US3196516A - Continuous casting and rolling of metals - Google Patents

Description

July 27, 1965 J. c. BONGIOVANNI CONTINUOUS CASTING AND ROLLING 0F METALS Filed Oct. 28. 1960 10 Sheets-Sheet 1 INVENTOR. JOHN c. BONGIOVANNI BY MJ/ July 27, 1965 J. c. BONGIOVANNI 3,195,516

CONTINUOUS CASTING AND ROLLING OF METALS Filed Oct. 28, 1960 10 Sheets-Sheet 2 Fig.1a

July 27, 1965 J. c. BONGIOVANNI 3,196,516

commuous CASTING AND ROLLING OF METALS Filed Oct. 28, 1960 10 Sheets-Sheet :5

INVEN TOR. JOHN C. BONGIOVANNI July 27, 1965 J. c. BONGIOVANNI CONTINUOUS CASTING AND ROLLING 0F METALS 10 Sheets-Sheet 4 Filed Oct. 28, 1960 INVENTOR. JOHN C. BONGIOVANNI /Mw mau w July 27, 1965 J. c. BONGIOVANNI CONTINUOUS CASTING AND ROLLING OF METALS 10 Sheets-Sheet 5 Filed Oct. 28. 1960 INVENTOR. JOHN C. BONGIOVANNI July 27, 1965 J. c. BONGIOVANNI 3,

CONTINUOUS CASTING AND ROLLING OF METALS Filed 001;. 28, 1960 10 Sheets-Sheet 6 H\ INVENTOR. JOHN c. BONGIOVANN! July 27, 1965 .1. c. BONGIOVANNI CONTINUOUS CASTING AND ROLLING OF METALS Filed Oct. 28. 1960 10 Sheets-Sheet '7 IN VEN TOR.

JOHN C. BONGIOVANN! BY MM July 27, 1965 J. c. BONGIOVANNI CONTINUOUS CASTING AND ROLLING 0F METALS l0 Sheets-Sheet 8 Filed Oct. 28. 1960 INVENTOR. JOHN C. BONGIOVANNI July 27, 1965 J. c. BONGIOVANNI CONTINUOUS CASTING AND ROLLING OF METALS Filed Oct. 28, 1960 10 Sheets-Sheet 9 FIG. IO

FIG. ll

INVENTOR.

JOHN c. BONGIOVANNI BY MM ATTORNEYS July 27, 1965 J. c. BONGIOVANNI 3,196,516

CONTINUOUS CASTING AND ROLLING OF METALS Filed Oct. 28. 1960 10 Sheets-Sheet 10 FIG. I2 4945- INVENTOR.

JOHN C. BONG IOVANNI 7 ATTORNEYS United States Patent 3,196,516 (IONTHNUQUS CASTING AND ROLLING 0F METALS John C. Bongiovanni, University Heights, ()hio (221 Elrntree Road, New Kensington, Pa.) Filed Get. 28, 1960, Ser. No. 65,8l8 '7 lairns. (Cl. 29-33) This is a continuation-in-part of my application Serial No. 833,538, filed August 13, 1959, now Patent No. 3,146,525, issued September 1, 1964.

The present invention is concerned with the direct production of sheet or strip or bar stock from metals in a molten condition. Specifically the present invention is concerned with method and apparatus whereby a molten metalmay be continuously cast and reduced directly to a sheet or strip or bar form.

In broad terms, the present invention, insofar as method is concerned, is directed to the formation of a molten body of metal of desired composition, continuously casting the same into an endless slab or ingot form, rectangular or round in cross section, and rolling or reducing the same while yet in a hot state for example into a continuous strip of desired gauge, the strip being then either cut into desired lengths of sheet or plate, or alternatively coiled and severed at desired coiled lengths. The invention will be discussed in terms of sheet or strip production with the metal as cast having a rectangular cross section, but a round section may be used; and also other product sections may be produced as later described.

With respect to the mill with which the invention is concerned, there is involved the combination of a direct casting apparatusof which several types are known to the artfor producing from continuously supplied molten metal a vertically descending slab in continuous form of approximately the desired final width of the strip or sheet stock; the molten metal being solidified in passing through the mold characteristic of such apparatus and partially cooled by water sprays or jets immediately beneath the mold, two sets of pinch rolls spaced below the nozzle serving not only for control of the casting speed for maintenance of the slab as a moving plug in the casting mold and providing a reaction or anchor means for tension to which the slab is subjected in the heavy reduction; and a vertically reciprocating roller type mill for the heavy major reduction of the metal.

In the combination a vertically reciprocating pair of rolls on each downward stroke engage the slab and are cammed toward each other to produce a complete reduction of the hot cast slab to desired thickness; While on an upward stroke the rolls, first separated into a non-working relation for slab clearance, are returned into working spacing for rte-engagement with the slab at about the top of the stroke. The main rolling portion of the apparatus-located directly below the casting mold so that the plane or centerline of movement of the metal from the the metal reduction is not absorbed from a power source only during the downward working stroke, for there is a "ice considerable potential energy available for metal reduction in any practical mill at the beginning of any downward working stroke due to the elevation of the mass of the reciprocating rolls and their mounting or carriage structure; and, therefore, such potential energy is absorbed by or fed into the reciprocating system also on the nonworking upward stroke of the rolls. Hence, the power requirements in the motor or prime mover for the rolling mill, and also the structural strength needed in elements of the power transmission system for the rolls, are lower for example than in prior horizontal Krause type mills. Also with vertical movement of a rollcarriage in contrast with horizontal movement frictional losses in the moving system can be greatly reduced furthering economy of energy requirements, and also thereby helping to reduce the structural and power motor requirements.

