US1821751A - Method of rolling sheet metal - Google Patents

Description

Sept. 1, 1931. J. M. FELTON ET AL 1,821,751

METHOD 0]? ROLLING SHEET METAL Filed July 12, 1928 WITNESS Patented Sept. 1, 1931 UNITED STATES PATENT OFFICE JOHN M. FELTON OF WHEELING, WEST VIRGINIA; AND CLARENCE H. VERWOHLT, OF

ST. CLAIRSVILLE, OHIO,

ASSIGNORS TO WHEELING STEEL CORPORATION, OF

WHEELING, WEST VIRGINIA, A CORPORATION OF DELAWARE METHOD OF ROLLING SHEET METAL Application filed July 12;

The invention relates to the hot rolling of sheet metal, particularly steel, to the llght gages which for decades have been rolled principally by the WVelsh process.

According to that process, sheet bars which vary in size depending upon the ultimate gages and sizes of the sheet metal desired to be produced, are first broken down by rolling them singly until reduced to thicknesses determined largely by practical working conditions. Several sheets are then matched in packs, reheated and rolled, and, for producing thinner gages, the rolled matched packs are doubled, again reheated and rolled, the doubling and reheating being repeated as many times as necessary to produce the desired thinness or lightness of gage.

One of the controlling factors of this sheet rolling process is the number of sheets which may be satisfactorily rolled in what is known as a single-iron pack, by which is meant a matched but undoubled pack. In the first pass, or first two passes, of a single-iron pack, the several sheets must be given a proper set, that is to say, they must be caused to adhere to each other, but in such a way as to prevent the pack from becoming a sticker, by which is meant a pack the sheets of which so firmly adhere to each other in spots or throughout that they may be separated only with difficulty, and in some cases scrapped.

To give all the sheets a proper set and thereby avoid sticking, it has been found impossible under practical working conditions to roll single-iron packs made up of more than five sheets. In fact, due to the difliculty of obtaining a proper set, it is seldom that single iron packs made up of more than four sheets are rolled. Also, under practical working conditions, it has been found impossible to roll singlesiron packs to sheets lighter than twenty-five gage. 'lherefore, to produce lighter than twenty-five gage sheet metal, it has been necessary to double and reheat the packs at least once, and frequently oftener,

1928. Serial No. 292,057.

both of which operations add materially to the cost of manufacture.

The object of this invention is to provide a practical method of rolling thin gage sheet metal, by which is meant throughout the specification and claims sheet metal lighter than twenty-four gage, without intermediate heating such as is required when packs are doubled, and with the economies of manufacture attending the elimination of doubling and reheating.

In the practice of our invention, sheets which have been rolled singly to such thickness as may be produced commercially in this way are arranged in single-iron matched packs and heated to substantially uniform temperatures. A plurality of the heated single-iron packs are then rolled singly and in rapid succession to give each a proper set, and two or more of the thus rolled packs are then matched into single-iron multiple packs and rolled to the desired thin ga e sheet metal, the entire-procedure being witliout any intermediate heating.

While the singly rolled sheets used in mak ing up theoriginal single-iron packs may be of various sizes and variously produced, it

is preferred to use suitable lengths of stripsheet which is now economically produced by modern continuous strip sheet mills. Such sheets may be from about fourteen to eighteen gage, although in its broader aspects the invention is unlimited to particular gages of the singly rolled sheets. The number of singly rolled sheets matched in single-iron pac ts'may vary from twoto five, depending largely upon the desired gage of finished sheet metal. The temperature to which the single-iron packs are heated depends in part on the gage of the singly rolled sheets. and in part upon the steel. For example, packs of sixteen gage sheets of regular open hearth steel may be heated to from 1350 to 1450 F;, while like gage sheets of 1800 F. However,'regardless of the tentperature to which packs are heated, all of those which later enter into a multiple sin gle-iron pack should be heated to substan tially uniform temperatures. The rolling of the single-iron packs may be done by passing two or three of them in alternation and successively through a single stand of rolls such as used in the Welsh process, but is prefcrably done in a continuous mill, by which is meant aplurality of stands of rolls arranged in tandem'regardless of whether or not any portion of a pack may be simultane ously engaged by more than one pair of rolls. It is only necessary to continue the rolling of the single-iron packs sufiiciently to give them a proper set, and this may be cf t'eetively done in two passes, although one or more than two passes may be used.

