[1]Patented J'une 20, 1933 1 9 1 4 , 5 8 7 UNITED STATES PATENT OFFICE GBORGE A. WISA OF PITTSBURGEE, PENNSYLVAN3:A, ASSIONOB rro SUTTOW EliGINEERING COMMANY, A CORPORATION OF PENNSYLVANXA. XETHOD OF FINISHING ROUNDS Application laed October 7, 1930, Serial No. 487,021. Renewed December 1, 1932. This invention relates to a methocl of descaag, sizing, rounding up, straightening, and polishing solid or hollow metallic rciunds by a continuous progressive and automatic operation. As round bars ancl tubes come from a hot ]hill, or other devices producing siniilar material, they are not true to size, are not roiind, carry scale, and are not straight. 10 The best "rounds" (which term throughout the s@ecification and claims will be used to designate both solid bars and tubes) are therefore, as initially produced, not suitable for certain purposes which.r.equire mat,erial 15 that is clean, straight, polished, and approximates true roundness and aceiirate size. It has, therefore, been previous practice to manufacture round sections for these purp@oses by such methods as drawing, cold 20 rollingj . or tiarning and polishing. These methods are all slow and expensive. My invention provides a.rapid and economical method of producing round sections 25 which, are, within a narrow tolerance bith as to'-accuracy of section and.' size. The method is a continuous one so that rounds are straic,,hteiied, descaled, @ -are brought closer to true section atid diameter,.and are 30 polished by a continuous, progressive, and automatic'operation. Rounds fiiiished aeFo@rding to my method thus approximate in their qualities those produced by the slow and expensive driwing and cold -rolling than any drawn round sections whi6h alre o@ecording to general practice. I approximate the ae6uracy in section and diameter which may be obtained by draw.40 ing, and the highest degree of straio,,htness 4,nd pol,ish, by a method which produces finished bars at a rate ma-ny times that at which they may be pr oduced by drawing or turn@ni, mothods. , , I 45, More specificaUy I enter the rounds. initially into one or more sets of straightening cross rolls, which initiaily break@ the scale on the stock, which 'Mitially straighten it to facilitate treatment during the later 50. stages of tUe process,@ and which serve as feeding rous for the instrumentalities acting upon it in the later stages of the process. These initial eross rolls pass the round. to a steel blast for descaling and removing some of the surface metal of the stock and through the steel blast to rounding, straightening, and polishing passes. The blast may obviously be of a suitable abrasive other than steel, steel being in general- the pre- 00 ferred abrasive. Because the stock is fed positively to.the passes in which it is subjected-.to relatively great piessure for truing, it is unnecessary that bars be pointed or swaged for intro- 05 duction into the truing passes. Because the stock is subjected to scale breaking and straightening before being subjected to the blast, the blast operates more efficieiitly in removing scale from the stock 7 and also if TO desired inremovmg some of -the surface metal. Because the descaling and scouring of the stock is followed by @ ro'unding and larities caused by the blast are smoothed out and eliminated in the final stages of the process. ]It s ' hould be under ' stood initiary- that my entire method is a Araightenin,& ''on.e, the stock being initially straightened for intro- 80 'due-iion to tho blast, and the straightening a@ction is progressively,c_6ntinued throughout its roundi I and polisli'mg. pg In the accompa dyin.g d -fawings Figure I 35 !M(@thods@ and are 'more accurately straight shows diagrammitically an arrangement of 85 which are straight, clean and polished and, polishing, any surface abrasions or irregurqunding, straightening and polishing rolls t W wh ic@ may be utilized in condue g thei me thod of mr invention; Figure is a ge neraijy 'similar view illustrating a varying contact surface of the rolls to . proauce go the rounding effect; Figure III is a diagrammatic section through a blast constituting one of the instrumentalities emplo ve d in conducting my method; Figtire IV is a diagramma-tic plan,view of a coinplo-te-in@tallation capable of coliducting @ly method and Figur@ V is a diagrammatic side eleva' tion of such installation. Iii coi4ducting my method, the, bars or houow rounds, are introduced into the ieed- "O'