The reduction of a continuously cast and endless slab further eliminates the waste of prior mills operating horizontally to reduce successive billets or slabs and resulting in butts or stub ends which cannot go through the mill. Also the vertical casting results in better temperature control of the metal in solidifying and thereafter in passing to the reduction region.

A greatly advantageous characteristic of the invention is the fact that there is achieved a practically instantaneous reduction, on the order of as a minimum, in thickness in an effectively hot rolling operation thereby changing the metal structure from an as-cast predominantly large or average open grain to a uniformly fine grain, with excellent homogenizing effect, and a consequent great increase in tensile strengths.

In addition to the above-described features, there are here disclosed as located beneath the rolling mill at very economic means for cutting off and handling the finished strip, either in coil form or in fiat sheets. For this purpose there is located immediately beneath the mill a power-operated shearsfor cutting the continuous product strip at appropriate points. Below the shears there are located, as alternative means of handling the finished strip, first a coiling apparatus for turning the strip length into say loose coil form; and therebeneath an up-ender device, a tilting sheet receiving and discharging mechanism. From the coiler there is provided a suitable coil ramp or other conveying means advantageously gravitational, whereby the final coils are directed to a point of loading or further handling. On the other hand, where the product is to be in sheet or plate form, the up-ender or tilting receiver accepting each length of material cut from the continuous strip in its vertically descending path is thereafter turned toward a disposition somewhat beyond horizontal to discharge the severed sheet onto a conveying systemagain advantageously gravitational-for carrying the same to a final point of loading or other disposition; as for example to a point where the same are stacked and baled or palletized.

The general object of the present invention is then the provision of an improved method and apparatus for the production of a continuous metal form from molten metal. Another object is the provision of method and apparatus for direct casting of metal into a continuous ingot and reducing the slab to strip, sheet, plate or bar form. A still further object is the provision of a method and apparatus for achieving a low cost conversion of merchant metal or molten metal to strip, sheet, plate or bar form,

. mum and alloys thereof, but also ferrousmetals.

particularly non-ferrous metals such as copper and alurni- Other object andadvantages of the invention will ap- 7 pear from the following description and the drawings wherein: Y a

FIG. 1 and FIG. 1a present in side elevation the rela-,

tions of the principal parts of a plant or mill forfcarrying;

out the method or'process of the present invention; certain parts being omitted in FIG. 1, and others being represented in generalized or outline form in FIG. 1a for overall clarity;

FIG. 2 is a somewhat enlarged side viewo'f the principal 1 part of the rolling mill proper; FIG. 3 is a front view corresponding to FIG. 2; FIG. 4 is a vertical sectional viewtaken generally as indicated by the lines 44 inFIG. 3"through the reciprocating housing and roll'carriage contained therein;

FIG. 5 is an irregular transverse sectional view taken;

indicated by the line 55 in 1 FIGS; 3 and 4; i

however, substantially as FIGS. 6 and 7 are front and sideviews respectivelyof the roll carriage frame; V I I I FIG. 8 is a fragmentary detail of aroll camming wedge block; adjustment means; 1

FIG. '9 is'a schematic representation of hydraulic and electric control circuitry for the rolling apparatus;

, FIG. 10 is a schematic representation of the positioning in a mill of the type described of brushes operating atvarious locations on the slab, pinch rolls, working rolls and product; p

' FIG. 11 is a fragmentary vertical section showing the For handling the strip-metal produced in the mill M,

there are arranged there-beneath (see FIG. 1a) on a lower floor'a shear device S, such as-a Halden type shear, and for manipulation of the sheared product a three roll upcoiler apparatus C into which thestrip-like product may be directed and there formed into a loose coil; here again I the apparatus being similar to prior well-known forms. With the coiling apparatus, for transport or conveyance of a finished coil of desired length away from the mill, 5 there is also associated a conveying device suchas, an inclined guide ramp for directing the coils for example to a loading dock. Below the coiler, as an alternately available means of handling the product, there is disclosed a plate or sheet receiver mechanism or up-ender T, a roller lined elongated frame which, from a position vertically aligned with the path of the strip produ'ctto receive the same as it is cut off at appropriate lengths in sheet or plate form by thelshears, is tiltable to, a position slightly beyond horizontal for gravity discharge of the received plate to a conveying system carrying the same toa baling area or loading dock. v 7

' The mill M has a sturdy upright frame comprised of four rigidly parallel spaced and anchored vertical columns "'10,"such as structural steel I'-beams with transverse spacers 10a,'wherein :a heavy integrally cast hollow housing H is guided for vertical reciprocation by four guide roller assemblies 11 at-each corner ofthe housing. A m ill power and driving system comprises. a' prime mover 12, such as i a three-phase high yoltageheavy duty motor; a pair of mounting for a work roll cleaning oscillatory type brush? a FIG. 12 is a further fragmentary section taken as indi-[- according to the present, invention is presentedby FIGS.

