US2891291A - Apparatus for continuous casting - Google Patents

Description

June 23, 1959 R. N. SCHNAC KE 2,891,291

APPARATUS FOR CONTINUOUS CASTING Filed Jan. 27, 1956 4 Sheet-Sheet 1 RICHARD N. SCHNACKIE' ATTORNEY June 23, 1959 N. SC HNACKE 2,891,29I

APPARATUS FOR CONTINUOUS CASTING Filed Jan. 27, 1956 4 Sheets-Sheet 2 INVENTOR RICHARD N. SCHNACKE ATTORNEY June 23, 1959 R. N. $CHNACKE APPARATUS FOR CONTINUOUS CASTING 4 Sheets-Sheet 5 Filed Jan. 2'7, 1956 INVENTOR RICHARD, N. SCHNACKE ATTORNEY June 23, 1959 R. N. SCHNACKE I 2,891,291

APPARATUS FOR CONTINUOUS CASTING Filed Jan. 27, 1 956 4 Sheets-Sheet 4 I INVENTOR 1 N. SCHNACKE ATTORNEY United States Patent 2,891,291 Patented June 23, 1959 time APPARATUS FOR CONTINUOUS CASTING Richard N. Schnacke, Newark, ()hio, assignor to Kaiser Aluminum & Chemical Corporation, Oakland, Caliir'., a corporation of Delaware Application January 27, 1956, Serial No. 561,859 19 Claims. (Cl. 22-572) This invention relates to the transfer of molten metal from one receptacle to another. More particularly, this invention relates to apparatus for transfer of molten metal from one receptacle to another as in the continuous casting of metal ingots, billets and the like wherein molten metal is poured from one receptacle, e.g., a feed trough, crucible, holding furnace or the like, into an open-ended mold and wherein the level of the molten metal contained within the mold is maintained substantially constant during the casting operation.

In the art of continuous casting of metals, it is common practice to provide an open-ended mold, to feed molten metal continuously into the top of the mold through suitable molten metal delivery means such as a stand pipe or pouring spout and continuously withdraw casting from the lower end of the mold. The source of molten metal may be contained in a crucible, ladle, furnace or other receptacle and wherein the molten metal is poured from such receptacle into a feed or transfer trough prior to passage downwardly through the sand pipe or pouring spout and into the mold. Alternatively, the molten metal contained in the receptacle may be fed directly into the stand pipe or pouring spout and into the mold. It is also common practice to provide suitable means for cooling the mold and in some instances applying a suitable cooling medium directly against the casting as it emerges from the mold. The metal may or may not be completely solidified in the mold; thus, the casting at the point where it emerges from the mold may contain a core or crater of molten metal, which crater is solidified by cooling the casting below the mold, as by applying a cooling fluid to the casting. The cooling fluid may be a liquid, preferably water, or a gas, such as air.

Cooling of the mold, and of the casting below the mold in those instances where desired, may be accomplished either by use of a cooling jacket, such as a water jacket, or by delivering coolant directly to the mold or casting, as by means of spray pipes or a perforated tank. Where ingots, billets and the like of relatively large cross-section are to be cast, a stationary bafiie or distributor is generally provided beneath the lower or exit end of the pouring spout or stand pipe for the purpose of causing the incoming molten metal to be directed outwardly in a predetermined fashion to reduce undesirable turbulence of the body of molten metal contained in the mold and to reduce the tendency toward an excessively deep molten metal crater. In continuous casting, the casting procedure may be a strictly continuous process (in which the casting is cut to length without interruption of casting procedure) or it may be semi-continuous; i.e., a casting of desired length may be cast, the flow of metal stopped, the casting removed and the procedure commenced anew. Continuous casting as herein used refers to either type of operation.

It is recognized, in the continuous casting of metal, particularly in the casting of metals wherein an oxide coating forms on the molten metal surface, as in the case of aluminum or aluminum alloys, that it is highly desirable that the level of the body of molten metal contained in the mold be maintained substantially uniform and at a predetermined height or position in the mold during the casting operation. Fluctuations in the level of the body of molten metal contained in the mold may lead to cold shuts, spill-outs (where molten metal in the crater or core breaks through the solidified shell) and other serious defects resulting in an excessively high scrap loss. Such fluctuations in the level of the body of molten metal can be caused by various factors. For example, in any given casting operation the level of the molten metal in the receptacle holding the source of molten metal falls where compensating additions of metal are not made thereby decreasing the pressure of the metal passing into the pouring spout or stand pipe and thus decreasing the rate of flow of molten metal into the mold. The rate of flow of molten metal into the mold can also be altered by other factors, among which may be mentioned obstructions in the path of flow of meal from the main body or source of molten metal to the mold and changes in temperature of the metal which affects the viscosity thereof.

It is common practice in continuous casting operations to provide an elongated rod passing down inside of the stand pipe or pouring spout and which, by manually threaded movement, co-acts with the exit end of the pouring spout to control the rate of flow of molten metal into the mold. When the rate of molten metal flow coming into the mold is altered by such factors, as above described, assuming the drop rate of the casting to be constant or substantially constant, there automatically occurs a fluctuation in the level of the body of molten metal contained in the mold. Due to the fact that the human element is involved in first detecting the change in level of the molten metal body and then manually threading the control rod or pin either downwardly or upwardly to compensate for such change in rate of metal flow, there may occur a substantial change in the level of the molten metal body and wherein a further compensating change in level will be effected by the operator in order to bring the level of the molten metal body to the desired point in the mold. Such fluctuations in the level of the body of molten metal tend to produce the undesirable results enumerated hereinabove.

Various proposals have been made heretofore for controlling the rate of flow of molten metal in order to maintain a substantially uniform molten metal level but such proposals have not been found to be completely satisfactory for one or more reasons, e.g., lack of adequate sensitivity to change in molten metal level, short life, high first cost and cost of maintenance.

According to the instant invention, maintaining the level of'the body of molten metal contained within the mold constant or substantially constant during the casting operation is accomplished by means of a novel regulator structure which is adapted to co-act with the lower or exit end of the pouring spout and wherein the desired coaction is brought about through the buoying action of the molten metal displaced by the regulator device and wherein no chambers containing air or other media are utilized.

