US950708A - Process of and apparatus for rolling tubes, solid round bars, and similar bodies. - Google Patents

Description

B.. C. STIEFEL.

Mousse. 0F AND APPARATUS A0A ROLLING mums, soun Roman BARS, AAD SIMILAR BODIES. APPLIOATIN FILED MAY 20, 1008. TFA AUA 9 W AMA u Amante@ aA. 1l, ww.

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u., STIEFEL PROCESS `0F AND APPARATUS FOR ROLLING TUBES, SOLH) Hmmm ARS, AND SIMILAR'BODIES. K APILIOATION FILED MAYBE, 1906.

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. l l 1 A R. C. STIEFEL. PROCESS 0F AND APPARATUS FOR ROLLING TUBES, SOLID ROUND BARS, AND SIMILAR BODIES'.

` APPLIoATroN funn MAY ze, 190s.

Patented Marl 0.

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'PROCESS OF AND APPARATUS RALPH CHARLES STIEFEL, OF ELLWOOD CITY, PENNSYLVANIA.

rou. ROLLING TUBES, SOLID nonno BARS, AND SIMILAR nomas.

anonce.

v Specication of Letters Patent.

Patented Mar. 1, 191e.

Appncation'mea may 26,1909. serial mi. 435,042.

To all 'whom it may concern:

le it known that l, RALPH CHARLES- STIEFEL, a citizen of the United States,'re siding at Ellwood City, Pennsylvania, have invented certain new and useful Improve'- ments in Processes of and Apparatus for tube or body durin to-lw longitudinally of thebodyl t.

.Rollin Tubes, Solid Round Bars, and Similar Bo ies,'of which the following is a specification, illustrated by drawings.

The invention is particularly useful for rolling and elongatlng tubes and tubular blanks .of iron or steel in a heated state upon mandrels to elongate the tubes and reduce the wall thickness; or with the omission of the mandrel it isfalso applicable to therolling of solid round bodies to elongate and re- 'pince their diameters.

"lt is also applicable to any metal that will stand the treatment.l

By a description of the invention in the preferred' torni as applied to the rolling of tubular bodies upon mandrels, its adaptability to solid bodies will be well under-l stood without further explanation.

The invention contemplates the application of' rolling pressure on the sides of' the its continuous passage through a pass an while in contact with rolls by which the pressure is applied.

' ln the preferred form of the invention the application of the acting forces is suchthat each successive cross section of the body is first compressed between surfaces that `crossroll it while confining the pressure within' narrow limits circumerentially', allowing and causing thc-metal to How circumferentiall'y while the body is being fed forward into the pass; then, as it pro esses, each section. is subjected to longitu inal'rolling while 'being confined and ,under pressure circumferentially 'through a -large proportion of the circumference, causingfthe netal an to consequently ,elongate and reduce then, each section as .it progresses farther is subjected to a smoothing cross-rolling action between parallell or approximately parallel faces, which permit or cause the metal to flow circumferentially to insure its substantial'lyncylindrical shape as it issues from thepass.`-v

ln the-drawings, Figure 1 is an elevation of two rolls for elfecting the improved proc `ess, as seen 'omlthe .exit end of the ass:

1 is a diagram explanatory of Flg. l

and Fig. 1b a similar diagram of a variation. Fig. 2 is a central longitudinal section of the same. Fig. 3 is a horlzontal section through the axis ofthe. pass. Fi 4 is a vertical section across the inlet en of the pass at approximately the irst points ofcontact be tween the tube illustrated and the rolls. Figs. 5, 6, and 7 are end view, longitudinal section, and 'horizontal section, of amodiica-4 tion, the rolls being slightly skewed. Fig. 8 shows a inodi'cationrhaving three sets of rolls acting eonjointly, in which a combined as well as separate etl'ect upon themetal will'be produced by the three sets, as hereinafterexplained. Figs. 9 and 10 are. central longitud'inal section and horizontal section of the axis of a pass to illustrate another modification. Fig. 11 illustrates another modifica` tion.

