US2265740A

US2265740A - Method and apparatus for supplying fluxing material

Info

Publication number: US2265740A
Application number: US314712A
Authority: US
Inventors: Walter J Morgan
Original assignee: American Cast Iron Pipe Co
Current assignee: American Cast Iron Pipe Co
Priority date: 1940-01-19
Filing date: 1940-01-19
Publication date: 1941-12-09
Anticipated expiration: 1958-12-09

Description

' 1941- w. J..MORGAN 2,265,740 METHOD AND APPARATUS FOR SUPPLYING FLUXING MATERIAL Filed Jan. 19, 1940 4,5heets-Sheat l Dec. 9, 1941. J,MORGAN- 2,265,740

METHOD AND APPARATUS FOR SUPPLYING FLUXING MATERIAL Filed Jan. 19, 1940 4 Sheets-Sheet 2 v Dec. 9, 1941. 4 w. J. MORGAN 2,265,740

METHOD AND APPARATUS FOR SUPPLYING FLUXING MATERIAL I Filed Jan. 19, 19 40 4 Sheets-Sheet 3 J Dec. 9, 1941. w. J. MORGAN 2,265,740

METHOD AND APPARATUS FOR SUPPLYING FLUXING MATERIAL Filed Jan. 19 1940 4 Sheets-Sheet 4 II C 1 If (v Q Q Q 2 w 115 Patented Dec." 9, 1941 A UNITED STATES PATENT OFFICE- ltIETHOD AND APPARATUS FOR. SUPPLY- ING FLUXING MATERIAL Application January 19, 1940, Serial No. 314,712 17 Claims. (Cl. 22-215) This invention relates to a method and apparatus for introducing fluxing material into a mold in casting, and more particularly to a material is used to form a fluid slag which will contain the impurities that may be entrained in the molten iron, and which will also minimize oxidation of the molten iron at its surface. otherwise in contact with the air by forming a film thereon.

It has heretofore been the practice in centrifugally casting iron pipe to introduce the fluxing material onto the molten iron just prior to or during the pouring of the iron into the mold. The fluxing material has thus floated on top of the iron as it traveled through the spout and into the revolving mold while the mold is spinning at a relatively low speed, the mold actin merely as a trough for the iron to be distributed lengthwise of the mold. when a certain portion of the iron has been so discharged into the mold,

.the mold is brought rapidly to a speed which will distribute the iron circumferentially of the mold and also to complete the distribution of the iron lengthwise thereof. During this period the fluxing material is reacting with impurities and bringing the same to the surface of the molten iron in the form of slag.

When the. fluxing material is so supplied there is a loss of fluxing material where sand molds are used, because the molten iluxing material tends to adhere to and react with the sand wherever it comes in contact therewith, producing a slag which adheres to the outer surface of the pipe, even after the pipe has been cleaned. The fluxing material that tends to collect on the face of the mold also has a deleterious efiect on the coating that is customarily applied to the inside of the mold. Furthermore, due to the heat of the iron in the ladle, and the time element involved, valuable properties of thefluxing material may be burned out and lost before it ever reaches the place where it is needed. The foregoing are also sources of loss of fluxing material, requiring the use of more fluxing material than actually needed to obtain the desired effect so far as the casting proper is concerned.

The introduction of the fluxing material into the mold on the surface of the molten metal as it is poured into the mold has also been productive of grave difficulties in the manufacture of centrifugally cast iron pipe because of the tendency of fluxing material to be trapped between the socket core and the mold at the bell end of the pipe. The fiuxing material by its acceleration of the slagging action in the molten metal brings slag to the surface of the iron with great rapidity, but while this is of advantage in the barrel of the pipe where the surface of the molten metal is free, in the confined space between the socket core and the bell the slag coming to the surface produces slag cavities, oxidized areas, and highly undesirable irregularities.

I have discovered that greatly improved results may be obtained if at least a thin layer of molten iron is distributed over all of the interior casting surfaces of the mold before the fluxing material is supplied to the molten iron. In accordance with the preferred procedure soda ash or other suitable fluxing material is blowninto the mold at the instant, or just after the instant, when the iron is deposited on the wall of the mold by centrifugal action to form the pipe and while the iron is still in its fluid stage. So introduced the fluxing material retains all of its advantages while the disadvantages of its use implicit in methods heretofore employed are avoided. At the same time it has been found that these beneficial results are secured with the use of a very much smaller quantity of fluxin material.

By introducing the fluxing material into the pipe at the proper time according to the present invention the fluxing material may be applied to the surface of the molten metal directly, where it is needed, and at the time when it is calculated to do the most good. Furthermore this -method of introducing the fluxing material permits the economical use of fluxing materials such as borax and form alloy mixtures which were not practicable if introduced at the pouring stage because of the loss of effectiveness before serving their intended function.

It is therefore an object of the present inven tion to provide a method and apparatus for supplying fluxing material in a casting method which assures that the fluxing material is supplied at that time when it is most effective to accomplish its intended purpose.

Another object of this invention is to provide a method and apparatus of the type characterized which enables the distribution of the fluxing material to be controlled and predetermined in order to obtain the desired results.

