US2030586A - Method and apparatus for rolling - Google Patents

Description

Feb; 11, 1936. I 'A,IJ. HAZLETT 2,030,586

METHOD AND APPARATUS FOR ROLLING Filed Oct. 20. 1934 2 Sheets-Sheet 1 I Feb. 11, 1936. A J. HAZLEfT 2 0 METHOD AND APPARATUS FOR ROLLING v Filed Oct. 20, 1934 2 Sheets-Sheet- 2 Patented Feb. '11, 1936 UNITED STATES I PATENT OFFICE MilIOom a corporation pany, Baltimore, Mil,

Application October 20, 1934, Serial No. 749,243

9Claims.

My invention relates to the art of rolling and. in particular, to the manufacture of so-called full finished" steel sheets in packs.

Users of full finished sheets, such as automobile body and metal furniture makers, demand a very high quality of product, particularly as to surface condition. Even the minutest indentation or imperfection in the surface of a sheet will cause it to be rejected, because such imperfections cannot be easily concealed, even though the fabricated article is to be painted or lacquered.

Full finished sheets are now usually. made by rolling breakdowns in packs. Great care istaken to prevent the sheets from adhering to each other. The preferred, loose condition of the breakdowns preserves the essential smoothness of the surface of the finished sheet but contributes to the occurrence of defects known to the trade as pinchers, "squeezers, spreaders. and "iioppers. These defects appear to result from the movement of a portion of the whole pack or of one or more breakdowns relative to the remainder of the pack. Such defects are very serious because they not only cause the rejection of the individual sheet in which they occur, but also because they are apt to cause denting or marking of the other sheets in the same pack.

The rolls of the usual two-high hand mill are" operated hot and, since they are turned in the 30 lathe while cold, they are turned concave so that when heated up to the'normal operating temperature, they will conform to true cylindrical shape as nearly as possible. As a practical mat-. ter, it is substantially impossible to maintain the shape of the rolls perfectly cylindrical for any length of time because of rolling interruptions,

a variable bearing friction factors, and different widths of product. The resulting irregularities in the roll contour aggravate the problem of pro- 40 ducing a high percentage of prime sheets because the irregularities in the roll contour resulting from the changing temperature of the rolls are the immediate cause of the defects above mentioned, viz., pinchers, squeezes-s, spreadersand The net result of the conditions outlined above is that the percentage of'prime sheets'turned out by hot pack rolling is very low, in some cases as sheets can be obtained to complete an order;

I have invented amethod and apparatus for rolling sheets in packs which eliminates the above mentioned defects and makes it possible to roll a higher percentage of prime sheets than has ever been obtained heretofore. The invention is very simple, yet highly effective, and does 5 not involve any material increase in the amount of equipment or the processing steps usually em ployed in conventional practice. In accordance with my invention, I start the leading end of a pack into the roll pass and then subject the remainder of the pack to a progressive, preliminary, rolling or flattening operation under pressures much lower than those encountered in the mill itself. This permits irregularities in the various sheets of the pack to be ironed out before the pack is gripped so tightly between the mill rolls as to make any further individual'adjustment of the sheets impossible. The apparatus which I use to carry out the method is simply a socalled billy roll" arrangement by which the portion of the pack approaching the mill pass is compressed against the surface of one of the mill rolls .to flatten the pack initially before entering the mill. When entering the pack into the mill, the hilly roll is moved out of the pass line so that it does not interfere in any way with the normal operation.

For a complete understanding of the invention, reference is made to the accompanying drawings, illustrating a present preferred embodiment of apparatus usefui'for performing the method. In the drawings:

Figure 1 is a partial end elevation of a sheet mill having the invention applied thereto;

Figure 2 is a partial side elevation of the mill; Figure3isaplanviewofthebillyrollarrangement;

Figure 4 is a side elevation thereof;

. Figure 5 is an end elevation thereof; and

Figure 6 is a partial sectional view along the 40 line VI-VI of Figure 3.

Referring now in detail to the drawings and for the present, to Figures 1 and 2, a rolling mill Ill comprises housings H having windows I! therein and rolls l3 and it having their necks l5 Journaled in bearings l6 disposed in the windows.

The construction of sheet mill shown is conventional and, therefore, need not be described fur- In order to carry out my invention, I provide trunnions ll projecting inwardly from the roll housings on the entering side of the mill. .The trunnions have a common axis parallel to the axes of the rolls and provide a pivotal mounting for a tiltlng billy roll frame having side plates I95 and a transom 20 extending transversely therebetween. 1

Apressureroli II andaguideroll 22 arejournaled on shafts-23 extending transversely of the frame In, on bearings 24. A cievis as is formed .2. 'ateachendofthetransomln. Apistonrodfl ings 2|.

reciprocating in a pneumatic cylinder 21 is connected to each clevis 25. The cylinders 21 are pivotally suspended from brackets 23 extending outwardly from the mill housings li The cylinders 21 are double acting and are controlled by a feed valve 13 through a simple system of piping indicated generally at 30. g

The side plates is are provided with lubricant tubes 3| extendingto points adjacent the bear- One side plate, specifically the one shown at the left in Figures 2 and 5, is provided with a nozzle pipe 32 having a plurality of openings therein. A steam supply pipe 33 lies in a groove formed in the inner face of the side plate, as shown in Figure 6, and, through a flexible connection, connects the nozzle pipe to a source of steam. The jets emitted by the nozzle pipe constitute an effective means for blowing scale of! the pack before it enters the mill.

