US2341589A - Hot top - Google Patents

Description

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grasso nor 'ron Benjamin F. Anthony, Cleveland Heights, Ohio, assigner to The Ferro Engineering Company,

Cleveland, (litio, a corporation of Ohio l Application July 30, 1942, Serial No. 452,845

(Cl. 2li-Mil i Claims.

This invention relates to improvements in hot tops, and has reference particularly to means for producing projections on opposite surfaces of a sinkhead to minimize the slipping of crane bits in the handling of the ingots.A Sinlrheads are ordinarily topered upwardly in order that the hot tops may be stripped therefrom. Such `tapered surfaces do not offer a good grip for the crane bits. In accordance with my invention, projections are provided having either vertical surfaces for engagement with the cranebits or outwardly extending beads, the under surfaces of which may be engaged by the crane bits.

One of the objects of the invention is the provision of exceedingly simple means for accomplishing the stated purpose; l

another object is the provision of means of the character described which will permit stripping of the hot top from the ingot without damage to the hot top refractory elements.

A further object is the provision of av novel method of producing' transverse beads or the like on ingot sinkheads.

Other objects and features of novelty will appear as 1 proceed with the description of that embodiment of the invention which, for the purposes of the present application, l have illusf trated in the accompanying drawing, in which Fig. l is a vertical sectional view of a hot top for ingot molds embodying the ypresent invention; y n

Fig. 2 is a perspective view of a refractory lining block in which is formed a wedge-shaped recess or cavity employed in connection with the invention;

Fig, 3 is a perspective view of the upper'portion of an ingot including a sinkhead having projections formed thereon in accordance with the invention; and

Figs. d, 5, and 6 are vertical sectional views of modified forms of the invention.

In the drawing, the upper end of an ingot mold is indicated at it in Fig. i, and in position in the mold there is shown a hot top of the composite type comprising an iron casing il with a lower internal ledge l2 and trunnions i3. The hot top may be supported temporarily in the position illustrated by means of blocks il: which rest upon the mold and engage the trunnions i3 or other projecting parts of the casing. These blocks are intended to be knocked out as soon as the hot top is'oated upon the metal poured into the mold.

Two courses of semipermanent lining blocks I5 and I6 are tted to the tapered inner surface of the casing Il and keyed in position by corner blocks il and it. Beneath the ledge ithere is a refractory bottom ring i5 held in position tem'- porarllywby wire clips 2li, the inner face of this Y ring being substantially ilush with the inner faces of lining blocks I6. Flow of hot metal 'upwardly between the hot top and the wall of the mold is delayed by sheet metal wiper strips 2l for a period long enough to insure the freezing of the metal there. The bottom ring I9 is used but once, and ordinarily adheres to the ingot whenY the hot top is stripped therefrom. The construction thus far described is a well known commercial construction. l

In accordance with the present invention, certain of the semipermanent lining blocks are modified to cause the sinkhead to be cast with projections on at least two opposed sides s uch that they may be engaged by the bits of an ingo/i'l crane to afford a better grip than can be obtained upon the otherwise tapered surfaces of the sinkhead. To this end two oppositely positioned blocks, such as blocksi 6 of the lower course, are formed with wedge-Shaped recesses or cavities 22, the big end yof th`ewedge being uppermost, as shown.

This cavity 22 may extend through the top surface 23 of the block, as herein illustrated, or it may begin below surface 23. The cavity may be molded inthe block when the latter is manufactured or it may be formed in the block by grinding. The angle of the wedge is preferably the same as the'angle of slope or taper of the lining face. The wedge angle should not ordinarily be greater'than the slope angle. If the said two angles are the same, the outer-face 24 of the cavity will lie in a vertical plane when the block is assembled in the hot top;

If the cavities 22 are left open, as in Fig. 4, the cast ingot willV have a sinkhead with two opposed vertically walled projections which will offer much better surfaces for engagement with crane bits than would be afforded by the tapered walls of the sinkhead. However, the invention may be carried a ystep further to produce beads or transversely extending projections' 25 onopposite walls ofthe sinkhead, one such bead appearing in Fig. 3. This result is effected by filling the cavities 22 of the lining with slurry ush with the adjoining faces of the lining block. The

`slurry used may vary considerably in composition. It should be a paste of such consistency as to retain its form after being put in place, and one which will not adhere strongly to the lining blocks after being subjected to the heat of the molten metal. After the cavities have been thus filled with slurry, one or more transverse furgive way readily in front of the vertical faces 24.

and no damage to the lining blocks will result. Hence in order to prepare the upper lining of the hot top for the next heat, it is necessary only to again apply the slurry and again wipe out the furrows 26.

