US1464702A - Rolling mill - Google Patents

Description

c. P. FULLER ROLLING MILL F'iled Oct. 23. 1920 4 Sheets-Sheet l f@ ,V 4 i )@@hif y ug. Mr, 1923.

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C- P- FULLER ROLLING MILL 4 Sheets sheet 5 Filed Oct. 23, 1920 K m m w W/T/VESSES Aug. 14, 1923.

11,464,7@2 c. P. FULLER ROLLING MILL Filed Oct. 23, 1920 4 Sheets-Sheet 4 FIE.

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CHA'NCEY E'. FULLER, 0F BELLE VERNON, PENNSYLVANIA.

ROLLING MXLJL.

Application led Uctober 28, 1920. Serial Ito. 418,965.

thickness, it is also adapted, by modification of the rolls for piercing a solid billet, and in fact for producing al finished tube from a solid billet. It may also be used :for reducing the diameter of the tube without reducing its wall thickness.

The primary object of the invention isto provide a crossrolling mill for producin finished tubes from hollow or solid billets in the one machine.

A further object is to provide a cross rolling mill which will, first, produce tubes that are smoother, straighter and more regular, with less relative expansion of diameter and less tendency to wall eccentricity than can be produced on existing cross rolling mills or on grooved rolling mills without the subsequent use of reeling machines; and, second, to produce tubes more expeditiously, and with better power elliciency than has heretofore been possible with cross rolling mills, or with combinations of grooved rolling mills and reeling machines. Other objects and advantages of the invention will be apparent from the detailed description following.

ln the accompanying drawlngs Fig. 1 1s an end view of the mill, a portion being broken away to more clearly show the structure; Fig. 2 is a vertical section taken on the line 2 2, Fig. l, Fig. 3 is a plan view ot the mill; Fig. i isa plan view and Fig.

" 5 a side view showing 'the rolls in their relations'to each other and to the mandrel; Fig. 6 is a transverse central section through the rolls, showing a tube lin the pass of the rolls; Fig. 7 is a detailed view of one form of roll and mandrel, shown in their oblique.

relation 'to each other and indicating" the nature of contact between the roll and the billet, and also showing the changes eected on the tube wall between the roll and the f mandrel; and Fig. 8 shows a rectilinear development of the line of contact el-g bei` tween a roll and the billet in relation to the mandrel.

in the drawing 1, 1 represent bed plates orfm1ll shoes, secured to the foundation and serving as the support for the mill. 2 represents an annular frame which in radial cross section at any point is substantially Hfshaped, havmg an outer annular ilanged portion 2a, an inner annular ilanged portion 2", and the connecting web portion 2c, which d is vcut away at points for mounting therein suitable gears as hereinafter described.

" lhis annular frame is provided with pro- ]ections or feet 3 which are secured to the shoes 1 by suitable bolts as shown.

. rllhe rolls 4 have theusual necks or journals 5 carried in the bearing boxes 6, which constitute the ends of the roll carriers 7. Each roll carrier is provided with an outg ward radial projection, of cylindrical shape 8, having therein a tapered socket into which the ta ered end 9 of adjusting screw l0 is forced Ey the heavy bolt 11 extending axially through the adjusting screw and into the roll carrier, as shown in Fig. 2. By this construction 'the adjusting screw is made virtually integral with the roll carrier, and serves as an outboard support to steady the roll carrier.

The projection 8 is slidable but non-rotatably secured, by means of key 12, in the cylindrical sleeve 13, which is mounted in the inner annular flanged portion 2b of the main frame. The sleeve 13 is provided with a square flange 14, which is engaged by two wedge kevs 15 and is thereby held from turning. 7The Obliquity or feed angle of the rolls is thus maintained, and can be varied by replacing keys 15 with other keys of different taper. y

Flach adjusting screw 10 is engaged by a threaded nut 17 which is rotatably mounted between bearing rings 18 located between the outer and inner annular portions 2a and 2b of the main frame. These nuts 17 are provided on their peripheries with bevel gear teeth and are engaged by a bevel ringgear 19 carried on six (or more) rolleribearing spools, 20, which serve as an eilillO `liquity or feed angles.

various sizes, without affecting their ob- One of t-he necks of each roll is provided with a suitable extension, such as that shown at 29, for having connected thereto a suitable driving means, which may be of any of the well known types now used for drivin cross or skew rolls. The driving means wi l be arranged to drive all three rolls-at the same speed.

