US1425537A - Continuous hot mill - Google Patents

Description

H. G. OBRIEN.

CONTINUOUS HOT MILL. APPLICATXQN mm SEPT. 4. 1919.

1 325,537 Patented Aug. 15, 1922 I 2 Q {3- A2511 i 2 Ew-E'a 5 k 2 5 --EEP UNITED STATES PATENT OFFICE.

HENBT G. 0mm, 0F Wm, OHIO, ASSIGNOB TO THE TBUKBUXJ: S'l'm comm, OP WARREN,- O ID, A CORPORATION 01! OHIO.

oozrrnwous 301' um.

of wider range, in the matter of thickness.

particularly, than otherwise can be got from a single mill installation, and this with v greatest economy of speed, power, and floor space.

Understanding of the invention will be aided .by reference to the accompanying sheet of drawings which shows diagrammatically and in plan a mill installation such as may embody my invention.

The mill so diagrammatically shown (a strip mill-though in this particular respect my invention is not limi ted-it might be a bar mill or a rod mill) consists of thirteen roll stands, indicated by the successive numerals 1 to 13. Of these the first seven roll stands constitute, in mill parlance, the roughing rolls or the roughing mill (using the word mill in a more particular sense than when applied to the entire assembly), and the last four constitute the finishing rolls or finishing mill. The two intermediate roll stands, 8 and 9, stand apart, as will resently appear, in respect to the mode of driving, but such segregation of these two stands is not essential to m invention in its broader aspects.

Heretofore the sucoemive rolls of continuous mills have ordinarily been driven from a common motor; in some instances the roughing rolls and the finishing rolls have been grouped. each group apart. and each driven as a group from one motor: it has even been proposed to drive each separate roll stand of a continuous mill by a motor f its own. But never heretofore. so far as I know, has it been proposed to drive a continuous mill as I drive it.and herein is the fundamental characteristic of my invention: l group the several stands of roughing rolls together and drive the group by one motor:" or perhaps. and as the drawings Specification of Letters Patent G. OBmaN,

' Patented Aug. 15, 1922..

Application fled September 4, 1919. Serial No. 321,680;

in 1 a plurality of groups and drive each group by a single motor; and then, respectr mg the stands of finishing rolls, I drive each roll stand by a separate motor.

By such an arrangement I have the economies of the group arrangement where it is altogether advantageous.at the roughing end, namely, of the mill; and I have the advantage of separate drive, where separate drive is advantageous, that is, at the finishing end of the' mill. Separate drive of the several roll stands of the finishing rolls is advantageous. in that the mill is made flexi ble in adapability to a product of varying gauge.

Referring to the drawing, a succession of roll stands 1 to 13 is shown, on the line of rolling A-B, the direction of the advance of the material under operation being indicated by the arrow 0. The grou of roll stands 1 to 7 inclusive. at the roug ing end of the mill is driven by a single motor 14; a second and intermediate group, consisting of the two horizontal roll stands 8 and 9 (which may be termed roughing rolls or intermediate rolls), may be driven by a single motor 15; while the four roll stands l013 inclusive at the finishing end of the mill are driven, each by a separate motor, 16-19 inclusive.

As indicated in the drawing, standsQ, 3, 5, and 6 of the roughing mill are stands of horizontally placed rolls, for fiat rolling, while stands 1, 4and 7 are edging passes. The rolls of these edging passes may if desired. be driven by means other than motor 14.

It should be remarked too that the motors 16-19 (and motors 14 and 15 also. if desired) are conveniently variable-speed motors.

Conliningattention next to the roll stands at the finishing end of the mill, and to their more minute construction, I find it advantageousand this feature, though not in itself alone a part of my present invention, is, when combined with the roll-driving arrangement already described, a consequent advantage- (for in such combination the flexibility of the mill, already alluded to is greatly enhaneed)-l find it advantageous to constitute the final roll stand 13, and preferabl the next to last stand 12 also a frictiou roll pass: a roll pass, that is to say, in which one of the pair of rolls and only one is positively driven. the companion roll turning by friction as work progresses becentrated within a s5 the use of which the tween the two rolls. And, further, I preferably'superadd to such friction-roll or' roll passes the invention of United States Letters Patent, N 0. 1,336,177, granted to Joseph Withers and myself, April 6th, 1920,the invention, namely, of positively driving the idle member of the roll pair, in case its rate of turning under the normal impulse by friction is arrested or falls below a certain predetermined speed.

F inall and herein lies a further consequent a vantage of my invention, I make the final roll stand, or the rolls thereof, and if preferred other stands of finishing rolls or the rolls thereof, removable and replaceable.

Heretoforesheet or strips of a certain thickness requiring certain limitation in roll dimensions, have imposed corresponding limitations on any given mill, and no mill could produce sheets or strips of thickness other than its rolls, because of their dimensions, were adapted to produce. If, for example, it be a strip one ei hthof an inch in thickness which is to be rolled, the friction roll (that is'to say, or linarily, the upper roll) of each finishin roll-pass must be a twelve-inch roll; but, if strip of liner gauge be required, twelve-inch rolls willbe inadequate to produce it. There is need for rolls of smaller diameter (ten-inch rolls, say) in pressure in the roll pass upon the metalunder operation will be consmaller area; furthermore, twelve-inch rolls are ordinarily made of such length of barrel that the fgive or springiness" will 'render the rollin o'f liner gauges uncertain and inaccurate. T ierollin of stri of. gauges finer than one eighth of an inch has heretofore required a se arate and distinct mill, for those gau es on or, as-has been more common! t e case, the liner gauges have been pro need by subsequent cold-rolling of the previously rolled 'rality of finishing-roll stands,

my hand.

one'eighth material-and has been accomplished at creased cost.

Now, by

that, of course, appreciably inproviding separate motors for the several passes of finishing rolls, and particularly by providing variable speed motors for driving the rolls of the several passes, new possibilities open; I can then make my several roll passes removable and replaceable, and, ado ting alternate roll passes of rolls of difiiirent sizes (of such dill'erent sizes, for example, as above su gested) I can render my improved nil flexible as no other mill known to me is flexible, and can in one and the same mill, with the adaptations described. roll material of wider range in dimension than has hitherto been achieved.

Thus in selecting and combini these several features of mill construction attain not merely the several benefits known to be attributable to them, but. more than that I attain a mill of economies and capacities never before attained, within my knowledge.

It will be understood that my invention to details of number and arrangement, but is broadly attained in the arrangement herein claimed.

I claim as my invention:

A hot mill for rolling metal including a plurality of roughing-roll stands and a plua common motor driving the rolls of the several roughing-roll'stands, a plurality of-motors corresponding in number with the finishingroll stands and connected 0 rativel ly, one to each of said Finishing-r01 stands. 1.

In testimony whereof I have hereunto set HENRY G. (JBRIEN Witnesses:

I)AUL N. (lin'roHLow,

FRANCIS J. TOMASSON.

Images