'llhe details of the bearings,l housings, mechanical adjustments and well known flexible driving connections for the rolls are not illustrated, assuch details do not concern the process of treatment .given to the metal or the combination of the rolls themselves, and as connections for driving adjustable shafts with axes set as shown are well known. :Tubular blanks and mandrels are; shown, but the mndrels arb of course` omitted. when treating `solid bod-ies. Guides1 for guiding the work/into the pass 'and out of it, as used-'in practice, are also` omitted as they explain the new invention. f Two rolls shown in Figs. 1,4 2, 3, and 41, have rollin symmetrica ly placed in respect to each other and. the axis of the pass. The axes of the rolls are parallel with each other and, as illustrated, are horizontal, lying in a common plane perpendicularl to the axis. of the pass.

A is the lower roll and Atthe upper roll., B, B and C, C are the axes of the roll and H H the axis of the pass; D is the mandrel; E the tubular""blank or billet; F andfGpV are thejourna-ls or shaft extension of, the rolls.

surfaces of similar shapes and are not novel with or necessary to Each roll has a flange presenting a plane i From theplane surface i .through between the rolls under the most perfect conditions, but some latitude in size .by a s light approaching or separation of the,

rolls 1s of course contemplated. 'It will be seen that at the cross section through the pass shown in Fig. l, which is in the plane of the two axes of the rolls, the metal is confined and radially compressed by the rolls through a large portion of its circumference by the curvedH surface between the point O andP of the roll A in Fig. l and the similar opposite surface of the roll A. From' P to Q, the roll may be straight and tangentialjof the curve O P, being therefore truly cylindrical so asgradually to leave the body E as seen in Fig. 1. Instead of the cylindrical ortion P Q, a concave surface as seen in IEig. 1", at P Q may be substituted so as to somewhat further embrace, com ress and conne the metal at the mid e of the pass, the radius of curvature of the surface indicated by these dotted lines beingmuch greater than H O in order that the end or edge of the rolling .surface shall not cut into the body that is being rolled.

The billet or tubular blank E, if of iron, steel, or similar metal at a temperature suitable for hot rolling the metal, is placed upon the mandrel D,lwhich is preferably cold, and is introduced .through suitable guides into the inlet end of the ass. The blank ybeing of slightly larger ra ms than the H O (Fig. la) will first make contact with the two rolls at two opposite points where the l blank first meets the converging surfaces L of motion of the flange of the upper roll A- at the point 1 (Fig. 2) of rst contact is forwar and downward, as indicated by the line 1-4 in Fig. 2, while that of the lower roll is upward and forward, as indicated by the line 1-3. The forward feedin components of the effects of the two ro ls are equal and are indicated by the line 1 5, as The rotating 'or cross rolling/effect of the two rolls at the points 1 of the pass is roughly indicated by the oppositely directed components of motion v5 3 and 5 4, but being on opposite sides of the body or blank, they both .tend to produce rotation in the same direction; right-handedly as seen in Fig. 4. As the cross sectionof the billet enters farther into the pass,- this gripping and` cross rolling,

pressure by the flanges on opposite sidesof the blanklncreases progresslvely in amount and in the width ofthe area of contact between the blank and the opposing flanges until and after the section reaches a point where the roll surfaces M act to compress the blank horizontally, diagonally, and also verticall on opposite sides (see Fig. 2). When t e given cross section reaches the transverse plane of the axes of the rolls, as at 7 in Fig. 2, the confining and rolling pressure extends circumferentially around two areas including more than half the total eriphery of the blank, as seen in Fig. 1.

ut at this cross section the motions of all points of the rolls in contact with the billet are longitudinally forward parallel with the axis of the pass. There is no cross rolling component.

