US2586596A

US2586596A - Induction pouring furnace

Info

Publication number: US2586596A
Application number: US127193A
Authority: US
Inventors: Luther W Bahney
Original assignee: Scovill Inc
Current assignee: Scovill Inc
Priority date: 1949-11-14
Filing date: 1949-11-14
Publication date: 1952-02-19
Anticipated expiration: 1969-02-19

Description

Feb. 19, 1952 L. w. BAHNEY 2,586,596

INDUCTION POURING FURNACE Filed Nov. 14, 1949 4 Sheets-Sheet 1 INVENTOR ATTOFiNZ HS Feb. 19, 1952 L. w. BAHNEY INDUCTION POURING FURNACE 4 Sheets-Sheet 2 Filed Nov. 14, 1949 INVENTOR [0/59" Wfiofimy BY MQBQ ATTORNEYS Feb. 19, 1952 L. w. BAHNEY INDUCTION POURING FURNACE 4 Sheets-Sheet 5 Filed Nov. 14, 1949 Y mm ATTORNEYS Feb. 19, 1952 w, BAHNEY INDUCTION POURING FURNACE 4 Sheets-Sheet 4 Filed Nov. 14, 1949 ATTORNEYS Registered Feb. 19, 1952 INDUCTION POURING FURNACE Luther W. Bahney,

Elizabeth, N. J., assignor to Scovill Manufacturing Company, Waterbury, Conn, a corporation of Connecticut Application November 14, 1949, Serial No. 127,193

9 Claims.

The above named applicant has made an invention or discovery of which the following is a specification.

This invention relates to a pouring furnace of the electric induction type for receiving molten metal from a melting furnace and for maintaining the metal in molten condition while discharging the metal, for example into a continuous casting apparatus.

It is an object of this invention to provide an improved furnace of the character described, of a compact construction which can be used effectively where the space available for the furnace and its actuating mechanism is limited. It also is an object of this invention to provide a furnace from which the metal can be discharged into a casting mold at a controlled uniform rate of speed, and in which the pouring operation can continue for long periods of time without interruption, except for the occasional replacement of parts. It is a further object of the invention to provide apparatus in which replacement of certain parts of the pouring furnace, when necessary or desirable, can be accomplished with only slight interruption in the pouring operation. These and other objects and advantages of the invention will be apparent from the following description.

The accompanying drawings show a furnace constructed in accordance with the present invention for attaining the objects of this invention. In the drawings:

Figure 1 is a side elevation of the pouring furnace showing its relation to the launder leading from the melting furnace and to the casting mold, when in pouring position;

Figure 2 is a side elevation similar to Figure 1, but showing the pouring furnace tilted back, i. e. to the left in this view, to lift the down spout from the casting mold as will be done when the operator has finished casting, or preliminary to removing either the down spout or the nose piece from the furnace;

Figure 3 is a side elevation similar to Figures 1 and 2, but with the pouring furnace moved a short distance away from the casting mold and tilted forward, i. e. to the right, to drain the pouring furnace and its heating unit;

Figure 4 is an end elevation of the pouring furnace looking toward the furnace from the right, as viewed in Figure 1;

Figures 5, 6 and 7 are top plan views showing the carriage on which the pouring furnace is tiltably mounted aid disclosing details of the linkage mechanism for tilting the furnace, the

positions of the carriage and the hearth corresponding, respectively, to Figures 1, 2 and 3.

Figure 8 is a horizontal sectional view through the furnace nose piece, substantially on line 8-8 of Figure 1, there being two parallel outlets for discharging molten metal;

Figure 9 is a view similar to Figure 8, except that in this modification the nose piece has but one outlet for the molten metal;

Figure 10 is a vertical sectional view through the nose piece substantially on the line I 0-H] of either Figure 8 or Figure 9;

Figure 11 is a vertical section, to enlarged scale, of the molten metal outlet shown in Figure 10, including the lower end of the graphite rod stopper used to control the flow of molten metal through the outlet in the bottom of the nose piece;

Figure 12 is an end elevation, partly broken away in section, showing the arrangement for securing the down spout in the pouring outlet, this being a view, to enlarged scale, substantially on line l2|2 of Figure 1;

Figure 13 is a horizontal sectional view through the means for securing'the down spout in the pouring outlet, taken substantially on line 13-13 of Figure 12; and

Figure 14 is an end elevation of a guard member for holding a carriage wheel on the track rail, taken substantially on line I4-l4 of Figure 1.