1, 1a.. Ata top floor of the mill, there is a furnace F- for melting or holding in molten state metal continually poured from the nozzle thereof to be cast through a dielike direct casting mold D into 'a slabor billet-like continuous. piece B; and immediately below B there are disposed the I us W, for partially cooling the slab and solidifying the controlled continuous water spray jets or cooling apparatfaces of lthe connecting rod' '19.

reduction gearing units 13,"13 Jon, opposite sides of the mill with input shafts-coupled by 'a' cross shaft 14, and

(at'the left of FIG. 3) the motor being also connected to the input on one side of, the unit13 by a suitable coupling 15. The output shafts of the reduction gearing units Icarry respective suitably counter-balanced fly wheels 17,

each having a crank pin 18 connected through a connecting rod 19 with the housing H through a wrist pin 20 journalled in bearings inserted in the housing. Suitable thrust washers are disposed between theinner faces of the wrist pin mounting formations of the housing and the adjacent V a The roller guide units 11 each'comprise a spacer block or mounting bar 21 secured on a respectivecolumn 10 and having rotatably mountedlon adjacent faces series of ' verticallyequispaced rollers 22, 23. The rollers, of one series arestaggered relative to those of the other series l and radially project beyond the face of the bar mounting metal while yet-in the mold'D. The mold may itself be" water cooled. Below Ware arranged in tandem two pair of pinch rolls, such as a conventional Horsburg and I ,Scott pinch roll drive, driven at a selected rate'to control 7 the rate of casting or production of'the slab at, D, the

the other;seri es, so that .eachcorner'of the housing is embraced and guided by. rollers 22, 23, bearing on respective vertical finished areasrunning from top to bottom of the housing. 1 v r .The roll carriage RCis an elongated generally open frame (see FIGS. 6 and ,7) here shown as formed by two pairs'of joined corner angle irons til-l, 4tlr (left"or right pair in FIGSQS and 6) connected by suitable cross struts or braces, such asfAtla, 41a and 40b,.41b at the'top'and rollsbeing located immediately below and in alignment with D and, W. In general, the furnace or other means continually pouring metal to the mold producing a slab of desired thickness and Width, the cooling apparatusand the pinch rolls may be similar to those' W611, knownnow' in the art for direct Casting processes. Byway of examtoward thebottom respectively, and 40,41c and 40d,'41d near the middle of the carriage, the front and back sides 7 between respective members 40-1 and 40-.r being open'and members 40ad being set. inwardly therefrom for clear.- ance relative to the hereinafter described camplates 55.

i The carriage also 'is guided and embraced at each corner ple, an aluminum slab B may have dimensions'onthei 7 order of 4 by 12 inches in leaving the mold. Where A inch, by 12 inch strip is to be could be cast as later noted.

produced, a round billet V reduction ofthe slab thickness. Insofar as the reduction be said to begener ally similarto that of on finished areas'by bearing "strip pairs 43 and 44 secured at-corners in thehollow central space of the housing, there being also a verticalinward slot ateach inside corner of thehousing for accommodation of a corre- For continuous reduction of the slab B to a plate, sheet a spondmg v'emcal carnage rack may be noted in or strip form, there is further provided on the next lower floor the reduction or rolling, mill M located vertically below the pinch rolls P, the mill M effecting thefmajor FIG. 4, 6 and 8 the'ra'cks-32 are carried on the lower end of the cornerangles 40'l;and 40-r which extend below the housing H even when the, latter is in its uppermost position, at which time the carriage RC is in its lowermost position relative to the housing H, as in FIG. 4.

For'effecting synchronized reciprocation of the roll carriage relative to thehousing during-reciprocation of the latter on'the millrframe four rack and pinion mech:

anisms are provided. Each comprises a vertical fixed rack 26 mounted outboard of a roller support bar 21 and meshed with pinion 27 carried on a transverse shaft within a gearing housing or frame 28, bolted or otherwise secured on a bottom surface of the main casting of the housing H. The pinion 27 is meshed in turn with a gear 29 carried on shaft 30 commonly with and rotatable with the pinion 31 meshing with a corresponding carriage rack 32. The pitch diameter of 29 is twice that of 27 and 31, whereby the movement of the roll carriage is half that of the housing H relative to the mill frame.

At opposite sides of the roll carriage RC, in the region between the respective middle vertically paired cross braces 41c, 41c and 40a, 40d there are formed corresponding parallel transverse slideways 48 for receiving in each a pair of opposed sliding bearing chock 4%, 49b for the roll neck bearings. Each chock is of a generally rectangular block form and has a large central aperture with a sleeve bearing journalling the roll neck of a corresponding roll R. The bearing checks 4% for one working roll, at their upper and lower ends, each have blind bores or holes formed in parallel fashion to receive the ends of vertically spaced paired single acting hydraulic cylinder units 51, with pistons 52 hearing against opposed shoulders on a corresponding one of the facing bearing blocks 45% supporting the other working roll. The cylinder units 51 hereinafter called balancing cylinders are constantly pressurized to extend the same in a dash-pot cylinder arrangement, and normally tend to spread the rolls from each other. Accordingly, each chock block 49a is provided with suitable passageways for hydraulic fluid leading to the balancing cylinders 51 from flexible hose connections pressured by hydraulic fluid supply system. There is a suitably sized window etween the frame members opening into the slideway at each side of the frame, and also in the housing, which are alignable for removal and insertion of the rolls and checks for servicing the assembled mill.

