US2400362A - Ladle - Google Patents

Description

May 14, 1945. H. E. McwANE ErAL LADLE Filed oct. 1;A 1942 3 Sheets-Sheet l Syvum/vbo@ V Slice/magg Patented May 14, 1946k LADLE HenryE. McWane and Hugh K. McGavock,

Lynchburg, Va. Y .f c

Application octob'ri, 1942, serialNo. 460,438

. 7 Claims.V (C1, 22-57) The present invention relates to casting and more particularly to a method and apparatus for introducing molten metal into the casting cavity Y of top gated permanent molds under controlled a conditions.

Top gating of molds presents several distinct advantages, probably the most important of which is the great reductionin sprue loss, but heretofore difliculty has been experienced in producing satis'- Vfactory castings in top gated metal molds due molten metal axially of the gate andbyfcon-Q trolling its velocity and restricting .its "cross-sectional area vto a size less than that of the gate, as disclosed in our copending application Serial No. 460,566 filed Oct. 2, 1942, theemetal may be introduced into the mold without coming in contact with the walls of the gate. By such method of pouring We are enabled to definitely control the metal with the result that a better casting is produced Yand that successive castings'V will be similar. An additional advantage of this controlled pouringis that it permits the use ofa cooler metal and therefore quicker setting in the mold. This not only Aprevents the formation of large fins but permits the casting to shrink, Aat' least partially, during the. pouring operation thereby reducing the amount of shrinkage strains.

VIn its broadest sense,our invention is directed to the idea of measuring a predetermined amount of molten metalfrom a supply in a foundry ladle into a supplementary ladle, operatively associated Spaced lin its cylindrical wall are a substantially radial filling orice for 'introducing' molten metal into the ladle, an elongated discharging duct arranged at righty angles toA thegilling orifice and a sighting apertureV for visually determining the amount of metal being poured into the ladle. l

The ladle is rotatable onaxial trunnions from a fillingiandjnonpouring position to a vpouring position in which the discharge orice Will lie in the axis of the mold gate. A'latch mechanism', releasable by the closing action of the mold, normally maintains the ladle in vits non-pouringpo sition. Upon release of the latch an overbalance Weightrotates the Vladle'to its pouring position, 15

with a casting machine provided with a separable,

top gated mold, then introducing the metal fromthe supplementary ladle intoy the mold in such a way that the metal entersvthe mold axially'of the gate and in a streamof less cross-sectional area than that of the gate.

In its more limited application, as disclosedin the specic embodiment shownr herein, we pro- `vide an enclosed cylindricalladle of refractory material enclosed in afheatinsulating casing.

its movement being 'retarded by a resilient damping device.- i A lost motion link, operable by the opening action ofthe mold, connectswith an eccentrically located pin carried by the ladle to return it toits non-pouring position. ADuring the rotation of theY ladle from its non-pouring to` its pouring position, metal flows from the interior of the ladleand through the` elongated discharge duct before discharging fromtlie ladle; This isfan 'important feature of the invention as'it permits theladle to position itself with yits pouring orifice in a vertical pouring position before the'metal discharges. l

One of the principal objects of the present invention is'to provide a method and apparatusfor introducingv a predeterminedamount of molten metalinto' top gated molds While controlling the direction and sizeof the stream of metal with respect to the mold gate. Y

Another important object is to provide a method and apparatus for introducing" apredetermined 'arnount'of molten metalintotop gated moldsy by directing a'streamofmetal of smaller cross-sectional .area than the mold gate lin a direction axially of the gate. l

Yet another object is to provide a method and apparatus for introducing moltenV metal into Vtop gated molds bythe rotation cfa ladle inwhich a predetermined amount ofV metal has -been admitted and from Whichvthe.discharger of metalnis delayed during rotation of the ladle.` Y

A Yfurther object of this invention is to. provide a ladle for pouring molten metal into separable Y molds which comprises means to maintain the ladle in a non-pouring position While the mold is open, releasing the maintaining means upon closing of the moldto allow' the ladle'to move to its pouring position and returning the ladle back to "its non-pouring position Vupon reopening of the mold. 1

A still further obj ect is to provide a ladle of the character above described in which friction between moving parts has been reduced to a minimum to assure easy operation of the ladle.

A still further object is to provide a pouring ladle of the above type which is simple and economical in its construction and upkeep, yet which is efficient in its operation and effective in its results.

Other objects and advantages will become readily apparent to those skilled in foundry practice from the following detailed description and by reference to the accompanying drawings which represent only a preferred embodiment of our invention.