30 indicates the mandrel or plug lying in the pass of the rolls and held in positionA by the usual mandrel bar 31 which will be mounted for withdrawal from the roll pass in a manner well understood by those skilled in the art.

In the mill described, the three rolls are identical as to shape and size, and all are positively driven at equal speeds. Corresponding points on each roll are all equidistant from the axis of the tube pass, and form the vertices of an equilateral triangle. The three planes in which lie the respective roll axes form the three faces of an equilateral triangular prism; and equal angles are formed between each roll axis and the intersections of its respective plane with the planes of the two other roll axes. The angles thus measured will always be less than As described, this angle may be varied, but the condition of equality ofangularity with respect to all three rolls will always be maintained. A section through the mill transversely to the pass line at any point will "show the peripheries of the three rolls as equal ellipses.

In consequence of the geometrical conditions just described, the actions of the three rolls upon the billet are identical, the rolls themselves forming the guides for the billet passing through the mill, and sliding orl friction guides being entirely eliminated. Furthermore, the billet is acted upon at three points spaced 120 lapart around its periphery, with the result that the tube is constrained against increase in diameter to a greater extent than with cross rolling mills having but two rolls.

The contour of the rolls may be varied, but for rerolling a hollow billet it is preferred to use rolls which are approximately hyperboloids of revolution, as illustrated in-v Fig. contact 7. Rolls of this contour have a rolling with the surface of the billet along an approximate helical element of considertact being shown 1n Fig. 7 by the line eg. This long contact results in forming smooth, substantially straight tubes. The hollow billet to be rolled comes into contact with the three rolls simultaneously at the points f (see Fig. V8) and is then pinched inwardly, that is reduced in diameter, entering the feeding-in pass ea which serves to grip the billet and force it into the reducing pass a-b. At a begins the reduction of the wall of the billet to the form shown in Fig. 8. From b the contact of the rolls is parallel to the mandrel and is of very considerable length, thus giving a true reeling action' which smoothes the tube both inside and out. The tube being compressed .between the rolls and the mandrel at three equalized distances around the periphery, when it leaves the parallel pass at g has a cross section which may be likened to a clover leaf, as shown in Fig. 6. Due to' the progressive rolling of the tube, this form cannot persist, but changes to a substantially true circular form as soon as the tube is free from the rolls. To prevent this transition from resulting in a spiral marking on the tube, it is controlled by rounding the profile of the exit end of the rolls to a radius as shown at 1, Figs. 7 and 8.

The result of rolling a hollow billet on rolls of the character described is a tube which is smooth both inside and outside, is uniform and substantially circular in cross-section, and is not bent, scored, or grooved as are tubes produced by the usual method in so-called plug rolls. Further more, the reeling or smoothing is effected in the same mill in which the reduction of wall Ythickness is effected, whereby is produced in one machine a finished tube, requiring no further operation other than passing the same through the usual sizing rolls to gauge it to the exact diameter required.

As compared with prior cross rolling mills, the described mill has the following peculiar characteristicst- No guides are required (except a bell-mouth inlet) since the work is constrained and guided by the rolls along three equi-spaced helices; the resultants of all working forces are concurrent in the center line, or else are symmetrical about the center line, and therefore all forces are balanced except the necessary rolling and feeding components; since all three rolls are driven (at equal speed) there is no pushing or pulling ofA the'metal over a guide or fricl tion roll; the provision of three helical lines of long contact, instead of two, permits the use of very large feed angles without sacrifice of smoothness, thus combining to a considcrabe extent the action of grooved rolls and cross rolls; the provision of three driven rolls reduces slip, which results in higher speed through the mill; constraining the tube radially at three points instead of two results in less expansion of diameter and greater increase of length, for the same reduction of wall thickness; the absence of frictional guides, and the fact that all forces are cbncurrent or symmetrical result in more efficient utilization of the power; and, finally, the provision of hy erboloid rolls aving contact with the bi1 et for a great length along three twisted lines or approximate helices produces tubes that are smooth, straight, and regular.

ln addition to the foregoing, the mill illustrated and described is of simple construction; the design permits of rugged proportioning of all parts; all adjustments are simple and easily made; and since this mill embodies the functions not only of a rolling mill, but also those of a reeler, there' is a great saving in oor space, size of crew,-1n vestment, and power required in the rolling of seamless tubes.

rlhe invention is not limited to the contour of the rolls illustrated, as this may be varied as found expedient in practice. The form illustrated however is well designed for producing smooth regular tubes from hollow billets.

