US1812508A - Method of making sheets and plates - Google Patents

Description

June 30, 1931.

C. W. BENNETT METHOD OF MAKING SHEETS AND PLATES 5 Sheets-Sheet 1 Filed June 21, 1927 Crop End 8 Bars or Z'WhicKQK June 30, 1931. c. w. BENNETT METHOD OF MAKING 'SHEETS AND PLATES Filed June 21, 1927 5 Sheets-Sheet 2 Witness CHHELE5 I44 EE/VNET C. W. BENNETT METHOD OF MAKING SHEETS AND PLATES June 30, 1931.

Filed June 21, 1927 3 Sheets-Sheet :5

Patented June 30, 1931 UNITED STATES PATENT OFFICE CHARLES W. BENNETT, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO AMERICAN SHEET AND TIN PLATE COMPANY OF PITTSBURGH, PENNSYLVANIA, A CORPORA- TION OF NEW JERSEY METHOD OF MAKING- SHEETS AND PLATES Application filed June 21,

The invention relates to the manufacture of rolled metal sheets and plates, and more particularly to the manufacture of light gage black plates of the class used in making tin plate.

One object of my invention is to provide a novel method of rolling sheets and plates in which reduction of the metal in the rolling operations is eiiected in a new and improved manner, and by which sheets and plates are produced, wherein variations in the gage of difierent sheets and plates and also in different parts of single sheets or plates are reduced to a minimum, when not entirely avoided and overcome.

In making sheets and black plates by existing methods it is the general practice to roll these materials from sheet bars, such bars approximating eight inches in width. The bars vary in length and also vary in gage and, because of differences in length and gage, in weight. The length of the sheet bars is governed by the width of the sheets or black plates to be made, and the thickness or gage and weight of the bars is determined by the length and gage of the sheets or plates into which the bars are rolled.

The sheet bars when being rolled extend lengthwise parallel with the axis of the rolls. At the commencement of the rolling operation, single bars are rolled on a two-high roughing mill. In this operation two bars are rolled at the same time, although they are passed singly between the rolls, one bar being handed over the top roll of the mill by the catcher while the other is being passed between the rolls by the roller. The single bars, after being given several passes, usual- 1y five, are matched by laying one on top of the other to form a pair and the matched pair is then given a few passes, usually three, in the roughing mill, so as to further elongate the metal and lessen its gage. The matched pair is then doubled, to form a pack of four thicknesses of metal, and again heated. The reheated pack is then again rolled on a two-high finishing mill, usually being given three passes, after which it is again doubled into a pack of eight thiclmesses. The pack of eight is then sheared on the 1927. Serial No. 200,423.

open end and reheated, after which it is given two or three passes in the finishing mill, which finishes the sheets in the pack to the specified finished length.

The above described operations which are typical of the methods in general use, are varied to suit conditions, packs of three being formed in some cases and, when making very light gages, packs of six, twelve, or more thicknesses of metal being rolled in the finishing mill.

Hot finished sheets and plates and particularly the light gages of black plates used in making tin plate, must have smoothly finished surfaces and be as nearly uniform and accurate in gage as is possible, because in many cases the use to which the tin plate may be put depends upon its surface condition and exactness to gage.

My invention provides an improved method in which accuracy of the gage of the finished sheets and plates is influenced and to a large extent controlled from the commencement of and throughout the seriesof rolling operations. By starting with a slab of calculated weight, which is afterward rolled into a thin flexible strip of relatively great length and by cutting the thin strip into sections in the novel way forming part of this invention, the production of materials of improved finish and desired accuracy of gage is made possible.

In making sheets and black plates by methods embodying my invention, the ordinary, universally used sheet bars are not used, a slab large enough to make a series of packs of sheets or black plates being employed instead of the sheet bars. As each slab forms a plurality of packs, and each pack a known number of sheets or plates, the slab necessarily will be of much greater size and weight than the usual pair of sheet bars ordinarily used in forming a pack for rolling such sheets and plates.

Referring now to the drawings forming partof this specification- Figure 1 is a perspective plan showing an ingot after being rolled to the width and thickness of the slabs into which the rolled ingot or manifold length slab is afterward sheared.