Referring to the drawings, Figure 1 shows the pouring furnace, designated generally at 2|, in pouring position, that is in position for discharging molten metal through the down spout 22 into the casting mold 23. The hearth 24 of the pouring furnace is generally rectangular in shape, as viewed from above, and is supported for tilting movement about a transverse horizontal axis. In the illustrative embodiment the hearth is secured to a shaft 29, end portions of which are mounted in bearings 30, on a carriage 3|.

The hearth 24 has an opening 25 at its forward end, which is the right-hand end as viewed in Figures 1 through 3. The opening 25 extends the full height of the hearth, but is made substantially narrower than the hearth by turning the forward ends of the side walls inwardly toward each other, as can be seen clearly at 26 in Figure 8.

Detachably secured to the open forward end of the hearth and forming an extension thereof is the nose piece 27. The hearth 24 and the nose piece 21 comprise metal shells lined with insulating material and firebrick, or other suitable furassacee nace lining materials, in accordance with ap proved practice. The nose piece may be detachably secured to the open end oi the hearth by bolts extending through openings in the matching flanged portions 28 of the metal shells.

In the bottom or the nose piece is a valved outlet 83 for discharging molten metal from the hearth, for example into a continuous casting machine. For casting large billets or cakes a single valved outlet ordinarily will be employed, as shown in Figures. but wire bars or small billets a plurality of valved outlets may be provided. Two outlets are shown iii] it it is desired to cast in Figure 8, Ior simultaneously casting two wire bars. Nose pieces as disclosed in Figures 8 and 9 may be interchangeably used on the hearth 2|.

As can be seen more clearly in Figures 10 and 11, in the illustrative embodiment the outlets 31 in the bottom of the nose place are in the form of tapered bushings which may extend through the lining materials and metal shell of the nose piece. These bushings are made of material which will withstand the high temperatures oi the molten metal for long periods of time. One suitable material is known as Zirconlte" and is made from zirconia.

Flow of metal downwardly through the bushing 33 is controlled by lowering and raising the vertically disposed valve rod 3!. The lower end oi the valve rod is pointed and, when lowered, seats in the upper end or the bushing 33 to stop the outflow of metal. Preferably the valve rod 14 extends upwardly above the top oi the hearth 24, where it is connected to means for adjusting the height of the rod relative to the bushing 33 to control the flowot metal.

In the illustrative embodiment, the upper end or the valve rod BI is adjustably connected by means of a. clamp bracket 35 to the upper end of a valve actuating rod 38, which is disposed parallel to the valve rod ll and is slidably mounted in brackets secured to the exterior oi the nose piece 2]. Vertical adjustment of the valve actuating rod 38 to open and close the out let 3! may be made by means of a cam arrangement ll. As shown, the two co-operating cam members encircle the valve actuating rod 36. The lower cam member is secured against rotation to one of the brackets on the nose piece. Resting on the upper cam member, which is rotatable about the valve actuating rod 36, is the collar 42 secured on the valve actuating rod. By turning the upper cam member, as by means 0! the handle attached thereto, the collar 42 and connected valve actuating rod I! are raised or lowered and, through the interconnection of the clamp bracket II, the valve rod N is simultaneously raised or lowered to open or close the outlet :1.

The material of the valve rod 34 should be selooted for its resistance to erosion by the flowing metal and to destructive action by gases in the furnace above the metal. For pouring oxygeni'ree copper, for example, a alve rod made of Acheson graphite such as is used for carbon electrodes will give long service.

Metal flowing outwardly from the bushing 33 is conducted through the down spout 22 directly into the castingmold 23, for example the upper end of a continuous casting machine. This down spout may be in the form of an inverted T, the metal being discharged into the casting mold through a plurality of openings in the upper surface or the cross member at the lower end of the down spout, so as to minimize turbulence in the metal within the casting mold. The down spout preferably will be made of metal which is resistant to distortion under the high temperatures encountered. for example a chromium alloy. In the course of time, however, the down spout may become distorted by the heat, making it desirable to replace the down spout with a new one.

