US1665700A

US1665700A - Centbieugal castikta

Info

Publication number: US1665700A
Authority: US
Publication date: 1928-04-10
Anticipated expiration: 1945-04-10

Description

J. K. HENCKEN CENTRIFUGAL CASTING MACHINE April 10, 192s.

Filed Nov. 14, 1925 4 Sheets-Sheet 1 April 10, 1928. 1,665,700 J. K. HENCKEN CENTRIFUGAL CASTING MACHINE Filed Nov. 14, 1925 4 Sheets-Sheet 2 Wren/or 3 /46/W April 10, 1928;

J. K. HENCKEN CENTRIFUGAL CASTING MACHINE Filed N0v. 14, 1925 4 She8tS-$hQ9t 3 ll JlHli 'J. K. HENCKEN .GENTRIFUGAL CASTING MACHINE April 10, 1928.

Filed Nov. 14. 1 925 4 Sheets-Sheet .4

mrewfar y Arm Patented Apr. 10, 1928.

JOHN K. nnnoxnn, on BROOKLYN, NEW YORK.

CENTRIEUGAL CASTING MAGHINE.

Applicatipn filed November pression, impact, and abrasive forces, as

well as stresses and strains resulting from changes in'temperature, all of which forces,

stresses and strains are represented in most severe forms; and it is not practicable to test the finished product otherwise than fragmentarily to determine the condition of its internal structure, so that defects :remain latent and undetected until-actual use develops'tl'iei'n, at times with disastrousconsequenccs.

moor-ding to present day methods of manufacturing railway rails, great dii'ficultycis experienced in obtaining afinished product -tree from defects resulting from blow holes, piping, segregations, coarse crystalline structure, and enclosed slag, oxides, and other foreign matter. These. defects do not result from the inability to produce steel of the proper composition the furnace, but arise out of the methods of castingthe ingots from which. the rails are rolled.

The general object of my invention is to obviate the above defects in the ingot casting process preparatory to rolling, so that rails of. a fine grain or texture may be consistently produced, free i from blow-holes, piping segregations, coarse crystalline struc ture and enclosed slag, oxides, and other foreign matter; and my invention is characterized by the provisionof a centrifugal mold, comprisinna rotary table, carrying a mold into which the molten metal to be cast in the form oi ingots or the like is intl(j)ClllCCCl, and in which itissubjected to strong centri'tugal action while 111 l1qu1d con- (htion and durlng the coohngand sohdifying process, in combination with means for skimming off and removing the lighter material which floats to the inner partof the mold and contains the impurities from which the pure metal is separated-by centrifugal action during the casting period,

14, 1925. Serial No. 68,970.

My invention is further characterized by the provision of means for constantly subjecting the molten metal, within the mold, to the action of a flame topreventoxidation at the surface of the metal during the filling up of the mold with molten metal, whereby ingots or the like are produced which are free from oxides throughout their cross sectional areas; and my invention also includes simultaneous casting and oxidizing-prevention treatment in a plurality of molds.

Certain specific objects of the invention and various advantages of the same will become apparent from the following description when taken in connection with the accompanying drawings, in which Figure 1 is a plan view ofthe machine embodying-my invention. 1

Figure 2 is a vertical central Section thereof taken onthe line 2+2-of Figure 1.

Figure 3 isa plan viewpart-lyin section of a modified mold. v

Figure dis a central sectionalview, showing the mold of Figure 3positioned within the rotary table and substituted for. the mold sections of Figure 1, and showing the modified form ot-scraper required. v p Figure is a plan view of another fied form of mold.

F igure (lisa central sectional view taken on line 6-6 ofFigureb, and showing" fragmentally in section the table into which the mold is adapted to fit.

With all of the, forms of my invention shown herein a rotarytable 10 is employed, such table being suitably housed, as is customary, within a. pit 11 formed in a suitable masonry or other structure 12 beneath the floor level of a casting room within which the machine embodying my invention may be installed. The table 10 suitably connected to the flanged portion 13 of a tubular drive shaft 14, provided at its lower end with a beveled gear 15, adapted to mesh with a fpinion 16, carried by, a driveshaft' 17, which is adapted to beconneeted'to a suit able :source of power, notshown, for rotat ing the table-10, The tubular shaft 14 is suitably journaled within a; bearing 18 mountedcentrally ofthe pit 11 and anchored to the masonry structure 12.1n order to adequately: support the table 10, a, plurality of roller bearings 19 are, provided. These bearings are ,suitably mounted upon the masonry structure 12 and are so located as to engage an annular bead orbearing sur face 20 formed on the uncerneathside of the table 10, relatively near its periphery.

The table 10 is provided with an upstanding annular flange :or wall 21 which is formed on its periphery with a plurality of fins or ribs 22 for the purpose of reinforcing the same against such stresses and strains as are imparted to the wall 21 due to the centrifugal force resulting from rota tion of the table. In addition to reinforcing the table, the fins 22 may also serve to"con duct away and dissipate, from the table 10 audits upstanding wall 21 heat which is derived from the molten metal during the castingv period.

