US1847713A - Rolling mill - Google Patents

Description

March 1, 1932. c, G|BBON$ 1,847,713

ROLLING MILL Fileq May 17, 1928 3 Sheets-Sheet l Maych 1, 1932. c. .1 GIBBONS ROLLING MILL s Sheets-Sheet 2 Filed May 17, 1928 March 1, 1932. C. J. GIBBONS ROLLING MILL Filed May 1'7. 1928 3 Shests-Sheet 5 n, o m

l st-Tented Mar. 1, 1932 UNITED STATES CHARLES J. GIBBONS, OF BRIDGEPORT, CONNECTIGU '1 ROLLING MILL Application filed May 17,

This invention relates to rolling mills particularly mills for rolling sheets or flat strips of metal, and has for an object to provide a rolling mill in which large reductions may be secured if desired or in which an improved finish may be given.

It is also an object of the invention to provide a rolling mill in which stocks of strips or sheets may be rolled without their welding or 1 sticking together.

It is another object of the invention to provide a rolling mill in which the rolls may be driven positively and in which a thin strip of metal may be drawn through the roll by means independently of the roll drive.

lVith the foregoing and other objects in view the invention consists in certain novel features of construction, combinations and arrangements of parts as will be more fully described in connection with the accompanying drawings. In these drawings,

Fig. l is an end elevation of a rolling mill and associated elements embodying my invention.

Fig. 2 is a diagrammatical front elevation of a rolling mill embod ing my invention, certain parts being bro en away to more .clearly show the construction and also showing a different arrangement of drive than that shown in Fig. 1.

Fig. 3 is a detail section substantially on line 3--3 of Fig. 2.

Fig. 4 is a partial plan view and a partial section showing somewhat diagrammatically a device for drawing the metal through the rolls.

Fig. 5 is a. diagrammatic endelevation of a four-high mill involving my invention, and

Fig. 6 is a similar View of a three-high mill embodying my invention.

Referring to Fig. 1, the rolls are mounted in a pair of suitable housings 10 and the mill. shown is afour-high mill similar to the arrangement of rolls shown in Fig. It in volves upper and lower work rolls 11 and 12 respectively each of which has a backing roll 13 of considerably larger diameter to back up and support the work roll. As shown the work rolls are of comparatively small diam eter, and therefore, do not have the requisite 1928. Serial No. 278,385.

strength and stiffness to withstand the heavy pressures required for the rolling operation and to give the large reduction desired and also to insure uniform gauge for the rolled strip. The large backing rolls 13 give this required strength and stiffness, the rolls 11 and 12 running on the surfaces of these backing rolls as indicated, which thus in effect provide roller bearings for the work rolls. The necks 14 of the backing rolls 13 are mounted in suitable hearings in the housings, and in order to reduce the resistance in turn oi these rolls these necks are mounted in roller bearings 15 so that there is no slippage between the work rolls and the backing rolls. It is preferred to make the work rolls 11 and 12 of diflterent diameters, and it is also preferred that the smallerroll be the upper roll for greater convenience in rolling, although the same effect as far as preventing sticking of the sheets of the stack is secured'if the smaller roll is the lower roll.

In rolling hot sheets in stacks, that is piled one above the other, if the work rolls are the same size considerable trouble is experienced by the sheets in the stack, indicated at 16, Fig. 5, sticking or welding together during the rolling operation so that it is difficult to separate them and it may be impossible to do this without spoiling the sheets. I have found that by making the two work rolls of diflerent diameters that this sticking or welding elfect is obviated even though the two rolls are driven at the same surface speed. This appears to be efi'ected by the fact. that diiferent diameters of working rolls have a slightly different effect or give different movements to the metal in their adjacent strips caused by the differences of the curvature of contact or the angle of contact'of the two rolls with the metal so that there is a slight slippage between the adjacent surfaces of the strips which prevents their welding or sticking, and this is true even if there are more than two sheets rolled at a time. There is also 21 tendency of the different sheets adjacent the rolls following around the rolls as they issue from between them which still further assists in. preventing their sticking. Either the work rolls or the backing rolls may be driven, 10o

. backing roll for it especially if it is used for relatively narrow strips as the roll may have sufiicient stren th. I have shown this arrangement in I ig. 6 in which there is no backing roll for the lower work roll 12 of larger diameter, but there is a backing roll 13 for the smaller roll 11. Boiler bearings 17 may also be provided or the work rolls if desired.

