metal and also to the fact that the sand molds are not adapted to sustain such pressure.

On the other hand, when casting molten metal in permanent molds under the usual practice of pouring the metal intothe moldat approximately the level of the sprue hole it is found to be impracticable to produce proper 39 castings in the more intricate molds having relatively small intaglio and relief parts due 7 to the lack of suflicient pressure behind the inflowingmetal to force-the molten metal intothose small parts and to the trapping of gas or air therein. I

In the die casting process commonly enn ployed for casting'molten metal in intricate molds having relatively small intaglio and relief parts it is customary to apply extraneous mechanical or air pressure behind the inflowing metal thereby increasingthe number of operations necessary to produce a perfect casting-and greatly increasing the cost of the casting apparatus and operation thereof due to the fact that the dies are frequently large and heavy and must be constructed in such manner as to Withstand the pressure to which the molten metal is subjected. 7

It. is found, however, that the mechanical or cylinder and plunger pressure mechanism and also the air or goose neck pressure devices under the present construction are 'not suitable, for handling molten metals with a melting point above 1500 F. due to the fact that the metal, from whichthe containers are made, is not sufiiciently strong to withstand In other words, I have sought toproduce in the mold a casting of greater homogeneityand density than has'liereto-fore been practised by .allowing the molten metal or metal alloyv to fall or drop intothe mold from .a

height suflicient to give the pressure at the mold necessary to produce such homogeneity and density.

of metals Another object is toprotect the descending stream or body of molten metal from the 7 source of supply to the mold against lateral deflection or contact with adjacent objects by surrounding the same with a guard or shield extending practically the full height of the drop or" the molten metal from the source of supply to the mold.

Another object is to provide means for con trolling the flow of the molten metal from the superposed source of supply to the mold in such manner that when liberated from the melting furnace or ladle it will have an unobstructed drop to the mold, the height of the furnace, ladle or other source of supply above the level "of the mold depending upon the pressure and velocityrequired for properly distributing the molten metal through the interior ofthe mold.

Another object is to control the discharge of the molten metal from the source of sup- Other objects and uses relatingto the in vention will be brought out in the following i 7 description.

In the drawings is represented a vertical sectional view, partly in elevation, of one form of apparatus for carrying out the various objects of the invention. 7

The apparatus comprehends three essential correlated stepsin the casting process viz.',

the installation, preparation and manipula- -tion.of the molds or casting machines and handling of the castings, all of which may be conducted within a relatively small space and also with a 'minimumamountof laborat thesame level or upon one floor of a building and second, the installation of the mel ing furnace or furnaces, melting pots or ladies, together with the preparation and reduction of the raw materials within the melt- "ingfur-naces to a molten state on a superposed floor of the building, and third, the liberation or release of limited quantities of the molten metal from the furnace, melting pot or ladle todropor fall through the intervening space theheight or head-drop of the molten metal.

a suitable base or v most convenient for manipulation thereof,

to thesprue holes. of their respective molds for producing the desiredcastingstherein,

from the source of supply of the mold depending somewhat upon the qualityof the metal and also upon the capacity of the mold, but in all cases will be sufficient to give the velocity andpressure required at the mold to produce acasting of maximum density and homogeneity. l I i As illustrated,'the mold 9-1 of any desired form, size or capacity is supported upon pedestal -Q- at a height the pedestal 2- being mounted upon a sub-base or floor A- of the building in which the apparatus is located.

The mold 1*is preferably made in sec tions capable of being separated any desired extent to permit the discharge or removal of the castingipreviously made therein and,

when'assembled for the reception of the molten-material, the sections will be firmly locked together by any ,well-known' locking means commonly used in metal molds; I

Any suitable means may be provided for opening'andl closing" the mold sections, said means consisting, in this instance, of opposed r on suitable standards 5 and operatively 5 5" connected to their respective sections by links 6 whereby the vertical 'movement of the levers in opposite directions will open and close the sections ofthe moldalong and uponits supporting base '2- The parts thus far described constitute what may be termed a casting machine and obviously a large number of these machines may be similarly'installed in more or less close ]uxtaposit on upon the same floor so that they may be conveniently operated with- 70." to molten metal 1s preferably mounted upon a superposed floor or'other support A"[ of the building as nearly as possible directly over the casting machines on the lower floor" and, as illustrated, comprises, in this instance, a cupola or melting furnace -7 mounted in a suitable frame work 8 some distance abovethe floor A, said melting furnace being provided with a hopper-shaped bottom having an outlet -9 controlled by a suitable gate or valve 10- A measuring pot or ladle 11 is supported in any suitablemanner directlybelow l the discharge opening'9 of the furnace to receive a limitedquantity-of the molten metal therefrom when the gate or valve 10'- is opened, said measuring pot or ladle '11 being provided with. an outlet -12 'which is controlled by a valve or-gate 13+-simi1ar-- tn the gate 10.