At the front and back sides (top and bottom of FIG. 5) of the vertical central opening of the housing H which accommodates the roll carriage, there are like opposed vertically extending channels or recesses wherein are mounted the cam plates 55 by bolts 55b to be vertically fixed relative to the housing H by thrust plates 550 but shit-table along bolts 55b toward and away from each other, and each cooperating with a respective one of the rolls R riding thereon. The shape (see FIG. 4) and function of the cam plates are hereinafter set forth. The cam plates are urged outwardly by compression springs interposed on each bolt between a nut thereon and the housing. Certain control and shifting means for the respective cam plates are also mounted behind the latter in the channels, including an elongated rather thin wedge plate 56 with its outer flat face bearing upon a corresponding flat surface 54a of the channel; and a larger hollow wedge or taper block 58 having sloping face 58a complementary to and bearing on the inner sloping face56a of the wedge 56 and an inner fiat face in contact with the fiat outer face of the cam plate 55.

It will be noted that the widths of both 56 and 58 are less than the corresponding dimension of the channel or recess whereby shifting of 56 and 58 from one side to the other (i.e., from left to right as viewed in FIG. 5) is permitted. The large taper block 58 has a central recess 58C (see FIG. 8) with parallel vertical walls between which there is received a closely fitting nut block 60. A power driven lead or adjusting screw 61 engaged in block 60, journalled at its inner end by a sleeve bearing 61a in one wall of the recess 54, extends through and is axially fixed in a bearinged aperture 61b in the opposite wall by retainers 61C for coupling at 62 to the reversible drive motor and reduction gearing unit 63 bolted to the right side of the housing H.

The taper block 58 is transversely slotted in the region of the screw 61 to permit not only axial shifting of the block as it is carried by the nut 50 but also an inward and outward shifting as it is moved along the taper of the opposed small block 56. The blocks 56 and 58 are also slotted transversely at top and bottom for the cam plate bolts 55b therethrough to permit the in-and-out movement of the taper or wedge blocks.

On the side of the housing H opposite the location of the motor 63 a double acting hydraulic piston unit 66, as a hydraulic reciprocating motor for a corresponding block 56, is mounted for reciprocation in direction transversely of the housing, that is, parallel to the direction of the lead screw 60 and to the axes of the rolls, and has its piston coupled to a stud 68 threaded into the broad side of the taper block.

Considering now the situation of FIG. 5, it is seen that one extreme working setting, a maximum spacing of the two cam plates from each other, and hence a maximum spacing of the rolls for any given position longitudinally of the cam plates is achieved under the conditions there appearing with 56 and 58 at the extreme right. However, upon withdrawal to the left of each block 56, as in FIG. 8, the blocks 58 and cam plates 55 actually follow so that the rolls immediately separate to clear the slab by action of balancing cylinders 51 upon the roll bearing chocks as in fact is intended to happen at the end of the downward housing or rolling stroke. However, upon simultaneous return of the two plates 56 by extending force of the units 66, the cam plates are then urged to return to the position of FIG. 5. However, when the power screws drive the blocks 58 to the left, the opposed tapers of 56 and 58 cause the blocks 58 and hence the cam plates 55 to move inwardly, thereby narrowing the roll spacing. Since the whole structure of the housing H, carriage RC and the other reciprocating components are in general symmetrical about the centerplane of the roll carriage, i.e., centerplane of the continuously cast slab and the product strip, the inward feed or retraction of the blocks 58 should normally be equal; and also the release and return of the same by operation of cylinders 66 should take place simultaneously.

Considering now a typical operation for conversion of aluminum to one-fourth inch plate 12 inches wide, the casting mold or die D of the furnace would be sized 4 by 12 inches to produce a hot billet of corresponding crosssectional dimensions. With the slab entering the pinch rolls at a four inch thickness, and as a typical operating temperature at about 850 F., approximately a five percent reduction is effected at the pinch rolls. Therefore, the slab thickness would be 3.8 inches on entering the mill proper. Rolls, each six inches in diameter and sixteen inches long in the roll body, would be typically used in the roll carriage. With a 44 inch stroke of the housing, there is effected a corresponding relative upward movement of twenty-two inches of the roll carriage relative to the roll housing or a movement of only twenty-two inches of the carriage downward relative to the mill frame, by virtue of the rack and pinion gearing previously described. On the downward or working stroke of the mill this relative movement of the roll carriage relative to the housing is in a reverse direction, that is, there is a 22 inch vertically upward displacement of the roll carriage relative to the housing; in other words, on the downward stroke of the housing this travel being subtracted from the total travel of the housing, the carriage is carried downward only 22 inches.

In FIG. 4 the relative position of the elements at the extreme upward position of the housing is shown in full lines; while the corresponding relation of the elements at the extreme downward position at the bottom of the stroke is shown in dashed outline for certain elements such as the rolls and cam plates.

Consider now atypical installation utilizing a 200 horse power motor, rated for 1750 r.p.m. at 440 volts, threephase 60 cycle power with 8 foot connecting rods, and a total mass of the reciprocating housing and all elements 7 carried thereby of approximately 10,000 lbs, and 60 strokes per'minute forthe working rate. With a four inch thick as-cast slab reduced to 3.8 inches infthe I 8- 'Iri the aforedescribedapparati s, the i011 carriage, rolls andhousing, along fwith the auxiliary equipment carried therebysuch as the hydraulicpistons for the Wedges and pinch rolls feeding at a rate of Vs inch for each working 7 stroke cycle, in other Words,.about 1.9 feet per minute at 850 F. and with an elongation factor of 15.2 in the rolling, there isobtainable a delivery of 5.7 inches "of the inchthick stripor plate per stroke or about 28.5 feet per minute or 1710 feet per hour. 'This would then .7

represent a conversion .of about 6480 lbs. per hour of aluminum.