A third stage of the procedure is reached as the given cross section of the billet, passing out from the most connedcross section of the pass, emerges toward the exit end of the pass and the rolls again make .contact with the billet only on narrow lines at opposite sides where the flanges of the roll still remain in contact with the blank. The last points of contact between the rolls and the blank are approximately located at the` points marked A8 1n Figs. Q'and 3; and at these points it cross rolling pressure on the surface of the 9 blank but in the direction that tends to rotate or twist the blank in a direction reverse to the tendency at the inlet end of the pass. y The surfaces N of the roll flanges at the exit will produce a smoothing effect tending to roll out and smooth away any bunching or crowding of the metal at opposite sides of the billet Vproduced in the previous portions of the pass, and which is shown in cross section of the blank E in Fig. 1.

Having thus followed the procedure ap plied to any one cross section of the blank, it will be seen that a simultaneous action is occurrin at the inlet and exit ends of the pass on iferent sections or portions of the same blank whereby at the inlet end the metalv is bein cross rolled by forces ap- 'plied to a limited area of the surface at opposite points, as in Fig. 4, and the metal v subjected to a right-handed twisting tendency; at the exit" end ofthe pass the .metal is subjected to a reverse rotary or .twisting tendency and iven a smoothing action; and at an interme iate cross section longitudinal rolling compression of the metal occurs between surfaces that contne the metal circumferentially \around the greater part of the eri hery. At the inlet of the ass the P P P metal'wlll flow mostly circumferentially of the'billet, as for example along the line WW of Fi 4; while at the middle portions of the pass t e metal is necessarily elongated and is prevented -from materially enlarging radially; It is vconsequently reduced in external diameter and thickness. At the exit end of tate at equal speed, andthe axial feed com-l ponents are approximately equal `at -alfl'other points of vthe Ipassm` The cross rolling component of motion of the rolls diminishes and again increases in reverse direction as the axial distance from the transverse plane Z,

Z through the central :point 7 of the pass varies. y

I prefer to have ythe forces at work upon the lank symmetrical, that vit to say balanced at diametrically opposite :points of the blank as it advances "throu h the pass; 4and this is 'the case in the application of the invention that I have fjust described. As lthe billet advances into =the inlet side of the.

pass, it is lirst subjected to a cross rolling and pressure 'by what I may call point contactor narrow line contact *between blank and roll. Subsequently itis subjected to an embracing surface contact and pressure, compelling the metal to yield longitudinally; and .lastly it is subjected to cross rollingfor smoothingv between opposedand substantially plane parallel surfaces.

Itwill be 'seenthat the action to which I subject the rblank differs radically from the.

common procedure 'of rolling out bars lor tubes between rolls having semi-circular or semi-elliptical grooves and that it differs equally `from the well known art of piercing or expanding billets or tubes by cross rolling between rolls by which the blank is not embraced circumferentially 'through any considerable portion of its periphery at any one instant.

In Figs. 5, 6, and 7 rolls with axes slightly oblique to each other and to the transverse plane ont the 'pass areshown for carrying out the 'process.

In Figs 1 to 4 inclusive the blank after coming in contact with the flange portions of the rolls haste travel -a considerable distance before it is embraced circumferentially to any` great extent; and during this period of its'progress it is subjected to torsional or twisting strain. In 'cases where `metals having less resistance to such strains than iron and steel are to be treated; or where the ythinness ofthe wall or other conditions make a diminished torsional strain preferable at. the entrance to the pass, this can vbe accomplished by disposing the roll axes slightly incline'dtoward the rear of the pass, las shown in Figs. 5, 6, and 7 ,making the con-verging entrance of the -pass 4more essonne abrupt (as will be 'clear from Fig. 7,) as

more prolonged straight sided exit end of the pass. The rotary -or twisting effcct of theexit Will dominate when the reduction .of diameter given to the blank is but slight.

