US1813129A - Rolling mill - Google Patents

Description

3- WHITE nonum um.

Filed Feb. 25, 1928 2 Sheets-She 1 l w I INVENTOR eg -12. ATTORNEY July 7, 1931. q wH|TE 1,813,129

ROLLING HILL lllll n INVENTOR Ola/ 1d Whit i I ATTORNEY -orsheetsofmetalandthelike.

Patented July 7, 1931 PATENT OFFICE.

cnanx wnrrn, or ASHLAND, xmrrucxr ROLLING MILL Application filed February 25, 1928. Serial No. 257,081.

This invention relates to improvements in rolling mills and it consists of the constructions, combinations and arrangements heroin described and claimed.

5 The object of the invention is toprovide a cluster-type, floating bottom'roll mill for the urpose of rolling either hot or cold strips or s eets, special provision being made for shifting the bottom working roll in a number 10 of wa s in respect to the top workin roll so that t e strip or sheet thickness can lated to a nicety.

Another object of the invention is to provide a mill having facilities for regulating the roll alinementas well as the sheet thicknesls adjustment during the operation of the mi 1.

A further object of the invention is to pro vide a drivin apparatus-by which the working rolls can be driven in such a manner that reguthe workin roll surfaces will pass over the sheet equall y regardless of any diameter differences of the working rolls.

A still further object of the invention is to provide a mill in which the character of the working roll adjustments is such as to particularly adapt the mill to the rolling of wide thin sheets or strips. I

Other objects and advantages appear in the following specification, reference being made to the accompanying drawings, in

Figure 1 is a cross section of a rolling mill illustrating the improved arrangement,

Fi ure 2 is a detail cross section taken on the l1ne 2-2 of Figure 1, the opposite and corresponding end of the mill being omitted.

Figure 3 is a longitudinal section illustrating the roll drivingapparatus, portions being shown in elevation, I

Figure 4 is an elevation of vone endof the mill, particularly illudzrating the driving motors of the supporting rolls, 7

Figure 5 is adiagram illustratingthe electric wiring of the rive motors of the working rolls.

As has tion is concerned withlthe rolhn of strips 7 There has been considerable activity among. persons been indicated already, the invenconcerned with the use of rolling mills with the end in view of roducing a mechanism that will suit a speci c'purpose, that is to say, a mechanism that will do a particular kind of work in the most eificient manner.

It is needless to introduce a discussion of the causes of production of scrap, other than to briefl deal with the subject by saying that a proli 0 cause is the misalinement of the working rolls. It is evident that misalinement of the working rolls will produce inac-. curate sheet thickness. Many instances of a defective product would be remedied by placing a properly adjusted mill at the disposal of the mill 0 erator.

The mill erein disclosed is principally concerned with the establishment of a flexible mode of adjustment of the bottom working roll. As willpresently appear, this roll can be adjusted up and down as well as obliquely in respect to the top working roll and horizontally in respect to the roll housing. With this range of adjustments any deleterious condition may be anticipated.

One of the fundamental purposes of the mill is to enable the rolling of thin and wide sheets or strips. The former are usually approximately eight feet long while the' latter may run into hundreds and even thousands of feet in length. It is of paramount importance. to keep either the sheet or strip goin straight.- This purpose is directly achleve by'being able to keep the working rolls in vertical almement.

. If, in the operation of the mill, one of the working rolls were to shift out of alinement tion, for example, in relationship thereto, the sheet or strip would be caused to go ofi' to one side or the other and being rolled to an-unequal thickness on one side or the other. By providing an adjustment such as herein disclosed, any such tendency of the mill can be instantly corrected so as to keep the sheet or strip on the proper forward course and avoid the necessity of shutting down the mill as is now the prevailing custom.

Much also depends upon ing the various rolls. Relatively large motors are employed for the working rolls bewith the other so as to mume an oblique posithe mode of drivi cause the major amount of power consumed in properly driving the working rolls has heretobefore arisen from the preceding circumstances.

g It is apparent that any such defect developing in a working roll will increase as the operation progresses. Any deleterious eflect o a roll defect upon the sheet will become magnified as the procem continues. On a.

long sheet any such defect will have what may be called a wind-up efl'ect on the stresses of a mill, and willcontinue on a long sheet, or in strip rolling, until such time as some adjustment between the circumferences of the working rolls becomes imperative to relieve the built up stresses in the mill.

The foregoin wind-up effect is the cause of chattering, buckling, marking of sheets, etc. It seems obvious that any mal-operation of the mill'must cause very high power losses. A Higher stresses are placed on the mill, drive rolling of a sheet. The following des'crip gears, etc., than ever required in the actual tion presents one mode of giving-the mill the necessar flexibility to permit the working roll sur aces (circumferences) to pass over the sheet equally regardless of diameter differenoes.