These rolls may also be used as a drawing mill, that is, a strip of metal may be drawn between the work rolls by a separate mechanism. This drawing device is shown in Figs.

1 and 4. It comprises a blocker having a rotary drum or block 18 driven by any suitable means, such as a friction clutch 19 associated with a gear 20 driven through a pinion 21. from a motor 22, and this block is so geared that it will draw the metal through the rolls at a greater speed than would the metal move under the action of the rolls when driven from their usual drive. In order to permit the rolls, therefore, to speed up a one-way drive is provided for the work rolls, that is, there is a ositive drive of these rolls in one direction, at this drive will ermit the rolls to rotate faster under the action of the strip. It is preferred also that the block 18 be an automatic block to automatically grip the strip of metal 23 as soon as the end thereof reaches the block. In the arrangement shown in Fig. 1 there is a gear drive for each of the work rolls 11 and 12, the drive for the roll 11 being shown as gear 24 and for the roll 12 as gear 25 on opposite sides of the housings and connected to opposite ends of the rolls, and both driven from a power shaft 26 by suitable gearing. Of course, this gear ing will be proportioned to drive the two rolls at substantially the same surface speed. The one-way drive from each gear 24 or 25 to its work roll comprises a pawl and ratchet drive, or other suitable types of one-way drives may be employed if desired. In the drive shown a ratchet 27 is connected by suitable coupling to the roll while pivoted pawls 28 carried by the gear wheel cooperate with this ratchet to form a positive drive for the respective work rolls, but will permit the rolls to rotate faster than this drive under the action of the strip of metal as it is drawn through by the blocker. This mill may, therefore, be used as a regular rolling mill with a positive drive for the work rolls or it may be used as a drawing mill where the metal is drawn through by a separate device. The pa'wls 28 are held in engagement with the ratchet by suitable springs 29.

In case the mill is used as a drawing mill the positive drive for the rolls will roll the forward end of the strip until it reaches the blocker and is gripped thereby and then the blocker will draw this strip through the rolls. Therefore, the entire length of the strip will be rolled to the proper gauge and it is not necessary to shift the rolls and set them for each individual strip. In old types of drawing mills it was necessary to separate the rolls in order to feed the strip to the blocker, then the rolls had to be reset to the proper gauge. This required considerable time and also was siderable length at its forward end which was not rolled to the same gauge as the rest of the strip,.and therefore, there was a length of several feet which had to be placed in the scrlap. These objections are obviated by my mi 1.

In Fig. 2, I have shown a slightly difierent arrangement of drive. In this arrangement both the work rolls are driven from the same end or side of the housing and they are given suitable relative speeds by the intermeshing gears 30 and 31 of any suitable type, such as the usual herringbone gear, connected with the respective rolls by the couplings 32, 33 and connecting bar 34. One of these couplings is a one-way drive the same as used in the arrangement of Fig. 1 and it may be a pawl and ratchet drive the same as in the first form. The ratchet 37 is connected to one of the elements while the pawls 35 are connected to the other element and are held in engagement with the ratchet by the springs 36. This gives the same one-way drive as used in the first form and will slip to allow the work rolls 11 and 12 to run faster than they would under the action of a positive drive the same as they would in the first form. It will be understood the gears 30 and 31 are proportioned to give substantially the same surface speed to the two work rolls. Here as in the other form, we can drive either of the work rolls or the backing rolls in the start of the rolling operation. Then after a suitable length has been rolled the block pulls the metal through. This operation can be secured with a fourhigh mill, a three-high mill, or a two-high mill. In case the backing roll or rolls is or are driven the one-way or ratchet drive is in the drive for the backing roll. When the block begins to pull on the strip then the one-way drive slips.

It will be obvious from the foregoing description that with a comparatively simple construction I have produced a rolling mill which may be used either as an ordinary rolling mill with a positive drive or it may be used as a drawing mill. Also with the use of relatively small work rolls I can secure large reductions with a single pass, and by using work rolls of ditferentdiameters I obviate the sticking or welding of the hot plates together when the mill is used for rolling hot sheets in stacks.

Having thus set forth the nature of my invention, what I claim is:

1. In a rolling mill for flat sheetmetal, a pair of cylindrical work rolls of diiierent diameters. a one-way positive drivefor one of said rolls, and means for drawing a tint strip between the rolls at a greater speed than is given the roll by said drive so that the strip is drawn between the rolls solely by the pull of the drawing means.