According to this invention, means are provided for detachably securing the down spout 22 to the nose piece 21, so that the down spout can be removed and replaced by a new one, and the pouring of metal resumed within such a short time that the operation of a continuous casting machine ordinarily will not be interrupted or otherwise aiiected for more than a few minutes.

Referring particularly to Figures 12 and 13, it will be seen that the upper end of the down spout 22 fits into an enlarged opening in the lower end of the bushing 33. Secured on the down spout, near its upper end, is a flange plate 38 which rests against the bottom of the nose piece 21 when the upper end of the down spout is pushed up into the bushing 13. Secured to the bottom of the nose piece, on opposite sides of the bushing 33, are two Z-shaped flanges 39. These flanges are spaced far enough apart to permit passage therebetween, with slight clearance, of the flange plate It as the upper end of the down spout is being inserted into or removed from the bushing 31. Preferably the flange plate 38 will be rectangular in shape and secured on the down spout in proper angular relation to the cross member on the lower end thereof so as to insure that the cross member will be turned correctly, relative to the casting mold, when the flange plate is turned so as to pass between the flanges ll.

The down spout, pressed home into the bushing 13, will be held flrmly in the nose piece with the flange plate 38 pressed against the bottom of the nose piece, by means of a slotted key plate 40. which may be slidably inserted between the flanges 39 under the flange plate 38. The outer end of the key plate 4.0 may be provided with an opening ll to facilitate ready withdrawal 0! the key plate when it is desired to remove the down spout from the nose piece.

It will be understood that the down spout may be removed from the nose piece and replaced without the necessity for draining the pouring hearth. All that is necessary is to close the valved outlet 33 by lowering the valve rod 34 until it seats in the bushing, and then to tilt the furnace back, by means which will be described hereinafter, from the position shown in Figure l to the position shown in Figure 2. Tiltin the furnace in this manner lifts the downspout from the casting mold and brings it into convenient position for removal and replacement. with the arrangement shown and described it is possible to remove and replace a down spout and to resume pouring of metal within a matter of a few minutes.

Figures 8, 9 and 10 disclose details of the furnace construction for holding back slag, graphite, charcoal, or other material which may be floating on the metal in the hearth 24 and for preventing the passage 01' such material to the outlet 33 in the nose piece 21. It has already been stated that the nose piece forms an extension of the hearth, but the floor of the nose piece, except for a relatively narrow edge at the line of union with the floor of the hearth, is raised slightly above the floor of the hearth. The diflerenco 5 in heights ordinarily will be of the orderof two to three inches.

Mounted in the nose piece, across the opening 26 in the front end of the hearth, is 9. skim plate 43 of carborundum tile or similar suitable material which transmits heat readily while holding back the molten metal. This skim plate may be slidable vertically in grooves formed between the hearth 24 and the nose piece 21, These grooves terminate a short distance above the floor of the hearth 24, so that molten metal may pass from the hearth, under the skim plate, and into the nose piece.

The distance between the lower edge of the skim plate and the floor of the hearth 24 is made less than the difference in heights between the floors of the hearth 24 and the nose piece 21, and may be of the order of one inch, for example. Hence, metal passing from the hearth 24 to the nose piece 21 must rise slightly, after it passes floating on the surface of the metal in the hearth 24 will pass under the skim plate and reach the outlet 33 in the nose piece.

Depending from the hearth 24 and detachably secured thereto, as by means of bolted matching flanges, is a heating unit 32. unit preferably is of the known electric induction type in which molten metal circulates in a continuous path from the hearth, through a restricted heating channel constituting the secondary of a transformer, and back to the hearth. To facilitate draining the channel of the heat ing unit 32. as must be done if it becomes necessary to replace the heating unit, or when it is desired to close down the furnace for any reason, the heating unit preferably is inclined outwardly toward the back end of the hearth, that is away from the nose piece 21. The plane through the axis of the heating channel is disposed parallel to the horizontal axis about which the hearth is tiltable, and at an acute angle to the vertical when the hearth is in pouring position. In the illustrative embodiment this acute angle is approximately 45", as may be seen in Figure 1.