Returning again to FIG. 4, the system is shown just as av downward stroke. is about to begin. The cylinders 66 are under pressure to drive the wedges 56 inward and thereby to bring the cam plates to their fixed spacing predetermined by the adjustment of the system. As the housing starts downwardly, with the carriage lagging, the

cam plates fever-run the descending rolls R, so that sloping cam surfaces in engagement with therolls not only rotate the rolls to cause the adjacent roll surface to move in an upward direction, but also urge the rolls in wardly. Hence, as the rollfcarriage descends, the'rolls also the adjusting motors, represent a large moving mass elevated duringthe upward nonworking stroke, and thereby require a certain'power input, not at that. timefused for metal reducing work; The ele'vati on" of this mass'represents an'increase'd potentialenergy of the 'sy'stem which reaches its maximum; of. course; at the .top of the upward stroke? Asthe. downward stroke begins, this potential energy then becomes available 'as part of the working system expending energy upon the metalbeing worked.

'This' accordingly lessens in some degree the load upon secondly by virtue of-the fact that the power-demand is are squeezed inwardly, eachfbiting intothe metal and carrying or drawing downward acrest of metal on opposite sides of the slab. Over approximately the first half minimized for the working stroke, a smaller or lighter construction is possible in many of the working elements of the drive system. 1 Furthermore, the very drive motor of the downwardstroke, say 14 inches ofroll descent, Y

the rolls'a're being" brought together. At about one-half of the downward stroke the rolls have reached the end of the inward cam slopes and there encounter straight parallelcam faces, and accordingly, over nearly the entire remainder of the stroke, the roll spacing is held constant at the actual spacing required by the thickness in the finished product. In this latter portion of the stroke,

then, crests of metal advanced'i n the bite are rolled' out into flat sheet form, therolls continuing down even after the sheet has actually been formed in fiat shape for a slight over-rolling portion of the stroke'which may overlap say an inch or so of metal finished on the preceding V V "ing the otherends to a reservoirreturn line for driving blocks 56 inwa'rdat one-setting, and reverses the cylinder connections to withdraw the blocks-on the' other setting.

stroke, to give a desired'finish' and flatness to the product.

The tandem pinch rolls, conventionally synchronous mo cycle of housing reciprocation. 'matically presented inFIG. 9, includes an electric motor and other 'driveequipment are themselves reduced in size. A generally conventional. pressurized hydraulic system and components may be used to keep the balancing cylinders 51 pressurized continuously and to operate the double acting cylinders 66 tomovej thetaper plates 'or blocks 55 in and out at the stated appropriate points in each full Such a system, vas schedriven pump SOQdeliVeringfluid from: areservoir 81 through an adjustable pressure regulator 82 with relief valve, through flexible hoses. to the cylinders 51; and also through a" regulator'and relief valve 82:: to a two-way tor driven through a very high gear reducti-o'n, restrain the slab to provide tension reactionto, the downwardly applied forces of the rolls during the downward working stroke, permitting only the slab advance corresponding to the established casting rate and feed roll drive is set. V Just before the end of the stroke .is reached, the cylinto which the pinch ders 66 are actuated to retract the same and release the cam plates, and also as may be noted from FIG. 4, a very slight outward taper or cam relief is encountered by. each roll; so that as t he ,strokeis completed, a slight outward or roll-separating movement is permitted under the action of the balancing cylinders. Thus, even before the down sheet portion, so that the normal slab feed is notimpeded.

ward stroke is quite completed, the rolls'are actually released from their rolling engagement with the finished During the upward or return stroke, though the housing and cam plates actually will'be overtaking the carriage rolls'permitting roll clearance ,Wllihlllfi increasing width of. the tapered slab end. Just as the carriage is approaching the top of its stroke, say one inch from the top, control means causes the cylinders 66 again to be' pressurized for extension to drive the wedge plates 56 inwardly,

thereby again restoring thei cam platesto the original control valve' 83, which selectively applies fluid under pressure to the outer ends ofthe cylinders 66 while open- 'the moving housing with the pump motor energized I through flexible electric cables, or alternatively the pump may be fixed, independent ofthe housing to which flexible hydraulic lines or hoses are run.

The control valve maybe a solenoidally operated type shifted by solenoid 83a fro-m one'sett-ing to the other under the control of single control switch 84,;which is tripped or cammed to opposite settings by a set of spaced lugs 85, 86, the switchjand lug set being on respective relatively moving members 'X, Y of which one is fixed, I as the mill frame, andthe other i s the reciprocating housing. The'lugs 85, 86 for example, may be pivoted but spring biased against a stop so that each may engage moving in the opposite direction. I On the other hand, the

control valve maybe mechanically 'actuated or tripped to one or the other setting (at the times previously described for ea'chcycle) by encountering vertically spaced dogs'or livery previously stat-ed for 'operatiens on aluminum the proper working spacing. The. rolling cycle' then begins again,.in the meanwhile the slab or billet having con-.

to as, as. v a 7 Withthe conditions of billet feed, stroke lengths and delugs near opposite ends of the housing strokes, similar roll supporting cam surfaces on a cam plate wouldhave longitudinal dimensions, that is,as projected on a longitudinal'line, a-s follows: a sloped surface of about seven and one-half degrees, 13.5 inches of thelength; a'straight portion of 7.1 inches with 5.7 inches thereof allotted to deliveryf or'rolling out an accumulated biteor crest 1 and 1.4'inchesfor over-roll of metal finishedon a previtinuously moved down by of an inch from the posit'ion.

stroke.

ous stroke; and a sharply sloped or release portiornof 1 /2inches'ofthe-length' vWithione set of such cam plates as used for fir inch thick product obtained in the approximately 16 to 1 reduction from a four inch billet, a product range of 7 to inches is practical from the stated size of billet. However, were it desired to hot roll with a greater reduction say from 4 inches to inch, the billet feed rate would preferably be reduced and the cam slope increased.