2. In a rolling mill for tint sheet metal, a air of cylindrical work rolls of diiterent iameters, a one-way positive drive for each of said rolls, and means for drawing a fiat strip between the rolls at a greater speed than is given by said drive so that the metal isdrawn through the rolls independently of the drive for the rolls.

3. In a rolling mill for flat sheet metal, a pair of work rolls of different diameters, a one-way ratchet drive for one of the work rolls to positively drive said roll in one direction only, a blocker adapted to grip a flat strip and 'draw it between the work rolls, and means for driving the blocker at a greater surface speed than the work rolls so that the metal is pulled through the rolls by the blockerindependently of the drive for the rolls;

4. In a rolling mill for flat sheet metal, a pair of work rolls of ditlerent diameters, an undriven backing roll for the smaller work roll, roller bearings for the necks of the backing roll so that it is free to run at the same surface speed as the work roll, a oneway ratchet drive for one of the working rolls to positively drive said roll in one direction only, a rotary blocker adapted to grip a fiat strip and draw it between the work rolls, and means for drivin the blocker at surface speed greater than t mt of the work rolls so that the metal is drawn between the rolls h the block independently of the. drive for t 1e roll.

5. In a rolling mill,'a pair of work rolls of relatively small diameter, an undriven hacking roll for each work roll of relatively large diameter, roller bearings for the bacle in rolls so that the backing rolls form roller bearings for the work rolls, a one-wa posi tive drive for each work roll, a rotary locker adapted to grip a strip of metal and draw it between the work rolls, and means for driving the blocker to draw oil? the metal at a, greater speed than the driven speed of the work rolls so that the metal is drawn through the rolls independently of the drive for the rolls.

6. In a rolling mill for flat sheet metal, a pair of cooperating cylindrical work rolls of different diameters on opposite sides of the work and capable of rolling a plurality of superimposed flat strips, means for driving the rolls to roll the be inning end ortion of the strip to gauge, an means for t Ien drawing the superimposed strips between the rolls independently of other driving means for the rolls.

7. The method of rolling a plurality of flat metal strips in supcrim iosed relation which comprises nissing the e innin end portion between tll\'(ll cylindrical ro is of different diameters and then pulling the re maindor of the strips through the rolls independently of other driving means for the rolls.

8. In a rolling mill for flat steel metal, a pair of eylindrirul work rolls, a drive for one of the rolls so as to roll to gauge the beginning end portion of a flat strip, a roller for coilin the strip after itlenves the rolls, and means for driving the coilnr at a greater surface speed than said drive gives the roll so that the remainder of the strip is drawn between the rolls by said ooiler independently of the drive for the roll.

9. In a rolling mill for flat sheet metal, a pair of relutivel y small eylindrioul work rolls, u drive for one of said rolls so as to roll to gauge the beginning end portion of a flat el rip. undriven untifrietion backing rolls for the work rolls, and means for drawing the remainder of strip between the rolls at a greater speed than is given by said'iirive and indepomloutly of said drive.

it). -In 11 rolling mill, a pair of cylindrical work rolls of dill'orent diameters capable of rolling u plurality of superimposed strips, a driving menus for one of the rolls cupab e of passing the metal between the rolls, an un driven anti-friction hacking roll of relatively large diameter for the smaller work roll, und menus for drawing the su wrimposed strips between the work rolls at a greater surface speed than said drive.

11. In a rolling mill for flat. sheet. metal, a pair of cylindrical work rolls, a one-way rutzeln-t drive for one of the rolls so that the roll may be positively driven in one direction only, an anti-friction bucking roll for each work roll, u blocker urrungod to grip a flat strip and pull it between the rolls, and means for driving the blocker at a greater surface speed than the rolls.

12. A method of rolling a flat metul strip which comprises rolling a short length of the end portion of the strip between power driven cylindrical rolls and then winding the strip on a block and drivingtho block at a greater surface speml than the power driven speed of the rolls so that the pull of the block is the driving: means for the rolls for rolling the renuiinder of the strip.

13. In a rolling mill for flat sheet metal, a pair of cylindrical. work rolls of relatively small diameter, a power drive for one of said rolls to roll the end portion of a strip, a ooilor III for coiling the flatstrip after it leaves the rollm and means for driving the eoiler at a greater surface speed than the power drive gives the roll so that the remainder of the strip is (1m \vn between the rolls by said coiier independently of the rell drive.

In testimony whereof I afiix 111v signature.

CHARLES. J. GEBBONS.

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