US1601551A - Cross rolling - Google Patents

Description

Patented Sept. 28, 1926.

UNITED STATES PATENT OFFICE.

PETTER IB. ABRAMSEN, OF DOB/MONT, PENNSYLVANIA.

CROSS ROLLING.

Continuation of application Serial No. 569,780, filed June 21, 1922. This application filed June 9, 1924. Serial No. 718,759.

The present invention relates to cross rolling and is particularly applicable to the rolling of rounds to reduce their diameter.

This application is a continuation of my application Serial No. 569,780, filed June 21, 1922.

The term rounds as employed in the iron and steel industry is used to designate rods, bars or other solid shapes having a circular cross section. In the usual method of manufacture, the rounds are made by first reducing the bloom or billet in diamond roughing passes to the form of a round cornered square. This billet is then passed through alternate oval shaped and diamond shaped roll passes until it is reduced to the required diameter. After each pass the piece is edged or turned 90 before going into the next pass. The round is finally passed a number of times through a round forming pass in the rolls of the finishing stand in an effort to get a truly circular cross section. The accuracy in the finished rounds is dependent upon the skill of the roller and the condition of the rolls, and therefore bars which are not truly circular are very frequently produced, not only because of the tendency to form fins on the edge of the round but also because any Wear in the finishing pass results in inaccuracies. These conditions, which are apparently unavoidable with the present method of rolling rounds, make it necessary where considerable accuracy is required to lathe turn, cold draw or cold roll the round.

I provide for reducing the round by passing it between rolls which impress circumferential furrows therein and thereby elongate it and reduce its average diameter.

The circumferentially furrowed round is then passed through a set of smoothing rolls which press down the ridges between the furrows, still further elongating the round and restoring a substantially smooth surface. These operations are repeated until the desired reduction is obtained. The rolls employed are preferably cross rolls between the faces of which the round rotates while traveling. A strictly circular cross section is thereby given to the round even though the rolls have become worn, and the rolls act on the metal uniformly along all diameters of its cross section, thus producing a rod or bar of more homogeneously worked metal than in the usual practice, in which the reducing rolls serve to alternately compress and elongate the fibres along diameters at 90 to each other. This repeated furrowing and pressing to which the metal is subjected greatly increases the mechanical strength of the rolled articles and insures uniformity therein.

In cross rolling as heretofore employed, considerable difficulty has been experienced in entering the bar in the rolls. This is due to the fact that the bar has been introduced by moving it along the path which it follows during the rolling operation proper and when the leading end of the bar comes in contact with the cross rolls these rolls exert a backward force which greatly hinders the entering of the bar. Once entered, the backward force is balanced by a corresponding forward thrust, but the entering itself has heretofore been attained with considerable difliculty. I provide for bringing the bar or other article to be rolled into proximity with the rolls and causing relative lat eral movement between the rolls and the bar to engage the bar in the rolls. This is preferably accomplished by moving the bar substantially longitudinally adjacent the rolls and then moving it laterally substantially in a plane parallel to the axes of the roll until engagement is accomplished. The bar is sufiiciently advanced longitudinally for the rolls to engage the side portions of the bar and the backward thrust is thereby balanced and entering readily accomplished.

This feature of my invention, while it is of general application, is particularly useful in connection with the previously described feature thereof, since the several reducing steps are preferably accomplished on the round by entering the bar in the mill or mills employed, first with one end leading and then with the other end leading. This makes it absolutely certain that the entire bar will be reduced even though the forward movement of the bar prior to its engagement with the cross rolls is a little greater than desired. here such a condition arises, as might be the case in a busy manufacturing plant, the leading end of the bar might not be reduced in conformity with the remainder thereof, but since the direction of movement of the bar is reversed in the next pass, this difficulty is overcome and the slightly Sept. 28 1926.

P. B. ABRAMSEN CROSS ROLLING Original Filed June 21, 1922 4 Sheets-Sheet 2 I VE TOR 4 Sheets-Sheet 5 1V I\..H 1 0 invzmoa Sept. 28 1926.

P. B. ABRA'MSEN CROSS ROLLING NEMAQ 4 Sheets-Sheet 4 GROSS ROLLING P. B. ABRAMSEN Original Filed June 21 1922.

C 11 Z?a$32623%???22 Sept. 28 1926.

Patented Sept. 28, 1926.

UNITED STATES PATENT OFFICE.

PE'ITER B. ABRAMSEN, OF DORIVIONT, PENNSYLVANIA.