Another object of this invention is to provide a method and apparatus of the type characterized which enables the fluxing material to be used obtained withthe use of smaller quantities of fluxing material than has heretofore been. possible.

Another. object of this invention is to provide a method and apparatus of the type characterizedwhich enables the use of fiuxing materialswhich have heretofore been unavailable.

Another object of this invention is to provide .a method and apparatusof the type characterized which avoids loss of fluxing material due to its contact with the molten iron during the pourmg period.

' Another object of this invention is to provide a method and apparatus of thetype characterized which assures that at least a layer of the molten iron covers the entire casting surface of the mold beforevthe fluxlng material is supplied, so as to eliminate the difllculties heretofore encountered by reason of contact of the fluxing material with the mold surface.

Another object of this invention is to provide a method and apparatus of the type characterized which assures that no fluxlng material is trapped in the cavity between the socket core and that portion of the mold which forms the outside surface of the bell.

Another object of this invention is to provide a method and apparatus of the type characterized which is time conserving, easy to operate and adjust, and highly efllcient in operation.

Other objects will appear as the description of the invention proceeds.

Stated broadly the present invention involves a method and apparatus whereby soda ash or other suitable fluxlng material is properly distributed to the iimer surface of the metal being cast at the precise instant when it most effectively performs its designed function with minimum deleteriouseffects. Applying the method to the casting of iron pipe centrifugally-at the proper instant, preferably automatically controlled by electrical actuation, and preferably at the time, or just subsequent to the time, when high speed rotation of the mold deposits the iron by centrifugal force throughout the walls of the mold, means are operated to blow 'a predetermined quantity of fluxlng material into the mold with the desired distribution of the fluxlng material lengthwise thereof.- Thus the fluxlng material may be blown entirely through the mold, even to a slight portion of it being discharged at the opposite end, in order to secure an adequate and substantially uniform distribution of .the fluxlng material lengthwise and circumferentially of the mold. The blast of air operates only for a predetermined short space of time, and then is preferably stopped automatically, although if it is desired that the fluxing material be supplied over a longer period of time such may obviously be done. The fluxing material may be supplied to the blast of air by hand or automatically, the quantity of fluxlng material supplied may be determined by I the operator or automatically, and the instant and duration of delivery may be determined by the operator or automatically.

The invention is'capable of receiving a variety of mechanical expressions, some of which are illustrated on the accompanying drawings, but it is to be expressly understood that the drawings are for purposes of illustration only, and are not to be construed as a definition of the limits of the invention, reference being had to the appended claims for that .purpose.

Referring in .detail to said drawings, wherein the same reference characters are employed to designate corresponding parts in the several figures:

Fig. 1 is an elevation, partly in vertical section, of an embodiment of an apparatus for carrying into effect the present invention, the same being shown somewhat diagrammatically;

Fig. 2 is a view of the apparatus of Fig. 1 as viewed from the left thereof Fig. 3 is a horizontal section of the apparatus of Fig. l on the line 3-3 thereof;

Fig. 4 is a diagrammatic view .to illustrate the automatic control of the means for'injecting the fluxing material;

Fig. 5 is a fragmentary detail of the automatic control Fig. 6 is a somewhat diagrammatic view illustrating other apparatus for carrying into efiect the present invention;

Fig. 7 illustrates-another apparatus for carrying into effect the present invention; and

Fig. 8 illustrates yet another apparatus for carrying into effect the present invention.

In conformity with the present invention, the fluxlng material is introduced into the mold by a blast or current of air after sufficient molten metal has been introduced into the mold'to wash all interior casting surfaces of the mold and, in the casting of iron pipe, to wash the surfaces between the socket core and the bell end of the mold so that all surfaces of the mold which are to contact the molten metal during centrifugal casting will have at least a'thin layer of molten metal thereon before the fluxlng material is blown into the mold. Preferably, in the centrifugal casting of pipe, the fluxlng material is not blown into the mold until suflicient molten metal has-been introduced into the mold to fill the cavity between the socket core and the bell end of the mold, which in the preferred procedure occurs at that instant or immediately after that instant at which the mold is speeded up so as to distribute the molten metal by the action of centrifugal force. Thereby the fluxlng material is excluded from this cavity and no slagging' action in the molten metal occurs therein. On the other hand, the more promptly the fluxing material is introduced after the casting surfaces by initiating the operation of a blower or by opening a valve to release a blast of air to entrain the fluxing material, and in either event either the quantity of fluxlng material or the instant of introduction may be determined manually by the operator or automatically, as hereinafter pointed out more in detail. In. whatever manner the fluxlng material is blown into the mold, it ispreferably introduced under such pres? sure as to assurea substantially uniform application thereof the full length of the mold. The

blast for example may be of sufficient force to carry' a small portion of the fluxlng material out of the opposite end of the mold. Also, as will hereinafter appear more in detail, the fluxlng material may be introduced, either simultaneously or by successive blasts, from opposite ends of the mold, and if a single application of fluxing material at either or both ends is not sumcient,

