US1881055A - Molding apparatus - Google Patents

Description

F. J. LEUTHNER MOLDING APPARATUS Original Filed Aug. 2, 1929 2 Sheets-Sheet l F. J. LEUTHNER MOLDING APPARATUS Oct. 4, 1932.

Original Filed Aug. 2, 1929 2 Sheets-Sheet Patented Oct. 4, 1932 PATENT oFFICF.

- rnnNx J. LEUTEN'ER, on SHARPSV'ILLE, PENNSYLVANIA MOLDING APPARATUS Original application filed August 2, 1929, Serial No. 382,941, and in Canada June 2, 1930." Divided and this v application filed September 16, 1930. Serial No. 482,170.

This invention relates to'molding apparatus, and more particularly to an improved core and extractor construction for use with y molds for hollow "castings. The invention still more particularly relates to an improved "collapsible core and. extractor particularly adapted for ingot mold casting. This. ap-

plication is a division of my copending appli-' cation, Serial No. 382,941, filed August 2, 1929, which has-'eventuated into Patent No. 1,783,805.. r As is well known in the art, an ingot mold is cast in a mold having an outer flask or chill and a central core member for providing the ingot cavity. It has long been the practice to cast ingot molds whose walls are substantially straight from end to end by the use of a" collapsible core. The known type of collapsible core and the straight sided in- 2 got molds which could be cast bythe use thereof are shown, for example," in United States Patents Nos. 868,607 and1,018,668, issued to Frank X. Leuthner, and No. 1,018; 669, issued'to said Leuthner and Frank Tickner; Such collapsiblecores comprise a central body or core bar surrounded by plates which are spaced apartat their edges and supported on the central. core bar, the bar being M tapered so that upon substantially axial move- 3Q ment'in the direction of its larger end, the plates are allowed to collapse inwardly, thereby facilitating the removal of the core from the casting. i

In the casting of ingot molds whose walls are substantially straight from end to end, ithas been customary to use such collapsible core bars which have their uppenportions extending a considerable distance abovejthe side plates and above the tops of the castings. an As will be 'seenfromthe patents above referred to, collapsible core bars of-this nature are adapted only for use in casting such straight sided molds. The size of the upper 7 portions thereof projecting above the top of the casting precludes their use WltliQCilSting whose Slltpfl at thetop is other than substantially straight.

Modern practice is tending toward the use of ingot molds whose walls neck in at the top,

59 consideringthe molds in the position they assume while they are being cast. Such .a mold is inverted when used for pouring ingots so that the necked-in portion serves as the bottom of the mold cavity and assists in shaping the ingot and in reducing the amount of poured metal which comes in contact with the bottom of the mold. A mold of this type cannot be cast about a collapsible core of the type above mentionedbecause of the fact that the size of such core precludes the formation 00 of the necked-in top as the metal is poured. It has therefore become the common practice in casting necked-in molds to use solid cores which do not have a large upper extremity extending above the top of the casting.

, The problems involved in the removal of a solid core from a cast ingot mold have been well known for years. It is necessary to lay the flask, casting and core on their sides and to ram the core and flask apart. This open ation is very detrimental to the flasks and cores and is also time wasting and therefore expensive. In fact, no fully satisfactory core has heretofore been provided for the casting of necked-in molds.

Furthermore, when necked-in molds are cast using solid cores, the gases which form during the casting operation are confined within the molds, producing bubbles and holes which are, to say the least, detrimental, go and which in many instances entirely spoil the cast molds. This is particularly true of bubbles and holes formed in the ingot cavity, which should be substantially smooth and uniform. v

I provide molding apparatus adapted to obviate the disadvantages in the present practice above noted, and to provide for'the use of a collapsible core in the casting of neckedin ingot molds. I also provide an improved 90 core extracting means adapted for use with an improved collapsible core whereby to greatly facilitate, quicken and cheapen the removal'of cores from east necked-in ingot molds.