CROSS ROLLING.

Continuation of application Serial No. 569,780, filed June 21, 1922. This application filed. June 9, 1924. Serial No. 718,759.

The present invention relates to cross rolling and is particularly applicable to the rolling of rounds to reduce their diameter.

This application is a continuation of my application Serial No. 569,780, filed June 21, 1922.

The term rounds as employed in the iron and steel industry is used to designate rods, bars or other solid shapes having a circular cross section. In the usual method of manufacture, the rounds are made by first reducing the bloom or billet in diamond roughing passes to the form of a round cornered square. This billet is then passed through alternate oval shaped and diamond shaped roll passes until it is reduced to the required diameter. After each pass the piece is edged or turned 90 before going into the next pass. The round is finally passed a number of times through a roundforming pass in the rolls of the finishing stand in an efiort to get a truly circular cross section. The accuracy in the finished rounds is dependent upon the skill of the roller and the condition of the rolls, and therefore bars which are not truly circular are very frequently produced, not only because of the tendency to form fins on the edge of the round but also because any Wear in the finishing pass results in inaccuracies. These conditions, which are apparently unavoidable with the present method of rolling rounds, make it necessary where considerable accuracy is required to lathe turn, cold draw or cold roll the round.

I provide for reducing the round by passing it between rolls which impress circumferential furrows therein and thereby elongate it and reduce its average diameter.

The circumferentially furrowed round is then passed through a set of smoothing rolls which press down the ridges between the furrows, still further elongating the round and restoring a substantially smooth surface. These operations are repeated until the desired reduction is obtained. The rolls employed are preferably cross rolls be tween the faces of which the round rotates while traveling. A strictly circular cross section is thereby given to the round even though the rolls have become worn, and the rolls act on the metal uniformly along all diameters of its cross section, thus producing a rod or bar of more homogeneously worked metal than in the usual practice, in which the reducing rolls serve to alternately compress and elongate the fibres along diameters at 90 to each other. This repeated furrowing and pressing to which the metal is subjected greatly increases the mechanical strength of the rolled articles and insures uniformity therein.

In cross rolling as heretofore employed, considerable difliculty has been experienced in entering the bar in the rolls. This is due to the fact that the bar has been introduced by moving it along the path which it follows during the rolling operation proper and when the leading end of the bar comes in contact with the cross rolls these rolls exert a backward force which greatly hinders the entering of the bar. Once entered, the backward force is balanced by a corresponding forward thrust, but the entering itself has heretofore been attained with consider able difficulty. I provide for bringing the bar or other article to be rolled into proximity with the rolls and causing relative lateral movement between the rolls and the bar to engage the bar in the rolls. This is preferably accomplished by moving the bar substantially longitudinally adjacent the rolls and then moving it laterally substantially in a plane parallel to the axes of the roll until engagement is accomplished. The bar is sufliciently advanced longitudinally for the rolls to engage the side portions of the bar and the backward thrust is thereby balanced and entering readily accomplished.

This feature of my invention, while it is of general application, is particularly useful in connection with the previously described feature thereof, since the several reducing steps are preferably accomplished on the round by entering the bar in the mill or mills employed, first with one end leading and then with the other end leading. This makes it absolutely certain that the entire bar will be reduced even though the forward movement of the bar prior to its engagement with the cross rolls is a little greater than desired. lVhere such a condition arises, as might be the case in a busy manufacturing plant, the leading end of the bar might not be reduced in conformity with the remainder thereof, but since the direction of movement of the bar is reversed in the next pass, this difiiculty is overcome and the slightly enlarged portion will be reduced when the now trailing end of the bar passes through the mill.

In the accompanying drawings, which illustrate more or less diagrammatically one embodiment of my invention,

Figure 1 is a side elevation of a cross rolling mill embodying my invention, showing in dotted lines a bar about to be entered therein;

Figure 2 is a section on the line IIH of Figure 1, but showing in cross section the bar in rolling position;

Figures 3 and 4 are a side elevation and a top plan, respectively, of a set of cross rolls for impressing the furrows in the rounds;

Figures 5 and 6 are a side elevation and a top plan, respectively, of a set of rolls for pressing down the ridges between the furrows; and

Figure 7 is a diagrammatic view of a mill layout comprising two sets of fur-rowing rolls, two sets of smoothing rolls and a set of finishing rolls, illustrating the stages in which the round is reduced.