The capacity of the pot or ladle 11 approximately equalto the capacity of the mold. "as 1' into which the molten metal is to be discharged therefrom.

The outlet of the pot or ladle '-11 is preferably disposed in vertical alinementwith the sprue hole as 14: of the mold so that when it is desired to produce a casting in said mold the gate 1? controlling the outlet 1 2' of the ladle ll-'- will first be closed after 10o which the gate 10-'controlling the outlet of the'furnace 7' will be opened to allow the molten metal to flow into the pot or ladle --l1-. I After a suitable quantity of the 1 molten metal has been allowed to flow into the pot or ladle -l1 the gate -l0 will be closed and the gate -13 opened thereby allowing the molten metalto drop directly'into the 3 inlet orsprue hole of the mold 1'. V

,11- is connected to the in let of themeld by The outlet of the measuring pet or ladle means of a'vertical tubular guard' 15 of 1 suflicient 1nter1or CLPEICltYOI' diameter to at c low the molten metal to drop or] fall there-- through without adhering to the walls there'- of, the purpose of said guard tube being to prevent material reductionlof the tempera ture of the molten metal inftra'nsit from the source of supply to the mold and also toprcvent lateral deflection of said molten metal from a straight vertical drop from. the source of supply to the mold and incidentally preventing contact of external objects with'the descendin stream orbody of molten metal.

The walls of the tubular-guard l5 are preferably'hollow to form an intervening chamber -16,+ which may be an air or vacuum chamber for heat-insulating purposes or may be filled with a heating medium to furtenmetal but will .be opened as soon as the mold sections are properly placed fOIl'GCQlVr ing the molten metal, said gate being oper ated byimeans of'axhand le'ver18 mounted on the base 2 V The walls of the measuring pot .or' ladle.

l1 may also be hollow to form an air or vacuum chamber '19 or for receiving a heating medium to prevent the reduction of the temperature ofthemolten m'etalftherein.

Suitable'pipes -l5' and 19 are connected respectively to the chambers 'l5 and 19 tobe used either for withdrawing the air from or supplying a. heating agent to said chambers. v

The gates and 13-' controlling the inlet and out-let of themolten metal to and from the measuring pot or ladle '-l1 are adapted to be operated'by separate levers and 2l' mounted on the frame 8 within convenient reaching distance of the operator or furnace attendant of the floor A' but, in some instances, it may be desirable to control these levers from the lower floor --A and, forthi's purpose, they provided with pendant operating rods '20 and -21" respectively, extending downwardly through openings in the floor A to levels within convenient reaching distance of the operators on the lower floor It will be understood from the foregoing description that the apparatus shown ismainly diagrammatic and is intended only as illustrating a'simple means for carryingout the casting process by elevating the source of supply for the molten metal a sufficient distance above the mold and in such relation thereto that when a charge of the molten metal is released from the source of supply it will enter all of the intaglio parts of the mold with sufficient force, velocity andpressurc to produce a more homogeneous and denser casting than has heretofore been practised in any known pouring process and at the same time eliminates the cumbersomemechanisms involved in the use of cylinder and plunger type or an pressure type of die casting machines. I f 7 Furthermore, under this construction and process the melt-ing furnaces and handling of all raw materials is done on a separate floor a considerable distance'above the casting floor so that the heat radiated by the furnaces on the upper floor does not have any inconvenient effect upon the temperature of the lower or casting floor which is also free from accuinto all parts of the mold.

mulations and handling o'fthe raw materials thus permitting a more expeditious and'ec'onoinical operation of the casting machines than has heretofore been practised. g

It will also be noted that under this con- 'struction practically all of the devices for controlling the discharge ofthe molten metal fromthe source of the supply to the measuring pot and from the measuring pot to the molds, together-with the operating devices for the mold sections may be controlled from the same floor on which the casting machines are placed.