In the drawings on which like characters of refe erence are employed to represent like parts throughout Figure 1 is a side elevation of a casting machine with our ladle in operative association therewith, showing lthe mold kopen and the .ladle in its non-pouring position;

Figure 2 isa plan view of the apparatus illustrated in Figure 1;

Figure 3 is a fragmental sectional View taken along the line 3-3 of Figure 2, looking in the direction of the arrows;

Figure 4 is a fragmental sectional View taken along the line 4-4 4of Figure I2, looking in the direction of the arrows;

Figure 5 is a view similar to Figure Bbut showing the parts in their pouring position;

Figure 6 is a viewsimilar to Figure 4 but showing the `parts in -pouring position;

Figure 7 is a transverse sectional View taken along the line 1-1 of Figure 4,'looking in the direction -of the arrows;

Figure 8 is a transverse sectional view taken along the line B--B of Figure 6, looking in the directionof the arrows;

Figure 9 fis across sectional vView ktaken :along the'line -5-9 of V'Figure-'2, flocking in the direction lFigure 10 is a fragmentalsectional viewitaken along the line Ill- |10 of Figure :2,l1ooking in Qth'e direction of the arrows.

Referring more particularly to the drawings there is illustrated a casing machine having a frame `I comprising a pair o'f lhor'izontalf tracks 2, one end of 'each of which, is rattached to an end plate 3 which supports a stationary mold block 4. A complementary mold block 'Sis carried'by a "plate 6 slidably mounted on the tracks `2. The

movable block 5 is adapted to Abe reciprocated into and out "of engagement'with'tli'estationary block 4 by'means 'ofa'pneum'a-ticmotor"I. When the' mold blocks=4 'and5 *are inoperative engagement they forma casting cavity which has `communicating therewith a gate 9 v"extending `vertically to the top face of the mold. Detailed description of the construction fand operation of such a casting machine is included inthecopending application of Henry E. McWana Serial No.

'422,91"2,'"led'Dececmber 13,1941, and Viurtlier'declamping rings :I 2. :The brackets 1 IEI 1 and I I lrare connectedFan'd held in lxed spaced relation`7 with each' ether by means ofa pair of :cross angles I3 and I4 attachedto the bracketsby-suitable means such as the cap screws I5.

The pouring ladle which is designated generally as I5 comprises an enclosed refractory cylinder I 'I clamped concentrically between a pair of circular end discs I8 and I9 by Vmeans of draw bolts 2S. The end discs I8 and I9 are of slightly larger diameter than the refractory cylinder il and a heat insulating disc 2I of asbestos or other suitable ma-terial is interposed between each end of the cylinder I1 and the end discs. Heat insulant 22 'such as asbestos Vcement is also molded around the cylinder as shown in Figures 4 and 7 to prevent heat loss from the ladle.

Each of the plates I8 and I9 is provided with a concentric shouldered trunnion 23 on which is tted an anti-friction bearing 24 between inner and outer retaining collars 25 and 2S. The bearings 24 are held in the clamp rings I2 of the brackets IIJ and Il t0 permit the ladle tc rotate about its axis in a definite position with respect to the mold.

The ladle, normally, is held yagainst rotation in a predetermined position Vby means of a pawl 2.1 Vpivoted at its lower end as shown at 28 to the bracket I8. The upper end of the pawl 21 is urged toward the periphery of the disc IB by meansof a compression spring 29 positioned between .the pawl and the cross angle I3. When the ladle is in its inoperative, or non-pouring position, as is shown in Figure 3, the pawl engages one of a series oi ratchet teeth 33 formed in the edge of the end disc I3. Upon disengagement or" the pawl from the teeth 3,0, by means to be described later, an overbalance weight SI, eccentrically attached to the end disc I9,wi1l cause Vthe 'ladle to be rotated about its axis until the onset weight abuts a stoplug 32 provided on the bracket II. In order to retard somewhat this rotational movement and thereby minimize theY stopu ping shock, a ,yieldable frictional element 33 is provided in the pathof the weight 3|. This friction element comprises a at spring 34, `One Vend of which is held by a rod 35, and then spirally wound about the rod and lextended vupwardly into lthe path of the weight; The 1911,35 is r0- tatably mounted inthe bracket 13 for adjustment ofthe position ofthe spring 314 andjs adapted to vbe locked in adjusted position `b y 'means lof alock nut '36.

YAs stated,'the 'ladleproper comprises arefractory cylinder Il. This cylinder'is closed .at both ends toprovide a reservoir 31 for `holding ya supply of moltenmetal38. A llingorice 39 is provided in 'the cylindrical wall of thegladle slightly onset diametrically from 'the center line. When the ladle is in the llingpositionas shown in Fig- 'ure 4', thefilling orifice ispostioned substantially verticallyan'd'when theladle `is in pouring position'it Yis "disposed horizontally and above the horizontal Acenter line of the ladle.