The regulator of the instant invention includes a valve adapted to be positioned beneath the lower end of the pouring spout which is immersed in the body of molten metal contained in the mold and wherein the valve is adapted for substantially vertically movement toward and away from the lower end of the pouring spout for altering the rate of flow of molten metal issuing from the pouring spot into the body of molten metal to compensate for any change in level of the body of molten metal. The valve member may be an integral part of or is alfixed to a frame, the upper portion of the frame surrounding the move downwardly away from the lower 5011 knife-edges bearing on one end of a suitable beam WhlCh in turn is supported by a knife-edge which acts as a fulcrum about which the beam can move. The state of balance of the valve, frame and beam assembly is such that the major part of the weight of the valve and frame is balanced and wherein the balance of the assembly is adapted to change upon partial immersion of the valve and frame assembly in the body of molten metal. Accordingly, when the valve, frame and beam assembly is installed in the casting station prior to commencing flow of molten metal down the pouring spout, the valve will end of the pouring spout to permit the first flow of molten metal passing down the pouring spout into the mold to be substantially unaffected by the valve. This is desirable in order to rapidly form the desired body of molten metal in the mold and thereby prevent any tendency of freezing in of the mold and bottom block, which forms a support for the casting, or freezing in of the bottom block with the Valve and frame and/ or molten metal distributor where such is used.

As the molten metal rises in the mold, the valve and a portion of the frame become immersed in the molten metal. At such time as the molten metal level rises to a predetermined point in the mold and on the frame, the

buoying action of the displaced metal will cause the valve and frame to rise thereby placing the valve in operating relationship with the lower end of the pouring spout. It will be understood that in setting up the proper balance of the valve, frame and beam assembly, not only must the buoying action of the displaced molten metal be taken into consideration but there must also be considered the downward force exerted on the valve and frame by the molten metal stream passing downwardly and out of the pouring spout. Only a nominal amount of trial and error experimentation is necessary in any given casting operation to determine that part of the weight of the valve and frame that need be balanced by the beam in order that in starting up the casting operation the molten metal will rise to a given level in the mold before the buoying action ofthe displaced molten metal will cause the valve to move upwardly toward the lower end of the pouring spout to effectively stop the flow of molten metal unless the bottom block is set in motion and moves downward. It is undesirable to stop the flow of molten metal into the mold due to the tendency toward excessive solidification of the body of molten metal in the mold and preferably the bottom block is set in motion prior to the time when the flow of molten metal in the mold would be effectively stopped.

In any given casting operation, when the level of molten metal reaches a predetermined point in the mold and the valve is in operative relationship with the lower end of the pouring spout, but preferably short of stopping the flow of metal into the mold, the bottom block will begin to move downwardly. Since the amount of molten metal flowing into the mold equals that being withdrawn in the form of a cast body, there will be established a given level for the body of molten metal in the mold. If at the start of the casting operation the rate of drop of the bottom block is such that the amount of metal being withdrawn in the form of a casting equals that flowing into the'mold, further rise of meta-l in the mold at such time will stop and the level will become constant. Oftentnnes it will be found that the rate of withdrawal of the casting from the mold is more or less than the rate of metal flow than that existing at the time the bottom block commences to drop. In such cases the state of balance of the valve, frame and beam assembly plus the buoyancy effect of the displaced molten metal and downward force of the flowing metal will cause the valve to move toward or away from the lower end of the pouring spout to establish equilibrium between molten metal passing into the mold and solidified metal being withdrawn from the mold and, accordingly, establishing a certain level for the body of molten metal in the mold.

Since the valve, frame and beam are supported on knife-edges and since part of the frame at all times proiects above the surface of the body of molten metal in the mold, the regulator apparatus of the instant invention is found to be very sensitive to changes in level of the body of molten metal in the mold. If, during the castin operation, there occurs a change in rate of withdrawal of the casting or rate of flow of molten metal into the mold, the regulator of this invention will quickly sense such change manifesting itself in a change in the level of molten metal in the mold and the valve will immediately move toward or away from the lower end of the pouring spout to alter the rate of flow of metal thereby compensating for such slight change in level of the body of molten metal. As a result, it has been found that the regulator of the invention maintains the level of the molten metal substantially constant during the casting operation with only slight fluctuations in metal level occurring.

To facilitate rapid adjustment of the state of balance of the regulator, the invention includes the provision of an adjustable counterweight on the end of the beam opposite that from which the valve and frame depend. Moreover, the regulator of the invention is such that it can be assembled with the remainder of the casting apparatus without the need of any rigid connections to such apparatus and can be removed therefrom merely by lifting the regulator out of operative relationship with the remainder of the casting apparatus.

lt will thus be seen that the regulator of the instant invention is simple and relatively inexpensive and yet is very effective in maintaining substantially constant level of the body of molten metal contained in the mold. Moreover, this regulator, once adjusted, is automatic in its operation or co-action with respect to the lower end of the pouring spout, thereby eliminating the necessity of manual control.

Accordingly, the primary purpose and object of the instant invention is to provide a novel regulator for use in the transfer of molten metal from one receptacle to another from which molten metal is issuing and Wherein by use of the regulator the 'levelof the body of molten metal in the receiving receptacle is maintained constant or substantially constant. Another object of this invention" is to provide a novel regulator for maintaining the level of a body of molten metal contained within a. receptacle into and from which molten metal is issuing constant or substantially constant and wherein said regulator is simple, inexpensive and automatic in its operation.

Another object of this invention is to provide a novel regulator for maintaining the level of the body of molten metal contained within the mold'constant or substantially constant during the continuous casting of metals.

A further object of this invention is to provide a novel regulator for use in the casting of metals which compensates for factors affecting the flow rate such as pressure, temperature, and obstructions to path of metal flow such that the level of the body of molten metal contained within the mold is maintained constant or substantially constant during the casting operation.

A further object of this invention is to provide an improved apparatus for the continuous casting of metals and which includes a novel regulator'apparatus for control of the level of the body of molten metal contained in the mold.

Other objects and advantages of the invention will be apparent from the following description, taken in conjunction with the drawings, and wherein: I

Figure 1 is an elevational view showing one form of casting apparatus embodying the principles of the invention with parts removed for the purpose of clarity,

Figure 2 is a vertical, sectional view taken along the line 2-2 of Figure 1,

Figure 3 is a top plan view of the valve and frame assembly shown in Figures 1 and 2 and also showing the arm means and knife-edges for suspending the frame and valve from the beam,

Figure 4 is a front elevational view of the apparatus shown in Figure 3,

Figure 5 is a side elevational view of the apparatus shown in Figure 3,

Figure 6 is a fragmentary, sectional view of the lower portion of Figure 2 but wherein a modified frame and valve assembly is shown,

Figure 7 is a front elevational view of the valve and frame assembly shown in Figure 6,

Figure 8 is a side elevational view of the valve and frame assembly shown in Figure 6,

Figure 9 is a top plan view of a modification of the valve and frame assembly shown in Figures 7 and 8,

Figure 10 is a sectional view taken along the line 10-10 of Figure 9,

Figure 11 is a side elevational view of the frame and valve structure shown in Figure 9, and

Figure 12 is a vertical, fragmentary, sectional view of one form of casting apparatus embodying the principles of the invention in conjunction with use of a molten metal distributor within the casting mold.

