US2078434A - Method of finishing rounds - Google Patents

Description

April 27, 1937. a. A. WISE METHOD OF FINISHING ROUNDS Filed April 11, 1935 MT IQ N.

ATTORN EYS Patented Apr. 27, 1937 PATENT OFFICE METHOD OF FINISHING ROUNDS George A. Wise, Pittsburgh, Pa., assignor 'to Sutton Engineering Company, a corporation of Pennsylvania Application April 11, 1935, Serial No. 15,776

3 Claims. (CI. 80-63) This invention relates to the cold rolling of solid metallic rounds for sizing and truing them within narrow tolerances.

The cold rolling of round stock, to size and true it, is disclosed in Abramsen' Patent No. 1,601,551, and in my own Patent No. 1,914,587. The first named of these patents discloses a method in which the round-stock'is repeatedly scrolled, and the scrolling rolled out, being thus by repeated action reduced in cross-sectional area and brought into closer approximation to true round. Both the Abramsen patent and German patent to Wirth 8: Co., No. 79,642 or 1895, which latter patent discloses the rolling of a tube wall to accurate guage and the tube to true circular section on a mandrel, permit the stock to elongate as it is reduced in cross-sectional area.

In my prior patent the stock is scrolled by rolling in a pair of cross rolls arranged to have with ita relatively narrow bearing area, and the scroll is subsequently rolled out by passing the stock successively through cooperating pairs of cross rolls having withthe stock progressively increasing areas of contact. In this process, elongation of the stock is permitted by increased linear speed in the roll passes from the entering end to the leaving end 01' the roll assembly, the stock being gripped simultaneously by two or more cooperating pairs of cross rolls during its passage through the roll assembly, or aligned group.

It is customary in the drawings of such patents I to show the scrolling and rolling down of the stock, as if the stock were plastic when cold, being thus subject to relatively ,deep scrolling and to ready flow under the influence of smoothing rolls. This is for-the purpose of illustrating the eiiect oi the scrolling and smoothing rolls, since the scrolling 01' steel rounds extends merely to a depth of from one to three thousandths of an inch, and it is a diflicult matter to produce surface flow of the metal even with the relief provided by the scrolling.

The object of my invention is to provide a process oi so working cold, or approximately cold rounds that maximum facility for flow of the metal at the surface of the stock is obtained; thus securing to an increased extent reduction in the cross section of the stock, while minimizing the tendency to strain the central metal of the rounds which usually is attendant upon the exertion of a high degree of rolling pressure upon cold stock.

By experiment I have proved that i! a round be so scrolled as approximately to isolate relatively small areas on the surface of the stock, the metal may in subsequent rolling down, flow in more than one direction in the intervals provided by the scrolling. There is the further advantage that in cross rolling, round stock frequently so adjusts itself in the pass that the contact area of the roll rides along the line of scrolling, rather than on-the high region of the stock adjacent the line of scrolling. In itself, the scrolling of a double spiral on the stock does not materially facilitate rolling down, nor does it improve materially the resulting product.

Primarily considered, my cold rolling process consists in oppositely scrolling the stock to produce thereon spirals opposite in sense, which intersect at intervals along the length of the stock, and then rolling down the stock to the necessary tolerance as to size and true circular section. These opposite and intersecting spirals may be either single or double spirals.

In the accompanying drawing, Fig. I is a schematic plan view of instrumentalities for conducting the process of my invention.

Fig. II is an elevation of a length of round stock upon which a single, uni-directional, spiral scrolling has been imposed.

Fig. 111 is an elevation of the stock after there has been imposed thereon an additional spiral scrolling, opposite in sense, to that first imposed upon the stock.

Fig. IV is an elevation of the stock, illustrating the step or rolling down the stock after it has been completely scrolled.

Fig. V is an elevation of a length of round stock, which has had imposed thereon a double spiral which is uni-directional in sense.

Fig. VI is an elevation of the stock after an additional double spiral scrolling opposite in trating the rolling down of the stock upon which the intersecting double scrollings have been imposed. I

Fig. X1 is a side elevation of a roll pass in which the rolls are arranged to impose a double spiral scrolling on the stock, and illustrating the action of the rolls in spiralling the stock.

It should be explained, in connection with the drawing, that the depth of scrolling is greatly exaggerated, both as to the depth and abruptness of the impression, and that the illustrated regularity in the pattern formed by the scrolling is, in practice, of extremely rare occurrence. Further, it should be noted that the marking on the face of the rolls in Figs. VIII to XI is, of the drawing, merely indicative of the width of bearing surface on the rolls, and does not illustrate a ribbed roll surface.