It Vwill be understood by those familiar with this art that my process, even in the entire absence of any cross-rolling effect at the entrance oity the pass prior to the longitudinal rolling and circumferential pressure, is characterized in the preferred forms described by a continuous progression and transmission from longitudinal rolling and circumferential compression to a substantially simple cross-rolling action without circumferential compression, and all in a single pass. V

In cases Where very large reductions of wall thickness or external diameter are required, I Vprefer to accomplish the total rcduction by successive repetitions of the process that I have Iso far4 described. This may be done by several sets of rolls as eX- cmplified in Fig. 8. I prefer to place the succeeding pairs of rolls so near the preceding lpairs that the blank and mandrel bar will comel within the grip of the last pair of rolls before leaving the rst pair, and to proportion the speeds of the succeeding pairsl of rolls to compensate forthe elongation rof the metal which-occurs in each pair of rolls, the succeeding pairs operating faster in proportion to the reduction of cross section of the blank that occurs.` Obviously, however,

.as a mandrel bar, which is preferably in a cold state, can only assume one forward speed for all its points, its speedwill be less than the 'feeding speed of they third or lastpair of rolls andgreater than the firstpair of rolls. By this use -of my process, therefore, I produce a longitudinal movement between the mandrel and the tubular blank. This also facilitates the 'removal of the tube from the mandrel bar after they leave the roll.

The process may be also utilized with a mandrel thatish'eld stationary so far as endwise movement is concerned but is free to rotate. This is illustrated in Figs. 9 and 10,

wherein a short mandrel or plug U is shown on the end of a bar T which is braced against Va fixed support S, allowing the mandrel U 4i ao,

only extends through-the middle and rear portions of the pass does not tend to reduce or prevent the somewhat dierent speed of rotation and consequent twist of the billet at the commencement of the pass where it is `first gripped by the roll flanges, as heretofore explained. Incidentally the rotation of the mandrelu causes it to wear more evenly on all sides, and to remain round much longer producing consequently a smoother'surface on the interior of the tube than if the mandrel did not rotate. I l The process may be 'also used to give-very slight reduction in thickness of the walls of the tubes where it is only desirable to reniove creases or irregularities such as are frequently produced in tubular blanks by the ordinary methodv of rollin a tubular blank over a stationary mandr or. plug. Similarly the method may be employed for merely rollingv A out rou'gh places on the outside surfaces of the tubes, such as are frequently produced in billets-'thathave beenApierced or rolled by defective or rough rolls or mandrels or injured by scale. In utiliing .the process for this purpose I prefer to mmnnize the lpressure and reduction occurring at the middle of the pass where the metal is confined circumferentially and to rely mainly on the last step of the process where the cross rolling action mainly occurs. A

If the rolls already described are 'drawn slightly farther apart vertically, that-is perpendicularly to their axes, the circumferential confning action will be lessened `or omitted while the cross rolling in reverse directions at the inlet and exit ends of the pass remains. Where it is desired to cross roll or reel a tube to compress it very slightly, so as toA remove creases or rough places inside or outside the first and last stages of the process or the last stage only ma be employed exclusively, thecentral portion of the passvacting merely as rotating guides for the tube 'I and mandrel, holding them in alinement in the centerl of the pass, while the wall of the tube is compressed and rolled spirally forward'between the flanged portions of the rolls.V Such guides can be made to lit the tube much closer vwithout practical inconvenience and ifthe tube tends to'bind between the`guides they at once act to roll it longitudinally forward insteadlof opposing it`as/ wquld-.xed guides vor idler rollers.

In F1g.,1l the rolls are shown with the curved portion corresponding to O P in Fig` 1a transformed into cylindrical and plane faces. Such rolls can embrace and confine the metal on four sides at the center ,of the pass or, when adjusted so that the horizontal dimension of thepass is less than the vertical, can.only cross roll the blank' between the opposed `anges.

It will be seen that in the various figuresrolls overlap the cooperating flange of the opposed roll to produce the rotatory or twisting tendency on the body being treated. It will also be seen that the rolls rotate approximately in opposite directions when their axes are inclined and exactly in opposite directions when their axes are parallel, as common in grooved rolls for longitudinal rolling. y

It will be clear to those skilled in the rollin art that the dimensions of either of a palr of rolls may be increased relatively to the opposing roll and the angular speed proportionately decreased without materially altering the surface speed and equal effects of the two rolls.