With further reference to Figures 1 to 5, inclusive, of the drawings which illustrate one embodiment of the invention as applied to the casting of a cylindrical metal body, an open-ended mold l is suitably mounted over a casting pit (not shown) by any of the conventional means. Within the mold l and extending therebelow is an embryo casting 2 comprising a body of molten metal 3 and solidified casting 4-, the body of molten metal 3 extending downwardly and forming a molten metal crater or core within the casting. Positioned above the mold is a suitable transfer trough 5 for conveying molten metal from a suitable source, e.g., furnace, to a point above the mold. Depending from the transfer trough 5 and projecting downwardly into the mold is a pouring spout 6 Positioned within the mold l and partially submerged in the body of molten metal is a regulator 7. The regulator includes a frame comprising a tubular member 8 having a partition 9 located intermediate the ends thereof. As will be seen from the drawings, partition 9 is shaped such that there is provided a plurality of openings it) through which molten metal issuing from the lower end of the pouring spout 6 may pass downwardly of tubular member 8 and into the body of molten metal 3. Tubular member 8 and partition 9 are made of suitable material having good resistance to erosion by the molten metal being cast. In the case of casting aluminum and aluminum alloys such members may be made from heat resistant cast iron. Affixed to partition 9, and centrally thereof, is a valve 11. The valve may be made integrally with partition 9 and tubular member 8 or may be formed as a separate member and afiixed to partition 9 by suitable means, e.g., screw 12, as shown. It is to be understood that although valve Ili, as shown, is in the form or shape of a cone the present invention is not limited thereto and the valve may take other forms, e.g., hemispherical or spherical. As in the case of tubular member 8 and partition 9, valve 11 is made from a material having good resistance to erosion by the molten metal flowing in contact therewith. in the case of casting aluminum and aluminum alloys, valve ill can be made of material such as heat resistant cast iron, ceramic coated steel, or ceramics such as silicon carbide or silicon-nitride bonded silicon carbide.

Secured to the upper rim of member 8 and extending upwardly are provided a pair of arms 13, at the upper end of each there being provided a knife-edge lid. Frame members 8 and 9, valve 11 and arms 13 pivotally depend from one end of a beam 15 by means of knife-edges 14 which ride on the beam. Beam 15 comprises parallel spaced arms 16, cross-member 1'7 and threaded rod 18 aifixed to member 17. Near the end of arms 16 away from threaded rod 18 are provided suitable V-grooves 19 which receive knife-edges 1d.

Afhxed to, and projecting upwardly from, each arm 16, adjacent the end thereof closest to threaded rod 18, is an arm 2.4 the arms 2b being joined at the top by a member 21. As shown in Figures 1 and 2, arms 20 and member 21 may be constructed as an integral as sembly. Projecting substantially horizontally from each arm 20, and intermediate the ends thereof, is provided a member 22. The members 22 each bear on a suitable knife-edge 23 which, in turn, is supported by members 24 suitably secured to the shell of transfer trough 5'. As shown in Figures 1 and 2, the upper ends of members 24 are afiixed to the ends of an elongated plate member 25 which, in turn, is aifixed to the shell of transfer trough 5, as by welding. Although knife-edge .23 is herein described as supported from the transfer trough, it is to be understood that it is contemplated, within the scope of the invention, that the knife-edge could be supported from other parts of the over-all casting apparatus such as the mold or from a member external of the casting apparatus.

It will be noted that horizontally projecting members 22 are provided on the lower edge thereof with a plurality of V-shaped grooves or notches 26, knife-edge 23 co-acting with one of said notches on each member 22. It has been found, in the use of a given regulator apparatus with different transfer troughs, that the transfer troughs may not all be identical in dimensions, therefore creating a problem in centering the frame within the mold and around the lower end of the pouring spout. The provision of plural grooves or notches 26 on the lower edge of each member 22 provides for suitable adjustment of the regulator apparatus such that the frame can satisfactorily be centered in the mold and around the lower end of the pouring spout with a minimum of eifort.

Provided in threaded connection with threaded rod 18 is an adjustable counterweight 27 adapted for movement along rod 18 for purposes of establishing the desired state of balance of the framevalve-beam assembly.

Affixed to, and projecting upwardly of, member 21 is a plate member 28 having a threaded opening 2.9 provided therein. Elongated threaded rod 30 passes through opening 29 in threaded engagement therewith, said rod 30 being provided with a suitable handle 31 at the outer end thereof for rotation of the rod. The function of rod 3d is to limit the downward movement of valve ill by contact of the inner end of rod 39 with the transfer trough 5". It has been found important that the valve never drop to a position where it is completely without the lower end of pouring spout 6, particularly at the beginning of the casting operation. If the valve were allowed to initially drop to a position completely with out the pouring spout to provide a completely open pouring spout for the the cast, the first rush of molten metal passing down the spout and into the mold might move the valve off-center to such an extent that when the buoyancy action of the displaced molten metal causes the valve to rise there is a risk that the top of the valve might abut against the lower end of the pouring spout rather than being: centered and passing upward within the lower end of the pouring spout. As such, there would be no control of the molten metal flow with the result that the molten metal might overflow the mold with possible injury to workmen and damage to the casting equipment before the flow of molten metal in the transfer trough could be stopped. With the pro elongated greatest flow rate at the beginning of.

'7 vision of threaded rod 30, the spacing between the inner end of the rod and the transfer trough can be adjusted such that in any given casting operation the valve it cannot move completely out of the space defined by the lower end of the pouring spout.