To describemy process, with reference to the drawing exemplary thereof, Fig. I shows a length of round stock A passed through a cooperating pair of scale-cracking cross rolls I and 2, and immediately thereafter passed through a pair of cooperating scrolling cross rolls 3 and 4. In order that the stock may be subjected to a straightening flexion during this initial action thereon, an intermediate pressure roll 5 is mounted between the passes I, 2 and 3, 4. If desired the stock may, as shown, be passed through this set of cross rolls in such manner that the scalecracking and initial scrolling are effected progressively along the stock as it moves longitudinally through both passes, and is rotated about its axis.

It will be noted that, as shown in Fig. I, the

scrolling 0!. produced by the initial treatment of the stock is a uni-directional scrolling in the form of a single thread imposed by a single narrow bearing surface of the scrolling roll on the stock. This scrolling pass is illustrated in detail in Fig. VIII of the drawing. As there illustrated, the roll 3 has a relatively wide area 3a which bears upon the stock, and the scrolling is effected by the relatively narrow bearing surface 411 of the roll 4. As will. be seen clearly in Figs. II and VIII, the scrolling of the roundstock does not, at this stage of-the process, produce areas on the surface of the stock which are wholly, or substantially, isolated by the scrolling. The second pass'in which the stock A is treated, comprises desirably the single independent pair of cross rolls li and 1, which rolls are so arranged as to impose upon the stock a spiral scrolling opposite in sense to that imposed by the initial scrolling rolls 3 and 4. It is to be understood that the stock must be removed from the initial roll assembly, in which scale is cracked and the primary scrolling imposed, before it is acted upon by the secondary scrolling rolls 6 and 1-.

Referring to Fig. IX of the drawing, it will be noticed that the roll I has with the stock a relatively wide bearing surface Ia, but that the roll 6 has with the stock a relatively narrow bearing surface (in. Further it will be observed that the rolls 6 and 1 are inclined to a common axis oppositely to the inclination of the rolls 3 and 4, and that they, therefore, impose upon the stock a spiral scrolling b, which intersects the spiral scrolling a, imposed by the first pair of scrolling rolls.

Referring to Fig. III of the drawing, it will be seen that this reverse scrolling produces substantially isolated areas on the face of the stock, the imposed scrolling giving relief for the flow of metal in all directions during a subsequent step of rolling down the stock. It also will be clear from an inspection of Fig. III that the purpose of scrolling the stock can not be defeated by travel of the stock through pressure rolls in such manner that the stock tends to ride along the line of the scrolling. This is for the reason that there is, in any position of the round, relief afforded in a direction angular to each scroll line.

The operation of rolling down is illustrated in Fig. I of the drawing as performed by a single pair of pressure rolls 8 and 9, which, as shown in Fig. X of the drawing, have both with the stock the relatively wide bearing surfaces 8a and 9a. Considering Fig. X of the drawing, it is seen how the bearing surfaces of these pressure rolls 8 and 9 overlap the scrolled surface of the stock, pressing down the high areas lying between the intersecting scroll lines.

As a finishing step the stock is passed through a set of cooperating cross rolls comprising the roll pairs l0 and II, and I3 and i4, together with the cooperating pressure roll l5. This stage of.

the final working of the stock is a final rolling down step, as Well as a straightening and polishing step. It will be noted that the rolls of this final assembly are inclined to each other in the direction, or sense, of inclination shown with relation to the rolls 6 and l of the second scrolling pass. The effect throughout the process is, therefore, one of an alternate, opposite rolling of the stock at the successive stations. Following the scale-cracking between rolls l and 2, the stock is scrolled in one directional sense by the cooperating pair of rolls 3 and 4, and in the opposite directional sense by the rolls 6 and l. The stock has the initial rolling down by the pressure rolls 8 and 9, which are inclined to each other in the sense of the rolls 3 and 4; and has a rolling down and polishing between the pairs of rolls I0 and II, and I3 and M, which are inclined to each other in each pair in the same sense as the rolls 6 and l, and in opposite sense to the rolls 8 and 9.

Desirably in the final treatment of the stock, the rolls l0 and II are brought to bear with considerable pressure upon the stock, to effect the final rolling down, while the rolls l2 and I3 bear lightly upon the stock, to effect smoothing and polishing. As, stated above, the entire assembly comprises roll pairs [0 and II, and I3 and I4, together with pressure roll l5, so that it exerts a straightening eifect upon the stock.