Means are provided for artificially cooling the electric windings of the induction heating unit. Air is forced by a blower 44 through conduit 45 to the heating unit 32. In order to avoid the necessity for providing a turning joint or flexible connection in the conduit connecting the blower to the heating unit, the blower and its driving motor 46 may be mounted on a bracket 41 secured to one end of the shaft 29. When so mounted, the blower turns with the-shaft as the hearth is tilted and remains fixed in position relative to the induction heatin unit, permittin a rigid connection therebetween.

The metal discharged from the pouring furnace 2! into the casting mold 23 is replaced, either continuously or intermittently, from a melting furnace. In the drawings, 48 is the end of a launder conveying metal from the melting furnace to the spout 49 which leads into the pouring furnace. Preferably this spout has entrance to the pouring furnace through one side thereof in such a manner as to permit the flow of metal into the hearth This heating duce the heat loss to the atmosphere.

24 when the hearth is in pouring position, as shown in Figure 1, and in holding position, as shown in Figure 2, and in any intermediate position. This result may be accomplished by having the spout 49 enter the hearth 24 through an arcuate slot 50 in one side of the hearth, the center of curvature of this slot lying on the transverse axis about which the hearth is tiltable.

It may be desirable to cover the pouring hearth for the purpose of protecting the molten metal from contact with the atmosphere and also to re- Figures 1 and 2 disclose a plurality of arch-shaped covers 12 extending transversely across the hearth 24 and arranged side by side to provide a cover for the hearth. Figures 1, 2 and 4 disclose a cover 13 for the nose piece 21, this cover naturally having an aperture for passage of the valve rod 34. At their engaging edges, these covers and the shell of the hearth and the shell of the nose piece may be provided with matching flanges to facilitate fastening and sealing the covers in place on the hearth by conventional methods.

The molten metal preferably will be kept out of contact with the atmosphere in its passage from the melting furnace into the pouring furnace. This may be accomplished by use of a sealing joint around the spout 49 between the two furnaces, for

example as shown in Figure 4. The arcuate slot.

50 is provided with a face plate or flange 5| facing the melting'furnace, the surface of this flange lying in a plane normal to the axis about which the pouring hearth is tiltable. A cooperating flange plate 52, slidably supported on bolts or rods extending from the melting furnace and closely surrounding the spout 49, closes the arcuate slot 50 for all positions of the hearth between the pouring and holding positions, shown in Figures 1 and 2, respectively. This flange plate 52 is pressed resiliently against the flange 5|, as by means of springs 53 surrounding the bolts or rods which support the flange plate, thus providing a joint which may be made sufliciently tight for the intended purposes. For the convenience of the operator, the throat of the arcuate slot 50 may be provided with a removable cover portion l4, generally similar to the covers H2.

The carriage 3i, with its bearings 30 in which the shaft 29 is mounted, is supported by four wheels 55 on two parallel rails 56, which are disposed so as to permit a limited movement of the carriage toward and away from the casting mold 23. It is not necessary to move the carriage along the rails when merely tipping the hearth 24 back from pouring position, shown in Figure l, to holding position, shown in Figure 2, or the reverse. However, when it is desired to drain the induction heating unit 32 it will be necessary to move the carriage away from the casting mold to provide clearance between the forward end of the hearth and the casting mold as the hearth is tipped forward. By removing the nose piece 21, as shown in Figure 3, the distance which the carriage must be moved away from the casting mold will be reduced.

Means are provided to hold the carriage 3| on the rails and to prevent tipping of the carriage, particularly the lifting of the rear end of the carriage from the rails when the hearth is tipped forward to the position shown in Figure 3. Means also are provided for accurately adjusting the position of the carriage along the rails so that the down spout will enter the casting mold when the hearth is tilted from holding position to pourhis position, and for holding the carriage securely in its adjusted position.

Extending over each rear wheel of the carriage and secured to the rail on which the wheel rests is a guard member 51, which has an inverted U shape. The ends of this guard member may be fastened to the top flange of the rail by means of a cooperating clamp member and bolt. A suitable clamp construction is shown in Figure 14.

The horizontal portion of the guard member lies between the wheel flanges at the upper edge of the carriage wheel 55. The clearance between the horizontal portion of the guard member and the wheel is made sufficient so that the guard member will not interfere with rolling movement of the wheel along the rail 56, between the vertical leg portions of the guard member, but the clearance is not great enough to permit any substantial movement of the wheel away from the rail, or any tipping of the wheel about the longitudinal axis of the rail.