I provide molding apparatus comprising a collapsible core having inner and outer core members, the inner core member havinga pin of relatively small diameter as compared with the size of such inner core member con- 100 .molding apparatus comprising an extractor provideimolding apparatus comprising a.

having means for engaging a flask and means for engaging a oorefor removal of the core from'the flaslnand a centering sleeve slldably connected with theextractor. I still further core and an upwardly extending member connected W1th the top-thereof, such member having'means for'leading oil gases formed I about the core.

' 'tion will become apparent as the following mentthereot proceeds. V I V In the accompanying drawmgs I have description of .a present preterred'embodiinvention wherein V F lgure 1' 1s a central verticalcross-sectlon through molding apparatus having an ingot shown a present preferred embodiment of the mold cast therein;

Figures 2 and 3 are side view-s tov enlarge scaleiof a'centeringsleeve;

- Figure 4 is'a top" view of the centering sleeve; l r

Figure 5 is 'a bottomview of the centering sleeve;

i Figure- 6 is a top view of a retaining block for the centering sleeve;

blo'ck;".x 7

Figure 8 is a and*-'- *Figu're 9 is a sideview ofthe extractor pin.

top view of the extractor pin;

ings, reference numeral'2 designates a mold base upon which is set a tapered core/bar-3 which formsthe inner memberof a collapsible core; Cooperating *with the bar 3- are side'plates 4 supported in the position shown in Figurel by the bar 3 and held inwardly by 7 bolts" 5; Upon downward movementof the struction as bar Eithefside plates 4 of the core collapse inwardly, whereby to facilitate removal of the *corefro'm the-casting; So -much of the conis described above is wellknown in the art. v

.- The corebar 3 has atop opening 3aifrom the bottom of which to the interior of the --core-bari leads a duct 33). Fitting into the opening 3a is'a-pin 6 which preferably of s'teeh The pin 6'is positivelyconnectedwith the core ibar 'a 'key6cr Which. passes through the coreybar and the pin to maintain thelatterin placef-Instead of being keyed tothe core bar however, the pin 6- maybe connected therewith by' being" cast integral;

.with. the core bar, by driven fit or by any other'suitable means. I r

, j'EX-tending' longitudinally through the pin -6'is aduct 6?). "This duct 'communicates'with ithe duct 3b at its bottom and also has lateral branches 60 leading outthrough' the pin 6 above the point of connection of the pin with Figure? is anend view of the retaining the core vbar. :The ducts are for the purpose of leading ofi' gases formed about the core during the casting operation; Unless such compared V V "'With' the size of the inner core member and 1 -1 Qther obgectsand advantages of the1nvenis of substantially the-same diameter as the hole to beprovided inthetop of the cast ingot mold (which' willbe in the bottom of I the mold'when used for casting ingots); .A

sand vmold wall 7 is formed about the core by the use of a suitable patternyas well known in the art. A flask 8 also rests upon the base 2 and is centered with respect to the core. A sand cheek 9 is formed within the flask. 8 also with the use of a pattern. The bottom of the core bar 3' is'provided with a lateral extension 10 which joins the'sand cheek and upon which the sandzcore wall 7 rests;

mold. iThe sand walls 7 and'9 serve respectively as the inner and outer mold surfaces,

the, metal -11 being poured in tocform an ingot mold having a necked-in upper extrem ity'12. As shown'in Figure 1 thejmetal at the top of the casting substantially abuts the 'The extension lO therefore serves as 'thebottom of the mold cavity forv casting the ingot pin 6 sothat the hole through thetop of'the i I V 7 casting is only slightly greater in diameter Referring more particularly to the drawthan the diameter of the pin;

In order to collapse the core it is necessary to exert a downwardpressure on the top of the pin 6 whereby the core bar 3 moves idownwardly and the'side plates 4 collapse inwardly, the entirezcore thenflfalling out. .I

provide novel extracting means adapted Jfor therewith a pair of oppositely disposed chains 14. 'Pivoted to the extremity of each chain 141isa lever 15. Pivoted' to theinner ends of the respe'ctivel'evers 15,as atj16, 16,

are 7 is an extractor pin'17 7 (see Figures 8 and 9); 1

Pivoted intermediate the ends of'the respective lever-s15 are chains 18 to the end of each of which is connectedia hook 19. adapted-to underlie and engage with a flange 20 on the flask 8. 1 V f Slidably: carried over the extractor pin 17 is a centering-sleeve 21. (see Figures 2, 3, 4,

and 5) which sleeve-has four upward extensions 22 eaclrhavingia; strengthening rib 23:

Hand each belngprovided' at its-upper extremity with'a hole 24; 'The extensions 22' merge into the sleeve 21, which has asub stantially cylindrical'inner surface 26 whose, 'diameter is slightly greater than the diam-l The sleeve is slidably connected with the pin 17-, as shown in Figure 1, a retaining block 28 having holes 29 being inserted between i the extensions 22 and pins fitted through the holes 24" and 29 to prevent the sleeve from becoming disengaged with the pin. The lower part of the sleeve has strengthening flanges 30,as shown in-Figures 2 and 3.

The internal diameter of the centering sleeve is somewhat greater than the external diameterof the steelpin Gin the'core and is adapted to embrace the upper part of the I pin 6 to center the extractor pin 17 with respect thereto;

The flask ispicked up through the agency of the extractor, and the core is extracted at the same time. A cranehook is lowered over the assembled flask and core having the casting formed therein. The hooks 19 are engaged with he flange 20 of the flaslgthe ring '13 is engaged with the crane hook and the sleeve 21 is placed over the upper extremity doing a downward pressure is hook is then raised bodily lifting the flask, and by so I exerted through the levers 15 and the extractor pin 17 against the steel pin 6 in the core, whereby the of the pin 6. The crane upwardly,

core is collapsed and as the flask is raised upwardly by the crane, the core drops out.

I The extracting, operation, when an improved collapsible core and an improved extractor, such as herein disclosed, are used, is

. greatly simplified over the previous method wherein the flask, core and casting were laid on their sides and the core and flask rammed apart with the attendant damage, delay and expense, as above mentioned. The pin 6 servesonot only to define the opening in the casting, but also toimpart the force exerted by the extractor pin 17 to the core bar, wherer by the collapsible core may be extracted from within the casting. The centering sleeve may be easily loweredover the upper extremity of the pin 6 and serves to positively center and position the extractor pin with rei 'spect to the c'orepin so that the downward force exerted by the extractor upon raising V r the crane hook is. axial not only through the extractor pin, but also through the steel core pin. This prevents damage. to

I the extractor or the core and effectively provides for ready extraction.

When the constructlon above described is used, so little pressure need be brought to bear upon the pin 6" in order to extract the core that the full cross'section of the pin is not needed for the extracting operation and consequently the ducts 6b and 60, above described, may be formed in the pin without impairing its usefulness, Also, as above described,'the ducts serve as a means for carrying off the gases which would otherwise remain within the casting and cause'undesirable imperfections therein.

which, when the extractor is in tated and cheapened and the amount of time and labor incident thereto is greatly reduced.

l/Vhile I have shown and described a present preferred embodiment of the invention, it is to be distinctly understood that the same is not limited thereto, but may be otherwise variously embodied within the scope of the following claims.

I claim:

1. An extractor comprising a centering device for centering the extractor with respect to a core, means for exerting downward pressure on the core associated with and vertically movable with respect to said centering device, means operatively connected with said first mentioned means for exerting upward pressure on a flask surrounding the core, and operating mechanism connected with said second mentioned means for simultaneously operating said first mentioned 'means to exert downward pressure on the core and said second mentioned means to exert upward pressure on the flask, the bottom of said centering device, when in operative position, lying substantially in the plane of the top of the flask.

2. An extractor comprising a centering device for centering the extractor with respect to a core, means for exerting downward pres sure on the core associated with and vertically movable with respect to said centering device, means operatively connected with said first mentioned means for exerting upward pressure on a flask surrounding the core, and operating mechanism connected with'said second mentioned means for simultaneously operating said first mentioned means to exert downward pressure on the core and said second mentioned means to exert upward pressure on the flask, said centering device having outwardly extending projections at its base the bottom surfaces of position, lie substantially in the plane of the top of the flask.

In testimony whereof I have hereunto set my hand.

' FRANK J. LEUTHNER.

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