In assembling multiple single-iron packs for subsequent rolling, the first of a series of them is suitably held until theremainder of the series are rolled and matched With the first, two, three, or even more, single-iron packs of from two to five sheets each being assembledto form a multiple single-iron pack. l/Vhen assembled, the multiple singleiron pack is rolled to the desired gage, preferably' in a'series of two or more continuously arranged roll stands, although the multiple single iron packs may, if desired, be rolled by passing them several times through a single stand of rolls as previously explained.

An important feature of our invention is predicated upon our discovery that in the rolling of thingage sheet metal in the manner described, multiple single iron packs of many more than five sheets become properly set so that they may be rolled without producing more stickers than are customarily produced Fender good working conditions by the Welsh; process, by which, as has been stated, it is impossible under practical working conditions to roll single-iron piacks made up of more than five sheets. We have also discovered that in the practice of our invention the sheet metal so retains its tempera- .ture that it may be effectively rolled to very light tin mill gages Without any intermediate heating, and that the temperature of the metal maintains the rolls at proper working temperatures.

As a specific example of our invention, we have rolled multiple single-iron packs of eight sheets each to thirty-four gage sheets without intermediate heating and without producing stickers. To roll sheet metal to this gage by the Welsh process would require two-doublings and two reheatings of single-iron packs each made up of two sheets. The invention may be further explained by reference to the accompanying drawing which is a vdiagrammatic plan view of a continuous mill and associated apparatus on which the invention may be practiced, al-

though it will be understood that other apparatus, and other arrangements of it, may be used.

In the drawing, there is shown a series of four stands of rolls, 1, 2, 3 and 4, having roller tables 5, 6 and 7 arranged between them, and a roller table 8 at the discharge side of rolls 4. The several stands of rolls may be driven independently, or by a single drive, as desired, and may be of any desired type with or with out roller-bearing backing rolls. Adjacent to the series of roll stands there is a continuous heating furnace 10 having a charging opening 11 through which single iron packs are placed in the furnace, and a discharge open ing 12 from which the packs are successively removed to a table 13' for transferring them to the first stand of rolls. In the apparatus here illustrated, the single iron packs are given a proper set by passing them through two stands of rolls 1 and 2, and are collected on a suitable matching table 15 at the end of roller table 6 adjacent to roll stand 3. When the de-' sired number of single-iron packs are assembled and matched upon table 15, the multiple single-iron pack is then passed through rolls 3 and 4, or as many additional stands thereof as may be necessary or desirable, to reduce the sheets to the required gage. When so reduced, the sides of the pack may be sheared by side shear 16 arranged at the end of roller table 8, and their ends may be sheared by an end shear 17 positioned beyond the side shear.

The advantages of this invention, and the economies incident to it, will be manifest to those skilled in the art. Not only is there eliminated the expense of the skilled hand labor required in the rolling of sheet metal according to the Welsh process, but there is also eliminated the expense involved in doubling and reheating of single-iron packs which characterizes the Welsh process, and which also characterizes such processes as have heretofore been proposed or used for the continuous rolling of light gage sheet metal. Furthermore, in the practice of the invention, large tonnages of light gage sheet metal may be rapidly produced by the use of relatively inexpensive apparatus.

We claim as our invention:

1. The method of rolling sheet metal to light gages, comprising heating to substantially uniform temperatures single-iron packs of matched singly-rolled sheets, rolling in the same roll passes a plurality of said heated packs singly and in rapid succession, matching the heated and singly-rolled packs into multiple single-iron packs, and rolling said matched packs to thin gage sheet metal, said two rollings ofthe metal being effected without heating it subsequent to said firstmentioned heating.

2. The method of rolling sheet metal to light gages, comprising heating to substantially uniform temperatures single-iron packs of matched single-rolled sheets, rolling in a single series of continuous rollpasses a plurality of said heated packs singly and in rapid succession, matching the heated and 5 singly-rolled packs into multiple single-iron packs, and rolling said matched packs in continuous r011 passes to thin gage sheet metal, said two rollings of the metal being efiected Without heating it subsequent to said first- 10 mentioned heating.

In testimony whereof we hereunto sign our names.

JOHN M. FELTON. CLARENCE H. VERWOHLT.

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