US1792801A - Core-bar extractor - Google Patents

Description

Feb. 17, 1931. H BLACKWELL 1,792,801

CORE BAR EXTRACTOR Filed June 5, 1929 2 sheets-sheet 1 lNvENTd @www5/mwa! ATTO NEY Feb. 17, 1931. BLACKWELL 1,792,801

CORE BAR EXTRACTOR Filed June 5, 1929 2 sheets-sheet 2 INVENTOR ATTORNEY Patented Feb. 17, 1931 Y ,i Y

UNITED STATES Hou/'Ann BLAcKwELn, or Heimann, omo, Assreivon lro VALLEY Month ANDQIR'ON [CORPORATION or` Homann, onto, Aconroaa'rron or NEW' Year:

conn-BAR nx'rnAoTon Application med June 5,-1929. serial 110,368,548.

- The present invention relates broadly to metallurgy and more'especially to an extractor for core bars used in the manufacture of ingot molds. Y

Ingot molds are cast within a flask having a sand face determining the exterior of the mold and around a core bar which is usually also provided with a sand face to determine stantial degree of hardness.

the matrix of the mold. Y. Ingot molds are large castings which weigh several tons and frequently-are several feet long-and in accordance with modern practice, the matrix of these molds often have a relatively small taper. The sandl facing around the core bars is compacted tightly to form a relatively hard sand surface. As the molten metal forming the ingot mold is poured Vinto the set-up, this hot metal` tends to bake or burn the adjacent sand on the core bar to a sub- The greatest degree of sand hardness is adjacent the ingot mold and the sand adheres very tightly to the inner surface of the mold. However, the sand also very tightly sticks tothe core bar.

' This is due to several reasons, one of which is that the core bar is usually provided with Y vent openings into which the sand is forced both during the ramming operation and also during the `casting operation of thevingot mold itself. As the molten metal freezes it contracts and very tightly binds the sanded core bar within the mold. It is particularly desirable that when the'corebar is stripped from the mold after the mold is frozen, that the sand layer between theA core bar and the mold shall be stripped froml the core bar and remain in contact-with the matrix walls of the mold untilthe moldrhas cooled down. This prevents, air currents from unevenly chilling the matrix walls of the mold and at the same time provides a heat insulating layer-which permits the heat adjacent the matrix side wall of the mold to be dissipated gradually thereby relieving casting strains.

It is necessary, however, in practice to remove the core barV from the `mold after it has been frozen and while it is hot in order to release the core Vbar equipmentl for further manufacturing uses.

Under the above conditions, it is not unusual for thecore bar to stick tightlyv within the set-up after' casting sov asto require substantial force to release the core bar.'

Various types ofV pressure devices have heretofore been utilized to release the core bar from the set-up afterjcasting, but under vthe modern practices of providing the matrix wall of the mold with a narrow taper, `the pressure devices of the prior art have not been satisfactory to remove the core bars without danger of breaking the core bars or of tearing the sand wall from the mold and at times injuring the hot mold itself. i' j The present invention overcomes the diiiiculties of the-knownprior art by providing the combination of pressure devices and mechanism for delivering hard sharp repeated impact blows .longitudinally of the core bar to loosen the core bar from the sand, and to extract the core bar after casting operation has been completed. .Y

There are two types of core bars in general use, one known as va collapsible core bar and the other as the rigid core bar. The molds of the modern practice with the narrow taper require great accuracy in the set-up particularly as to the core bar, and this is best secured by the use of rigid core bars which are the most difficult to strip after casting.

More specifically, the present invention comprises a pressure device wherein the element of the device which presses upon the head of the core bar is provided with'a power hammer, preferably of the compressed air type, which delivers a series of sharpimpact blows to the head of the core bar during the time when pressure is being applied longitudinally of the core bar to drive the same .out lof the sand within the mold. j

The disclosure herewith comprises a preferred form of the present invention, but it is to be understood that this disclosure is illustrative and is not to be considered in the limiting sense in view of the fact that other specific mechanisms of carrying out the present invention will be apparent to those skilled in the art. i

Throughout the several figures of the drawings, like parts are indicatedby like char -actersl i ivi Fig. l is an elevational view showing the present invention in operative relation to an ingot mold cast in an ingot mold set-up, with a po-rtion of the set-up shown in section.