In the illustrated embodiment of the invention, there is shown a pair of furrowing rolls 2 and 3 for impressing by rolling a series of furrows in a round. The metal is, of course, hot during the reducing operation. For the sake of simplicity in illustration, the driving mechanism, etc., is not illustrated, as such mechanism will be readily understood by anyone skilled in the iron and steel industry, the cross rolls being mounted and driven the same as in usual practice. Figures 1 and 2 show more or less diagrammatically one form of mill which may be employed wherein the roll 2 is driven from a shaft 4 and the roll 3 is an idler roll carried by hearing blocks 5 mounted in a frame 6 and laterally adjustable with respect to the roll 2 by screw-downs 7. A leader A is supplied to the mill from a roll table or other convenient source and is carried on pivotally mounted guides 8, of which there may be any desired number. These guides are connected by links 9 and when in the position shown in Figure 1 support the bar with the leading end adjacent the rolls 2 and 3 but out of contact therewith. A stop 10 is provided for limiting the forward movement of the leader until the rolling operation commences. lVith the leaders in the position shown in Figure 1 the guides 8 are rotated clockwise, at which time camlike portions 11 are effective for moving the leader laterally and into engagement with the cross rolls 2 and 3. It will be noted that by this movement the leader is introduced with its forward end well up into the rolls, so that the effect of the backward thrust, which is ordinarily very dimcult to overcbme when it is attempted to enter a bar in the usual way, is entirely eliminated.

The leader passes through the cross rolls and during the rolling operation is held in position by the guides 8 and by a top guide 12 which serve to guide the bar in its proper path during the rolling operation.

lVhile the above described apparatus for entering is highly desirable and readily applicable to commercial rolling, it will be understood that the entering of the bar may be carried out by otherwise causing relative lateral movement between the rolls and the bar. For example, this may be done by operating the screw-downs 7 to separate the rolls 2 and 3, placing the bar between them and then moving the roll 3 toward the roll 2 to engage the leader A.

The cross rolls 2 and 3 are provided with single endless ribs 13 which are effective for rolling a series of circumferential furrows 1% in the bar or leader A. The furrows are preferably somewhat wider than they are deep in order to prevent laps. The rolls are preferably placed at the proper angle to give a perfect thread since this insures that all the metal will be subjected to mechanical work and further prevent laps. This angle is, of course, the helix angle of the thread, and I have found that very good results are secured by making the angle of the rolls substantially the angle whose tangent is 1/31416. As shown in the drawings, this angle gives two complete threads on a length of bar substantially equal to the diameter thereof. lVith the rolls so disposed all the metal is subjected to mechanical work and a clean furrow without laps is pro-- duced, as best shown in Figure 4.

As will be readily apparent to anyone experienced with cross rolls, the rolls both rotate in the same direction as indicated by the arrows, thereby causing a rotation of the rounds between them in the opposite direction as indicated by the arrow applied to the round. The ribs 13 bite into the round at opposite points thereon and when the bar is once engaged, exert a forward and backward thrust which is effective for elongating the bar and at the same time they thread it forward by virtue of their rotation and the furrows in the bar. It is therefore highly desirable to leave the bar free to elongate during this step of circumferential furrowing, for otherwise piping of the round will occur and instead of the product being a solid homogeneous bar, there will be a tendency toward the production of a bar with a hollow center or with a center of exceedingly poor physical characteristics.

in Figures 3 and 4, guides 15 and 16 have been shown, but it will be understood that any desired form of guides may be employed, as for example, those shown in Figures 1 and 2. If desired, the guide 16 may be used in connection with the entering guides shown in Figures 1 and 2 and a guide similar to the guide 15 but open at the bottom may also be employed in connection therewith.

After the bar has been furrowed and elongated, it is passed through the smooth: ing rolls shown in Figures 5 and 6. This set of rolls comprises cross rolls 17 and 18 provided with guides 19 and 20 of any desired form. Each roll has a cylindrical center portion 21 and tapered end portions 22. As the round passes to the left between these rolls, as shown in Figure 6, the ridges between the furrows 14 are pressed down. Preferably the smoothing rolls completely flatten out these ridges so as to restore the round to smooth cylindrical form. This pressing down also exerts an elongating force in both directions, so that the problem of entering the bar in the smooth rolls is present just as much as it is in the furrowing rolls. It is, therefore, desirable to provide for suitably entering the bar in the smoothing rolls in some manner as above described, in connection with the furrowing operation.