Referringnow to Figs. V, VI, VII and XI of the drawing, I have illustrated the imposition of intersecting double spiral scrolling upon the stock, and the rolling down of such double spiral scrollmg. In Fig. V, a double spiral scrolling c of the stock B is shown, and in Fig. XI a roll arrangement is shown for imposing upon the stock that scrolling. Rolls I6 and I1, shown in Fig. XI, are a pair of cross rolls, each of which has with the stock a narrow bearing surface shown respectively as the bearing surfaces Isa. and "a. This pair of rolls is, for double scrolling of the stock, mounted in tandem with rolls I and 2, replacing the pair of cooperating rolls 3 and 4 for imposing the single spiral a upon the stock A.

After the stock has been passed through thepair of rolls l6 and II, it is passed through asec- 0nd oppositely inclined pair of rolls corresponding-in the process to the roll pair 6 and. 1. Fig. VI illustrates the effect produced when both rolls of this oppositely inclined pair have with the stock a narrow bearing surface, to impose upon the stock a double spiral scrolling d which is opposite in sense to'the spiral scrolling c. The stock B is then passed through a finishing stand, or set,

of rolls inclined to each other in sense opposite that of the initial scrolling rolls is and I1 and amass 3 the-initial pass of smoothing rolls, and inclined stockin'one definite angulardirectiomrollingin toeachotherinthesamesenseasthepasso! thestockasecondspiralgrooveoppositeinsense secondary scrolling rolls. and of appreciable depth intersecting the first It will be understood that the imposition oi! ingroove while providing for rotation of the stock 5 tersecting double spirals tends to the production in the opposite angular direction, and restoring 5 of areas approximating complete isolation on the an uninterrupted surface to the stock with imsuri'ace of the stock more closely than is obtained provement in approximation to mathematical by the imposition of intersecting single spirals. roundnessotthe stockbyroilingontthe inter- An intermediate eiiect may be obtained by impossecting spiral grooves while providing for rotation 1o ingonthestockadoubiespiralscroliingtointerofthestock. o sect with a single spiral. 2. Die herein described method of cold rolling I have observed that the opposite scrolling of solid metallic rounds which consists in approxithestockresultsinafinishedproductoibetter matelyisolatingareasonthesuriaceoithestock' internal structure than that resulting from the by a succession of separate and individually comspirallin and t smoothing oi. round plete step mpri r lli in t st a m 15 stock upon which a merely uni-directional spiral of appreciable depth describing a double spiral has been imposed. This is clearly for the reason about the stock while providing for rotation oi that there is present a 1 tendency to open the stock in one definite angular direction. rollthecentralregionoithestock. Alsothereis inginthestockasecondspiralgrooveopposite so apparently produced a deep working of the stock, in sense and or appreciable depth intersecting a during the rolling down along lines out of paralthe first groove while providing for rotation of the lelismwiththelongitudinalaxisoithestock. stockinth nm ans fl di m Hie eiiect is thus that the higher regions between par t a ivi ually c mplete step restoring 'scroli linesareworkeddown, rather thanpulled anuninterrupt surface tothe stockwith along,asthe stockiselongated andreduced. m vem t in ppr xim to m th as It may be noted further that the imposition of roimdness of the stock by rolli ut t e interintersecting spirals permits a greater reduction sectins sp r grooves While Pr i o rot tion inthecrossrollingofthestockthancanbeetofthestock; tected by the imposition of one spiral scrolling 3. The herein described method of cold rolling followed by a rolling down of the stock. If it is solid metallic rounds which 001 in isolat 3o desiredtoproducestockwhichisequivalentasto area-sonthesuriace oithestockbyaon sizing, accuracy of section, and finish, to that proor separate and i div dua y comp t st p c0m-. ducedbycoiddrawing,itmaybedesirahlefirstto p srolii s t est a v app follow the procedure here described, and to then depth describing a double spiral about the stock as subject the stock to the treatment described in while nr di a for tat n o t e sto in one as my Patent No. 1,914,587, omitting the blasting definite angular direction, rolling in the stock a step described in that patent. It will be undersim u le pira gr v interse t s th stood that in such multiple process, the rolling first groove while providing for rotation of the during treatmentasinmyeariier patentmay stockintheoppositeanglflfl dir hm ass be relatively light. separate and individually complete step restoring 40 I claim as myinvention: an uninterrupted surface to the stock with im- 1. The herein method of cold rolling m em t i pp xim t m hem tical solidmetallicroundswhicheonsistsasasuccesroundness oi thestockby rolling th to to sion of separate and individually complete steps cause flow of the metal of said isolated surface infirstmllingaspiralgmoveotappa-eciabledepth areas while providing for rotation of the stock. 45

inthestockwhileprovidingiorrotationotthe GEORGELWISE.

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