Extending over each front wheel of the carriage and secured to the rail on which the wheel rests is a guard member 58, which also has an inverted U-shape. The guard members 58 may be secured to the rails in the same manner as the guard members 51, and the horizontal portions of the guard members 58 lie between the flanges at the upper edges of their respective wheels as described for the guard member 51.

The spacing between the vertical legs of the guard member 58 is considerably less than for the guard member 51. Extending through each leg of the guard member 58, disposed parallel to the axis of the rail 56 and aligned with the center of the wheel 55, are tapped openings to receive the adjusting screws 59.

When installing the guard members 58, they are clamped to the rails 55 with the carriage 3| approximately in the right position for the down spout 22 to enter the top of the casting mold 23. The carriage may then be moved slightly along the rails by adjusting the screws 59 until it is exactly positioned. When it becomes necessary to move the carriage away from the casting mold, which in normal operation will occur at infrequent intervals, the guard members 58 will be removed from the rails.

The mechanism disclosed in the illustrative embodiment for tilting the hearth 24 about its transverse axis into the several positions shown in Figures 1, 2 and 3 will next be described. Secured to the shaft 29- and hearth 24. located on the shaft interiorly of the shaft bearings 30, are two similar, parallel lever arms 60. By turning these lever arms, the shaft 29 will be turned and the hearth 24 will be tilted.

The ends of the lever arm 60 are connected by a shaft Bl, which is linked by means of the parallel connecting rods 62 to a parallel shaft 55. The shaft 63 extends through the side members it of a horizontally disposed frame 64 near the forward end of the frame, i. e. the end nearest the casting mold 23. Extending through the side members of this frame near its other end is a shaft 65, arranged parallel to the shaft 63.

In the illustrative embodiment, the side members ll of the frame 64 are channel shaped members which are disposed with their flanged sides facing outwardly. Arranged parallel to each of the side members 66, outside of the frame 64, is a channel shaped member 81, the flanged side thereof being closely opposed to the flanged side of the member 88. These channel members 81, which are considerably longer than the carriage rails 58, are firmly secured to the same foundation or structure as the rails ll, so that they cannot move upwardly toward the hearth shaft 2!, or move relative to each other.

Mounted on the ends of the shafts 53 and ll, in the elongated spaces between the channel shaped

members

66 and 61, are frustro-conical shaped rollers 65 which can roll along inside the channel members 61 when the frame 54 is moved. When the side members are channel shaped, as in the illustrative embodiment, these rollers may be backed up with frustro-conical shaped blocks fitting in the spaces between the flanges of the side members Ii. It will be apparent that the horizontally disposed frame 04 is capable of movement in a horizontal plane. guided by the channel shaped members I, and that the frame will be firmly held between the members 66 at all times by reason of the engagement of the rollers 68 with the flanges of the members 61. As the frame 54 is moved forward and back, the connecting linkage will turn the shaft 29 and tilt the hearth 24.

Hydraulic mechanism conveniently is provided for moving the frame 64 to tilt the hearth 24. In the illustrative embodiment, a hydraulic cylinder 69, two of which are shown, is connected to a crosshead H secured to the outer ends of the channel shaped members 51. The hydraulic rams iii are connected to the end of the horizontally disposed frame 54, so that actuation of the hydraulic mechanism will move the frame back and forth and, through the interconnecting linkage, tilt the hearth.

Stop means may be provided for limiting the extent to which the furnace may be tilted to the rear. For example, brackets 15 secured on the hearth 24 near its rear end may engage the stop members 15, secured to and projecting upwardly from the carriage ll, when the hearth is tilted back to the holding position, as shown in Figure 2.