Figure 7 illustrates diagrammatically a mill provided with two sets of furrowing rolls alternated with two sets of smoothing rolls and a set of finishing rolls. Each of these mills may be provided with entering means, as shown in Figure 1, but the details thereof have been omitted in this figure for the sake of clearness.

As shown in Figure 7, the leader A. is passed in the direction indicated by the arrow through the first set of furrowing rolls 13, resulting in the production of a furrowed bar C. This furrowing operation is completed from end to end of the bar before any further operation is attempted, for it is desirable to leave the bar free to elongate at all times during the rolling operation. After the furrowing has been completed the furrowed bar G is passed in the direction indicated by the arrow through smooth rolls D, resulting in the production of a round E of smaller diameter. This reduced round is fed to the furrowing stand F, resulting in the production of a smaller furrowed bar G, which bar is passed through smoothing rolls I-I, resulting in a still further reduced round J. This alternate furrowing and smoothing may be repeated as many times as is desired but in the particular mill shown in Figure 7 the above steps only are employed to reduce the bar to proper size, after which it is passed through a set of hyperbolic finishing rolls K which finish the round.

It will be noted that during the reduction of the leader A to the finished bar the leading and then with the other end leading. This is highly desirable in that if at any stage the bar should happen to be advanced a little too far prior to bringing it into engagement with the cross rolls, no difficulty will be encountered in entering the bar in the succeeding pass, and furthermore, the slightly enlarged end will be the following end in such pass and will be readily re duced therein.

The round is formed with an accurate circular cross section and since the rolls operate uniformly around its entire circumference and the round is rotated as it passes through the rolls, wear on the rolls does not result in a noncircular cross section, as is the case with the rolls now commonly employed. Furthermore, wear on the rolls may be taken up by adjusting them, as by the screw downs 7, without affecting the accuracy of the product. The rolls may also be dressed and adjusted without the necessity of relegating the dressed rolls to the production of larger sized rounds, as is the case with ordinary rolls.

The working of the metal uniformly along all diameters thereof not only results in a uniform circular cross section, but also in a uniform physical composition within the round. The physical composition is far more uniform than can be obtained with the present rolling method and much greater accuracy in size can be obtained than by such methods. Therefore, some of the finishing operations, such as lathe turning or cold drawing, may be entirely dispensed with.

I thus provide for cross rolling a solid round by alternately furrowing and smoothing same. I further provide a method of general application for entering the article to be rolled in the cross rolls by causing relative lateral movement between the rolls and the bar to engage the bar in the rolls.

YVhile I have specifically illustrated and described my method and the preferred ap paratus for carrying it out, it is to be understood that the invention is not limited to the illustrated forms but may be otherwise embodied within the scope of the following claims.

I claim:

1. The method of cross rolling, comprising the steps of bringing the article to be rolled into proximity with the r lls, then moving the article laterally int o ngage ment with the rolls, and moving the article longitudinally during rolling, substantially as described.

2. The method of cross rolling, comprising the steps of bringing the article to be rolled into proximity with a pair of spaced rolls, then moving the article laterally into engagement with the rolls, and moving the article longitudinally during rolling, substantially as described.

Ill

3. The method of cross rolling, comprising the steps of bringing the article to be rolled into proximity with the rolls, then causing relative lateral movement between the rolls and the bar to engage the article in the rolls, and moving the article longitudinally during rolling, substantially as described.

4. The method of cross rolling, comprising the steps of bringing the article to be rolled into proximity with the rolls, then moving the article laterally and substantially in a plane parallel. to the axes of the rolls into engagement with the rolls, and moving the article longitudinally during rolling, substantially as described.

5. The method of cross rolling, comprising the steps of moving the article to be rolled longitudinally to a point adjacentthe rolls, and then moving the article laterally into engagement with the rolls with the leading end of the article sutliciently advanced for the rolls to engage the side portions of the article, substantially as de scribed.

6. The method of cross rolling, comprising the steps of successively passing an arucle through a plurality of passes, in each pass moving the article to a point adjacent the rolls and then moving the article later ally into engagement with the rolls with the leading end of the bar sufficiently advanced for the rolls to engage the side portion of the article, and reversing the direc tion of movement of the article in each pass, substantially as described.

7. Cross rolling apparatus, comprising a pair of cross rolls, said rolls being adapted to move the article being rolled longitudinally during the rolling operation, and means for moving the article to be acted on thereby laterally into engagement with the rolls, substantially as described.