Figure 2 is a perspective plan showing diagrammatically a single slab and the number of ordinary sheet bars of which it is an equivalent in size and weight.

Figure 3 is a perspective plan showing the. long, thin, flexible strip into which the single slabs of Figure 2 are rolled in practicing my invention (the thickness of the strip relative to its width and length, as shown, being exaggerated), and also showing the way in which the long, thin strip is cut into strip sections of uniform weight in accordance with my invention. v

Figure 4 is a'perspective plan showing a pair of the strip sections into which long strips like that of Figure 3 are cut and matched preparatory to being doubled.

Figure 5 is a perspective plan showing the matched pair of strip sections of Figure 4 as doubled, to form a pack of fours, preparatory to rolling the so-formed pack to length and gage in a finishing mill.

Figure 6 is a perspective plan illustrating the pack of fours of Figure 5 after being partly rolled, preparatory to being doubled intov a pack of eights.

Figure 7 is a perspective plan showing the rolled pack of fours of Figure 6 as it is doubled to form a pack of eights preparatorv to reheating and rolling in a finishing mill, to gage and length, when rollingv packs of eights is contemplated.

Figure 8 is a perspective plan illustrating the pack of eights of Figure 7 after being rolled to elongate and reduce it in thickness and form sheets or plates of the desired gage. Figures 9A and 913, when joined on the lines IXIX, form a diagrammatic plan showing a preferred form of mill adapted for use in carrying out my improved method.

Figure 10 is a diagrammatic side elevation showing a pile of the long, thin strips, the spacing shear by which the single strips are cut from the multiple length strips, and the doubler by which matched pairs of the single strips are doubled into packs of fours.

In the accompanyingdrawings, the numera1 2 designates the heating furnace in which the slabs are heated in preparation for rolling them. These furnaces, of which three are shown, preferably will be continuous furnaces of the gravity discharge type shown, where-- in the slabs are charged into the furnace at or ne'ar one end and are dischargedat or near the opposite end, through a suitable opening at 'the end or else'in the furnace 1 bottom.

Located in line with each other and with the'slabdischargeopenings of the heating furnaces 2'is a series of stands of reducing rolls forming a continuous mill by which the short, thick slabs A of Figure2 are rolled into the long,'thin strips E of Figure 3.

The first stand of rolls 3 is a-two-high stand of horizontal edging rolls to which the individual slabs A are delivered edgewise from the furnaces 2. On the discharge side of the rolls 3 is a slab shear 4 by which double length slabs are cut into single slabs, as is necessary in some cases. (For example, when the single slabs A are so short that delivery of them from the furnaces 2 would be difficult.)

On the discharge side of the shear 4 are two-high stands of rolls 5 and 5 forming the first and second of the fiat reducing passes .in the continuous mill; On the discharge side of the rolls 5 is a universal mill consisting of a pair of vertical rolls 6* and a pair of horizontal rolls 6', the vertical rolls 6 rolling the edges of the metal delivered from the rolls 5". A single stand of vertical edging rolls may be substituted for the universal mill formed by the pairs of rolls 6 and 6 when found desirable.

As shown, a two-high stand of rolls 7 and six four-high stands 7*, 7, 7 7, 7., and 7 are located on the discharge side of the universal rolls 6*, 6 these rolls forming a series of successive fiat passes by which the metal is further elongated and reduced in gage. The top and bottom rolls of the four-high stands are backing-up rolls which enable greater reductions in thickness of the metal in the successive passes. The number of stands of rolls used to form the continuous mill, and the numberoof four-high stands shown are merely illustrative and obviously may be varied as is found necessary or desirable;

Suitable feed tables (not shown) will extend between the furnaces 2 and the edging rolls 3. Also between the rolls 3 and slab shear 4, and from the shear 4 to the rolls 5, and similar feed tables will be provided between the succeeding stands of rolls 7*, 7", 7", 7 7 7 and 7 to convey the metal from one stand to the next and away from the last,

roll stand 7 At the .end of the continuous mill are tracks 8 for the trucks or cars on-which the strips,.while still heated-from the rolling operations, as delivered from the continuous,

mill and while still heated from the rolling operation, are formed into piles, and a turntable 9 at the ends of the tracks 8, andhaving tracks 10, is employed to turn the loaded trucks at right-angles to the tracks 8 andde-.

liver them onto the tracks 11. H

An overhead traveling crane (not'shown) removes the piles of rolled strips and delivers them to the storage beds v12 at the rear of. the spacing shears 13. In front of each 7 The doubled packs K are then stored until required .for rolling into sheets or plates.

