US664128A - Method of manufacturing black plates or other sheets. - Google Patents

Description

` Patented Dec.' I8, |900. W. C. CRONEMEYER. METHOD 0F MANUFACTURING BLACK PLATES 0R OTHER SHEETS'.

(Application led Jan. 17, 1900.)

(No Model.)

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WILLIAM C. ORONEMEYER, OF ALLEGHENY COUNTY, PENNSYLVANIA, AS- SIGNOR OF ONE-HALF TO SAMUEL DIESCHER, OF PITTSBURG, PENNSYL- VANIA.

METHOD 0F MANUFACTURTNG BLACK PLATES 0R OTHER SHEETS.

SPECIFICATION forming part of Letters Patent N o. 664,128, dated December 18, 1900.

Application led January 17, 1900. Serial No. 1,731. (No specimens.)

To LZZ whom it may concern:

Be it known that I, WILLIAM C. CRoNn- MEYER, a citizen of the United States of America, and a resident of Allegheny county, State of Pennsylvania, have invented certain new and useful Improvements in Methods of Manufacturing Black Plates. or other Sheets, of which the following is a specification.

In the accompanying drawing,which makes part of this specification, the ligure shows in plan a virtually diagrammatic View of a sheetmill with the shears and furnaces by which my method can be practiced.

One purpose of my invention, generally stated, is to devise a method by which black plates and other sheets may be produced in a rolling process from a slab or bar of such a size and so manipulated that doubling or folding is avoided in the process.

Further purposes of my invention are to reduce the number of heatin gs and shearings to which the metal is subject during the process, to diminish scrap and loss by oxidation, to greatly reduce the manual labor required, and produce a longer sheet than is now possible, all as more specifically hereinafter described.

The hot-rolling process as it is now ordinarily carried on and has been for many years in sheet-mills is thus' practiced: Two slabs or bars after being suitably heated are passed consecutively through a two-high mill, one being passed back over the top of the upper roll by the catcher as the other is introduced into the bite of the rolls. After these pieces have had several passes each they are put into the heating-furnace and reheated. When the partly-formed sheets are again taken from the furnace, they are too thin to be satisfactorily rolled singly, so they are placed together and rolled through as a pair, one on top of the other. When the combined sheets by elongation become again too thin to be profitably rolled, the two sheets are together folded through the middle transversely, so as to become twice as thick and half as long. After folding the double sheet is sheared at the open end, because it is impossible to make the ends perfectly matched when folded, thus requiring the ends to be squared. After folding this double sheet is reheated and then rolled again until it is so thin that further rolling will not be economical, when it is doubled or folded another time, sheared again V at the open ends, and reheated, rbc., until the whole pack, which frequently is ultimately sixteen sheets thick, has been brought to the desired gage. It is also necessary at frequent intervals to open up the sheetsthat is, tear them apart or separate them with the tongsso that they may not become cemented together as one sheet.

The doubling of the sheets is accomplished by bending the sheet with tongs, the workmen treading upon the fold, thus making a rough bend approximately as accurately as possible, and then taking the roughly-bent sheet and putting the bend under a power-actuated arm or squeezer, which completes the crease. Although the workmen become very skilful, it is obvious that bending the sheet While hot by merely tramping upon the same does not secure a perfect matching or alinement of the two ends of the sheet. Again, as the ends of the sheet do not roll to a straight edge, but are either convex or concave, no alinement can be obtained. Therefore this matching must be accomplished by shearing the ends, which results in scrap and waste. Furthermore, the doubling and shearing in- Volve a great deal of manual labor, so that the piece is greatly increased in cost as well as chilled by the length of time it is out of the rolls and being handled by the men. As a necessary consequence the piece has to be heated three or four times before itis finished, each heating involving Waste, added loss of time, expense of fuel, and the Workmen are idle. The doublers also are skilled Workmen receiving correspondingly high wages. The number of manipulations to be performed under the old practice requires at least ve operatives at each stand of rolls. Another necessary labor which has to be performed each time a fresh pass is given to a piece is screwing down the roll to make the pass the required size for the reduction. This results from theefact that the piece is roughed down and finished by a series of passes on one and the same set of rolls. Loss by oxidation in passing a single or double sheet of a large superficialarea through the rolls is not inconsiderable, especially in the finishing part of the process. My present invention either greatly minimizes or abolishes these disadvantages which have inhered in the art for many years.

I will first explain the apparatus by which my process can be practiced and afterward explain the steps of the method itself.

In the drawing, A is a heating-furnace for the billets or slabs.

B B are a series of rolls, preferably arranged tandem and preferably two high, having suitable conveying devices C U between them. Preferably these rolls are arranged with the stands so far apart that the piece is out of the bite of one pair before it is in the bite of the succeeding pair; but it may be possible to adjust the differential speed of the rolls so exactly that the mill shall be aI strictly continuous mill.

D D are su-itable shears for shearing the plates after they have gone through the series of rolls B B, which virtually constitute a ronghing series.

E E are reheating-furnaces for the plates.

F F F/ F/ constitute two preferably parallel and preferably tandem series of finishingrolls having suitable conveyers G G G Gr.

H H are the shears for trimming both edges of the piece after it has been brought to the desired gage.