The upper end ofthe shield or guard tube -'15 is supported upon suitable posts- 22, on the upper "floor A- through the medium of adjusting screws 28-' which permits the guard tube to be adjustedvertically. v

The measuring pot or movably supported upon the upper end of the guard tube 15to permit the use of ladle 11 is reladles of'difi'erent capacities and may be raised andloweredwith the guard tube the adjustment of the screws 23 to per mit its removal and replacement and also to adjust it in proper alinement with the outlet of the measuring furnace and inlet of the guard tube. Y

The lower end of the guard tube is provided with a nozzle '-2 lwhich maybe removed when necessary to permit the opening therethrough to be cleaned from any material which may adhere to the walls thereof.j

A gate or valve ,,25,is movable in the lower end of the guard tube +15 to control the flow of the molten metal therethrough and to serve as an additional safety means for preventing the discharge of molten metal a from the interior thereof particularly during {the removal of the nozzle.

Operation used inma'lring the casting will be supported "in a plane a considerable distance above the mold which is to receive the'molten metal to form an intervening air space through which the molten metal must travel in transit from the container to the mold, but it is obvi'ous that this space will necessarily vary according to thequa'lity of themetal and size or intricacies of the mold,,but in all cases will be suflicient to cause an appreciably. greater velocity of travelof the molten metal when entering than whenileaving the container soas to obtain the necessary head-pressure and velocity for driving the molten metal The capacity of the container, such, forexa mple, as the ladle being approximately equal to the capacity of the molds, it follows that when the charge from the ladle is releasedwit will travel ina more or less cohesive body through the intervening space The container for the molten metal to be t a a gates 13, 17and 25:, in the meas uring pot and guard tube Will'be' instantly j 7 with graduallyincreasing velocity or mo greater velocity than when 'leaving'the con-, tainer which has the effect of forcing the mentum so as to enterthemoldat a far molten material into all parts of the mold.

During thereduction of the metal to'a'molten state ready for casting Within the; melting .furnace or cupola 7' the gateor valve 10 will remainclosed and when the mold and other parts ofrt he apparatus are all; set ready for casting the gate or valve -13 in the outlet of .themeasuring pot or ladle 11. and also the gat'es in the lower end of the e guard tube 1 5i and nozzle -24 will be closed- Then, when itis desired to produce the desired casting in the mold, the valve -10 in the outlet of the, melting furnace will first be opened to allow the molten metal to 'fill'the measuring pot, or ladle ,.11 whereupon said valve will be closed and the opened to allowthe casting charge to drop 'throughthe intervening space into themold and in viewof the accelerated speed of this "charge as it enters the mold it is evident that l its-velocity and weight will-force the metal under relatively high pressure-into all of the;

inta'glio parts of the-mold to complete the casting and as soon as the casting is suffi ciently" set or hardened the sections of the mold may be separated by any suitable means to permit the casting to be withdrawn;

The mold sections may then be replaced and the. various gates or valves manipulated to repeat'the operation'justdescribed. a

7 As previously stated, he apparatus an process are particularly simple, expeditious or free from such gases and vapor, and, there-' and highly efiicient as comparedwith the apparatus and processes now in common use andgreatly increases the output for a given period of time with a'minimum expenditure of time and labor.

An important "result of dropping the V moltenrmetal fromj an appreciable height. through the guard tube and into the mold is that the gases and vapor from themolten metal are allowed to escape to, atmosphere in transit through said space sothat ,molten metal entering the mold is substantially pure 7 fore, has a far greater'density and homoge- "*What I claim is neity than would be possible if the gases and vapor were retained in thefmolten metal when filling the mold.

' 1'; In an apparatus for casting molten 'al in'a mold having a sprue, a measuring pot 1160 having a capacity approximately, equal to that of the mold andvprovided wit-han inlet i a in its top and an outlet in its bottom, separate gates controlling the inlet and outlet, and an upright conduit having a straight vertical passage therethrough leading directly from the outlet of the measuring pot the sprue of the mold. U

2. In an apparatus for casting molten metal in a mold having asprue, an upright con duit having straight vertical passage there- 7 through discharging at its lowerend di-e rectly into the sprue of the mold and its upper end of sufiicient height to cause'the'momentum of the molten metal admitted thereto andrpassing through said passageto drive said molten metal into all parts of the cavity of. the mold, and means for limiting each end of said passage to about the capacity of the mold to enable the entire charge toibe.

precipitated as a unit into the mold) 3. In an apparatus'for casting molten met-' al in a mold having a sprue, an upright conduit having a straight Vertical passage therethrough, a nozzle secured to the lower end. of the conduit to form. a continuation thereof charge directly into the sprue of'the mold,'a

charge of molten metal admitted to the upper and having its lowerend' adapted to;dis-

container for the charge ofmolten metal discharging directly intothe upper end of said passage and having a capacity substan- I tially equaltothat of the mold, and a valve controlling the dischargeof the molten metal from the container into said passage and 7 e5 fromthe container into

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