Without attempting to set forth many other modifications, I claim and desire to secure b Iietters Patent the following:

I. lbe improvement in theart of rolling tubes or round bodies, which consists in subjecting such a body to a continuous and progressive rolling and l compressive pressureA while moving forward in a suitable 'pass by pressing and cross rolling the body in the inlet end of the pass between approximately parallel rolling faces, thereb tending to rotate the bod while allowmg the metal to ow circum erentially, simultaneously subjecting the cross sections of the body farther within the pass to confining `and rolling pressure'around a large part of itsv periphery from surfaces moving substan- 'tial y longitudinally of the passwith little or no cross rolling motion', whereby the metal flows and elongates in an axial direction and simultaneously subjecting the cross sections of the body in the exit portionof the p'ass to rolling pressure between approximately plane surfaces moving transversely to the pass 'and tending to rptate the body reversely to the inletportions of the ass, for substantially the purposes set fort 2. The improvement in the art of rollingl tubes or round bodies, which consists in subjecting such a body to a Acontinuous and progressive rolling and compressive pressure While moving forward in a suitable pass by subjecting the cross sections 'of thefbody to confining and rolling pressure around a large part of its erlphery from surfaces moving substantial y longitudinally of the pass with little or no cross rolling motion, whereby the metal flows and elon ates in an axial direction and simultaneous y subjecting the cross sections of the body inthe exit portion 4of the same pass to rollin pressure between approximately plane sur aces mov- `ing transversely to the ass and tending t rotate the body, for su stantially the purposes set forth. Y

@3. The improvement in the art of rolling jecting sucha body to a continuous and proof the drawings the flanges of the respective gressive rolling and` compressive pressure tubes or roundbodies, which consists in sub-v lili periphery from surfaces moving while moving forward in a suitable ss, to

subjecting Athe cross sections of 'the circumferential confining and longitudinal rolling pressure varound .a large part of its 4substantially longitudinally of the pass with little metal flows and -elongates in an axial fdirec- ,tion and simultaneously lsubjecting the cross sections vof 'the bodyin the exit portion "of the' same pass to rollin pressure between approximately plane sur' aces moving tra'nsversely to the ass and tend-ing to rota-te the body, the said) metal bei-n supported internally upon a Asubstantial y ihard mandrel for substantially 'the ,purposes vset forth.

4. 'lllhe improvement :in VNthe art of 'rolling tubes or round bodies, which xconsists in s bjecting suchbody to a continuous and o- A approximately plane sur 5. The improvement in the art of rollingv tubes or round bodies, which consists in subjectmg such a body toa contlnuous and progresslve rolling and lcompressive presJ sure lwhile moving forward in a suitablev pass, by subjecting the cross sections of the body to circumferential confining and longitudinal rolling pressure around a large part of its eripherv from surfaces moving substantia ly longitudinally of the pass with little or no cross rolling motion, whereby the metal flows and elongates in an arial ydirection and simultaneously subjecting. the crosssections of the body `1n .the exit portion of the same pass to rollin pressure between approximately planesur aces moving transversely to the pass and tending to rotate thev body, and supporting the body internally during the latter actlon upon a mandrel \that is held against axial motion as the metal moves over 1t.

' 6. 'The improvement in the art of longitudinally rolling tubes or round bodies,

characterized by subjectin each advancin' -cross section to longitudinal rolling an lcircumferential 'compression throughout a largevportion-of 'the lperipher and. then rol ing the bodn by pressure etween opposing cross .ro ing surfaces havin relativelyA narrow limits of contact with .the

body, the said successive treatments occuror no cross rolling motion, whereby the 'tudinally ro faces for longitudinally progressively' and in continuitupon hettlody, for substantially'the purpbses set 7. The im rovement inthe art of "longitudinally ro ling tubes Vor round bodies, characterized 4Vby first cross rol-ling the body between surfaces having narrow lines or arcas lof `Contact with 'the body and rotating the body, then subjectin each advancing cross section to llongitu inal rolling and circumferential compression throughout a lar e portion -of 'the periphery, and then rol ing the bod H by pressure between opposing cross roling surfaces havin -relatively narrow limits -of contact wlth the body, the said successive treatments occuring -pro ressively and in continuity 'upon the body, '-or substantially the -purposes set forth. A