When used, the-"doubled packs are: taken tointo a-long slabof known width and thick nessfor gage. Themanifold length-slab-will then becut into single "sl'abs A -or, in some cases,- into slabs of double lengthr Each slab A" (as is shown. in Figure 2) will have a width B--substantially. tlie same as that of the sheets or plates to be rolled from the slabsl The slabs havean arbitrarily fixed thickness G and alength D, .whi'ch, after mak: ing due allowances for loss by oxidation in heating and: in rolling, as well as for the scrap or discard formed in Z'shearing the finished sheets or plates to length and width, will have the amount or weight of metal re-' quired-tdformthe predetermined number of packs of sheets,'when rolled into a'strip Stated another .way the slab length D will equal the weight per oot of eight inchsheet bars required for a. given order of sheet bar s,

multiplied by: a'factor, thisfactor. taking. into account the number 'of packs of eight' sheets each that is to be made from;the'

slab,'plus the loss of metal in theslab heating and rolling operations and in the'scrap formed in shearing oil; or cropping the ends For example, assuming that fourteen'packs of eight sheets each are to be'madeffrom'each slab A in filling an orderjand that in the continuous mill thereis a'scrap'loss of 5.625

per cent., the factor 2.9 times the sheet bar weight (in pounds per foot)" used on this order under the old method of rollingwill give the slab length, D in'inches For: the average run' of gages and pack lengths rolled, the slab lengths .will range between and 42 inches.

practice from slab to finishedsheet or plate for a given mill but'it should be understood that a factor may be readily computed for any mill where thescrap lossin. the continuous mill varies from the figure of 5.625 or where the-hot m'ill practice under. the old method of rolling has dictated a diiferent range of sheet bar foot weights for specified gages'of sheets or'plates; V a

Each lab A, after first being. heated; is

rolled, preferablyfin' a continuous mill like.

that shown in the Figure 9A- or the drawings and is thereby formed into a long thin and flexible strip E'havi nga width F which is substantially the same. as the slab width,;a

thickness G approximating '.O5 inches (18; Jgage), and a length H of from '80 to. 170 feet.

It being impracticable to heat all ofthe slabs equally or uniformly, the temperature.

at which any one slab is rolled will vary from that of others when rolling the slabs into strips of a size and weight for filling a given order. The result of such unequal rolling temperatures is that, although rolled close to the desired gage orthickness, the gage of each multiple length strip E will vary somewhat from that of others of the same lot of strips. .It is obvious that the thicker strips will be of less length than the thin ones.

Because of these practical conditions it follows and will be readily seen that if the successively rolled strips E should be cut to a constant length, some of the strip sections 1,

would be heavier than others and that this difference in the weight of the strip sections I would be reflected in the pack length of packs of the sheets or plates later rolled from different strips. This might result in such an excessive scrap lossand such variations in the gage of the sheets or plates in the successively rolled packs as to become prohibitive.

The dilficulties are readily overcome in practicing my improved method because of the novel way in which the multiple length strip E is out into be described.

In forming the strip sections I, a spacing strip sections I,-as will now shear: 13, preferably an automatic spacing shear; is employed, this shear enabling a 'multiplelength strip to be cut into a predetermined number of sections of equal length or of lengths which vary by pairs in regularly increasing or decreasing proportion.