Over the pit 11 and the tab1e10 is positioned a suitable floor 23 which serves to cover the machine within the pit 11 and thus guard the opcratorsor other foundrymen against hazardous risks incident to centrifugal casting. This floor may be of any suitable material such as heavy sheet metal and is shown as supported on the lower flanges of horizontally disposed I-beams 25 w nch are arranged over the pit 11 and are adapted to support certain other elements, hereinafter described, entering into the structure of the machine embodying my invention. It may also have additional cross beams to support it, indicated as 24 in Fig. 1.

The table 10, at its periphery, is provided with an annular groove 26which forms, with the upstanding flange 21, a pocket 26 adapted for the reception of the several forms of annular molds hereinafter more particularly described, the pocket 26 being ranged in an end-to-end relation, to {it into the pocket 26 asshown. Each section is formedwith a base portion 29 from which project side walls 30, the side walls being slightly tapered, as shown, to permit the ingots to be readily removed from their respective mold cavities. The mold cavities are separated from each other by end mus 31 which are also slightly tapered to facilitate removal of the ingots. Each of the mold'sectionsis preferably provided with a plurality of lugs 32 which enable the sections !to be withdrawn, as by means of suitab'le tongs and derric'ks, from "the casting table through an lopenin g in the floor 23 provided witha trap'door34 which may be closed duringthecasting operation. 1 i

It will be notedthatjthe end walls 31 do not extend to the inner edges of the side walls but lie wholly within the mold,

These end walls terminate short of the side walls 30 so as to permit a skimming tool 35 to be projected into the mold during the casting operation for the purpose of skimming oil' the inner surface of the molten ime :11, whereby slag and other lighter impurities are separated from the pure metal which is thrown, by centrifugal force, to the outer portion of the mold. The skimming tool 35 is suitably mounted within a holder 36 and is retained therein by any suitable means, such as a set screw 37. The holder 36 is preferably formed integral with a trough 88 which comprises a rear curved wall 39 and a base plate 40, the forward edge of which base plate may be beveled or inclined as shown at i1. The skimming tool 35, together with its associated chute, is suspended from a carriages-2 which is mounted to operate upon the I-beams and is adapted to be adjusted thereon, to effect a corresponding radial adjustment of the skimming tool 35,105 means of a screw shaft as, one end of which is journaled to the carriage 4L2, whereas the other end is provided with a hand-wheel 1 1 and maintained inscrew-threaded engagement with a bracket or yoke 41-5 secured to the I-beams 25. As the molten metal is removed from the mold 28, it is directed into a vertical chute 4.6 into which the trough 38 projectsv The chute 41-6 is suitably supported by the I- beams 25 and projects downwardly through. the tubular shaft 1% and is adapted to transfer or direct the skimmed olf material into a slag car or the like, not shown, which may be arranged beneath the masonry structure 12.

' The molten metal is directed int-o the mold" 28 tlirongl'i a nozzle supported upon the Lbeams 25. The outlet end 48 of the nozzle is disposed horizontally and is curved in the general direction of rotation, as indicated by the arrow A in Figure 1, so that the flow of molten metal into the mold is facilitated during'the operation of the machine.

In order to guard against oxidation of the metal as it is being built up within the mold 28, "oxidizing-prevention treatment may be carried onsimultaneously with the molding operation, and to enable such treatment to be effected Ihaveprovided a pair of arcuate shaped gas burners L9 which are so arranged asto direct their respective flames upon the surface of the metal within the mold. These burners are supported concentrically with respect to the axis of the table by means of brackets 50 and are connected bymeans of distributor pipes 51 to a common supply pipe '52 which is supported by the nozzle 47f Into the common supply pipe lead a pair of pipes 53and 5 1, the former of which may carry air and the other gas, the two fluids being mixed together within the common supply pipe 52 and the former being Ill) utilized to support combustion of the other. If desired, the may be shut "oil by a valve and by leaving open the valve '56, controlling the air supply, air alonen'iay be directed onto the surface of the molten metal to cool the same after the casting operation and prior to removal of the ingots; 1

In Figure 3, I have shown 'a modified form of mold 557 which is in. theformoi'. an annular ring, provided with a pair of annular mold cavities 58 which are separated by means Of an intermediate rib or wall TlllS mold. is adapted to be placed 'Wl'illllll filler 60 is in the be provided for each cavity 58. These blocks are removable and are inserted atdiagrann matically oppositepoints so as toimaintain balance in weight between opposite halves of the mold. The blocks 62 are formed with inclined faces 63 which, when the castings shrink as they cool, will permit a suitable tool to be introduced into the mold cavities 58 behind the molded rings to facilitate their removal. These rings may be removed by first prying out one end of each thus enablmg the rings to be grasped by a suitable .tool and thereafter stripped from the mold and withdrawn through the opening as the table 10 is slowly rotated while they. are in a semi-plastic condition.

mold of the type shown in Figures 3 and 4 may be prevented by the action of the flame ot the burners 49 as previously described. It will be further understood that the impurities are removed from the metal when em1 )loying the type of mold shown in F igures 3 and 4 through the instrumentality of a scraper tool as also previously described.