successive blasts may be employed at one or both ends of the mold for introducing successive charges of fluxing material. The introduction of 'fluxing material is preferably eflected during a short period of time, but as will hereinafter appear more in detail the delivery of the fluxing material may be prolonged over more time by casting flask or mold, for example, a mold for the centrifugal casting of iron pipe. Aligned with the axis of the mold, but terminating a short distance from the end thereof so as to allow the mold to be rolled into and out of the machine without interference, is a spout II which may be mounted in any suitable way, as by a bracket I2 mounted on a stationary portion l3 of the apparatus and preferably including a provision for vertical adjustment of the bracket, as by the set screw i4, so that said spout may be raised and lowered for proper alignment with the axes of different sized molds. Spout Ii as here shown has an approximately 90 bend and is'attached in any suitable way, as by a coupling l5; to a hopper l6 formed on or suitably attached to the underside of the hollow platform ll of an apparatus for supplying predetermined charges of fluxing material at predetermined times to the hopper l6. As here illustrated, the opening from the inlet l8 to the hopper is controlled by a check valve l9 pivoted on the platform I! or the wall of the hopper at 20, and here shown asprovided with an exteriorly extending lever arm 2| which may be manually or automatically operated to dump a charge of fluxing material from the inlet i3 into the hopper 16, or the lever 2| may act as a counterweight for the check valve l9, holding the check valve closed as shown in Fig. 1 until the charge has been deposited thereon, whereupon the weight of the charge will overcome the weight of the lever arm 2i to cause the valve l9 to pivot around its axis 20 and deposit the charge into the hopper I3.

Platform I1, as here shown, is integrally mounted on or. suitably attached to the upper end of a hollow housing 22, which in turn is mounted on any suitable support, here shown as a hollow column 23 to which said housing 22 is bolted at 24, said column beingshown as bolted at 25 to the base 23. Suitably attached to the platform II, as by bolts 21, is a bin 23, here shown as of inverted conical form, and provided with a cover 29 which may be raised and lowered into contact with the upper edge of the bin for filling the same or gaining access to the interior thereof. As illustrated, the bin is also provided with a 'sight opening 3!]. closed by a cover plate 3| which may-be secured in position by means of a wing nut 32 on bolt 33.

Journaled in said platform l1 at 34 is a vertical shaft 35 which carries a rotatable table 36 that is also joumaled on the platform I! and has a bushing as shown at 31. At its upper end shaft 35 has suitably mounted thereon, as by means of va spider 33, a rotatable hood 33 in the form of an' inverted conical member which occupies the central portion of the bin 28, and preferably has its wall substantially parallel to the wall of said bin. Attached to the lower end of said shaft 35, and having a foot hearing at 40 in the top wall of the column 23, is a bevel gear 4| which is in mesh with a bevel gear 42 mounted on a stub shaft 43 suitably joumaled in the wall of the housing 22. Attached to the exteriorly projecting end of the stub shaft 43 is a pawl and ratchet mechanism 44 (see Fig. 2), actuated by a lever 45 which projects into the path of a suitable lug 46 carried by the hood 41 of the casting machine. Lover 45 may be returned to its upper position by a spring or by a second lug on the hood which engages the lever in the upward movement of the hood. Hood 41 may be raised from the solid line to the dotted line position as shown in Fig. 1 to admit the mold, and each time said hood 41 is lowered into its operative full line position, lug 46 engages lever 45 and moves the same through a prede-' termined arc to rotate the stub shaft 43 through the pawl and ratchet mechanism 44. Rotation of stub shaft.,43 produces, through bevel gears 42 and 4|, a predetermined rotation of shaft 35 and table 36.

Mounted on the platform l1, adjacent the entrance iii to the hopper I6, is a scraper element 48 (see Fig. 3) the same preferably being mounted adjustably in a bracket 49 so as to project to a greater or less extent over the rotating table 36. In place of this provision, the lug or lugs 46 may be adjustably mounted on the hood or provided with set screws to vary the throw of the lever 45.

Therefore upon predetermined rotation of the member 36 a predetermined charge of fluxing material is scraped from the rotatable table 36 into the inlet it of the hopper IS. The charge so scraped into the inlet [8 is deposited on the check valve l9 which then dumps it into the hopper "5 as above described.

Communicating laterally with the hopper I6 is a pipe 50 (see Figs. 2 and 3) which in turn communicates through pipes 5| and 52 with the casing of a solenoid-operated valve diagrammatically indicated at 53. In place of a solenoid-operated valve any other suitable form of quick opening valve may be used, but a solenoid-operated valve is preferred to provide for electrical actuation of thevalve at the precise instant at which it is desired that the fluxing material be blown into the mold. Communicating with the solenoid-operated valve casing through pipe 54 is a tank 55 which may be supplied with compressed air from any suitable source.

At the designed instant when the fiuxing material is to be injected into the mold, valve 53 is electrically actuated to open quickly, and the sudden release of pressure from tank 55 causes the air under pressure in said tank to blowthe fluxing material in' hopper I6 through the nozzle II and through the inlet aperture 56 in the flask or mold III, as shown in Fig. 1. The check valve 19, during this operation prevents blowing of the fluxing material back into the bin 28. The volume and pressure of the air released from tank tributed with substantial uniformity in circumferential directions as well as lengthwise of the mold.