It'may be stated that the particular mode disclosed is subject to variation in practice. The various working and supporting rolls are shown driven independently. The mo tors of-the driving rolls, for example, are

balanced as to the electric loaddepending upon the tightening effect of the work passing through the" mill'to hold the circumferonce speed of the rolls the same.

This balancing of the electricload of the driving motors of the working rolls has an advantage over any known similar mode of driving the workln rolls. It is a common. experience in t e'operation of a mill that one of the rolls will expand more than the other so as to present a circumference larger than the complimentary roll. By balanclng the electric load of the driving motors the motor of the larger roll will exerclse what might be termed a yielding function. There will-be the delivery of the same amount of power to both rolls, but the motor of the larger roll will give way sufiiciently to compensate for the enlargement about the condition of a,uniform circumferential speed of both rolls.

This is of utmost importance in rolling the wide thin sheets or strips previously mentioned. If the larger roll were permitted to exercisethe natural function which would result from the increased diameter, namely the increase of circumferential speed,there would be a slippage of the larger roll in respect to the sheet, thus placing an'abnormal and unusual stress upon the mill. This is a defect of all driving rolls which are either geared together or driven by independenanon-electrically balanced motors. 0

Another outstanding advantage of electrically balancing the driving motors of the working rolls is that the necessity for accurately matching the working rolls is obviated. One may actually be larger than the other, yet a uniform circumferential speed of each roll will be maintained by virtue of coupling the driving motors as stated. The non-uniformity of the working rolls'may, in practice, occur in this way :It sometimes happens that one of the rolls will become.

chipped. It is then required to grind the roll down until the chipped place disappears. This makes one roll smaller than the other,

but the two rolls can be used as companions by virtue of'the fact that it is possible to maintain a uniform circumferential speed by virtue of the coupled motors.

In mills having rolls driven otherwise, the same circumstance would require dressing both rolls down to a uniform size, obviously incurring great expense both as regards the mechanical operation itself and the requisite shutting down of the mill.

It might be found that a betterresult may be gotten by making one of the driving mo--' tors larger than the other, rather than both of the same size, so that the larger motor would control the speed of the working rolls. It is also conceivable that one motor may be made to drive both working rolls. A differential'gear would be required to insure the delivery .of the same amount of power to each working roll. Such diflerential gear should be provided with a slip clutch between the driven units in order to insure the turn ing of both rolls when the mill was not loaded.

The clutch in the latter position would only a be required to transmit the ainountof power that should go to each roll to insure that both rolls turn when the mill is not loaded. The

roll housing includes a base 1.-which has uprights -2 provided with s'upportsfor. the

various bearing blocks concerned. The drawings show only one of the uprights, but it is i2: Reference is made to thedrawings. The

.porting rolls.

ing parallel, although the bottom Working roll is capable of such ad'ustment that the axis thereof assumes an oblique position in reference tofthe top working roll. The work 5 passes between the .rolls in order that the desired operation may be performed thereon.

Pairs of rolls 6 and 7 support the bottom and top working rolls 3 and 4 respectively, that is to say, the supporting rolls carry much of the thrust imposed upon the working rolls engendered by the passage of the work between the latter. The airs of rolls named are herein respectively nownas the bottom and top supporting rolls. The bottom and top working rolls are located in what may be termed-the troughs of the pairs of supblocks 8 of the upper sup- The bearin are fixed upon the upright porting rolls of the bottom supportin rolls 6 are movable upon the base 1, 'belng guided by the tongue and groove 10, 11, shown ,in Figure 2, or their equivalent. These bearing blocks are free to move toward or away from each other or they may be moved bodily in either direction across the base. It is also possible i to move the set of bearin blocks 9 atone end of the rolls independent other end.

Mill screws 12 and 13 back the bearing blocks 9 and eithercause or permit the foregoing adjustments at one end ofthe sup.- port. Similar screws at the other end of the rolls perform a similar function. The screws are mounted upon the upright 2 of the mill frame. They are operated by appropriate means such as the worm drives 14 and 15. The bottom and top supporting rolls are driven in any known manner, the directions of turning being indicated by the arrows in Figure 1. a

For driving the various rolls, the following mechanism is provided. One end of the bottom working roll 3 is appropriately formed at 16 to receive one'element 17 of.

an electric motor 22. The motor is appropriately mounted, for example, upon-a bracket 23 on one side of the gear train housing.