Fig. 2 is a view illustrating a section through a` preferred form of pneumatic hammer or 'pile driver.

Fig. 3 is a plan view portion of the top of the mountings for the hammer.

Fig. Ll is'aplan view'looking iqwa-rdly at the bottom 'face or anvil of 'the hammer.

Referring now to the drawings and more especially to Figs. l, 3, and al. Theipreferred embodiment or the invention comprises 'a crane hook ring l adapted to receive a crane hook 2. This 'crane-hook ring provided 1with chain eyelets l through which toggle chains are anchored, This crane Yhook ring is also p'roi/*ided'with ahead 6 in which guide rods 7 are securely anchored by the guide rods being provided 'with tapering heads that pass through tapering openings in the headG and are wedged in the position by wedge keys 8. Tubular guide pipes S are mounted to slide on the guide rods 7 and these guide pipes 9 carry an upper frame l() and a lower frame ll in which aibofdy l2 of an air hammer is carried. rlhis airh'ammer is provided With a valve casing 14e -to which an air simply hose l5 is suitably at- `ached so that by the application of compressed air, from suitable source of compressed air, the air hammer operatednhen and as desired. The lower j i Aame ll pivot bolts 1G in whichthe inner ends| o toggle` arms 17 are pivotally an Vior'ed with the toggle chains 5 being L .-ichorl i to the otl er end of these toggle arms i7. flock chains lll are pivotally secured to to 17 by moans of key bolt clevises niej.' le adjustab set in diffe on the toggle arms l! to ci pressure of the dev'ee on `ie core liar, by passing the key bolts through openings 2O or iv permitting the key bolts to remain as ilstratet in openings near to the pivot bolts The lower end of the hook chains 18 are ,rovided with hooks 2l adapted to engage the "Jop frange of flaskQ-l. Thelower end of the bony l2 of the air hammer is adapted to bepositioned over and rest upon the head 25 the core bar 2G. The air hammer is provided with ananvilfiu that valso bears on head 25 of the core bar. The head 25 of the core barmay be constructed with a small opening` prises a. rigid member provided with vent openings 30 and is mounted upon a core bar base 3l, which extends beneath the stripping plate carried by the 'flask 24;. The flask 24 carries a sand facing lil and the core bar 2G carries a sand facing 35. An ingot mold Bis'shownin VFig. l ashaving been cast and frozen between the sand facings 34 and 35.

lt will be observed that when the extractor is in place as illustrated in Fig. l, the `crane hook 2 enga-ges the crane hook Vring l and through the connected parts lifts the set-up from the casting bottom 37. This result is brought about'by'the fact that the ingot mold sticks to the hardene l sand in the flask, supzortcd'b.7 the stripping plate 32,"and by the sandinlthe lug pockets 38 of the flask 'that extends beneath the lugs 39 on-the ingot mold. rihe sand 35 around the core bar has also been tightly compacted and slightly burned during the casting operation so that, as'previously explained, when the crane hook lifts, the

ask core bar and ingot mold are all raised short distance from the casting bottom. lil/hilo in this slight-lylraised position, air is admitted through the air hose l5 and the air hammer begins to operate by striking the anvil 27 sharp quick blows. The weight of the parts causes the toggles, comprising the toggle chains and toggle arms, to exert a strong pressure through the bottom of the body l2 of the air hammer upon the head 25 of the core bar. As the quick, shaipblows of the air nammer strike the anvil 27 and deliver the shock directly to'the'core bar, the core bar is loosened ygraduallv and gently from the sand and as the core bar drops out of the sand, the base. of the core bar drops back into lplace'on the casting bottom 27. The crane'may then vertically lift the mold, with the sand lining'i'n the matrix of the'mold,ofi` the core bar thereby 'stripping thecore bar from the cast ingot mold which remains in the flask. rEhis operation as previously explainedis accomplished by pressure-plusthe combined effect of rapid impact blows on the corebar and the effect has been to'remove the core bar Without injury to any ofthe several parts. As this operation takes place, `the guide pipes 9 have slid downwardly on the guide rods 7-so that the air hammer follows up the'movementofthe core bar until it is entirely loosened from thecorebar sand. The crane now lifts the flask and mold to a suit- Nle place in the'plant Vwhere the C-clamps zu are knocked loose vfrom the flask, thereby opening` the flask and peruiit-tingr the hot mold wit-litho sand thereon to'be stacked in a hot pile to cool.