In a continuous casting operation using the regulator of the instant invention, the pouring spout 6, frame members 5; and 9 and valve iii are first heated to a suitable temperature to minimize the possibility of undesirable solidification of molten metal on these members. A bottom block (not shown) is moved upwardly and received within mold l. Thereafter the frame and valve assembly is positioned in the mold, the transfer trough and pouring spout are positioned over the mold with the lower end of the pouring spout 6 projecting downward into the chamber defined by the mold, the beam assembly is suspended in pivoting relationship from the knife-edge 2.3 and the knife-edges M at the upper ends of arms 13 are positioned in pivotal relationship with beam 15 by disposition in grooves 3% provided in arms in. Knife-edge 23 is positioned in the proper notch or groove 26 provided on the lower edge of members 22 to facilitate centering of the frame and valve in the mold and around the lower end or exit end of pouring spout 6. The inner end of threaded rod 3b is adjusted by means of rotation of handle 31 such that the spacing between the inner end of the rod and the shell of transfer trough 5 will permit valve 11 to drop to a point where the upper end of valve 11 is still positioned within the space defined by the lower end of pouring spout 6. The adjustable counterweight 27 is positioned on threaded rod 18 such that prior to the flow of molten metal down through pouring spout 6 the assembled frame and valve will be in their lowermost position. The state of balance of the valve-frame beam assembly is made such that upon passage of molten metal down through the pouring spout and into the space defined by the mold and bottom block (not shown) the molten metal at first flows into the mold with substantially no throttling action being performed by valve and upon continued flow of the molten metal and the building up of a body of molten metal 3 the frame will progressively become submerged in the body of molten metal until at a point prior to complete submersion thereof the frame and valve will move upwardly due to the buoyancy action of the displaced metal and the valve will progressively move further into the lower end of the pouring spout.

Where only a single casting is being produced, that is, only a single regulator device is in use, the bottom block is preferably set in motion and moved downwardly prior to the time when the buoyancy action of the displaced metal would cause the valve to move upwardly into contact with the lower end of the pouring spout and effectively stop the how of molten metal. Since the amount of molten metal flowing into the mold should equal that being withdrawn in the form of a cast body there will be established a given level for the body of molten metal 3 in the mold. If at the start of the casting operation the rate of drop of the bottom block is such that the amount of metal being withdrawn in the form of a casting equals that flowing into the mold, further rise in the level of the body of molten metal in the mold will stop and the level will become constant. Where the rate of withdrawal of the casting from the mold is more or less than the rate of molten metal flow into the mold existing at the precise time the bottom block commences to drop, the balance of the valve-framebeam assembly will cause the valve to move toward or away from the lower end of the pouring spout to establish equilibrium betweenthe amount of molten metal passing into the mold and the solidified metal being withdrawn from the mold and, accordingly, establish a given level for the body of molten in the mold.

As discussed hereinbefore, the state of balance of the regulator assembly is very sensitive to any change in level of the body of molten metal contained in the mold during the casting operation and if during the casting operation the level of the body of molten metal starts to fluctuate, as by moving upwardly or downwardly, the regulator assembly will immediately detect such change and the valve will be caused to move upwardly or downwardly to rapidly compensate for such fluctuation.

The last portion of the molten metal to be cast is passed downwardly through the pouring spout and through the frame and permitted to pass down through the mold to form solidified casting. As the level of the body of molten metal 3 drops at the end of the casting operation the frame and valve will also move downwardly since the amount of displaced molten metal is being reduced and, accordingly, the buoyancy force is also being reduced. However, while the valve and frame are still in contact with molten metal the transfer trough 5 and pouring spout 6, as well as the valve, frame and beam assembly, are raised such that the frame clears the top of the mold. Then the beam 15 is lifted off of knifecdge 23 by grasping the counterweight and associated threaded rod and the regulator assembly removed from the remainder of the casting apparatus. This prevents the possibility of the valve and frame being frozen into the top of the casting as the last portion of the body of molten metal solidifies. it will thus be seen that by means of the instant invention there has been provided a novel regulator apparatus which is inexpensive, simple, provides ease of assembly and disassembly from the remaining casting apparatus and which is very effective in maintaining the level of the body of molten metal contained within the mold constant or substantially constant during the casting operation, thereby eliminating or substantially reducing the occurrence of cold shuts, producing a cast body having a substantially smooth surface and substantially reducing the danger of spill-outs as well as to minimize any tendency toward cracking of the cast body.

Although Figures 1 through 5, and the above description thereof, pertain to using but a single regulator device, it is to be understood that the casting of plural bodies util zing the same transfer trough and utilizing the regulator apparatus of the invention for each pouring spout is within the scope of the instant invention and, in fact, is the preferred practice, particularly in the casting of relatively small bodies. Where it is desired to cast in multiples utilizing the same transfer trough, it is often found impractical to provide for the same rate of flow of molten metal to each of the pouring spouts immediately upon entrance of molten metal into the transfer trough. it is common practice to have the molten metal enter an elongated transfer trough at only one end or at the middle thereof. The molten metal first entering the transfer trough will pass into the pouring spouts closest to the entry point of the molten metal prior to any molten metal flowing into the pouring spouts spaced farthest away from the entry point of the molten metal into the transfer trough. In such cases, it is desirable to utilize suitable plugs, e.g., graphite plugs, positioned in the upper end of the pouring spouts which are most closely situated to the entry end of the molten metal into the transfer trough until such time as the molten metal has flowed throughout the complete length of the transfer trough and then the plugs may then be removed and molten metal will flow into all of the pouring spouts at approximately the same time. Alternatively, all of the pouring spouts may be plugged in similar fashion and molten metal. delivered to the transfer trough and a suitable depth of molten metal provided in the transfer trough and thereafter all of the plugs removed substantially simultaneously such that the same rate of molten metal flow is present in all pouring spouts.

Although the description of the invention, taken in conjunction with Figures 1 to 5, makes specific reference to the casting of bodies having circular cross-section, it is to be understood that the invention has application to the casting of metal bodies of any desired cross-section, e.g., square, elliptical, hexagonal, etc. It is also to be noted that the specific embodiment of the regulator apparatus of the invention shown and described with reference to Figures 1 to 5 of the drawings, although applicable to the casting of metal bodies of relatively large cross-section, has particular application to the casting of bodies of relatively small cross-section, e.g., 5 inches in diameter, in that frame member 8 being of tubular shape prevents the incoming molten metal from spout 6 flowing directly radially and impinging on the mold wall with possible burning thereof occurring.

Figures 6 to 8, inclusive, of the drawings show a further embodiment of the frame and valve assembly of the invention which is particularly applicable to the casting of metal bodies of relatively large cross-section, e.g., 12 inch by 12 inch square, 16 inch diameter, etc. Since the apparatus shown is similar to that of Figures 1 and 2, with the exception of the frame and valve assembly, the same numerals have been used to designate similar parts.