When it is desired to move the carriage 3i along the rails from the position shown in Figure 1, the furnace first will be tilted from pouring position to the position shown in Figure 2, so as to lift the down spout 22 clear of the casting mold 23. Then G clamps will be placed over the brackets 15 and the stop members 16 to hold the furnace against tilting forward. If it is desired to move the carriage only a short distance, up to about an inch or two, the screws 59 will be adjusted to permit such movement, but if the carriage is to be moved away from the casting mold a greater distance, the guard members 58 will be removed from the rails. The carriage then can bemoved along the rails by actuation of the hydraulic mechanism until the carriage reaches its desired new position, or until the rear wheels 55 engage the rear legs of the guard members 51. Upon removal of the c clamps the furnace can be tilted by further actuation of the hydraulic mechanism, the carriage being held against movement by reason of engagement of wheels 55 with the guard members 51, or by chocks placed under the wheels.

Means also may be provided for limiting the extent to which the furnace may be tilted forwardly when it is being brought into pouring position. For example, stop members 11 may be clamped to the channel members to limit the movement of the frame 54 to the rear. These stop members 11 will be removed when it is desired to bring the hearth to the position shown in Figure 3.

It is believed that important advantages of the present invention will be evident from the foregoing description. The invention as herein described may be variously modified and embodied within the scope of the subjoined claims.

I claim:

1. A pouring furnace for metals and alloys, comprising, in combination, a hearth, means supporting said hearth for tilting movement about a transverse horizontal axis, said supportin means being mounted on a carriage which is movable horizontally in the direction of the longitudinal axis of the hearth, an arcuate-- shaped opening in one side of the hearth through which molten metal may be poured into the hearth, the center of curvature of the arcuateshaped opening being located substantially on the aforesaid transverse axis so that molten metal may be poured into the hearth when the hearth is in different tilted positions, means for tilting the hearth, a nose piece detachably secured to one end of the hearth and forming an extension thereof from which molten metal may be discharged, and an induction heating unit depending from and detachably secured to the hearth toward its other end.

2. A pouring furnace according to the preceding claim including, in combination, a track on which the carriage is mounted for movement of the hearth horizontally along its longitudinal axis, and means limiting the extent of movement of the carriage along the track and at the same time securing the carriage against tilting on the track when the hearth is tilted.

3. A pouring furnace for metals and alloys comprising, in combination, a hearth, means supporting said hearth for tilting movement about a transverse horizontal axis, said supporting means being mounted on a carriage which is movable horizontally in the direction of the longitudinal axis of the hearth, an arcuate-shaped opening in one side of the hearth through which molten metal may be poured into the hearth, the center of curvature of the arcuate-shaped opening being located substantially on the aforesaid' transverse axis so that molten metal may be poured into the hearth when the hearth is in different tilted positions, means for tilting the hearth, a nose piece detachably secured to one end of the hearth and forming an extension thereof, an outlet through the bottom of said nose piece for discharging molten metal from the hearth, a down spout detachably secured in said outlet, said down spout being removable from the exterior of the nose piece, and an induction heating unit depending from and detachably secured to the hearth toward its other end.

4. A pouring furnace for metals and alloys, comprising, in combination, a hearth, means supporting said hearth for tilting movement about a transverse horizontal axis, a nose piece detachably secured to one end of the hearth and forming an extension thereof from which molten metal may be discharged when the hearth is tilted to pouring position, an induction heating unit depending from and detachably secured to the hearth toward its other end, means for tilting the hearth back from pouring position to holding position, and from holding position to pouring position, an arcuate-shaped opening. in one side of the hearth through which molten metal may be poured into the hearth, the center of curvature 10 of the arcuate-shaped opening being located substantlally on the aforesaid transverse axis so that molten metal may be poured into the hearth when the hearth is in pouring position, and also when the hearth is in holding position, and in any intermediate position.

5. A pouring furnace for receiving molten metal from a melting furnace and for discharging the molten metal into a casting mold,

comprising, in combination, a hearth for receiving the molten metal, means supporting said hearth for tilting movement about a transverse horizontal axis, an induction heating unit depending from the hearth and detachably secured thereto toward one end of the hearth for maintaining the metal in molten condition, a nose piece detachably secured on the other end of the hearth and forming an extension thereof, a pouring outlet in the bottom of the detachable nose piece, a skim plate mounted in grooves formed between the hearth and the nose piece at their junction, said skim plate separating the metal in the hearth from the metal in the nose piece, except for a narrow sp ac e between the lower edge of the skim plate and the bottom of the hearth which permits passage of molten metal from the hearth under the skim plate into the nose piece, the bottom of the detachable nose piece surrounding the pouring outlet being higher than the bottom of the hearth and higher than the lower edge of the skim plate, so as to prevent passage of any material floating on the metal in the hearth into the nose piece and the pouring outlet.