'The 'discharge' ,duct indicated generally as 4B, and which forms one Vof the principal Vfeatures of this-invention, comprises a longitudinal channel 4I 4formed in the cylindrical wall of therefractory block'l 'l' andhasitsendscurved inwardly, as -shown'in Figure 8, to communicate with'the interiorof 'the reservoir-"31. 'Intermediate its ends thechannelfil isfslightly enlarged as'shown at y'42to vaccommodate-1a slight overow of metal and a pouring orifice 43 oi-somewhatf'smaller crossksectional karea thanthe mold gate 9 connects'the enlarged portion 44 of the-=channel-4l with the exterior-tof the ladle, -When the ladle is in iilling position, 1this pouring duct 40 vis vdisposed substantially horizontally, 'the `lower ;edge.of the channel-:4| -lyingsubstantiallyrin 'the horizontal median plane of the ladle. When the ladle is rotated toits pouring position, however, ask shown in YFigure 6. the pouring duct will be vertically disposed and the axis of the orifice 43 Vwill coincide I with the axis ofthe gate 9. vIt is to be noted that the Vouter end of the'orice 44, that is the end formed in the insulant 22 -is somewhat'larger than that portion of theY oriiice 43lwhich passes through the refractory l1, ,asl indicated at 44, to serve 'the purpose of preventing the metal from freezing to the mouth of the orifice 43.

A sighting aperture 45 is also providedin the cylindrical wall of the ladle, adjacent oneof the end walls of the cylinder |1, so that it will be subl. stantially aligned withone of the inlet ends of perfectly one casting.

In order to synchronize the operation of the ladle. with the casting Vmachine, an L shaped bracket 48 is attached to the upper face of the movable plate Spi themachine and in'alignment with the end disc I8 of the ladle. An extension 41 is Yprovided on the horizontal portion ofthe L shaped bracket andhas threaded into its outer end a pin 48 .provided With a lock nut 49.

The pin 48 is adaptedto move in the path of and release` the pawl 21. f

Pivotally attached to the upper end of the L' bracket by means of an anti-friction bearing 58 is a rod having the upper and lower surfaces of one of its ends provided with longitudinal grooves 52. This end of the rod 5| is also vertically slit and fitted with a transverse screw 53 to provide a clamp for the open end of a U shaped loop 54. The vloop passes around an anti-friction roller 55 carried by a crank pin 56 eccentrically mounted on the face of the ladle disc I8, the closed end 51 of the loop being adapted to engage the roller.

The pivoted rod 5| and loop 53 form a lost motion link 58 by means of which operative connection is effected between the movable mold block and the ladle. In order to eliminate operating drag as much as possible, the distance between the arms of the loop 53 is made slightly greater than the diameter of the roller 54, as shown in Figure 10, and an adjustable counterweight 59 is provided on the opposite end of the rod 54 to effect a balance ofthe link 51.

In operation, molten metal is poured from a foundry ladle through the filling orice 39 into the reservoir 31 until its level has been observed through the aperture 45 to have reached the level of the lower surface of the discharge channel 40. The casting machine is then put in operation to move the movable mold block 5 into engagement withthe fixed block 4 to form the casting cavity 8 and the gate 9. Immediately prior to the mold closing, the pin 48 contacts the pawl 21 and during the final closing movement'of the mold re.- leases the pawl from engagement with the ratchet teeth 3|) to allow the ladle to be moved, by means of its overbalance weight 3l, to its pouring position. As the weight 3| approaches the stop lug 32 the momentum of the ladle is slightly retarded by means of the yieldable frictional element 33 to eliminate rebound from the stop 32.

Due to the elongation of the discharge duct 40 there is a suilicient delay in the eliiux of the molten metal to permit the orifice 43 to position directly over the mold gate '9 before vany metal is discharged from the ladle. i The metal flows in a straight vertical line downward, without coming in contact with the walls of the gate 9, to f ill the mold cavity 8 and enough of the. gate to compensate for the setting shrinkage lol. the casting.

' After the metal has set, the mold is cracked in position until the mold again closes on the. next casting cycle.

As stated above, metal is admitted into the reservoir 31 until its level reaches the level of the discharge duct. The amount of metal poured into the reservoir without overflowing may be varied, however, by changing the horizontal level of the entrance to the channel 4|. Toaccomplish this the lost motion link 58 may be either lengthened or shortened by means of theadjustf able connection between the loop 52 and the arm 5| to effect the relative position of. the. entrance to the channel 4| above or below the horizontal median planel of the reservoir 31. The pawl 21 will then engageA another of the ratchet teeth 30 to hold the ladle in the changed lling position. Obviously, the more the channel is raised above the horizontal line the more metal may be poured into the reservoirwithout over-iiowing, or, if desired the level of the channel 4| may be raised higher and the metal quantity be determined by overiiow through the aperture 45.