. For reducing the diameter of a tube without reducing its wall thickness, the mandrel 30 may be omitted.

l claim:

l. ln a rolling mill the combination of three power driven cross rolls identical in shape and size, set at th-ree uniform intervals around a central pass and atv equal distances radially therefrom, and with their axes making angles greater than 45C to a plane normal tO the pass axis, 'and having equal angles of Obliquity tO said pass, means for bodily adjusting all said rolls equally toward and from the pass Without altering their Obliquity, each roll being approximately a hyperboloid of revolution.

2. ln a rolling mill the combination Of three power driven cross rolls identical in shape and size, set at three uniform intervals around a central pass andat equal distances radially therefrom, and having equal angles of Obliquity to said pam, and means for bodily adjustin all three of said rolls equally toward an away from the axis of the pass without altering their Obliquity to the pass.

3. ln a tube rolling mill the combination of three power driven cross rolls identical in shape and size, set at three uniform intervals around a central pass and at equal distances radially therefrom, and having equal anglesl Of Obliquity to said pass, in combination with a plug or mandrel lying in the pass, said rolls and mandrel having contours to form, irst, a gripping or feeding-in pass between the rolls, second, a wall reducing pass between the rolls and 'the mandrel, and, third, a parallel reeling pass between the rolls and mandrel.

4. ln a tube rolling mill the combination I of three power driven cross rolls identical in shape and size, set at three uniform intervals around a central pass and at equal distances radially therefrom, and having equal angles of Obliquity to said pass, in combination with a. plug Or mandrel lying in the pass, said rolls and mandrel having contours to form, first, a gripping or feeding-in pass between the rolls, second, a wall reducing pass between the rolls `and the mandrel, third, a parallel reeling pass between the rolls and mandrel, and, fourth, a gradually diverging exit Or rounding-up pass between the rolls.

5. In a rolling mill the combination of three power driven cross rolls identical in shape and size, set at three uniform intervals around a central pass and at equal distances radially therefrom, and having equal angles of Obliquity to said pass, means 'Or radially adjusting all three of said rolls equally toward and away from the axis of the pass, and means for maintaining equal the Obliquity of each Of the three rolls with respect tO the pass, `the means for radially adJusting the rolls and the said maintaining means being independent of each other.

6. ln a rolling mill the combination of three power driven cross rolls identical in shape and size, set at three uniform intervals around a central pass and at equal distances radially therefrom, and having equal angles of Obliquity to said pass, each roll being mounted to have a swivel movement about a normal axis substantially midway of the length of its Working face, whereby its Obliquity to the pass can be varied, and means for maintaining equal the Obliquity of each of the three rolls with respect to the pass.

7. ln a rolling mill the combination of three power driven cross rolls identical in shape and size, set at three uniform intervals around a central pass and at equal distances radially therefrom, and having equal angles of Obliquity to said pass, each roll being approximately a hyperboloid of revolution, each roll being mounted to have a swivel movement about a normal axis substantially midway Of the length Of its working face, whereby its Obliquity to the pass can be varied, and means for maintaining equal the Obliquity of each of the three rolls with respect to the pass.

8. ln a rolling mill the combination of three power driven cross rolls identical in shape and size, set at three uniform intervals varound a central pass and at equal distances radially therefrom, and having equal angles of Obliquity to said pass, each roll being mounted to have a-swivel moveliti@ llll ' ment about a normal axis substantially mid ad]usting the three rolls equally toward orv away from the axis of the pass.

9. In a rolling mill the combination of l0 three power'driven cross rolls identical in shape and size, set at three uniform intervals around a central pass and at equal distances radially therefrom, and having equal angles of Obliquity tO said pass, each l5 roll being mounted to have a swivelling movement about a. normal axis substantially midway of the length Of its working face, whereby its Obliquity to the pass may be varied, means for retaining the rolls against swivelling movement, and means for bodily ,adjusting the three rolls equally toward or away from the axis of the pass, said retaining means and adjusting means being independent Of each other.

In testimony whereof, I have hereunto set 25 my hand.

CHAUNCEY P. FULLER. `Witnesses:

- R. C. THOMPSON,

W. A. MITOHEUR.

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