As shown in the drawings, the frame comprises a ring member 35 from which depends an arm 36, the opposite ends of which are affixed to the bottom of ring 35 at approximately diametrically opposed points on the ring. A valve 37 is detachably aflixed to the lower portion of arm 36, as by means of screw 38. As in the case of valve 11 of Figures 1-5 of the drawings, valve 37 can be of a configuration other than the conical shape shown, e.g., spherical, hemispherical, etc. Moreover, the valve may be made as an integral part with ring 35 and arm 36. However, due to the fact that the valve is subjected to the greatest erosion by contact with molten metal pouring down the spout 6, it is preferable that the valve be separable from the arm 36 in order to permit replacement of the valve after excessive wear has occurred. The ring 35, arm 36 and valve 37 are made of a material having good resistance to erosion by the molten metal flowing in contact therewith during the casting operation. In the case of casting aluminum or aluminum alloys, the ring, arm and cone can be made of heat resistant cast iron or suitable refractory material. Inasmuch as in normal handling and casting the ring and arm are often subjected to contact with other members and the valve is subjected to the greatest erosion by the flowing molten metal, it is desirable, in the casting of aluminum and aluminum alloys, to make the ring and arm of heat resistant cast iron and make the valve of a refractory material such as silicon-nitride bonded silicon carbide, silicon-carbide or ceramic coated steel.

It is also to be noted that although frame member 35 is shown as a ring of circular cross-section, it will be understood that member 35 may have a configuration other than ring-shaped, e.g., square, etc., and the crosssectional shape of the member can be other than circular, e.g., square or semi-circular. However, based on a consideration of factors such as cost of manufacture and susceptibility to erosion, it has been found that the ring construction having a substantially circular cross-section is preferred.

As seen in Figure 6, valve 37 is positioned, in operation, substantially below the level of the body of molten metal. Such a relationship is desirable in minimizing turbulence of molten metal at the surface of the body of molten metal and eliminating or substantially eliminating entrapment of oxide inclusions in the ultimate castmg.

In utilizing the frame and valve assembly shown in Figures 6 to 8 in a casting operation of the state of balance thereof with the remainder of the regulator apparatus of the invention and the movement thereof in response to the creation of the desired body of molten metal within the mold at the beginning of the casting operation, as well as the action thereof in response to fluctuations in the level of the molten metal body during the casting operation, are the same as that described in detail hereinabove with reference to the embodiment of the regulator apparatus shown in Figures 1 to 5. However, it has been found with the use of a frame member involving ring 3ft that, in view of the fact a larger portion of the mass of the frame is concentrated within a relatively short vertical distance, the sensitivity of this embodiment to fluctuations in level of the body of molten metal contained in the mold is substantially increased. At the beginning of the casting operation, wherein molten metal is allowed to pass down into the mold with substantially no throttling being effected by valve 37, the molten metal level will rise a considerable distance on arm 36 prior to any noticeable change in position of the frame and valve assembly due to the buoyancy action of the displaced metal. This is due to the fact that the bulk of the mass of the frame and valve assembly is concentrated in ring 35. At such time as the level of the body of molten metal contacts the lowermost portion of ring 35 and thereafter the ring proceeds to be progressively immersed in the body of molten metal, the movement of the frame and valve assembly upward is very rapid for a given rise in the molten metal level in view of the large increase in displaced molten metal occurring within a relatively short distance of vertical rise of the level of the body of molten metal. Accordingly, it will thus be seen that with the embodiment of the frame and valve assembly shown in Figures 6 to 8 any fluctuation in the level of the body of molten metal contained in the mold will be limited to a relatively small vertical distance in view of the high sensitivity of the frame to fluctuations in level.

Figures 9 to 11, inclusive, illustrate a further embodiment of the frame and valve assembly of the present invention and which, in effect, is a combination of the frame and valve assemblies shown in Figures 1 to 5 and Figures 6 to 8 of the drawings. As will be seen, a ring member 40 is affixed to the lower end of arms 13 and depending from the lower portion of ring 40 is a receptacle 41 provided with angularly disposed openings 42. De tachably mounted within receptacle ll is a valve 43, similar to valves 11 and 37. The angularly positioned openings 42 are provided to allow passage of the molten metal issuing from the lower end of the pouring spout into the body of molten metal contained in the mold and to provide control as to the direction of flow of the molten metal issuing from the frame and valve assembly into the body of molten metal contained in the mold. It will thus be seen that the frame and valve assembly combines the features of control of distribution of the molten metal into the mold as well as high sensitivity of the assembly to slight fluctuations in the level of the body of molten metal contained in the mold. Also, some skimming action will be performed by recptacle 41.

Figure 12 of the drawings illustrates the use of the regulator apparatus shown in Figures 6 to 8 in conjunction with the use of a molten metal distributor used for causing the molten metal passing into the body of molten metal contained in the mold to be directed outwardly in a predetermined fashion to reduce undesirable turbulence of the body of molten metal, to prevent pre-freezing of the upper portion of the body of molten metal and to avoid an excessively deep molten metal crater. As will be seen, mold 54 contains casting 51 which comprises a solidified portion 53 and the body of molten metal 52 which forms the crater or molten metal core of the casting. Positioned within the mold and partially immersed in the body of molten metal is a suitable distributor 54 provided with suitable means, e.g., arms 55, for positioning the distributor centrally within the mold and around the lower end of the pouring spout 6. The frame and valve assembly comprising parts 35, 36, 3'7 and 38 is positioned within distributor 54 in alignment with pouring spout 6. The relationship of the frame and valve assembly and the distributor is such that during the casting operation the frame does not contact the distributor in order to prevent any adverse effect upon the sensitivity and operation of the frame and valve assembly. The molten metal passing out of the lower end of pouring spout, through the valve and frame assembly and into the distributor will issue from the distributor and into the body of molten metal by passing through a plurality of directional feed apertures i; provided in the distributor. The number, shape and location of the directional feed apertures provided in the distributor will depend primarily upon the relative size of the mold and distributor and the cross-sectional configuration of the body to be cast.

Although the invention has been described in detail with reference to control of the molten metal level in the mold of a continuous casting apparatus, it is to be understood that the invention is not limited thereto and is of general application in the field of transferring molten metal from one receptacle to another receptacle which contains a body of molten metal and wherein the body of molten metal is being progressively depleted.

Various changes, omissions and additions may be made to this invention without departing from the spirit and scope thereof as set forth in the appended claims.