With the previously described cam plates and the same feed rates, a 2 inch billet thickness would be preferred to produce /s inch product thickness, representing the reduction ratio for which the cams were specifically designed.

Generally, it may be said that the common metals of ductile character or capable of normal hot rolling are susceptile to operations as here contemplated, excepting of course certain special alloys thereof, and the same cam plates and billet size (therefore direct casting mold) may be used therewith as for aluminum by varying the rate of billet feed and the final thickness produced. Of course the temperature of the billet in arriving at the reciprocating rolls is selected according to the hot rolling temperature requirements of the particular metal, e.g. 2000- 2200 F. for a 1020 or mild steel; 1800 for copper. Even for these metals, where the same reduction ratio of approximately 16 to 1 is used as first described for aluminum, about the same cam configuration and feed would be used, the specific energy requirements merely demanding varied power.

The temperature of the metal actually being cast into the mold will, as well known to the art, depend upon the specific metal composition and mold environment; for example with various aluminum alloys requiring temperatures over a range easily as broad as 12001500 F.

In a schematic fashion, FIG. 10 shows disposed on opposite sides of the path of billet travel a pair of rotationally driven Wire brushes 11% disposed below the location of the cooling water spray system and above the pinch rolls P, for the purpose of cleaning the slab of any scale or other adherent debris; two pairs of rotary cleaning brushes 11)]. for the pinch rolls P each contacting a respective roll substantially diametrically opposite the point of roll contact with the slab; two pairs of slabcleaning rotary brushes 162 and 193 respectively below the pinch roll and below the range of movement of the working roll carriage. As various type mounting and drives for these rotary bristle brushes are known to the art they are no further described here.

More importantly, for cleaning the working rolls and preventing the same from going out of correct effective shape by accumulation of scale or the like, these rolls are each provided with a bristle brush longitudinally oscillated parallel to the roll axis. More usually the bristle brushes operating on the slab are wire bristle brushes, while those for cleaning the various rolls are comprised of natural organic or synthetic plastic bristles for protection of roll finish, though at times metal brushes may be used.

One suitable form of mounting for the oscillating brushes 164 within the roll carriage is shown in the fragmentary views of FIGS. 11 and 12 of one brush mounting. The elongated brush 1114 is secured in a pair of spaced clamps 105 each having its base slidably mounted on a respective pin 1% secured on a slide block 1117. The slide blocks 167 (see FIG. 12) are mounted below, and for oscillation parallel to, the corresponding roll by vertically spaced parallel rods 108 and 169 having ends respectively fixed in and slidably supported at opposite sides of the roll carriage frame; the blocks being slidable on fixed rod 1% and secured in fixed parallel spaced relation on slidable rod 1&9.

To oscillate the blocks 187 and hence the brush 104, depending inclined cams 111, 112 are secured to the vertically reciprocating housing H in such position as to be contacted by respective opposite rounded ends of the rod 161?, so that as the roll carriage itself reciprocates vertically in the housing, the rod 109 is carnmed endwise 1% in opposite direction on up and downwardly carriage movement by the correspondingly formed surfaces of the cam plates.

The brush clamps 1% are slidably mounted on the respective parallel pins 1% so that they may follow the rolls in and out relative to the slab to maintain cleaning contact therewith; and accordingly means must be provided to move each brush along with its roll, while permitting the brush itself to oscillate endwise. One means for this purpose (see FIG. 12) is the use at the end of each brush of a short channel shaped brush guide 114 secured to the outer end of the adjacent bearing chock as at 4% and disposed in the general orientation of clamp to embrace the corresponding brush end in slidable relation.

In place of the use of a mold with a rectangular opening, a mold may be used having a circular discharge opening for casting a round billet. This may be desirable in some instances from cost considerations inasmuch as round molds for direct casting are more readily available as standard items, and also from an operational viewpoint. Where four inch strip, for example, i the desired product, a four inch diameter round billet would be cast.

Other product forms that may be produced by the method and apparatus of this invention are shown by way of example in FIGS. 13a where 130, 13G designates the cross section of a pair of square rods which are rolled in continuous length; in 13b, where 131, 131 designate the cross sections of a pair of round rods or bars which may be rolled in continuous lengths; and in PEG. 130, where 132 designates the cross section of a bar form in effect comprised of two opposed outwardly divergent roughly wedge shaped or triangular portions 132L, 132R merged or joined at their apical regions, providing a continuously rolled stock, which may be vertically longitudinally slit at the central narrowed region to provide two wedge shaped bars suitable for use, for example, in production of commutator segments.

The roll form must of course be changed from the cylindrical form used in production of plate or strip stock to a contoured roll form of such shape that when the opposed working rolls are at their position of closest approach to each other in the working stroke, the intersections of the proximate surfaces of the two rolls with a plane through the roll axes defines or is substantially identical with the shape of the opposite sides of the desired product. Thus in FIG. 13a the rolls have cooperating opposed circumferential grooves 135 of right angle cross section; while in FIG. 1312 the grooves 136 have a semicircular cross section. For the product indicated by 130, the rolls will have the form shown in FIG. 14 where, beginning at a region spaced inward from each end, a roll tapers or diverges outwardly toward the middle of the roll.