It is to be understood that any other suitable means may be provided for feeding predetermined charges of fluxing material to the hopper I0, or :thehopper I may be supplied with fluxing ma- ,terial by. hand.

. Referring next to Fig. 8 which illustrates a simplified and therefore a preferred apparatus bodiment of Fig. 1, or hereafter to be described,

may be associated with said hopper 00 if preferred. Hopper 60 as here illustrated is mounted adjacent to or formed as a part of a bin for the fluxing'material, and at least the hopper 00 is also adjustably supported, as from a bracket 05 by means of bolts 01 projecting through a slot 00 in said bracket 00. Thereby the entire apparatus may be adjusted vertically as required when nozzle 00' is to be aligned with the axes of different sizes of molds.

5 Projecting into the nozzle 00 (see Fig. 4) is an air pipe 00 which extends beyond the communication between the hopper 00 and the nozzle 00 so that air blown therethrough will have an insplrating action on the fluxing material introduced into the nozzle 00 from the hopper 04'. Air pipe 00 communicates with the casing ll of a solenoid-operated .valve, and the casing of saidvalve in turn communicates with an air tank 'II supplied with compressed air through conduit I2, as heretofore described in oonjunc tion with the embodiment of Fig. 1. In this embodiment a bracket arm I0 projecting from the hood I0 carries, by means-of the depending stem II, a spring pressed stopper element 10 which may slide on the stem I0 against the tensionof a spring 'II abutting against an adjustable nut 10. A suitablequantity of fluxing material having been deposited in the hopper 00, by hand or otherwise, while the hood I0 is in its elevated position, lowering of the hood to its operative position for casting causes the stopper I0 to engage the lower portion of the hopper 04 (see Fig.

4) and close of! communication between said hopper and the nozzle 00. Therefore the blast of air admitted to the nozzle 00 through the air pipe 00 will not cause the fluxing material to be blown back through the hopper. Owing to the yieldable mounting of the stopper I0 on the stem IS the stopper accommodates itself to the bottom of the hopper; at the same time the stopper is pressed into air sealing relationship with the bottom of the hopper by the Spring 11.

i The structures shown in Figs. 1 and 8 may be ation of the mold the solenoid of the solenoidoperated valve is energized to open the valve and permit the fluxing material to be blown into the mold.

Figs. 4 and 5 illustrate "one suitable system for effecting this result. As here shown the sole-' '03 are adapted to be connected with the mains 05 through contacto'rs 06 that are moved into closing position by a coil 01 in a circuit 08 which contains a switch or'push button 09 that is designed to be operated by the pouring ladle. As here-shown the automatic time switch 02 also has a shunt circuit therearound including a hand switch 9| so that the solenoid 00 may be operated, if desired, by the manual manipulation of the switch 0|.

Referring to Figure 5 one suitable form of tim switch is illustrated. As here shown a shaft 05 is driven in any suitable way from the motor--00 of Fig. 4. Shaft carries a contact arm 00 which rotates in the direction of the arrow 01. Mounted on arm 06 is a contact point 00 adapted-to engage a contact point 00 in an auxiliary circuit. Arm 06 also carries a second contact point I00 adapted to engage a contact point I M mounted on a lever I02 which is pivoted at'I02 on the guard I00. Exteriorly of the guard I04, lever I02 is provided with a weight I00. Guard I00 is provided with a pair of stop lugs I00 and I", both of said lugs preferably carrying set screws I00 and I09 so that the magnitude of the throw of the lever I02 may be adjusted. Lever I02 and arm 06 are initially in the position indicated by the dotted lines, with contact point I00 engaged with contact point III and lever I02 in contact with screw I00, arm 00 and screw I00 through guard I00 being in the circuit 0I referred to in connection with Fig. 4. As shaft 05' rotates, arm 06 rotates in the direction of the arrow 01, but contact points I00 and I" remain in engagement because the lever I02 pivots about its axis III by reason of its weight I00. When lever I02 engages screw I00, however,; further movement of lever I02 is prevented and continued rotation of arm 96 disengages contact points I00 and III.

Initial engagement of contact points I00 and IN energizes the solenoid-operated valve to effeet the injection of the fluxing material by the blast of air from the associated tank. As soon as a contact point I00 leaves contact point "I the solenoid 00 is de-energized and the valve closes automatically, as by the action of a spring. Continued rotation of arm 00 brings contact point 00 into engagement with the contact point I! to initiate the next step in the cycleof the casting machine which need not here be explained as the invention is not concerned thereautomatically operated in anysuitable way. I

Preferably the actuation of the solenoid-operated valve to effect the blowing of the fluxing material into the mold is eflected automatically so that theinjection of the m xing material shall occur at that instant when it will best serve its function without deleterious effects. To this end means are preferably associated with the.

mold or with its controlling means whereby at a predetermined instant in the sequence of oper with. By adjusting one or both of the set screws I00 and I00 the instant at which the solenoidoperated valve is actuated'may be nicely predetermined and the length of time during which said valve is open may be closely adjusted. Lugs I00 and I0! and the lug of pivot I02 are preferably mounted by means ofbolts in slots in the guard I00, and additional adjustment may thus be obtained by moving one or more of said lugs in said slot to predetermine the instant at which the solenoid-operated valve is opened and the time during which it remains open.