The spacing shear 13 employed in shearing the long strips into sections is preferably of the single cut type, although shears of the type using a plurality of sets of cutting knives may be'used if desired. The long strip is run into shearing position with the front end 'of the-strip projecting beyond the shear "knives just 'sufliciently to cut ofi the scrap end. At the same time a marker or target on the shear (not shown) is set up at s v :the rear end of'the strip at the point where, The factor 2.9i'stypical ofthe rolling.

when the'strip is sheared, the rear scrap end or fishtail will be cut off. This marker or target is connected to the shear feeding mechanism in such manner that when the shear is placed in operation the strip will be fed "forward and sheared into-a predetermined have a constant or substantially constant weight or, what. is the same thing,each strip section although differing somewhat in gage -or in. length from the others, will have the right amount-of metal tomake with a second strip section a doubled pack of the required size.

The strip sections are then matched in pairs J and the pairs are then doubled by the doubler 14 to form a pack K of four thickto a degree of thinness that makes further heating desirable or necessary, as is the case when the material is to be finished in packs of eight thicknesses of metal.

When to be further rolled, the now elongated pack L of four thicknesses,'before it is reheated, is again doubled and in this Way formed into a pack of eight thicknesses of metal. After being thus doubled, the pack M is reheated and again rolled in the finishing mill until it has been elongated to the required length, which also reduces the pack M to a finished pack N of eight thicknesses of the desired gage. The rolled packs N are then sheared to dimensions and, after being sheared, are separated and finished in the usual known manner. In fact, the matching, doubling, and rolling operations after the strip sections are cut may be, and preferably are, the same as are carried out in existing methods of rolling sheets and plates from sheet bars after the sheet bars are roughed v down and first doubled.

Thevlong thinstrips E rolled from theslabs A on the continuous mill ordinarily will emerge from the last stand of rolls 7 at a temperature high enough to make it desirable to pile the strips quickly soas to minimize oxidation and to contribute the flatness .moved to the spacing shears 13 where the strips E are fed singly to one or another of the shears 13 and are cut into the'predetermined number of sections as has been described.

A plurality of the strips may be fed to the shears instead of singly, when found desirable or necessary. When the strips E are found to be sufliciently. uniform in length to permit feeding a plurality of them to the spacing shears, the shearing operating is facilitated and the necessity of matching a plurality of the cut sections I is avoided.

While it is not new to use mechanical doublers in making hot rolled sheets and tin plates whereby packs of heated sheets or plates are doubled at different stages of the rolling operations, I believe it is new to emsheared in multiple thicknesses, not requiring matching, they are passed directly to the doubling table, and in either case being doubled into packs of four, six or more thick- IIGSSGS.

The doubled packs, when made in this manner, are then placed on crates or racks in orderly piles for removal in lots of several tons at a time to the furnaces for reheating preparatory to hot rolling. The furnaces,

which preferably will be continuous furl naces, will be so arranged that the crates of doubled packs are set at the rear of the furnaces and the doubled packs are fed forward, one at a time, from the crates or piles into and through the furnaces to emerge at the opposite ends in position to be fed to the hot mills for further reduction.

The advantages of my invention, which will be apparent to those skilled in the art, result from the novel form 'of slab used in making the strip sections from which the plates are rolled and the way in which strip sections of uniform width and substantially uniform gage and weight are formed.

Whilecertain specific steps of the method in certain relation to each other have been described, it is to be understood that the invention is not limited thereto, since various modifications may be made without departing from the invention as defined in the appended claims. Slabs made in accordance with my invention may also be employed in rolling single sheets or in rolling packs of two, three, five or six thicknesses of metal.

The length of the strip sections cut from a multiple length blank may vary progres sively from one end to the other of the long thin strip to compensate for differences in gage at different points in the length of the multiple length blank, provided the predetermined number of multiples fixed upon in calculating the weight of the slab is preserved.

For example, eight pieces or strip sections maybe cut from a strip of forty feet in length, or sixteen sections from one of eighty feet, or thirty-two pieces from a strip of onehundred and sixty feet in len th. In such cases the first two sections cut rom the multiple length strip may be somewhat longer or shorter than the last two, with a graduated difference for each pair of the intermediate strip sections, this being done to take care of the differences in gage'from' end to end that may, and usually do, occur in hot rolled strips of such length. The exact amount of variation in length that is necessary will readily be determined by'gaging a long strip at different points in its length and proportioning the length of the predetermined number of cuts in pairs from shorter to longer, corresponding to the gage variation. The spacing shear will do this for a known gage variation from end to end of the strip.