My method of using this apparatus is as follows: The slabs or bars are heated to a proper working heat in the furnace A, which may be of any suitable type, preferably a continuous furnace which has openings or doors at both ends and through which furnace the bars or slabs are passed and in which they are brought to the required working heat and from which they are discharged to the rolls. As heretofore stated, I have arranged the mills with a roughing series of rolls B B, through which the bar passes by the aid, preferably, of mechanical conveyers. When it has passed these rolls, it reaches the shears D D in the form of a plate, skelp, or sheet and is now of such a degree of thinness and length that it would not be profitable to roll it farther as a single piece. It is accordingly cut up by the shears D D' into shorter sheets and made into a suitable pile either by manual or mechanical piling, which will be suited for reheating in the furnaces E E and rerolling in the iinshing-rolls F F F F'. The pieces arethen sheared at H H. As already stated in the plan as laid out on the drawing to which this description refers, I have arranged the mills in three groups or series, in each of which the rolls are arranged in tandem fashion. However, these three groups or series perform only two kinds of work. The first one, consisting of six stands of rolls, (though not limited to this number,) does what is in practice termed roughing work. The other two series are to do the finishing work-that is, to gradually reduce the sheets to the desired thinness. Both of the latter series of mills perform the same work-that is, they finish the product from the roughing-mills. rlhe object of a double set of finishingmills is to expedite the work, as one set of finishing-mills could not well keep pace with the capacity of the roughing-mill, although one finishing set may pos sibly be used.

The number of stands of rolls in the finishing-mills may be more or less than shown on my drawing. The required number-of stands of rolls for either kind of work depends chiefiy on the thickness of the slab, bar or bars, and the thickness or gage of the finished sheets. In other words, the greater the difference in thickness between the slab or bar and the finished sheets the more redlicing work is to be done by the rolls and the more stands of rolls will be required. Accordingly in determining lthis question in any practical case in view the designer of 'the plant must determine the number of stands with reference to the total reduction desired from slab to finished plates or sheets.

The slab vor bar furnace and the series of roughing-rolls are relatively so located that the delivery of the hot bars from this furnace to the roughing-mills is done in the most economical and expeditious manner practicable.

The roughing-rolls are preferably located in tandem line, so that when the slab has passed the first stand of rolls it automatically enters the second stand and in similar manner the third, fourth, &c., to the end of the series. I do not, however, limit myself to the tandem arrangement of the roughing or the finishing rolls,as any arrangement of rolls whereby a sequence of reduction is obtainable commercially will answer. Each of these stands of rolls accomplishes a certain reduction in the thickness of the slab and a corresponding elongation of saine in the direction of motion. Thus, for illustration, if the total reduction effected by the series of roughing-rolls is such that the thickness of the piece after the last pass is only one-sixteenth of the original thickness then the length of the piece thus rolled will be sixteen times the original length. Accordingly in the case mentioned a slab of eight inches in width in the direction of motion would grow to eight times sixteen-that is, one hundred and twenty-eight inches, or ten feet and eight inches.

rlhe sheets enter the reheating-furnaces in packs and are maintained in this condition undisturbed while passing through these furnaces for the purpose of being reheated for further reduction in the finishing-mills.

From the foregoing description it will be apparent that some of the advantages that I obtain are these: Instead of being reheated the slab passes from its first original heating through the whole series of roughing-rolls. There is only one reheating necessarynamely, at the furnaces E E-although my invention is not inevitably limited to roughing down at a single heat. Again, the con- IOO IIO

IIS

process.

stant readjustment of the rolls for each succeeding pass is avoided. The rolls are once set for a given gage and remain so set until the mill is put upon a different order. The doubling is entirely eliminated and the shearing greatly diminished.

In my process I reduce the number of men required to roll With the present method from about iifty to seventy-five per cent, I also turn out iive to ten per cent. more sheets from a 'ton of material than the old method by converting the greater part of the Waste in doubling and shearing and also in squaring or trimming into sheets.

In the processes as practiced at present there is considerable Waste by oxidation. This is reduced materially by my packing the eight sheets, or Whatever number may be rolled in a iinished pack, on top of each other immediately after leaving the roughing-mill and shears and sending this pack through the furnace, and thereby reheating but once instead of heating and then reheating each tim e the sheets are doubled, as in the old This means that the sheets in my process are exposed less to the air while hot and that therefore there is less oxidation. I also by means of finishing my sheets more rapidly by passing them through a series of rolls and doing the packing in one operation instead of a number of doublings, as in the old process, and omitting the passing of the sheets back over the top rolls, as in the old process, expose the heated metal less to the air, and therefore have less oxidation than in the old method.

In the old method the length of sheets is limited by the trouble it takes to pass them back over the mills on account of their Weight. In my method the sheets can be rolled in greater lengths. My sheets may be left full length when coming from the iinishing-mill, so as to be adapted for use for continuous roofing.

By the Word continuous as used in the claim I do not wish to be undersood that the finishing necessarily is to be done in what are known in rolling-mill practice as continuous rolls, but that the finishing rolling operation is to be continuous in the sense that it shall not be ,interrupted by othel` steps, such as shearing, doubling, reheating, &c.

Having described my invention, I claim- The process of manufacturing black plates or sheets, which consists in subjecting a slab of metal to a continuous roughing operation; subdividing the product of said roughing operationinto sections; piling said sectionsinto a pack; reheating the pack; and subjecting said reheated pack to a continuous finishing rolling operation.

Signed by me at Cleveland, Ohio, this 16th day of January, A. D. 1900.

WILLIAM C. CRONEMEYER.

Witnesses:

' PAUL A. ZIZELMAN,

J. P. REIFF.

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