What is claimed is:

l. in apparatus for transferring molten metal, the combination of a receptacle positioned to receive molten metal from a source thereof, said receptacle adapted to contain a body of molten metal and wherein metal is progressively removed from said receptacle, delivery means for feeding molten metal into said receptacle, the exit end of said delivery means extending down into the chamber defined by said receptacle, a regulator for coaction with said delivery means for controlling the amount of molten metal fed into said receptacle, said regulator comprising a frame means, a valve means affixed to said frame means, said frame means adapted to be partially immersed in said body of molten metal and adapted for substantially vertical movement, said frame means being provided with means for passage of molten metal from said delivery means to said body of molten metal and below the surface thereof, said valve means being positioned below, and in substantial alignment with, the lower end of said delivery means, said frame means being pivotally suspended from balance beam means, the state of balance and the buoyancy of the molten metal displaced by the frame means being such that the upper part of said frame means is maintained above the surface of the body of molten metal, said valve means adapted to move substantially vertically relative to the lower end of said delivery means upon change in the level of said body of molten metal which changes the position of said frame means to maintain substantial equilibrium between the molten metal being fed into said receptacle and the metal being withdrawn therefrom,

2. in apparatus for transferring molten metal, the combination of a receptacle positioned to receive molten metal from a source thereof, said receptacle adapted to contain a body of molten metal and wherein metal is progressively removed from said receptacle, downwardly directed delivery means for feeding molten metal into said receptacle, the lower end of said delivery means extending down into the chamber defined by said receptacle and adapted to extend at the lower end thereof into said body of molten metal, a regulator for coaction with said delivery means for controlling the amount of molten ietal fed into Said receptacle, said regulator comprising a frame means, a valve means afiiXed to said frame means, said frame and valve means being positioned in the chamber defined by said receptacle, the upper part of said frame means adapted to surround the lower portion of said. delivery means, said frame means adapted to be partially immersed in said body of molten metal and adapted for substantially vertical movement, said valve means being positioned below, and in substantial alignment with, the lower end of said delivery means, said frame means being provided with means below the upper part thereof for passage of said molten metal from said delivery means into said body of molten metal, said frame means being pivotally suspended from balance beam means, the state of balance and the buoyancy of the molten metal displaced by the valve means and frame means being such that the upper part of said frame means is maintained above the surface of the body of molten metal, said valve means being adapted to move su stantially vertically relative to the lower end of said delivery means upon change in the level of said body of molten metal which changes the position of said frame means to maintain substantial equilibrium between the molten metal being fed into said receptacle and the metal being withdrawn therefrom.

3. In apparatus for transferring molten metal, the combination of a receptacle positioned to receive molten metal from a source thereof, said receptacle adapted to contain a body of molten metal and wherein metal is progressively removed from said receptacle, delivery means for feeding molten metal into said receptacle, the exit end of said delivery means extending down into the chamber defined by said receptacle, a regulator for coaction with said delivery means for controlling the amount of molten metal fed into said receptacle, said regulator comprising a frame means, a valve means affixed to said frame means, said frame means being provided with means for passage of molten metal from said delivery means to said body of molten metal and below the surface thereof, said frame means adapted tobe partially immersed in said body of molten metal and adapted for substantially vertical movement, said valve means being positioned below, and in substantial alignment with, the lower end of said delivery means, said frame means being pivotally suspended on knife-edge means from balance beam means, the state of balance and the buoyancy of the molten metal displaced by the frame means being such that the upper part of said frame means is maintained above the surface of the body of molten metal, said valve means being adapted to move substantially vertically relative to the lower end of said delivery means upon change in level of said body of molten metal which changes the position of said frame means to maintain substantial equilibrium between the molten metal being fed into said receptacle and the metal being withdrawn therefrom.

4. In apparatus for transferring molten metal, the combination of a receptacle positioned to receive molten metal from a source thereof, said receptacle adapted to contain a body of molten metal and have metal progressively removed therefrom, downwardly directed delivery means for feeding molten metal into said receptacle, a regulator for coaction with said delivery means for controlling the amount of molten metal fed into said receptacle, said regulator comprising a frame means, .a valve means affixed to said frame means, said frame means adapted to be partially immersed in said body of molten metal and adapted for substantially vertical movement, said frame means below the upper part thereof being provided with means for passage of molten metal fromsaid delivery means to said body of molten metal and below the surface thereof, said valve means being positioned below, and in substantial alignment with, the lower end of said delivery means, balance beam means being supported on knife-edge means, said frame means being pivotally suspended on knife-edge means from said balance beam means, the state of balance and the buoyancy of the molten metal displaced by the frame means being such that the upper part of said frame means is maintained above the surface of the body of molten metal, said valve means being adapted to move substantially vertically relative to the lower end of said dolivery means-upon change in the level of said body of molten metal which changes the position of said frame means to maintain substantial equilibrium between the molten metal being fed into said receptacle and the metal being withdrawn therefrom.

5. In apparatus for transferring molten metal, the combination of a receptacle positioned to receive molten metal from a source thereof, said receptacle adapted to contain a body of molten metal and have metal progressively removed therefrom, downwardly directed delivery means for feeding molten metal into said receptacle, a regulator for coaction with said delivery means for controlling the amount of molten metal fed into said receptacle, said regulator comprising a frame means, a valve means aflixed to said frame means, said frame means adapted to be partially immersed in said body of molten metal and adapted for substantially vertical movement, said frame means being provided with means for passage of molten metal from said delivery means to said body of molten metal and below the surface thereof, said valve means being positioned below, and in substantial alignment with, the lower end of said delivery means, balance beam means including an adjustable counterweight means on one end thereof, said frame and valve means being pivotally suspended from the other end of said balance beam means, the state of balance and the buoyancy of the molten metal displaced by the frame means being such that the upper part ofsaid frame means is maintained above the surface of the body of molten metal, said valve means being adapted to move substantially vertically relative to the lower end of said delivery means upon change in the level of said body of molten metal which changes the position of said frame means to maintain substantial equilibrium between the molten metal being fed into said receptacle and the metal being withdrawn therefrom. i i

a 6. ln apparatus for transferring molten metal, the combination of a receptacle positioned to receive molten metal from a source thereof, said receptacle adapted to contain a body of molten metal and have metal progressively removed therefrom, downwardly directed delivery means for feeding molten metal into said receptacle, a regulator for coaction with said delivery means for controlling the amount of molten metalfed into said receptacle, said regulator comprising a frame means, a valve means affixed to said frame means, said frame means adapted to be partially immersed in said body of molten metal and adapted for substantially vertical movement, said valve means being positioned below, and in substantial alignment with, the lower end of said delivery means, balance beam means, said frame means being pivotally suspended from said balance beam means, the state of balance and the buoyancy of the molten metal displaced by the frame means being such that the upper part of said frame means is maintained above the surface of the body of molten metal, adjustable means affixed to said balance beam means for limiting the extent of downward movement of said valve and frame means, said valve means being adapted to move substantially vertically relative to the lower end of said delivery means upon change in the level of said body of molten metal which changes the position of said frame means to maintain substantial equilibrium between the molten metal being fed into said receptacle and the metal being withdrawn therefrom.