I claim- 1. The method of making sheets and plates, which consists in cutting long metal slabs of known width and thickness into slabs of the length and weight necessary to make a predetermined number of acks of sheets or plates, rolling the cut 5 abs into long thin flexible strips of known width and gage, and

then cutting each rolled strip into a predetermined number of duplicate sections,matching a plurality of the strip sections and rolling the matched sections into sheets or plates of the desired length and gage and determining from the overall length of the long, flexible strip the length into which the individual sections are cut.,

2. The method of making sheets and plates, which consists in cutting long metal slabs of known width and thiclmess into slabs of the length and weight necessary to make a predetermined number of packs of sheets or plates, and rolling the cut slabs into long thin flexible strips of known width and gage and then cutting each rolled strip into a predeter-' mined number of duplicate sections, and

varying the length of the sections into which, individual strips are cut to compensate for variations in the temperature at which a series of strips are successively rolled and thereby form strip sections of accurate and uniform weight, matching a plurality of the strip sections and rolhng the matched sections into sheets or plates of the desired length and gage.

3. The method of making sheets and i plates, which consists in cutting-long metal slabs of known width and thickness into slabs of the length and weight-necessary to make a predetermined number of packs of sheets or plates, and rolling the cut slabs into long thin P flexible strips of known width-and gage, then cutting the rolled strips into a predetermined number of sections and thereby form duplicate strip sections of accurate and uniform weight, matching and doubling a plurality of 5 the strip sections and hot rolling the doubled sections into sheets or plates of the desired length and g e.

[4. The method making sheets and plates, which consists in cutting long metal slabs of known width and thickness into slabs of the length and weight necessaryoto make a pre-v determined number of packs of sheets or plates, and rolling the slabs into long thin flexible strips of known width and gage, then cutting the rolled strips into a predetermined numbervof sections and varying the length weight, matching and doubling a plurality of the strip sections and hot rolling the doubled sections into sheets or'plates of the desired length and gage.

5. The method of making sheets and plates, which consists in rolling slabs intolong thin flexible strips of known width and gage, then cutting each rolled strip into a predetermined equal number of sections and varying the length of the sections into which individual strips are cut, to-compensate for variations in the temperature at which a series of strips are successively rolled and form strip sections of accurate uniform weight matching a plurality of duplicate strip sections and rolling the matched sections into sheets or plates of the desired length and gage.

6. The method of making sheets and plates, which consists in rolling slabs of predetermined size and weight into long thin flexible strips of known width and gage, then cutting each rolled strip into a predetermined equal number of sections and varying the length of which consists in cutting long metal slabs 0 known width and thickness into slabs of the length and weight necessary to make a predetermined number of packs of sheets or plates, and rolling the slabs into long thin flexible strips of known width and gage, then cutting each rolled strip into a predetermined number of sections and thereby form strip sections of accurate, uniform weight, then matching and doubling pairs of duplicate strip sections and finally hot rolling the doubled sections to length and gage.

8. The method of making sheets and plates, which consists in cutting long metal slabs of known width and thickness into slabs of the length and weight necessary to make-a predetermined number of packs of sheets or plates, and rolling the slabs into long thin flexible strips of known Width and gage, then cutting each rolled; strip into a predetermined number of sections and varying the length of the sections into which the individual strips are cut to compensate for variations in the temperature at which a series of strips are successively rolled and thereby form strip sections of accurate and uniform weight then matching and doubling pairs of Zduplicate strip sections, and finally hot rolling the doubled sections to le rth and s ss T 9. The method of making sheets and plates,

which consistsin putting long metal-slabs of known width and thickness into slabs of the wvidth and weight necessary to make a predetermined number of 'packsiof sheets 'or plates, and rolling the slabs into long thin strips-are cut to compensate for variations.