Furthermore with change in the roll form it may be necessary to accommodate the transverse shape of the cam plates to the shape of the rolls, as indicated also in FIG. 14 where the cam plates 55 have a shallow recess 140, triangular in cross section extending longitudinally to the inclined and straight portions of a cam throughout its length, to accommodate the circumferential central bulge produced on the roll by the outwardly tapering port- ions 137, 137, while the opposite side marginal portions of the cam plate face 141, 141 may retain the same flat form disclosed for the cam plates where flat stock is being rolled, to support the cylindrical end portions of the roll face. The recess 148 may be of such shape that it merely provides clearance with respect to the roll bulge or it may actually support the central part of the roll, as may be required by working stresses produced under particular operating conditions. Where the roll form is varied from a cylindrical shape merely by circumferential grooves and the remaining portions of the interrupted cylindrical surface provide adequate bearing surface, the straight and inclined portions of the cam working face may be transversely flat, as would beithecase said pinch roll means.

in FIGS.- l3a or 13b. a It will be noted that the form of the product bar of for the roll 'forms used FIG. 13c (seealso FIG. 14) is such that the loads imposed 1 upon the rolls are balanced along the rollaXis, since the product form is symmetrical about a vertical longitudinal 1 central plane;.and for a like purpose of balancing stressfor loads inFIGS. 'l3a'and 13b the rolls are grooved to pro duce two square elements or two round elements from the continuously cast billet or bar, which in'all threeof the- 'FlGURES lsa, b and c is round in cross section as indi V cated by the dashed circle 145 in ea'ch case.

I claim: a i a j 1. A mill for the continuous conversion .ofmetal into a rolled form from molten metal comprising: a direct casting mold for producing a moving straight hot billet from molten metal, billet cooling means located adjacent saidmold for maintaining the metal in solid billet form as it leaves the mold, constant speed power-driven tandem pinch roll means engaging said billet on the side of 'said cooling means remote from the mold to control the rate of delivery of said billet from the mold, vertically reciprocating cooperating paired roll means adapted to engage there-between successive increments of the billet length and i to move toward each other to a predetermined spacing during a first portion of each working stroke away from the mold andthereafter to be maintained at said spacing for substantially the remainder of the stroke,'and means to separate said rolls during the return stroke to a spacing exceeding the thickness of the billet as delivered from 2; A mill for the continuous conversion of metal'into a rolled form 'from molten metal comprising: a direct casting mold for producing a ver'tically descending hot billet from molten metal, billet cooling :means located adjacently below said mold'for maintaining the metal in solid of each pair respectively engaging the back-oi a cam plate and an inner wall of the housing, means for shifting a first of said blocks in a vertical plane to a selected position to predetermine a working spacing for the rolls, and means for quickly'retracting and advancing the second Wedge block from and into wedging engagement relative to the fir st, as the' housing approaches the bottom of a downward stroke and the top of an upward return stroke respectively; said cam plates having like roll camming iaces in-clu-ding'respective slopedi-lower surfaces mutually upw-ardlyconvergent and respective substantially vertical- V 'ly straight mutually parallel upper surfaces. 7

6. A'mill for thecontinuou's conversion of metal into a rolled form from molten'meta-l comprising; means for producing a vertically descending'hot billet directly from molten metal,constant speed tandem pinch roll means engaging said billet below the first said means to'determine'a delivery rate of said billet, a rigid frameand a housing mounted and guided thereon for vertical reciprocatiommeans for reciprocating'the housing,;a roll carriage vertically. guided in said housing with said billet extending therethrough, vertical racks on the frame and carriage and gear means meshing with said racks for re- 'ciprocating the: carriage in lagging rela-tion to the housing, a pair of horizontally spaced horizontalrolls mount- 6d insaidoarriage on opposite sides of the billet path for movement toward anda-way from the billet, a pair of vertically extended cam plates for backing'up the'respechot. billet form as it leaves the mold, constant speed tandem pinch roll means-engaging "said billet below said cooling means to control therate ofzdescent of said billet from the mold, vertically reciprocating cooperating paired roll means adapted to engagetherebetween successive-in:

V crements of thebillet length and to move toward each other to a predetermined spacing during a first portion of each working downwardgstroke and thereafter to be malntained at said spacing for substantially the remainder of the stroke, and means to separate said rolls during the return stroke to a spacing exceeding the thickness of th mine a delivery rate of said billet, a'rigid frame and a housing mounted and guided there-on for vertical reciprocation, means for reciprocating the housing, a roll car riage vertically guided in said housing with'said billet extending therethr-ough, vertical rack-son the frame and of metal into tive rolls,' said plates vertically fixed in said housing and shiftably mounted for varying horizontal spacing between the rolls, 'means biasing the rolls away from each other against cam surfaces on the respective cam plates, and

respective means supported between each said cam plate and'the housing. for adjusting. the working spacing and releasing the rolls; the last saidmeans including a pair of cooperating wedge blocks having faces incontact with each other, saidblocks of each pair respectively engaging the back of a cam plate and an innerwall of the housing, meansfor shifting a first of s-aid'blocks in a vertical plane to a selected position to predetermine a Working spacing for the rolls, and means for quickly retracting and advancing the second wedge block in a vertical plane from and into wcdging engagementrelative to the first, as the housing approaches the bottom of a downward stroke and the top of. an upward return stroke respeci tively; said camgplates having like roll camming faces ineluding respective sloped lower surfaces mutually upwardly convergent and respective substantially vertically a Istraigh-tmutually parallel upper surfaces.