7. In apparatus for transferring molten metal, the combination of a receptacle positioned to receive molten metal from a source thereof, said receptacle adapted to contain a body of molten metal and have metal progressively removed therefrom, downwardly directed delivery means for feeding molten metal into saidreceptacle, the lower end of said delivery means extending downwardly into the chamber defined by said receptacle, a regulator for coaction with said delivery means for controlling the amount of molten metal fed into said receptacle, said regulator comprising a frame means, a valve means afiixed to said frame means, said frame and valve means being positioned within the chamber defined by said receptacle, the upper portion of said frame means adapted to surround the lower portion of said delivery means, said frame means adapted to be partially immersed in said body of molten metal and adapted for substantially vertical movement, said frame means being provided with means for passage of molten metal from said delivery means into said body of molten metal, said valve means being positioned below, and in substantial alignment with, the lower end of said delivery means, balance beam means being pivotally supported on knife-edge means and including an adjustable counterweight means provided on one end thereof, said frame means being pivotally suspended on knife-edge means from the other end of said beam means, the state of balance and the buoyancy of the molten metal displaced by the valve means and frame means being such that the upper part of said frame means is maintained above the surface of the body of molten metal, said balance beam means being provided with adjustable screw means for limiting the downward movement of said frame means, said valve means being adapted to move vertically relative to the lower end of said delivery means upon change in the level of said body of molten metal which changes the position of said frame means to maintain substantial equilibrium between the molten metal being fed into said receptacle and the metal being withdrawn therefrom.

8. In apparatus for transferring molten metal, the combination of a receptacle positioned to receive molten metal from a source thereof, said receptacle adapted to contain a body of molten metal and have metal progressively removed therefrom, downwardly directed delivery means for feeding molten metal into said receptacle, a regulator for coaction with said delivery means for controlling the amount of molten metal fed into said receptacle, said regulator comprising a frame means, a valve means atfixed to said frame means, said frame means comprising a vertically extending tubular member provided with a partition means intermediate the ends of said member, said tubular member and said partition means defining passages for movement of molten metal through said tubular member and into said body of molten metal, said valve means being cone-shaped and being detachably mounted on top of said partition means, said delivery means extending downwardly such that the lower end thereof is adapted to be positioned within the chamber defined by said receptacle, the upper part of said tubular member adapted to surround the lower end of said delivery means, said frame means adapted to be partially immersed in said body of molten metal and adapted for substantially vertical movement, said valve means being positioned below, and in substantial alignment with, the lower end of said delivery means, said tubular member being pivotally suspended on knife-edge means from balance beam means, said balance beam means being pivotally supported on knife-edge means, the state of balance of said frame means and the buoyancy of the molten metal displaced by the valve and frame means being such that the upper part of said tubular member is maintained above the surface of the body of molten metal, said valve means being adapted to move vertically relative to the lower end of said delivery means upon change in level of said body of molten metal which changes the position of said frame means to maintain substantial equilibrium between the molten metal being fed into said receptacle and the metal being withdrawn therefrom.

9. In apparatus for transferring molten metal, the combination of a receptacle positioned to receive molten metal from a source thereof, said receptacle adapted to contain a body of molten metal and have metal progressively removed therefrom, downwardly directed delivery means for feeding molten metal into said receptacle, the lower end of said delivery means extending into the space defined by said receptacle, a regulator for coaction with said delivery means for controlling the amount of molten metal fed into said receptacle, said regulator comprising a frame means, a valve means afifixed to said frame means, said frame means comprising a ring member and a relatively narrow 'U-shaped member afiixed at the ends thereof to said ring member, said valve means being cone-shaped and detachably affixed to said U-shaped member substantially coaxially with said ring member, said ring member consisting of substantially the greater part of the mass of said frame means, said ring member adapted to surround the lower portion of said delivery means, said frame means adapted to be partially immersed in said body of molten metal and adapted for substantially vertical movement, said valve means being positioned below, and in substantial alignment with, the lower end of said delivery means, balance beam means being pivotally supported on knife-edge means, said frame means being pivotally suspended on knife-edge means from said balance beam means, the state of balance and the buoyancy of the molten metal displaced by the valve means and frame means being such that part of said ring member is maintained'above the surface of the body of molten metal, said valve means being adapted to move vertically relative to the lower end of said delivery means upon change in the level of said body of molten metal which changes the position of said ring means to maintain substantial equilibrium between the molten metal being fed into said receptacle and the metal being withdrawn therefrom.

10. In apparatus for transferring molten metal, the combination of a receptacle positioned to receive molten metal from a source thereof, said receptacle adapted to contain a body of molten metal and have metal progressively removed therefrom, downwardly directed delivery means for feeding molten metal into said receptacle,'a regulator for coaction with said delivery means for controlling the amount of n1 Len metal fed into said receptacle, said regulator comp ising a frame means, a valve means affixed to said frame means, said frame means comprising a ring member and a cup member affixed to said ring member at the bottom thereof, said cup member being provided with a plurality of angularly disposed openings for passage of molten metal from said cup mem-- ber into said body of molten metal, said valve means being cone-shaped and detachably affixed within said cup member and at the bottom thereof substantially coaxially of the ring member, the greater part of the mass of said frame means being concentrated in said ring member, said frame adapted to be partially immersed in said body of molten metal and adapted for substantia ly vertical movement, said ring member surrounding the lower portion of said delivery means, said valve means being positioned below, and in substantial alignment with, the lower end of said delivery means, balance beam means being pivotally supported on knifeedge means, said frame means being pivotally suspended on knife-edge means from said balance beam means, the state of balance and the buoyancy of the molten metal displaced by the valve means and frame means being such that part of said ring means is maintained above the surface of the body of molten metal, said valve means being adapted to move vertically relative to the lower end of said delivery means upon change in the level of said body of molten metal which changes the position of said ring means to maintain substantial equilibrium between the molten metal being fed into said receptacle and the metal being withdrawn therefrom.

11. in apparatus for the continuous casting of metal bodies, the combination of an open mold adapted to contain a body of molten metal, downwardly directed delivery means for feeding molten metal into said mold, a regulator for coaction with said delivery means for controlling the amount of molten metal fed into said mold, said regulator comprising a frame means, a valve means affixed to saidframe means, said frame means adapted to be partially immersed in said body of molten metal and adapted for substantially vertical movement, said frame means below the upper part thereof being provided with means for passage of molten metal from said delivery means to said body ofmolten metal and below the surface thereof, said valve means being positioned below, and in substantial alignment with, the lower end of said delivery means, balance beam means being supported pivotally on knifeedge means, said frame means being pivotally suspended on knife-edge means from one end of said balance beam means, said balance beam means including provision of adjustable counterweight means at the other end thereof and means for limiting the downward movement of said frame and valve means, the state of balance and the buoyancy of the molten metal displaced by the valve means and frame means being such that the upper part of said frame means is maintained above the surface of the body of molten metal, said valve means being adapted to move vertically relative to the lower end of said delivery means upon change in the level of said body of molten metal which changes the position of said frame means to maintain substantial equilibrium between the molten metal being fed into said receptacle and the metal beingwithdrawn therefrom.