in the temperature at which a series of strips are successively rolled -'=an-d form strip sections. of accurate, uniform weight, then matching and doubling pairs of duplicate stri sections, hot rollingihe doubled pairs,

again doubling the rolled pairs and rolling the twiceidoubled pairs to length and gage;

' 10. The' method of. making sheets and plates, which consists in cutting loiig metal slabs of known width and thicknessinto slabs of the width and weight necessary to make a predetermined number -'of packs of sheets or plates, androllingthe slabs into long thin.

flexible strips of known'width .and oifr'om series-of strips are successively rolledand form strip sections of accurate, .uniferln weight, matching a plurality"- of duplicate strip sections and hot: rolling the matched sect1ons;into sheets or plates of the desired length and gage.

11. The method plates, which consists in cutting long metal slabs oi known width and thickness into slabs of-the lengthand weight'necessary to make a predetermined number-of packs of sheets or lates,.and rolling the slabs into long thin exible strips ofknown width and of from 16 to 18fgag'e, then cutting each rolled strip into. a predetermined number of 'SGQtIOIIS Of a length dependent upon the temperature at which the slab. is rolled and thereby forming strip sections of accurate uniform= weight,'. matching duplicate strlp sections and hot rolling the matched 55; sectionsinto sheets or plates of the "desired length and gage.

'12. The method plates which .consists in cutting longmeta'l make a predetermined number 'ofpacks of sheets'or plates, androlling the slabs into sections and varying the length of the secof making sheets and of making sheets and,

tions into which individual strips'are cut, to

compensate for variations in the temperature -at'which a series of strips are successively sheets or plates, and rolling the slabs into long thin flexible strips of known width and gage, then cutting each rolled strip into a predetermined number of sections and varying'the length of thesections into which the individual strips are cut, to compensate for variations in the temperature at WlllCh a series of strips are successively rolled and form. strip sections of accurate, uniform weight, then matching anddoubling a plur-ality of duplicate strip sections and hot rolling the doubled se'ctions'to length and gage. e "14;. The method of making 'sheets and plates, which consists in; cuttinglong metal p slabs of knownwidth and thickness into slabs 16 to 18 gagefthen cutting each rolled strip. I into a predetermined number of sections and varying the length pf thesections in'towhich individual strips are cut, to compensate for variations i'n the temperature at which a number of sections and varying the length of the sections into which individual strips are cut, to-compensate for variations in the temperature at which a seriesof strips are successively rolled and form strip sections of accurate, uniform weight, then matching and doubling a plurality of duplicate strip sec- 1 tions, hot rolling the doubled strip sections, again doubling the rolled .strip sections and then rolling the twice doubled sections tolength and gage.

15. The method of making rolled sheets and'plates, which consists in rolling slabs into long, thin, flexible strips of known gage and width, stacking the stripsas rolled and while still heated from the rolling operation in piles, cooling the piles of strips, then shearing the strips into sections of accurate and uniform weight, matching and doubling a en plurality of uplicate strip sections and t heating and rolling the doubled sections to 1 length and gage.

16. The method of making sheets and plates, which consis'ts'in cutting long metal slabs of lmown width and thickness into slabs of the width and gage necessary to make a predetermined. number of acks of sheets er plates, and rolling the sla into long thin flexible strips'of'known width and gage, then ,cutting'each rolled strip into a predetermined number of sectionsrand varying the length of the sections into which individual strips I tI'B cut, to compensate for variations in the emperature at which a series of strips are :uccessively rolled and form strip sections of Lccurate, uniform weight, then matching and loubling a plurality of duplicate strip secions, hot rolling the doubled strip sections, lgain doubling the rolled strip sections and hen rolling the twice doubled sections to V ,ength and gage.

1 The method of making rolled sheets Llld plates, which consists in rolling slabs nto long, thin, flexible strips of known weight, stacking the strips as rolled and While still heated from the rolling operation .n piles, cooling the piles of strips, then :hearing each strip into sections of accurate Hid. uniform weight, and then matching and loubling a plurality of duplicate strip sec- ;ions and heating and rolling the doubled sections to length and gage.

In testimony whereof, I have hereunto signed my name.

CHARLES W. BENNETT.

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