While we have shown and described only a preferred embodiment of our invention we wish it to be understood that we do not conne ourselves to the precise details herein set forth by way of illustration, as it is apparent that many changes and variations may be made therein by'those skilled in the art without departing from the spirit of the invention or the scope of the appended claims.

We claim:

l. In combination with a casting apparatus having a stationary mold part and movable mold part adapted to be moved into operative engagement with the xed mold part to provide a casting cavity and a top gate therefor, a ladle associated with the fixed mold part for rotational movement with respect thereto, a discharge opening inthe ladle, and means associated with the movable mold part to effect rotation of the ladle upon movement of the movable mold part into engagement with the fixed mold part to align said opening axially with respect to said gate.

2. A rotatable ladle for introducing molten metal into the casting cavity of a mold having a vertically disposed top gate, a reservoir for the molten metal, said reservoir having a cylindrical wall, said wall having a substantially radially disposed discharge orice therein for eiiuxof the metal, means to cause'rotation of the ladle to eiect axial alignment of the discharge orifice and the mold gate, and conduit means having an entrance normally above the level of the molten metal in the reservoir and connecting the reservoir with the discharge orice, the said conduit means being disposed within said wall and having a portion thereof extending longitudinally of said metal into the Vcasting" gaat/ity of aiuola having a verticany' disposed top gate, a' ,reserxfilfof the molten metal, aldisoh'ar'ge Orc'e foreflluxof the metal, `means 'to .causerotation .of the `ladle .to effect axial alignmentf of l,the discharge orioe'fand the mold gate, fand 'a ,ohanne'lfconnecting the reservoir with tneydischargelorioe,fsaid vchannel of molten metal nomine discnargeprifee anni said axial alignment'has beeiieffected l 4. In arotatalole ladle'no' introducing molten metal. into v'the casting i loaviijlvof a moldhaving a vertically ,disposed top gate, a ,cylindrical reservoir vfor the jlnolten Irietal, 'al substantially radial discharge',duotgoommlitrig Withth fser'voir, holding means engageable With the ladleto maintain a -predetermined angular dispos ion 'of the oarlidjby the ladlefto mr'art rotatonalmovementtontheladle to einefotakial alignment of Vthe discharge .orioe an'd gate upon aseof the holding means.

. 1o having e length siinieieni fte delay initial jefnux .5. In a rotatable 4ladle f or introducing molten metal into the oastirlg'-V oavity oiajnol'd having a verticallydisposed gate,.a oyl indrical reservoirV Vfor' the molten no etal,A asubs'tantially radial discharge duot communioating with therelservoir,

holdingmeansengageaole with thexlaldle toL main-- mine Dredefmind'aieulr di OStiQnof the discharge c'nfie. anldmeocentriov `Aglot'ec'i means carried Vlov Ythe ladle Ato 'impart rotational 'movem'entto the ladle toeffefct axiaialignment "of the holding means, o 'and yi'l'dalole 'mean'sfengsageable with the eoCentricA Weighted I Iiearls to damn "said rotational mover:lent:`

dsharge orifice andgate upon releasep'f the`1`I` ,6. In roomlonaton with a y,casting apparatus part to vform a 4casting Ica'vity and f a' .vertically disposed "top f gate therefrlf a cylindrical' ladle,

means Loarried' by the` fxed mold part to mount tlefladle forirotat'ioiial 'tn ove'len't,` a substantially radial'disoharge duet in the ladle, holding vmeans eng'ageable withthe ladleto' maintaina nonpouring position .tlojereof, frotatio'n imparting means associated with, the ladle toeffeot a pouring positionff the' ladle upon release oflsaid holdingmeans, and felease means associated with the movable mold'part to releasesad holding means llrpon lInoveienent'of the mOYable mold ,part into engagement Withthe Astatior'iary mold part.

' '7.Infc'ombination 'Witha casting apparatus having a stationary mold partfan'd reciprocating 'mold' ,partadapted to' engage the" stationary mold part to form a`.ca 'stin"g1cavity and a" vertically disposed'v top gate therefor; a oylindrical ladle,

means carried'by the xe'dnlrnold nartto mount the ladle for rotational movement, a substantially radial discharge durotfin the ladle,holding meansv engageable Witl1"tl-1eI ladle `to` maintain a nonpouring position' thereof, rotation imparting means assfioiated with the ladle to eieot a pouring fwith thewladl'e toefe'ct a counterrotaton of the ladle upon lmovement of the vnovable mold part away'from thestationary'mold part.`

HUGH KL McGAvoCK.

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