8. Cross rolling apparatus, comprising a pair of cross rolls, said rolls being adapted to move the article being rolled longitudinally during the rolling operation, means for introducing the article to be rolled thereto, and means for causing relative lateral movement between the rolls and the article to engage the article in the rolls, substantially as described.

S). Cross rolling apparatus, comprising a pair of cross rolls. said rolls being adapted to move the article being rolled longitudinally during the rolling operation, means for guiding the article to be rolled into proximity therewith, and means for moving the article laterally and in a plane substantially parallel to the axes of the rolls into engagement with the rolls, substantially as described. i

10. Cross rolling apparatus, comprising a pair of cross rolls, means for advancing an article to be rolled adjacent the rolls and with the leading end of the article sufiicient- 1y advanced for the rolls to engage side portions of the article upon lateral displacement thereof, means for moving the article laterally into engagement with the rolls, and means for thereafter guiding the bar longitudinally in engagement with the rolls, substantially as described.

11. Cross rolling apparatus, including a pair of cross rolls, means for guiding an article to be rolled into proximity with the rolls, a stop for limiting the movement of the article. at a point where the leading end of the article is su'lliciently advanced for the rolls to engage side portions of the article upon lateral displacement thereof, and means for moving the bar laterally into engagement with the rolls and out of engagement with the stop, substantially as de scribed.

12. Cross rolling apparatus, including a pair of cross rolls, means for guiding an article to be rolled into proximity with the rolls, a stop for limiting the movement of the article. at a point where the leading end of the article is sulliciently advanced for the rolls to engage side portions of the article upon lateral displacement thereof, means for moving the bar laterally into engagement with the rolls and out of engagement with the stop, and means for thereafter guiding the bar longitudinally in engagement with the rolls, substantially as described.

13. The method of reduc'ng rounds com prising the step of pressing down the ridges between the furrows of a circumferentially furl-owed round while leaving it free to elongate, substantially as described.

14;. The method of reducing rounds comprising the steps of cireumferentially furrowing a round and thereafter pressing down the ridges between the furrows, the round being left free to elongate in each step, substantially as described.

1.5. The method of reducing rounds comprising the steps of circumferentially furrowing a round and thereafter pressing down the ridges between the furrows and repeating said steps until the desired reduetion is obtained, the round being left free to elongate during each step, substantially as describec.

16. The method of reducing rounds comprising the steps of impressing two parallel helical continuous screwthread-like circumferential grooves in the round, and thereafter pressing down the ridges between the grooves, the round being left free to elongate during each step, substantially as described.

17. The method of reducing rounds comprising the steps of impressing parallel helical continuous screwthread-like circumferential grooves in the round, thereafter pressing down the ridges between the grooves, and repeating the steps alternately until the desired reduction is obtained, the round being left free to elongate during each step, substantially as described.

18. The method of reducing solid rounds comprising the steps of passing them by a roll having a single rib which ClICL11I1fI611- tially furrows them, and thereafter rolling down the ridges between the furrows, substantially as described.

19. The method of reducing solid rounds comprising the steps of passing them be tween two cross rolls, each having a single rib whereby two continuous helical circumf-erential grooves are rolled in a round, and thereafter rolling down the ridges between the grooves, substantially as described.

20. The method of reducing rounds comprising the steps of passing them between two cross rolls, each having a single rib whereby two continuous helical circumferential grooves are rolled in a round, and thereafter rolling down the ridges between the grooves, and repeating the said steps alternately until the desired reduction is obtained, substantially as described.

21. Apparatus for reducing rounds comprising a set of cross rolls having ribs for circumferentially furrowing a round passed between them, the ribs being arranged to permit elongation of the round as it is furrowed, and a set of smoothing rolls for pressing down the ridges between the furrows, the smoothing rolls being arranged to permit elongation of the round as it is smoothed, substantially as described.

22. Apparatus for reducing rounds comprising a plurality of alternate sets of ribbed rolls for circumferentially furrowing a round, the ribs being arranged to permit elongation of the round as it is furrowed, and smoothing rolls for pressing down the ridges between the furrows, the smoothing rolls being arranged to permit elongation of the round as it is smoothed, substantially as described.

23. Apparatus for reducing solid rounds comprising a set of cross rolls, each having an endless rib thereon for engaging a round opposite its engagement by the rib of the other roll, whereby the two roll ribs form two parallel continuous helical circumferential grooves in the round, and a set of smoothing cross rolls for pressing down the ridges between the furrows, substantially as described.

In testimony whereof I have hereunto set my hand.

PETTER B. ABRAMSEN.

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