Another apparatus for carrying into eii'ect the present invention is shown in Fig. "I. As here illustrated an automatically operated bin IIO, which may take the form of that illustrated in Fig. 1, is provided for supplying predetermined charges of fluxing material to the hopper III which communicates with nozzle I I2, here shown as bent through 90 asillustrated in the embodiment of Fig. 1. The automatically operated bin H is driven through shaft II3 which in turn is rotated by suitable gearing within the housing II4 from a stub shaft II5 that-carries a pinion H6 in mesh with a pinion III on a second stub shaft I I8. Pinion I I1 is operated through a pawl and ratchet mechanism, II9 from a lever I to which is suitably connected a rod I2I carrying adjustable stops I22 and I23 and extending through an aperture in a bracket I24 carried by the hood I24. When the hood is raised bracket I24 engages stop I23 to move the ratchet lever arm I20 in one direction, and when the hood is lowered bracket I24 engages stop I22 to move said ratchet arm in the opposite direction. Thereby each movement of the hood I24 out of and back into operativeposition effects a rotation of the shaft I I3 to cause a predetermined charge of fluxing material to be delivered through a suitable conduit communicating with the hopper II I, as heretofore described in conjunction with the embodiment of Fig. 1. By adjusting the stops I 22 and I23 the extent of rotation of the I apparatus and therefore the amount of charge delivered may be varied as desired.

In this embodiment, in 'place of a valve for admitting a blast of air to the nozzle, a blower I25 is suitably mounted on the standard I26 and has its outlet nozzle I21 directed into the hopper I I I. Blower I25 is preferably driven by an electric motor, and its circuit is preferably opened and closed by automatic means associated with the mold or its controlling mechanism, so thatthe instant of actuation of the blower may be nicely predetermined, as heretofore described in conjunction with Fig. 4. It is to be expressly understood, however, that within the broader aspects of the present invention, the instant of delivery of the fluxing material to the mold may be determined by the operator ineach of the embodiments heretofore described, and therefore in place of the solenoid-operated valve, a manually operated but preferably quickly opening valve may determine the instant when the blast of air is applied to the fluxing material in the embodiments of Figs. 1 and 8 and, likewise, the starting and stopping of the blower I25 may be controlled by the operator, as by a manually operable switch.

Fig. 6 is a diagrammatic view to illustrate other features of the present invention. The rotatable mold I30 is here shown as provided at its bell end with a hopper I3I, nozzle I32, air pipe I33 and solenoid-operated valve I34 which may be of the character above described in conjunction with Fig. 1 but which is illustrated as of the form embodied in Fig. 8 and diagrammatically illustrated .in Fig. 4. In this embodiment, however, the source of compressed air is not in communication with a pressure tank as in the embodiments of Figs. 1 and 8, but the solenoid-operated -valve I34 is in communication with a conduit I35 which may lead from any suitable air compressor or other source of compressed air so that there is a continuous source of pressure at said valve I34.

Fig.6 further illustrates how the molten iron I4I projecting from the ladle I42. As the ladle moves from full line to dotted line position its arm I will engage the arm I40 at a predetermined instant in the pouring operation and pivot the scoop I36 around its pivot I3'I to deposit the contents of the scoop on the molten iron flowing into the mold as illustrated. Thereby a predetermined quantity of fluxing material may be applied to the surface of the molten iron flowing into the mold, if such is found desirable, to minimize oxidation at the surface of the molten metal during the pouring period. As the quantity of fluxing material supplied at the pouring end of the mold may be materially less than that required for the complete. fluxing function, danger of the fluxing material contacting the mold or being trapped in the cavity between the bell end and socket core is minimized, while taking advantage of a reduction in oxidation of the iron during the pouring period. When the predetermined amount of molten metal is poured into the mold, the fluxing material desired to complete the fluxing action may then be injected through the automatic apparatus indicated at the left of the figure at the proper instant for carrying into eflect the objects heretofore described.

In place of the ladle operated mechanism for injecting fluxing material into thespigot end of the mold, the machine may be equipped with automatic apparatus at the spigot end, and by suitable control thereof it may blow into the mold at the desired instant a predetermined charge of fluxing material. Furthermore, as will be understood by those skilled in the art, the mechanism for blowing fluxing material into the mold may be operated a plurality of times for injecting successive charges of fluxing material, if such is preferred, and this is true whether the apparatus be provided at one or both ends of the mold, and it is also to be understood that if preferred the period of introduction of the fluxing material at one or both ends may be extended, as for example by introducing the fluxing material progressively on a continuing current of air rather than substantially instantaneously by means of a blast of air. If desired, successive blasts may be used to introduce successive charges at one end or successive charges may be introduced in alternation from opposite ends. In any event the precise time for the introduction of the fluxing materialand the duration of such introduction may be nicely predetermined so that the fluxing material will be introduced at that time when it will do the most good and at the same time produce the least deterimental effects in so far asthe casting is concerned.