Having explained the construction of the apparatus, I shall now briefly outline the operation thereof whereby the method of my invention is performed.

The tilting billy roll arrangement is normally maintained in the position shown in solid lines in Figure 1. In this position, the pressure roll II is substantially tangent to the pass line indicated at 34 and permits the introduction of a packto-themillintheusual manner. Assoon as the pack has entered the roll pass, the roller operates the valve 23 to cause the cylinders 21 to tilt the frame It to the dotted line position shown in Figure 1. The pack immediately assumes the position indicated by dotted lines in Figure l and is progressively flattened between the pressure roll 24 and the upper roll I3 of the mill It. The pressure exerted on the material by the roll II is obviously not as great as that to which-the material is subject in the mill itself. It is suflicient, however, to flatten the sheets of the pack transversely in a progressive manner before the advancing portions of the pack have been r pped between themill rolls after which further lateral adjustment of the individual is impossible. In addition to stretchin the sheets crosswise against the top roll and ironing out the irregularities in the pack before'it enters thebite of the mils, the pressure roll holds thepackflrmlyagainst the work rollsothat no miilrollsandthepackoc-- slippage between the ours. The guide roll 22 holds down the'traiiing end of the pack and prevents fluttering thereof.

I have found the hilly roll arrangement de-.

scribed herein a very eflective means of reducing the occurrence of the defects usually observed in hot rolled sheets. The pressure mil 2| appears to exert a very eifective smoothing or ironing action on the sheets while they are still fairly loose in the pack, and removes any fullness which might, inelongation, wrinkle the sheets and cause pinchers, squeezers, etc.- The invention makes possible a marked increase in the percentage of prime sheets produced on a given'mill, with a consequent reduction in the cost thereof. Imperfect sheets, of course, have rather small salvage value and must be charged against thegcost of the primes actually turned out. The invention does not disturb any of the advantages of the ordinarysystem of pack rolling butactually increases the utility thereof, The speed of operation need notbe affected by the invention and the cost of the necessary equipment is quite small.

'- ducing rolls subs and practice of the method of my invention, it will be apparent that many changes therein may be made without departing from the spirit of the invention or the scope of the appended claims.

' I claim: 4

1. In a rolling mill, spaced housings with reduclng rolls journaled therein, a frame tiltably mounted between said housings, a pressure roll journaled in said frame for cooperation with one of said mill rolls to cause material entering the mill to depart from the common tangent to the mill rolls, a nozzle tube carried by said frame,

and means including said tube for discharging fluid or'vapor jets directed on to the material.

2. In a method of rolling sheets, the steps including entering a pack of sheets between reducing rolls, substantially along the line of the common tangent thereto, deflecting successive portions of the pack away from said line, and maintaining them in contact with one of said rolls as they enter the pass between the rolls.

3. The method defined by claim 2 characterized by the additional step of progressively holding down portions of the pack rearwardiy of the portion deflected into engagement with one of said rolls.

4. In a method of making sheets, the steps including heating a pack of breakdowns, entering the leading end of the pack between reducing rolls substantially along the plane tangent .to

both rolls, and deflecting the remaining portions of the pack into agement with one of' said rolls prior to its bei engaged by both the rolls.

5. In a method making sheets, the steps including entering. pack of sheets between retially along the plane tangent to both rolls, progressively pressing the 'pack across its width between one of said rolls and another roll, and maintaining subsequent portions of the pack in contact with said one of said first mentioned rolls as it enters the pass between the rolls. 7

6. In a method of making sheets, the steps including entering a pack of sheets between reducing rolls substantially along the plane tangent thereto in common, and subjecting the portions of the packprogressively to a preliminary rolling between one of said rolls and another roll before they pass between the rolls first mentioned,

- 7; In a method of making sheets,-the steps including entering a pack between reducing rolls substantially along the plane tangent thereto in common, and progressively flattening successive portions of the pack bypassing them between one of said rolls and another roll as they appreach the flrst mentioned rolls.

8. In a method of making sheets, the steps including entering a pack between reducing rolls substantially along the plane tangent thereto in common, and subjecting the remaining portions of the pack progressively to a preliminary ironing out between one of said rolls and another roll.

. 9; In a method of making full finished sheets, the stepsinsluding forming a pack of sheets, beating them to rolling temperature, entering the leading end of the pack between reducing rolls substantially along the plane tangent to both rolls, and causing the subsequent portions of the pack to depart from said common tangent to the rolls and pass between one of said rolls and another roll before entering therebetween, under suficient presaire to prevent lateral creepinglof the pack. Y

ADAM J. H AZLEII.

Images