The outer face of the cavity may be inclined somewhat upwardly and inwardly, especially if a long cavity is desired as in the case of the modiilcation illustrated in Fig. 5, where a lower course block 30 has a cavity with a vertical rear 4 wall 3| that regis-ters with a cavity in an upper course block 32 the rear Wall 33 of which may be inclined inwardly and upwardly` away from the vertical. As illustrated, a series of furrows 34 are formed in the slurrywith which the upperavity is filled and a further furrow 35 is formed in the slurry filling the cavity of thelower block. Of course, one or more of these furrows may be omi-tted. In any event, the resulting bead or`4 beads will clear the walls 33 and 3| when the hot top is stripped from the ingot.

Fig. 6 illustrates a somewhat extreme case in which a block is formed with a cavity having a rear face 36 inclined upwardly and outwardly away from the vertical and whereina furrow 31 is 'formed in the slurry filling the cavity. Here the contraction of the sinkhead upon cooling is relied upon to move the bead 38 on the sinkhead 39 inwardly beyond the vertical plane 40 through the bottom edge of the wedge-shaped cavity.

Such an arrangement is permissible where contraction is considerable, as in the case of large hot tops.

The cavities can be formed in either the top or the bottom course of 'a two-course liningor in 4 any course of a more than two-course lining.

The invention may also be employed ina composite hot top in which the lining is a one-piece refractory that is appliedin the plastic state and dried, the baking being effected by the heat of the metal in the first use of the hot top thereafter. A lining of this sort may be termed a rammed lining and the cavities may be formed by projections on a core member employed to confine the plastic material While being rammed intoplace.

Now, when ingots with exposed sinkheads have to be'y loosened from their molds by a stripper crane or handled in the soaking pit building by soaking pit cranes, particularly if th exposed sinkheads grow cold, hard and smooth, the projecting vertical faces of the beads 25 aiiord excellent surfaces against which crane bits Will lodge and the delays that would otherwise occur if the bits could not get a firm purchase .on the sinkhead are eliminated. I n addition -to preventing delays, my invention also prevents damage to jmolds occurring when the molds have to be swung against rigid objects to dislodge the ingots. In gots so dislodged generally have to be banked, to

be rolled later, which interferes with orders and schedules., f

Another diiliculty overcome by the invention is that the dropping of ingots in and around the soaking pit building is eliminated, thereby reduc- `ing damage due tothis cause which has been suffered heretofore` by railroad'tracks. rolling having an approximately vertical outer face which Y runs downwardly to the inner surface of the refractory element, whereby any projection formed upon the sinkhead within said cavity will not interfere with the stripping of the hot top from the ingot.

2. In a hot top shaped to provide an upwardly tapered sinkhead, a hardened refractory element extending throughout its perimeter to the bottom of the hot top the inner surface of the said element being formed with a horizontally extending furrow, said element having in the space vertically beneath said furrow plastic material adapted to give way readily when the hot top is stl'ipped from the ingot.

3. In a hot top shaped to provide an upwardly tapered sinkhead, a hardened refractory element having in its inner surface a cavity of the shape of a wedge with its big end up, 'the angle of the wedge being approximately that of the taper angle of the hot top. l

I4. In a hot top shaped to provide an upwardly taperedy sinkhead, a casing, two courses of semipermanent lining blocks therein. each of two opposite blocks of the lower course having therein a cavity of the shape of a wedge with its big end up, said cavity extending from the upper end of the block downwardly, the angle of the wedgel being approximately that of the angle of slope of the hot top lining, whereby opposed projections may be formed upon the lower portion of the sinkhead.

5. In a. hot top shaped to provide an upwardly I tapered sinkhead, a casing, two courses of semi' permanent lining blocks therein, each of two opposite blocks of the lower course having thereinA a cavity of the shape of a wedge with its big end up, said cavity extending fromthe upper end of the block downwardly, the angle of the wedge being approximately the same as the angle of slope of the hot top, the lower portion of said i cavity being lled withslurry flush with the 1ining wall. i

6. The method of providing ingot sinkheads with opposed outwardly extending beads or projections, which consists in the provision of hard` refractory walls with cavities in exposed inner surfaces thereof, said cavities having approximately vertical outer faces, illling said cavities t with slurry ilush with the adjacentsurfaces of Will Clear the said walls, and forming transverse furrow: in the slurry near the upper ends of the cavities in order to produce beads on the sinkhead when the metal is poured and solidiiles in the hot top.

7. In a hot top shaped to provide an upwardly tapered sinkhead, a hardened refractory element exposed to the metal to be poured, said refractory element extending throughout its perimeterto the bottom of the hot top, said hot top having cavities in opposed inner surfaces of the shape ofH 'big yend up wedges, said cavities b'eing formed exclusively in said hardened refractory'element.' "and being so dimensioned that when the. sinkhead has cooled and the hot top is stripped from theingot the projections formed in the cavities the lining at the lowerl endsoi the cavities. i BENJAMINl ANTHONY.

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