In the practice of the method and in the operation of the apparatus as exemplified by the casting of iron pipe, when the flask-or mold I0 has been put. into the casting machine the hood of the machine is lowered, and this actuates the 3 ployed, to discharge a predetermined amount of fluxing material into the hopper. In place of circuit which initiates the rotation of the motor that rotates the mold. This initial rotation is relatively slow, around 25 R. P. M. for example,

1 which is not suflicient to distribute the molten iron centrlfugally on the inside of the mold.

,The ladle containing the molten iron is then 1 tilted in any suitable way, as by a hydraulic cylinder, to pour the molten iron into the mold. When As this time the molten iron is disgoes into action, it quickly accelerates the motor and thereupon the revolving mold is brought up 1 to a speed wherein centrifugal action distributes the molten metal circumferentially of the mold as well as additionally distributing the same lengthwise thereof. This acceleration is preferably accomplished in a plurality of steps, five for example.

Immediately after the last accelerating step of the controller is effected so as to bring the mold l to its full speed, in the preferred procedure, the fluxing apparatus is operated, preferably going into action automatically as by means of the switch heretofore described in conjunction with Fig. 5. Whether the fluxing material be blown into the mold by a rotary blower,as in Fig. 'l,

or by the suddenly released blast from a tank of compressed air as in Figs. 1 and 8 or by the pressureinacompressedairlineasinllmt, the blast of compressed air flowing through the hop- 1 per or the nozzle into which the fluxing material has been deposited from the hopper picks up the fluxing material and distributes it with substan- "tial uniformity both lengthwise and circumferenjtially of the molten metal now distributed circumferentially 7 around the" wall of the mold. After 'a predetermined period of time which is preferably brief, although as before pointed out a longer period of introduction upon a continuing air current maybe employed if preferred, the switch controlling the fluxing apparatus is opened, and after a predetermined period of time during which the mold is revolved at high speed, the mold is accelerated, preferably in a plurality of steps, for example three, after which the mold may be rotated at a lower speed for a predetermined time, depending upon the casting procedure employed.

: In place of a single injection of the fluxing material, just described, a small amount of fluxing material may be carried into the mold by the molten metal, as by use of the apparatus shown in Fig. 6, or such apparatus as disclosedin conjunction with the embodiments of Figs. 1, 7 and 8 may be operated a plurality of times to intro.-

' duce successive-blasts of fluxing material during the-casting operation, or 'both ends of the mold may be supplied with such apparatus and operated simultaneously orin alternation one or more 1 times for producing the desired introduction of fluxing material. In fact a plurality of injectdevices may be provided at one or both ends a of the mold, delivering through a single noziile an automatically supplied chargeyacharge of 1 fluxing material may be placed in the hopper by hand, as heretofore pointed out. The operator then presses a button or'otherwise closes the or a cluster of multiple nomles, or a single nozzle may be provided with a plurality of automatic feed apparatus or a plurality of solenoid valves in separate lines may be automatically and-successively operated at predetermined intervals of time, etc., so that the desired introduction of. fluxing material in desired amounts and at desired intervals may be employed. Hence the method of the present invention provides for wide flexibility in securing that introduction of fluxing material that is found most desirable for the particular metallurgical and operating conditions existing.

Furthermore, the apparatus of the present in vention, as heretofore explained, provides a relatively wide latitude in adjusting the instant at which the fluxing material is introduced, and also the period during which the injection continues, so that as different sized molds are used and different melts are employed the instant and the duration as well as quantity of injection can be nicely regulated to best suit the metallurgical and operating conditions then existing.

Experience has demonstrated that castings formed in conformity with the present invention are much superior to those heretofore obtained. As no fluxing material need be introduced into the mold until all inner casting surfaces of the mold are wet by the molten metal, the fluxing material does not come into contact with the mold surfaces to remove any of the facing material, and there is no fluxing material or reaction products therefrom adherent to the exterior of the casting. When pipe is cast as heretofore explained, no fluxing material is trapped in the cavity between the socket core and the bell and hence the surfaces hereat are composed of clean, hard metal without the slag pockets. corrosion areas and other irregularities that have heretofore been present. At the same time the fluxing material is introduced into the mold at the earliest available time at which this can be done without detrimental effects, and hence before the metal cools to any substantial extent it is supplied with the fluxing material to accelerate slag ins and bring the impurities to the surface,

' while a thin film of the fluxing material is mainence having demonstrated that under some circumstances substantially the same results may be obtained although only one-third as much fluxing material is used as heretofore conventionally employed. As the fluxing material is not introduced until it is needed, fluxing materials heretofore unavailable, because they were burned by the molten metal during the pouring period, now are readily available. The present invention also is characterized by the facility and ease. with which embodiments may be controlled andad'- justed to meet varying operating conditions, so that in each instance the introduction of the fluxing material may occur at that instant or at such successive instants as best calculated to effect the desired results in conformity with the principles heretofore explained. In practicing the invention in conformmy with the preferred embodiments, the time of the introduction of fluxing material is not subject tohuman factors,

i may be delivered to the hoppers by hand rather than automatically, the instant of introduction may still be controlled entirely independently of the operator so as to assure the most efllcient effects from the use of the fluxing material.

