US1683001A - Metal rolling - Google Patents

Description

J. B. TYTUS METAL ROLLING Sept. 4, 1928.

Filed April 9, 1925 Patented Sept. yAll, 192.8.

UNITEDy STATES PATENT OFFICE.

.TOEN n. fryfrus, or MInDLETowN, oHIo, AssIGNon To THE AMERICAN ROLLING MILL com-PANY, or MInnLEToWN, oHIo, A CORPORATION or oIIIo.

METAL ROLLING.

Application mea April 9, 1925. serial No. 21,814.

My invention relates to processes for rolling hot metal and particularly to continuous processes, wherein the metal piece is moved from one stand of rolls to another 'without being given m'ore than one pass in each stand.l

It is the object of my invention to provide a rolling mill which will produce bye single reductions of afmetal 'piece in successive stands of rolls,wa .product which has` not hitherto been practical to 'produce in this manner. The product which I produce is a thin, flat piece of metal, such as iron and steel.

In the steel industry the terminology for the product of rolling mills is usually traceable to the kind of process by which the product h as been formed. Thus the product of a plate mill is called plate, and of a jobbing mill and sheet mill are called sheets and of astrip mill, the product is called a anything like as fine a gauge as the sheet mill,

and the strip mill cannot produce a material which is anywhere nearas wide as either a plate mill or a sheet mill.

The product which I produce by my mill and process is that which lies between the zone of possible production o n the plate mill of today. and the usual production on the f sheet mill.

produce is made' `on'the iobbing mill, which is hand fed with heated bars, which are iirst rolled single and then in pairs, the entire operation being hand controlled, usually on two stands of rolls, not tandem, one forl roughing andone for finishing.

It is my object to make such material at,

a high rate of speed with minimum of labor, by a continuous process. v j

It is my object to provide an arrangement of furnace,'shearsl and mill stands, together with feed-.tables 'intermediate' the several At the present time the product whichr Iy machine elements, which will result in sufliclent supply of hot pieces of manageable llength 'to the rolls, lfor successive or continent.

I accomplish my object by that certain construction and arrangement; of parts and that certain processing of the metal which will be hereinafter more speciiically pointed out and claimed.

' In the drawing:

Figure 1 is a plan view partially in diagram of my de vlce. l

Fi re 2 is a sideielevation thereof.

In t e drawings I have `shown a furnace 1, in which are live rollers 2, that feed a metal piece which is long,"wide and thick through the'furnace. The furnace is operated so as to conserve the heat of the piece during shearing, and the shears -3 are lo` cated at the exit end 'of the furnace, so thatl -Y each piece as itis sheared off from the long piece will have a substantially equal temperature to begin with.l

From the practical p. ointof view it is' found highly desirable y me to employ in the rolling process of my new mill a single piece which is fairly long in the direction of' its pathv through the rolls. The usual sheet bar, for example, is only around eight inches in length, as used, being cut from a narrow thick bar and ,then turned Aat right angles and fed through the obbing or sheetmill.

. Accordingly invmyprocess I use a wide -thick plate or-it might be termed a slab, and

cross cut the slab by shears to givepieces fwhich have substantial dimension lengthwise, and Ycrosswise have the dimension which yit is desired to have. in the nal product.

1th my newmill the'pieces are reduced singly and without reheating, which is an economy 1n time and expense, but demands high speed operation, and accurate fit of the piece, as soon as it gets its preliminary, reduction, to the remaining rolls of the successive stands.

I find it to be impractical to use sheet bars turned crosswise in my process, and can conceive of no practical way/in which a properly heated, uniform temperature, and'uniform cross section piece can be provided for a high speed reduction mill of my new type, exceptby some such mode I have f described, namely, to provide a succession of A between the main rolls 8, 9 and 10a.

'ing a single side' 'guide bar 13 for the piece,

` I show feed tables 11 between the several stands of rolls, 4and prefer to make these tables oflskewed driven rollers 12, and havwhich directs it toward the middle of each stand of rolls. ,I

Ishow the lfirst three stands of rolls arranged in tandem, and the last two stands, equally spaced Jfrom the stands preceding them, which will result in their operating as continuous mill' stands, if the piece is long enough.