, V ,50 4. A mill as described in claim 3, including means for 7. A mill 'for the continuous conversion of metal into 7 a rolled form from'mo'lten metal comprising: means for producing a vertically descending billet directly from molten met-aL constantspeed tandem pinch roll means I engaging said billet below the first said means to deterruins a feed rate of said billetpa rigid frame and a housmg mounted and. guided thereon forve'rtical reciprocatron below the pinch roll means, power driven means for reciprocatingthe housing, a roll carriage supported and guided in said housing for vertical reciprocation along a stud billet extend ng therethrough, cooperating means on the frame and carriage for reciprocating thecarriage in carriage and gear means meshing with said racks for re ciprocating the carriage in lagging relation to thehousmg, I

a pair of horizontally spaced horizontal rolls'mounted'in said carriage on opposite sides of the billet path for movement toward and away from the billet,,a pair of V611,

tically extended cam plates fo'rbacking' up the respective rolls, said: plates vertically fixed in said housing and hor'i zon-tally shiftably mounted for'varying horizontal spacing between said rolls, and respective mean-ssupportedL between each said cam plate and the housing for adjusting the working spacing and releasing the rolls; the last a 7 said means including a pair of wedge blockshavingcom plime ntalfily sloped cooperating contact-faces, said blocks lagging relation to the housing, a pair of horizontally Spaced horizontal rolls horizontally shiftably mounted in but vertically fixed relative to said carriage on opposite sides of thebillet path for movement toward and away from the billet, .a pair of variably spaceable. vertically extended. roll' backing cam plates mounted in said housing, and means supported in the housing and acting on the cam plates for establishing a d-ownwar-d stroke Work- 'ing spacing of. the plates and for releasing the plates and thereby'the' r-ollsqas theihousing approachesthe top of an upwardreturn stroke and the bottom of a downward working stroke respectively; said cam plates having like roll camrning faces including respectively sloped lower surfaces mutually upwardly convergent to respective sub- 13 14 stant-ially vertically straight mutually papallel upper 2,791,8 12 5/57 Dangelzer 225 7.2 surfaces. 2,827,944 3/58 Grossu 29- 3313 References Cited by the Examiner 2,854,732 10/ 5 8 Hessenberg 29528 UNITED STATES PATENTS 2, 07,151 10/ 59 Peterson 29-33- 13 9,471 12/ 52 Field 2 5 FOREIGN PATENTS Norton France- 406345 7/ 89 Norton 2933-3 519 979 4/40 Great Britain 441,374 1 1/9O Norton 2 9--33.3 705,721 7/02 Trotz 2933.3 I i t 2,139,215, 12/38 Waggon 29 528 10 R CHARD H. EANB Prlmary r- 2 739 323 4 5.7 Ackemnan t 22 57 2 WHITMORE A. WILTZ, HYLAND BIZOT, Examiners.

Claims (1)

1. 7. A MILL FOR THE CONTINUOUS CONVERSION OF METAL INTO A ROLLED FORM FROM MOLTEN METAL COMPRISING: MEANS FOR PRODUCING A VERTICALLY DESCENDING BILLET DIRECTLY FROM MOLTEN METAL, CONSTANT SPEED TANDEM PINCH ROLL MEANS ENGAGING SAID BILLET BELOW THE FIRST SAID MEANS TO DETERMINE A FEED RATE OF SAID BILLET, A RIGID FRAME AND A HOUSING MOUNTED AND GUIDED THEREON FOR VERTICAL RECIPROCATION BELOW THE PINCH ROLL MEANS, POWER DRIVEN MEANS FOR RECIPROCATING THE HOUSING, A ROLL CARRIAGE SUPPORTED AND GUIDED IN SAID HOUSING FOR VERTICAL RECIPROCATION ALONG A SAID BILLET EXTENDING THERETHROUGH, A COOPERATING MEANS ON THE FRAME AND CARRIAGE FOR RECIPROCATING THE CARRIAGE IN LAGGING RELATION TO THE HOUSING, A PAIR OF HORIZONTALLY SPACED HORIZONTAL ROLLS HORIZONTALLY SHIFTABLY MOUNTED IN BUT VERTICALLY FIXED RELATIVE TO SAID CARRIAGE ON OPPOSITE SIDES OF THE BILLET PATH FOR MOVEMENT TOWARD AND AWAY FROM THE BILLET, A PAIR OF VARIABLY SPACEABLE VERTICALLY EXTENDED ROLL BACKING CAM PLATES MOUNTED IN SAID HOUSING, AND MEANS SUPPORTED IN THE HOUSING AND ACTING ON THE CAM PLATES FOR ESTABLISHING A DOWNWARD STROKE WORKING SPACING OF THE PLATES ADN FOR RELEASING THE PLATES AND THEREBY THE ROLLS AS THE HOUSING APPROACHES THE TOP OF AN UPWARD RETURN STROKE AND THE BOTTOM OF A DOWNWARD WORKING STROKE RESPECTIVELY; SAID CAM PLATES HAVING LIKE ROLL CAMMING FACES INCLUDING RESPECTIVELY SLOPED LOWER SURFACES MUTUALLY UPWARDLY CONVERGENT TO RESPECTIVE SUBSTANTIALLY VERTICALLY STRAIGHT MUTUALLY PARALLEL UPPER SURFACES.

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