The lair hammer is of a common type well M known in the art, butin order that the disclosure herewith shall-be entirely complete,

a brief de'scriptionof the air hammer pre- Vsaid body portion and comprises a cylindrical body 41 provided with a piston portion 42 adapted for reciprocation within suitable cylinders inthe body 12. The valve casing 14 is attached to thel side of the body portion l, 12 and connects with suitable conduits 44 and 45 adapted to control the compressed air through a control valve 46'so that'when compressed air is admitted through the air hose Y 15, the hammer head is rapidly reciprocated within the body 12 in such manner that the impact end of the cylindrical portion of the hammer head 41 strikes the anvil 27 to deliver the blows to the core bar as previously described.

Other forms of impact members may be utilized such as mechanically operated hamp `mers or electrically operated hammers, but

in accordance with the present disclosure, the

air hammer is the preferred form of impact device.

Having thus described my invention, what I claim is member being slideably mounted between said toggle members, means connected with said toggle members and adapted to engage a flask to enable a crane to lift said flask with the body member pressing upon the head of the core bar, and means to deliver rapid impact blows to the head of said core bar.

3. In a device of the class described coniprising a body member, toggle members cooperating with said body member, means connected with said toggle members and adapted to engage a ask to enable a crane to lift said flask with the body member pressing upon thehead of the core bar, and a power hammer to deliver rapid impact blows to the head of said core While said body member is pressing uponsaid core bar.

4. In a device of the class described, a crane hook ring, toggle members carried by said crane hook ring, a pressure member adapted to cooperate With the head of a core yis'lifted. 1. In a device of the class :described coml prising a Vbody member, toggle members co- 1 Y l operating with saidV body member, means bar, engaging. meansV secured to said toggle members and adapted to engage `a flask whereby a cranemay lift the flask with the pressure member applying pressure to said core .barA head, and means todeliver-sharp f impact .blows to said core bar head. l

5. 'In' a device ofthe class described, in combination, means to lift a flask and simul- 'taneouslyapply pressure to a core bar head,

and devices carried by said means and adapted to deliver .sharp impact blows to said coreV bar head.l i 'A' i 6..In a device of the class described, in

combination, means to lift a flask and simultaneously apply'stripping Vforcesrto a core bar head, anda power hammer carried by said means and adapted to deliver sharp impact ,blows to said core bar head.

7. Aidevice for stripping core bars from ingot molds `cast in a flask comprising meansV to lift the flask and apply pressure to the head of the core bar in the direction of its length, and devices to apply sharp impact blows to the head of said core, bar in the direction of its length. n

8. A device for stripping core bars from ingot molds cast in a flask comprising means to lift the flask with the ingot mold and core bar in the mold, and devices to apply sharp impact blows to the head of said corebar in the direction of its length while the flask 9. A device of the class described comprising an apparatus ,for extracting sanded core bars from an ingot mold cast within a sand lined flask comprising means to apply pressure to said core bar in the direction of its length, and devices to deliver sharp impact blows to said core bar while the same is under pressure to loosen the core bar from the sand surrounding the same.

10. An extractor for sanded core bars for ingot molds cast in a sanded flask comprising means to apply an extracting force lengthwise of said core bar to kremove same from said mold, and devices to apply sharp impact blows to said core bar while said extracting force is elective.

11. An extractor Jfor sanded core bars Within an ingot mold cast in a sanded flask com prising means to apply an extracting'force to said core bar in the direction of its length tending to remove the same from said mold,

, and anautomatic hammer operable to deliver sharp impact blows to said core bar to loosen the saine from the sand surrounding said core bar while said extracting force is effective.

.12. A core bar extractor for extracting ion Y nested to the lower ends of sadtoggle chains, a pneumatic Yhummer sldezibly mounted upon Suid guide mein-bers, `pivots for sajd toggle-arms carried 'by said pneumatic hamv; mer, and hook chains carried by said toggle HO'WARD BLACKWEEL.

Images