The motor 22 is solel confined to the driving of the bottom r01 3. I w I A similar motor 24 serves to drive the top working roll 4. A gear train comprising a pinion 25 on the motor shaft 26, and a large supporting rolls.

The bearing blocks 9' y of the set at the gear 27 in connection with the spindle drive 28, properly reduces the driving speed. The spindle drive is connected with one end of the working roll 4 by a couplin 29 and an appropriate formation 30 on t e working roll, as in the instance first described.

Each supporting roll of the two pairs 6 and 7 has an independent driving motor.

mode chosen for illustration herein comprises the use of brackets 36 which, in the instance of the motors 31 and 32, are attached to the movable bearing blocks 9 of the lower In the instance of the u per supportingrolls, brackets 37 support t e motors 33 and 34 from the frame of the mill. The reason for the specific arrangement is that the lower supporting rolls 6 are adjustable, and should carry the driving motors therewith, while the upper supportingrolls 7 are relatively stationary and the driving motors thereof therefore may be stationarily mounted.

Brief consideration may be given to the character of the various driving motors. All of the motors are preferably of the direct current type. The various sets must be balanced as to the electric load. The mode of balancing the motors 22 and 24 of the drivin rolls is representative of all. The wiring 0 these motors is' diagrammatically illustrated in Figure 5, but inasmuch as the wiring shown is employed by electrical engineers for the purpose it is deemed unnecessary to either discuss the theory or describe the details to any extent. I

The operation is readily understood. Considerit necessary to decrease the thickness of the work 5. This is accomplished by moving v the bottom working roll 3 closer to the top working roll 4. Both mill screws 12 and 13 blocks 9 closely together and elevate the bottom working roll.

Should it be desired to increase the thickne ss v of the work,a contrary operation is followed. The mill screws 13 are turned reversely, permitting the'bearing blocks 9 to separate and the bottom working roll 3 to lower accordingly. The technique of operating the rolling mill. sometimes requires the working roll .to be offset. The offsetting of the working roll 3 in respect to the top working roll 4 is accomplished by turning one of the mill screws outwardly and the other in wardly'in respect to the frame. a

The result of the latter operation will be to shift the bottom working roll to one side or the other of the top working roll. igure 1 illustrates the bottom working roll 3 as beinglocated at one side of the vertical center through the top working roll 4. Ad ustments of the roll 3 in a direction radially of "the roll 4 are now made by turning the screw 12 in the outward directlon. The mode by which such adjustments are accomplished can readily be perceived from the drawings.

Should it ever become necessary to move theroll 3 so that the axis thereof departs from the presupposed original parallelism with-the axis of the roll 4 it is only necessary toadjust the bearing blocks 9 at one end of the bottom supporting rolls 6 more than at the other end. The range'and varieties of adjustments are particularly unlimited. Any desired relative location of the bottom roll 3 can be acquired. With the latter advantage it becomes obvious. that any desired roll condition-can either be created or rectified. 4 i

By virtue'of making it possible to adjust the various rolls independently and collectively, as well as applying the driving power so that the roll surfaces will pass over the sheets equally, it is considered that amill .of great flexibility has been originated. Any

development of diameter differences of the working rolls can be instantly compensated for by making the proper adjustment of the bottom supporting rolls 6. A development of diameter differences will become apparent from the nature or behavior of the product.

- The reatest power is applied to the working rol s 3 and 4. The supporting rolls 6 and 7 must follow the working rolls, and inastard the various mode of speeds so that all of.

the rolls would turn at exactly the proper speed. The extreme flexibility of the adj u stment of the bottom working roll 3 aifords the big advantage. The arrangement is particularly advantageous in rolling the thin 'de sheets that are now being rolled in the tra e. I

While the construction and arran ement of the improved rolling mill is that o agenerally preferred form, obviously modifications and changes may be made without departing from the-spirit of the invention or the scope of the claims.

I claim: 1 l. A rolling mill comprising a pair of working rolls in substantially .perpendiculiar alinement, sets of supporting rolls with y small motors. The

blocks closer and thereby elevate or lower the respective working roll in respect to the complementary working roll along the line of said substantial perpendicularity.

2. A rolling mill comprising-a pair of working rolls, sets of supporting rolls for each working roll, sets ofbearings blocks for each end of each set of supporting rolls, and meansfor independently adjusting each set of bearing blocks of one set of supporting rolls either in relative diverse directions or simultaneously in one direction.