-8. The im rovement in the art of longi- Elling tubes or round bodies, characterized by first-cross rolling vthebody between surfaces both tending to twist or rotate in a like direction, then rolling it longitudinally, and then cross rolling -it fbetween isurfaces tending to twist or rotate it ina llike direction to eachother but reverse to the first said direction, for substantially the purposes set forth. Y

'9. The improvement in the art of rolling `tubes .or round bodies, characterized by first cross rolling Ithe body between rol-ls 'having 'surfaces `tending Eto twist or .rotate it in a like xtiirec'tion and xthen in the same pass be-A tween the same rolls cross rolling its advanced portions between surfaces tending to twist or rotate in a direction reverse to the first said direction, whilecontinuing the first cross rolling on other portions, for substantially the purposes set forth. 10. Machine for reducing metal comprismg a set of rotary members arran ed to form a single pass, at least one of sai members having a central portion and an outer flange portion, said central portion being 11o constructed and arran ed to grip the billet circumferentially to ein ate it and roll it substantially lon itudina y, and said flange portion being inc ined to the axis of the pass erate transversely upon and cross roll the blank as it passes from the central portion, for substantially the purposes set forth.

1l. Rolls forming a pass and having surfaces for longitudinall rolling and circumferentially confining tide body being rolled and having opposed surfaces in the same pass for cross rolling the body, the acting surfaces of the rolls being convergent at the mouth ofthe pass. i 12. Rolls forming a pass and having surrolling and circume body being' rolled, surfaces for cross-rollferentially connin t and havin op ose ing Ithe bo y, t e acting surfaces oft-he rolls 13o being convergent at the mouth of the pass, in combination with a mandrel for internally supporting the body at the Vpoints of longitu mal and of cross rolling.

13. Rolls forming a ass and having surfaces for longitudinal y rollin while circumferentially confining the ody being rolled and opposed surfaces for cross-rolling the body, the acting surfaces of the rolls being convergent at the mouthof the pass, in combination .with a mandrel supported tol'otate Without traveling in respect to the ro s.

14. `Rolling mechanism comprising rolls forming a pass and having inclined axes for imparting endwise and rotary motions to a blank While gripped thereby longitudinally and circumferentlally, each of the said rolls having a concave central portion for circumferentially confining and longitudinally rolling the body, and a flange for crossrollin the body, and imparting rotation, for su stantially the purposes set forth.

15. 'Rolling mechanism comprising rotary rolls forming a pass, for imparting endwise and rotary motions to a blank While grippedv thereby longitudinally and circumferentially, each of the said rolls having a concave central ortion for circumferentially confining and). `longitudinally rolling the body, and a flange for cross rolling the body and imparting rotation, the flanges of the rolls converging at the mouth of the pass.

16. In combination, a plurality of pairs of flanges for rotatin or cross rolling the said.

body or blank an a coperating mandrel of length to extend simultaneously into a plurality of the passes, at least one of which lhas such cross rolling flanges.

17. In combination, a pair of rolls forming a pass, the axis of each roll beingv perpendicular o'r nearly so to the pass axis, the

rolls rotating in opposite dircctlons and having opposed overla ped flanges making contact with the vwor piece along longitudinally disposed lines at the exit end of the pass, for reducing cross rolling in like directions, t e opposing faces of the flanges of the rolls convergin at the entrance end of the pass, substantia ly as set forth.

, 18. Rolling members formin a pass and having axes inclined to each ot 1er and each having a circumferentally confining and longitudinally rolling surface portion and a cross rolling flange portion that makes acting contact against the work piece on lines disposedy along the pass.

In testimony whereof -I have signed this specification in-the presence of two subscribing Witnesses, May 21, 1908.

RALPH CHARLES sfrIEEEL.

Witnesses:

R. T. BROWN, VLESLIE H. MANN.

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