' If the operation were slow, at least while l the piece is'thiclnthere mightbe a chance Yfor obtaining enough reduction if the mills were like the plate mill stands of the presentv day, but economy of operation makes'as one of my chief objectives Aa very 'high speed operation with minimum labor.

If the operation were slow, and the capacity of the mill kept low, it might'be possible to control the shape of the rolls ofthe several stands, and permit them torun hot I and attain a greater reduction per pass.

However, the high capacity operation, re- Asul'ting in a rapid heating of the rolls byl the' great volume of pieces passing between them, requires a cooled vroll mill operation, and accordingly I provide for an ample iow of water over the rolls as by means of spray pi es 14.

ith plenty of Water on thez rolls' I- am able to arrive at a desired. controlled vtemperature thereof, which gives me oneyfactor which is' controllable in providing for proper bite of the rolls on the piece. By delivering the pieces to .the mill at a uniform temperature and uniformcro section, for any given run, and passing themthrou h at high Speed without reheating, I'can re y upon definite cross sectional and temperature characteristics ofthe vpieces in each stand..V

I have discovered asthe principle gov- Verning Afitofa piece to' a 'roll' stand in hot.

rolling practice, that the iece will enter the L- ystand and pass through ll smoothly, `if'the active 'pass Kbetweenthe rolls ofthe stand, as they engage over 1thepiecc is such as to be a little less convex, than the shape of the piece, furnished to the stand, said convexity running'lengthwise f the Pass, and Cro/Sgr, wise of the piece. The best practice is to reduce the vcontour (cross sectional periphery) of the piece so as to retain the same or slightly decrease the ,proportionate thickness of its middle as to its edg'es, which as can be observedrequires more reduction of the thicker than the thinner parts of a piece in each pass. The mere control of the screw is not enough to insure proper pass since for required reductions of a piece there are I qu1te definitel limitations .in screw adjustment, and the piece must have a required length when finished.

In control `of pass in successive stands of rolls operating on a piece, there are a number of factors of importance, i. e.,'the

original composition, shape, temperature ofthe rolls, the nature, and temperature of the piece, and the pressure on the rolls in the form of screw In building my` mill I provide for the extreme of rigidity form the rolls of large diameter in`proportion to length, also giving rigidity. By roviding an extremely rigid mill I am ena led to 'control the screw on the rolls lin the sev-4 eral stands, to give desired reductionof pieces passed through singly, and to bring j single pieces down tol comparatively ine gauge. `YVhengthe housings are springy, the

`natural elasticity of partsrequlres of the screw that it take up all of lthis lelasticity before a reduction can be made on a thin piece, then the strain on the bearings of the rolls would be almost as4 eat whenthere was no piece in them asvif the piece were there, which makes excessive wear. In a springy, stand of rolls it is ve l accuracy t take up enough o the spring by turning down the screw, to obtainydeslred reductions." y

The use" of three high stands of rolls, witha small diameter middlel roll, gives more rapid reduction to the piece without sacrifice of the necessary rigidlty. `The middle roll can be drawn out leaving the. mill two hig Also the piece is met byI one positively driven roll, i..e., one of the main rolls Iinstead ofpassing between two idler rolls;

diicult w ith v in the housings, and

as in afour hi h roll stand, with the two' ijniddle vrolls o small diameter. Furthermore, thekmultiplication of factors in controlling roll shape when engaging the piece, by use of four rolls, will give greater diilicultythan where but three are used.

By description in the foregoing of Aspecial expedients, as being of primary nnportance, I do not wish to be taken' as meaning that equivalent expedients could not be adopted. It is my purpose in theclaim that follows to state'the invention inherent in my application from its different aspects, and in the specifications have given a description of a way of accomplishin without'intentmf limiting the scope of my claim; R f

the entire objective,

isc

Having thus described my invention, what successive stands of rolls, without reheating,

ciaimas new and desire to secure by Letmaintaining said rolls cold, and providing ters Patent, is in each stand for enforcing a, transverse 10 That process of reducing thick Wide metal convexity on the piece with each stand en- 5 to thin plates Which consists in furnishing forcing a, less conveXity than the preceding :L series of heated pieces to thick metal, pass: stand.

ing said metal in single thickness through JOHN B. TYTUS

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