12. An apparatus according to claim 11 wherein said frame means comprises a tubular member having a partition member provided therein intermediate the ends of said member, said tubular member and partition member defining openings for passage of molten metal into said body of molten metal, the upper part of said tubular member being adapted to surround the lower part of said downwardly directed delivery means, said valve means being cone-shaped and being detachably aflixed to said partition and being positioned substantially coaxially with said tubular member.

13. An apparatus according to claim 11 wherein said frame means comprises a ring member and a U-shaped strip member aflixed at the ends thereof to the lower portion of said ring member and at substantially diametrically opposed positions on said ring member, said frame means having the greater part of the mass thereof concentrated in said ring member, said valve means being cone-shaped and being detachably affixed on the upper surface of the lower portion of said strip member and being positioned substantially coaxially with, and below, said ring member.

14. An apparatus according to claim 11 wherein said frame means comprises a ring member, a cup member positioned below and afiixed to the lower portion of said ring member, said cup member being provided with a plurality of .angularly disposed openings for passage of molten metal'from said cup member into said body of molten metal contained in the mold, the greater part of'the mass of said frame means being concentrated in said ring member, the valve means being cone-shaped and detachably aflixed inside said cup member and at the bottom thereof, said cone-shaped member being positioned coaXially with, and below, said ring member.

15. In apparatus for the continuous casting of metal bodies, the combination of an open mold adapted to contain a body. of molten metal, downwardly directed delivery means for feeding molten metal into said mold, the lower end of said delivery means extending down within the chamber defined by said mold, molten metal distributor means positioned within said mold and bencath' said delivery means adapted to contain a body of moltenmetal and for controlling the direction and velocity of the molten metal passing into said body of molten metal, a regulator for coaction with said delivery means for controlling the amount of molten metal fed into said distributor means, said regulator comprising a frame means, a valve means amxed to said frame means, said frame and valve means being positioned within said distributor means and wherein the upper part of said frame means isadapted to surround the lower portion of said downwardly directed delivery means, said frame means adapted to be partially immersed in said second mentioned body of molten metal contained within said distributor means and also adapted for substantially vertical movement, said valve means being positioned below, and in substantial alignment with, the lower end of said delivery means, balance beam means being pivotally supported on knife-edge means, said frame means being pivotally suspended on knife-edge means. from said balance beam means, the state of balance and buoyancy of the molten metal displaced by the valve means and frame means being such that the upper part of said frame means is maintained above the surface of the body of molten metal contained within said distributor means, said valve means being adapted to move vertically relative to the lower end of said delivery means upon change in the level of said body of molten metal which changes the position of said frame means to maintain substantial equilibrium between the molten metal being fed into said receptacle and the metal being withdrawn therefrom.

16. A regulator for use in controlling the flow of molten metal from one receptacle to a second receptacle containing a body of molten metal being progressively depleted and wherein downwardly extending delivery means are provided for feeding molten metal into said second receptacle, comprising a frame means, a valve means afiixed directly to said frame means, said frame means adapted to be positioned in said second receptacle and partially immersed in said body of molten metal and adapted for substantially vertical movement, the upper part of said frame means adapted to surround the lower end of said delivery means, said frame means below the upper part thereof being provided with means for passage of molten metal from said delivery means to said body of metal, said valve means adapted for positioning below, and in substantial alignment with, the lower end of said delivery means, balance beam means pivotally supported on knife-edge means, said balance beam means including an adjustable counterweight means on one end thereof, said frame and valve means being pivotally suspended on knife-edge means from the other end of said beam means, the state of balance and the buoyancy of the molten metal displaced thereby being such that the upper part of said frame means is maintained above the surface of the body of molten metal, said valve means adapted to move substantially vertically relative to the lower end of the delivery means upon change in level of said body of molten metal which changes the position of said frame means to maintain substantial equilibrium between the molten metal being fed into said second receptacle and the metal being withdrawn therefrom.

17. An apparatus according to claim 16 wherein said frame means comprises a vertically extending tubular member, a partition member provided intermediate the ends of said tubular member, said tubular member and partition member defining means for passage of molten metal through said tubular member, said valve member being cone-shaped and being detachably mounted on top of said partition member substantially coaxially with said tubular member.

18. An apparatus according to claim 16 wherein said frame means comprises a ring member, a substantially U-shaped relatively narrow member, said U-shaped mem her being positioned below said ring member with the ends of said U-shaped member afiixed to said ring member at approximately diametrically opposed locations thereon, the greater portion of the mass of said frame means being concentrated in said ring member, said valve means being cone-shaped, the bottom of said coneshaped valve means being detachably aflixed on said U- shaped member substantially coaxially with said ring member.

19. An apparatus according to claim 16 wherein said frame means comprises a ring member, a cup-shaped member positioned below said ring member with the rim of said cup member affixed to the lower portion of said ring member, said rim portion of the cup member being coextensive with the ring member", said cup member being provided with a plurality of angularly disposed openings for passage of molten metal therethrough, the greater part of the mass of said frame means being concentrated in said ring member, said valve means being cone-shaped, said valve means being positioned within said cup member and detachably affixed to the bottom thereof and being substantially coaxial with said ring member.

References Cited in the file of this patent UNITED STATES PATENTS 964,916 Iunger July 10, 1910 1,139,887 Mellen May 18, 1915 1,686,823 Leyland Oct. 9, 1928 1,983,579 Ennor et al. Dec. 11, 1934 2,161,776 Orr June 6, 1939 2,243,425 Junghans May 27, 1941 2,301,027 Ennor Nov. 3, 1942 2,371,456 McGill Mar. 13, 1945 2,618,477 Short Nov. 18, 1952 FOREIGN PATENTS 256,026 Switzerland Feb. 16, 1949 844,956 Germany July 28, 1952 860,243 Germany Dec. 18, 1952 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,891,291 June 23, 1959 Richard N. Schnacke It is herebir certifiedthat error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 19 for "meal" read metal line 65, for "vertically" read vertical column 7 line 73 after "molten" insert metal column 10., line 54L, for "recptacle" read receptacle Signed and sealed this 3lst day of January 1961.

(SEAL) Attest:

KARL H. AXLINE ROBERT C. WATSON Attesting Oflicer Commissioner of Patents

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