It will therefore be perceived that the several,

objects of the present invention have been accomplished by the method and apparatus as heretofore disclosed. While the invention has been exemplified by particular reference to its embodiment in the casting of iron pipe, the invention, particularly with respect to some of its broader aspects, has wider utility, as will now be apparentto those skilled in the art. The preferred practices and apparatus have been described with considerable particularity, but it is to be expressly understood that the invention is not restricted thereto. and that the invention is capable of being embodied in a variety of ways, changes may be made in the details of the method steps, and in the details of construction, arrangement, proportion, etc., of the elements of the apparatus, without departing from the 'present invention. Reference is therefore to be had to the appended claims for a definition of the invention.

What is claimed is:

1. In a casting machine of the type employing a tubular mold. a nozzle separate from but aligned with an open end of the mold and having an end opening through which fluxihg material may be blown axially of the mold, a hopper in communication with the nozzle for receiving charges of fluxing material, and means 885001? ated with said hopper and nozzle for applying a sudden blast of compressed air to a charge of fiuxing material in said hopper at a predetermined instant after molten metal has been distributed over the casting surfaces of the mold to blow said charge through said nozzle and axially along said mold to distribute the same lengthwise and circumferentially thereof.

2. In a casting machine of the type employing a' tubular mold, a nozzle separate from but aligned with an open end of the mold and having an end opening through which fluxing material may be blown axially of the mold, a hopper in communication with the nozzle for receiving charges of fluxing material, means associated with said hopper and nozzle for applying a sudden blast of compressed air to a charge of fluxing material in said hopper at a predetermined instant after molten metal has been distributed over the casting surfaces of the mold to blow said charge through said nozzle and axially along said mold to distribute the same lengthwise and circumferentially thereof, and means associated with said hopper for intermittently delivering predetermined charges of fluxing material thereto.

3. In a casting machine of the type employing a tubular mold, a nozzle aligned with an open end of the mold and having an end opening through which fluxing material may be blown axially of the mold, a hopper in communication with the nozzle for receiving charges of fluxing material, means associatedwith said hopper and nozzle for applying a blast of compressed air to a charge of fluxing material in said hopper to blow said charge through said nozzle and axially along said mold to distribute the same lengthwise and circumferentially thereof, means associated with said hopper for intermittently delivering charges of fluxing material thereto,

charge-delivering means.

and means actuated by the movement of a portion of the casting machine 4. In a casting machine of the .type employing a tubular mold, a nozzle aligned with an open end of the mold and having an end opening through which fluxing material may be blown axially of the mold, a hopper in communication with the nozzle for receiving charges of fluxing material, means associated with said hopper and nozzle for applying a blast of compressed air to a charge of fluxing material in said hopper to blow said charge through said nozzle and axially along said mold to distribute the'same lengthwise and circumferentially thereof, and means actuated by the movement of a portion of the casting machine for predetermining the instant at which said charge is blown into said mold.

5. In a casting machine of'the type employing a tubular mold, a nozzle aligned with an open end of the mold and having an end opening through'which fluxing material may be blown axially of the mold. a hopper in communication with the nozzle for receiving charges of fluxing material, and means associated with said hopper and nozzle for applying a blast of air to a charge of fluxing material in said hopper to blow said charge through said nozzle and axially along said mold to distribute the same lengthwise and circumferentially thereof, said last named means including a source of compressed air, a valve for admitting said compressed air to said nozzle, and means for operating said valve to deliver a sudden blast of compressed air to the charge of fiuxing material in said hopper. V 6. In a casting machine of the type employing a tubular mold, a nozzle aligned with an open end of the mold and having an end opening through which fluxing material may be blown axially of the mold, a hopper in communication with the nozzle for receiving charges of fluxing material, and means associated with said hopper and nozzle for applying a blast of compressed air to a charge of fluxing material in said hopper to blow said charge through said nozzle and axially along said mold to distribute the same lengthwise and circumferentially thereof, said last named means including a source of compressed air and an electrically operated valve for quickly admitting compressed air to said nozzle, and electrically operated means for actuating said valve and controlled by a movable portion of said casting machine to determine the instant at which said charge shall be blown into said mold. r

'I. In a casting machine of the type employing a tubular mold, a nozzle aligned with an open end of the mold andhaving an end opening through which fluxing material may be blown axially of the mold, a hopper in communication with the nozzle for receiving charges of fluxing material,

and means associated with said hopper and nozzle for applying a blast of compressed air to a for operating said end of the mold andhaving an end opening through which fluxing material ,may be blown axially of the mold, a hopper in communication with the nozzle for receiving charges of fluxing material, means associated with said hopper and nozzle for applying a blast of compressed airto a charge of fluxing material in said hopper to blow said charge through said nozzle and axially along said mold to distribute the same lengthwise andcircumferentially thereof, and means actuated by the movement of said ladle as it delivers molten metal to the mold for depositing a charge of fluxing material onto the surface of the molten metal being poured into the mold.