'3. A rolling mill com risinga base and uprights, a pair of wor in supporting rolls for the wor ing rolls, bearing blocks mounted upon the base, means associated with the base and the adjacent set of bearing blocks permitting movement of the latter, and mill screws mounted upon the uprights opposing said last bearing blocks rolls, sets of for either moving or permitting movement I of said blocks in the purpose described; ,7 v

4,- .A rolling mill comprising working rolls, and means so driving the working rolls as to compensate for'variations in the diametricalsizes of the rolls and maintains uni- ,-form"circumferential speeds ,during the pass ing of the material therebetween.

plane of the base for the .5. A rolling mill comprising working rolls, associated supporting rolls, and means .so driving the various rolls as to compensate for variations in the diametrical sizes of the various-rolls and to maintain uniform circumferential speeds during the passing of the material between the working rolls.

6. A rolling mill comprising working rolls,

means for driving the working rolls, a plurality of supporting rolls for each working roll, driving means to independently drive each supporting roll, and means coupling the driving means to produce. uniform circumferential speeds both when the rolls arethe same in diameter and when the diameters vary to prevent slipping of the circumferi ential surfaces in respect to the work during the passing of the material between the latter.

7. A rolling mill comprising working rolls, an electric driving motor for each roll, said motors being balanced as to the electric load to prevent relative slipping of circumferential surfaces during the passing of the material between the working rolls.

8. -A rolling mill comprising a frame, a pair of working rolls, a set of supporting rolls for one of the supporting rolls, bearing blocks for the working rolls being movably mounted uponthe frame, separate driving means for each supporting roll, and means separately supporting the respective driving means upon certain bearing blocks.

9. A rolling mill comprising a frame, a pair of working rolls, a set of supporting rolls for one of the working rolls, bearing blocks for the supporting rolls being mov ably mounted upon the frame, a motor for each supporting roll, driving means interposed between each motor and the respective supporting rolls, and brackets by which the motors are supported upon adjacent bearing blocks.

10. A rolling mill comprising a frame, a pair of workingrolls, one set of supporting rolls for each working roll, bearing blocks for each set of supporting rolls being mounted upon the frame, means for adjusting the bearing blocks of one set of supporting rolls, an independent drive for each supporting roll, and means for mounting thedrives of one set of supporting rolls upon the frame, and means for mounting the drives of the other set of supporting rolls upon certain blocks thereof of the adjustable bearing.

11. A rolling mill comprising a working roll, a pair of supporting rolls in the trough of which the working roll is situated, and adjusting means operative upon the supporting rolls from remote sides for simultaneously urging the supporting rolls together horizontally and thus raise the working roll in its relative position.

12. A rolling mill comprising a working roll, a pair of supporting rolls in the trough of which the working roll is situated, a base over which the supporting rolls are shiftable and adjusting means supported upon the base and applied to the remote sides of the supporting rolls being simultaneously adjustable in opposite horizontal directions causing the working roll to separate the supporting rolls and impart the thrust both in the direction of the base and oppositely against said adjusting means.

13. A rolling mill comprising a working roll," a pair of supporting rolls in the trough of which the working roll is situated, and adjusting means applied to the remote sides of the supporting rolls being simultaneously operable in similar horizontal directions as regards a lateral shifting of both support--.;, ing rolls in one or the other direction thus yarying the location of the working roll.

14. A rolling mill comprising a pair of working rolls, a pair of supporting rolls the troughs of which the respective working rolls are situated to receive the thrust, and means by which the pair of supporting rolls of one of the working rolls'is either pushed together or spread apart horizontally to increase or diminish the. pressure upon the work.

. 15. A rolling millcompris'ing a frame, a pair of working rolls, a pair of supporting rolls for one of the working rolls revolubly mounted upon the frame but fixed in relative position, and a pair of supporting rolls for the other working roll revolubly mounted in respect to the frame but singly or collectively shiftable in horizontal directions in position relative to the frame thus to variously locate the second working roll in respect to the first.

16. A rolling mill comprising a frame, a working roll, a pair of supporting rolls, bearing blocks for the ends of the supporting rolls riding horizontally upon the frame, and screws mounted on the frame in horizontal alinement bearing upon the remote sides of'the bearing blocks to act as abutments for the spreading thrusts imposed uplon the supporting rolls by the working r0 1.

17. A rolling mill comprising a frame, a working roll, a pair of supporting rolls, bearing blocks for the ends of the supporting rolls riding horizontally upon the frame, screws mounted on the frame in horizontal alinement bearing upon the remote sides of the bearing blocks to act as abutments for the spreading thrusts imposed upon the supporting rolls by the working roll, andmeans for mechanically turning the screws.

18. A rolling mill comprising working rolls, supporting rolls associated with each working roll, and an electric driving motor for each of the working and supporting rolls, said motors being balanced as to the electric load.

CLARK WHITE.

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