The scraper tool 64 may be somewhat modified, lmwevcr, as shown in Figure 4; so as to present two cutting edges 65, one for the upper cavity 58 and the other for the lower cavity 58.

In Figures 5 and 6, wherein I have shown still another modified form of mold 66, a helical cavity 67 is provided in such mold. One convolution of the cavity is separated from the adjacent convolution by means of a helical wall 68. This helical wall, it will be noted, is of a width somewhat less than the side walls 69 of the mold so as to upstanding flange permit the use of the straight edge cutting tool 85 shownin Figural. The modifiedv form oil mold (i6 is adapted to bev retained within the pocket 26 otthe table ll) bythe same riugoll that is employed to retain the mold 57 properly positioned.

In order to facilitate removal of the cast metal, when the modified form of mold 66 is employed, the upper convolution 0t the cavity 67 may terminate with an inclined bottom wall 70 which, whenthe cast metal contracts or shrinks as it cools, will permit a suitable toolto be introduced into the 'cavity at the rear of the casting.v By means of such a tool one endot the casting, while in a plastic or semi-plastic state, may be with- Lll2UYI1,ll1LlS enabling it to be grasped by a suitable tool'eo that it may be stripped. from the spiral cavity '67 through the opening 33 as the table slowly rotated. From the foregoing, it will be apparent that separation of the pure and uncontaminated metal from the impure metal may be effected in the same general manner. That is to say as the metal is introduced into the molds from the nozzle 4:8 it, by centrifugal action, is thrown outwardly away from the Center of rotation and as the metal builds up within the molds, the purer and denser metal which is heavier thanthe impure and less dense metal-displaces the impure and less dense metal which is torced,.due to such displacement, towards the center of rotation. As the molds becomefilled with metal the scraping-oil tool removes the'surface metal and directs it into the'chute 46. As soon as the rejected or cast-oil metal is observed as entering the chute, "t becomes known that the molds are full andpouringoi": the metal may then be discontinued. However, no ex act period throughout which pouring of the v a metal shouldv continue can be stated, inas- It will be understood that oxldation of the molten metal when casting with the much as varying factors, such as speed of rotation, the kind and quality 01" metal employed, and degrees of purity and character oi. texture required in the finished product, may determinethis.

The type of mold shown in Figures 1 and 2 for castingingots may be employed when conditionsare such as to require many passes through the rolling mill to produce the lin- :ished article, and molds oi the types shown in Figures Zlto (3 inclusive, may be employed when it desired to cast the molten metal to more nearly its finished shape and di mensions, in which case fewer passes through the rolling mill may be required. Regard less of the type of mold employed Iinuch time, labor and expense may be saved at the rolling mill, by subjecting the ingots or the lilre to fewer passes to produce the finished article, since a great number of passes, as heretofore required, are not necessary to reduce the material to a line grain or texture for the reason that castings produced in accordance with this invention are of aline grain or texture due to the absence of the coarse crystalline structure and the absence of the impurities which have been separated from the pure metal during the casting period.

Having described certain embodiments of my invention what is claimed is:

1. A'centritugal casting machine comprising a centrifugal mold, means for introducing'molten metal into the mold means tor subjecting the introduced metal to centrifugal action within the mold whereby the relatively heavy metal is forced towards the periphery of the mold and the, lighter material is moved toward the axis o'l' rotation, skimming means projecting into the mold for removing said lighter material from the mold, and means for receiving the lighter material so removed. and for directing it out of the vicinity of the mold.

2. A centrifugal casting machine comprisinc: a rotary table, a mold carried by said tal le, means for introducing molten metal into the mold, means tor rotating said table and said mold whereby the introduced metal is subjected to centrifugal action to force the relatively heavy metal'towards the periphery ot the mold andto movetho lighter material towards the axis of rotation, a skimmer projecting into said mold for removing the lighter material from the mold, and means cooperating with said skimmer for directing the removed material out of the vicinity otsaid table.

3. Acasting machine comprising a-rotary table having an annular pocket formed therein, an annular mold carried within said pocket and having mold cavities of a depth less than that of the mold, means for introducing molten metal in the mold, means for rotating said table whereby the introduced metal is subjected to centrifugal action to force the relatively heavy metal towards the periphery of the mold and to move the lightor material towards the axis of rotation, a

. skimming tool projecting into said mold for removing the lighter material from the mold,

and means for receiving the lighter material the lighter material towards the axis of rdtation, a skimming tool projecting into said mold for removing the lighter material from the mold, means for receiving the lighter material so removed and for directing it out of the vicinity of the mold, and means for varying the position of the skimming tool with respect tothe depth of the mold.

A casting machine comprising a rotary table, an am'iular mold carried by said table, means for introducing molten metal into said mold, means for rotating said table whereby the introduced metal is subjected to centrifugal action to force the relatively heavy metal towards the periphery of the mold and to move the lighter material towardsthe axis of rotation, the latter named means comprising a tubular -shatt,"n'1e:msfor removing the lighter material from said mold during rotation, and :means for directing the removed material through said shaft to a point remote from said table.

In testimony whereof, Ihave ai'lixed my signature to this specification.

JOHN K. HENCKEN.