9. In a casting machine of the type employing a tubular mold, a nozzle aligned with an open end of the mold and having an end opening through which fluxing material may be blown axially of the mold, a hopper in communication with the nozzle for receiving charges of fluxing material, means associated with said hopper and nozzle for applying a blast of compressed air to a charge of fluxing material in said hopper to blow said charge through said nozzle and axially along said mold to distribute the same lengthwise and circumferentially thereof, means for automatically closing communication between said hopper and nozzle to prevent the fluxing material from being blown back through the hopper, and means for automatically operating said, last named means from a movable part of the casting machine.

10. In a casting machine of the type employing atubular. mold,- a nozzle aligned with an open end of the mold and having an end opening through which fluxing material may be blown axially of the mold, a hopper in communication with the nozzle for receiving charges of fluxing material, means associated with said hopper and nozzle for applying a blast of compressed air to a charge of fluxing material in said hopper to blow said charge through said nozzle and axially along said mold to distribute the same lengthwise and circumferentially thereof, means associated with said hopper for intermittently delivering charges of fluxing material, thereto, and means for moving said last named means a predetermined amount each time a movable part of the casting machine moves into a predetermined position.

11. In a casting machine of the type employing a'tubular mold, a nozzle aligned with an open end of the mold and having an end opening through which fluxing material may be blown axially of the mold, a hopper in communication with the nozzle for receiving charges 'of fluxing material, means associated with said hopper and nozzle for applying a blast of compressed air to the charge in said hopper to blow said charge through said nozzle and axially along said mold to distribute the same lengthwise and circumferentially thereof, and means associated with said hopper for intermittently delivering charges of fluxing material thereto, said last named means including a rotatable table, a scraper cooperating with the table, and means operated by a movable part of the casting machine for rotating the table each time said part moves into a predetermined position.

' 12. In a casting machine of the type employing a tubular mold, a nozzle aligned with an open end of the mold and having an end opening through which fluxing material may be blown axially of the mold, a hopper in communication with the nozzle for receiving charges of fluxing material, means associated with said hopper and nozzle for applying a blast of compressed air to a charge of fluxing material in said hopper to blowsaid charge through said nozzle andjaxially along said mold to distribute the same lengthwise and circumferentially thereof, means for predetermining the instant when said blast of compressed air isapplied to said charge of fluxing material,

and means for adjusting said last named means to vary the time when said charge is blown into said mold.

13. In a casting machine of the type employing a tubular mold, a nozzle aligned with an open end of the mold and having an end. opening through which fluxing material may be blown axially of the mold, a hopper in communication with-the nozzle for receiving charges of fluxing material, means associated with said hopper and nozzle for applying a blast of compressed air to a charge of fluxing material in said hopper to blow said charge through said nozzle and along the axis of said mold to distribute the same lengthwise and circumferentially thereof, and means actuated .by the movement of a portion of the casting machine for predetermining the amount of the charge to be blown into said mold.

14. In a casting method of the character described, the steps of introducing molten metal into a tubular mold while rotating the mold around its axis to cause the molten metal to wet all of the casting surfaces thereof, increasing the speed of rotation of the mold after suiTicient molten metal has been introduced into the mold to at least wet all of the casting surfaces thereof to distribute said moltenmetal centrifugally over the casting surfaces of the mold, and blowing fluxing material over the surface of the molten metal in the mold only after all casting surfaces of the mold have been covered by the molten metal to protect the same from the fluxing material. l

15. In a casting method of the character described, the steps of introducing molten metal into a tubular mold while rotating the mold around its axis to cause the molten metal to wet all of the casting surfaces thereof, increasing the speed of rotation of the mold after sufllcient molten metal has been introduced into the mold to at least wet all of the casting surfaces thereof to distribute said molten metal centrifugally over the casting surfaces of the mold, and blowing fluxing material over the surface of the molten metal in the mold only when said molten metalhas been centrifugally distributed over the casting surfaces of the mold by the increased speed of rotation of the mold;

'16. In a casting method of the character described, the steps of introducing molten metal into a tubular mold while rotating the mold around its axis to cause the molten metal to wet all of the casting surfaces thereof, increasing the speed of rotation of the mold after suflicient molten metal has been introduced into the mold to at least wet all of the casting surfaces thereof todist-ribute sa'id molten metal centrifugally over the castingsurfaces of the mold, and by a sudden bast of compressed air distributing fluxing material throughout the surface of the molten metal in the mold only, at a predetermined instant after all casting surfaces of the mold have been covered by the molten metal to protect the same from the fluxing material.

l7. Ina casting method of the character described, the steps of introducing molten metal into a tubular mold while rotating the mold around itsv axis to cause the molten metal to wet all of the casting surfaces thereof, increasing the speed of rotation of the mold after sufiicient molten metal has been introduced into the mold to at least wet all of the casting surfaces thereof to distribute said molten metal centrifugally over the casting surfaces of the mold, and by a sudden blast of compressed air distributing fluxing WALTER J. MORGAN.