6. A pouring furnace for receiving molten metal from a melting furnace and for discharging the molten metal into a casting mold, comprising, in combination, a hearth for receiving the molten metal, means supporting said hearth for tilting movement about a transverse horizontal axis, a nose piecedetachably secured on one end of the hearth and forming an extension of the hearth, an induction heating unit depending from and detachably secured to the hearth toward its other end, a pouring outlet in the bottom of the detachable nose piece, means for controlling the amount of metal flowing through the pouring outlet, a skim plate mounted in grooves formed between the hearth and the nose piece at their junction, the said skim plate separating the metal in the hearth from the metal in the nose piece, except for a narrow space between the lower edge of the skim plate and the bottom of the hearth which permits passage of molten metal from the hearth under the skim plate into the nose piece, a down spout in the pouring outlet, means detachably securing the down spout in the pouring outlet, and means for tilting the hearth out of pourin position to permit removal and replacement of the down spout.

7. A pouring furnace for discharging molten metals and alloys into a casting mold, comprising, in combination, a hearth, means supporting said hearth for tilting movement about a transverse horizontal axis, a nose piece detachably secured to one end of the hearth and forming an extension of the hearth, an induction heating unit depending from and detachably secured to the hearth toward its other end, an outlet through the bottom of said nose piece for discharging molten metal from the hearth, a down spout in said outlet, and means for detachably securing the down spout in the outlet, said means comprising a collar secured on the down spout near its upper end so as to lie against the bottom of the nose piece when the down spout is pushed into the outlet, Z-shaped flanges secured to the bottom of the nose piece on opposite sides of the outlet, the spacing between these flanges permittin passage of the down spout collar therebetween as the down spout is pressed into or withdrawn from the outlet, and a slotted key plate which is slidably inserted between the flanges, under the down spout collar, to lock the collar against the bottom of the nose piece and hold the down spout securely in the outlet.

8. A pouring furnace for receiving molten metal from a melting furnace, and for discharging molten metal into a casting mold comprising, in combination, a hearth for receiving the molten metal from the melting furnace, means supporting said hearth for tilting movement about a transverse horizontal axis, an induction heating unit depending from the hearth toward one end thereof and detachably secured to the hearth, a nose piece detachably secured to the other end of the hearth and forming an extension of the hearth overhanging the casting mold, an outlet through the bottom of said nose piece for discharging molten metal from the hearth, a down spout in said outlet for conveying the molten metal directly into the casting mold, said down spout being removable from the exterior of the nose piece and detachably secured to the nose piece, means for tilting the hearth about the aforesaid transverse horizontal axis to lift the lower end of the down spout from the casting mold and thus permit replacement of the down spout on the nose piece, a carriage for the hearth-supporting means whereby the hearth may be moved away from the casting mold after the hearth has been tilted to withdraw the lower end of the down spout from the casting mold, the hearth-tilting means being capable of tilting the hearth in the opposite direction after the nose piece has been detached therefrom, so as to drain the induction heating unit preparatory to replacing the induction heating unit depending from the hearth.

9.'A pouring furnace for metals and alloys comprising, in combination, a hearth, an induction heating unit depending from and detachably secured to the hearth toward one end thereof, means supporting said hearth for tilting movement about a transverse horizontal axis, said means including a horizontally disposed shaft to which the hearth is rigidly secured; a lever arm rigidly secured to the shaft for tilting the hearth, two spaced, parallel channel members disposed below the hearth with their flanged sides facing inwardly toward each other, said channel members being secured against relative movement toward the shaft, 9. frame lying between said channel members, parallel transverse shafts extending through the sides of said frame, round blocks mounted on the ends of the parallel transverse shafts in the spaces between the flanges of the channel members, whereby the frame may be moved along a line parallel to the axes of the channel members while being confined therebetween, hydraulic actuating means for moving the said frame longitudinally between the channel members, and a connecting rod linking the frame to the lever arm which is secured to the hearth for turning the shaft and tilting the furnace as the frame is moved.

LUTHER W. BAHNEY.

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

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