[2]2 1,914,587 ing, straightening, and scale breaking rolls, a set of which is indicated generally by the reference numeral 1 in Figures IV and V of the drawings. These rolls may be variously formed and arranged, but so cooperrate as to exert a straightenino, eiffect on the stock, aiid to cause its rotaivion about its own axis. It is also desirable that they have a relatively great. surface contact with the 20 stock, in order to break efficiently the scal6 thereon. With the installation shown, the stock i5 forced by the rolls 1 into the primary set 2 of reducing cross rolls, and is subjected to 15 the steel blast 3 as it progresses. From the pr.,mary set 2 the stock passes by uninterrupted progression through other sets 4 and 5 of cross rolls. The general arrangement of these sets 2, @Q 4, and 5 may be any suitable arrangement, alihough each is shown as comprising two pairs of cooperating cross rolls and an in,termediate idler roll. The only general re26 quirement is that the rolls be so arranged @s to exert a strailrhtening effect as the stock is rounded, trued in section, and polished. As scale is broken progressively aloiig thelength of the stock, it progresses, with the scale broken, past the blast. Primarily the 30 blast scours the stock and tears off the scale which h@s been already ' broken and loosened on it. As the round section is rotated about its own axi , all points on the periphery of the stock are subjected 'equally to the 35' sicale breakirig and blasting actions; and as it ha.s also been subjected to a prelinlinary straizhteni.nlr. it may be passed close to the mouths of blast nozzles 6 so that the bldsting step may be most efficiently conducted. For the latter reason, the size and number of the nozzles, and th6 pressuke at which the blasting material is delivered, will be a minimum for the'dosired P17pose. Where bars are over size they may be cut down S'o that they'are within the specified .tolerance, by the blasting step - of the process. The cutting effect of the blast for this purpose may bo, increased in several ways. 1 0 Thus the longitudinal speed of the stock mo.y be decreased by decre'asin the speed of the rolls. The regulati rspeed may be made in any desired manner, but is conveniently- made by regulating the si)eed of a va@riable speed motor, or jiiotors, di@iving the rolls. The decrease-d speed at which the stock progresses through the blast obviously ri,@ ,sults in an indreased cutting action by the blast 60 Other modes of regulating the b'last action are effected by- regulation @of the blast itself. Thus the'number of nozzl6s in actioii and the pressure at which they deliver abra-, sive may either be increased, or the size of 06 the nozzles m be increased to inerean the ay cutting effect. The most convenient mttnner of reo-ulating the cutting by the blast itself is to provide initially more nozzles than are necessary for a normal des ' caling and scouring step, and cutting in the requi- 70 site additional number of nozzles for the desired trimming down of the stock. - It should be understood that the blasting stop does not affect the sectional contour of the stock to produce a true round from stock 75 which is initially out of round. For example we will assume that a bar is eight thousandths of an inch over size, and seven thousandths out of round. Assuming that the tolerance for size is four thousandths, 80 and that the stock is cut down so that it may be brought within this tolerance by the subsequent operations, the stock is stifl seven thousandths ou t of round. The "rounding up" is effected subsequent to the 85 blasting 6r cutting step in the complete, performance of the finishing.process. The stock is Oitted by the blast, and these surface irregularities 'also are remedied by 90 the subsequent steps of the process. A@ the forward end of the stock progresses past the steel blast,- it is entered between the initial pair of cross rolls of the set 2. In this respect the primary set I of -.rolls serves as feeding rolls for the set 2i A nd the stock 95 is tl-ius positively entered. The idler roll 7 of the entering pair of rounding and reduction cro@s rolls is so conto'ured'as to have a narrow contact A with its cooperatin-& driven roll 8. The stock is 100, therefore subjected to-pressure-on a narrow area, which facilitates roundiiag and reduetion. I The bar is subjected to' further pressure by the action of the second pair of cross @olls, which corriprises, the idler 9 and 105 the driven 'r6ll 10. The idler 9 of this pair is so contoured- that it also has a narrow contact with its cooperating driven roll 10, although the contact B is wider than that of the entering pair. 110 In the second set 4 of rolls the coniact C of i.dler 11 with its driven roll 12 is appreciably wider tha@n that of idler 9 with its roll 10, and the bearing D of'idler 13 with it4g driven roll 14 is wider than that of the 115, pair immediately preceding. . This set of rolls therefore . performs an initial smootliing effect on the stock, although it continues to some degree the ro'u'nding and reducing 120, effect of the first set 2. In the, final set 5 of cross rolls the final smoothing and polishing step is performed; t'he first pair 15 and 16 having a bearing E wider than the'bearing D, and the final pair 17 ind IS having the widest bearing F. It should be understood that the stock is subjected to highpressure throughout the entire worki . hg porfion of the process, which follows the bli'st-ing gtep. In the initial pair of cross roM,, the bear@ng being least, the
[3]elffective pressure is greatest. In succeeding passes the effe6tive pressure is progressive-@ ly decreased in favor of a wider area of contact for smooth ' ing and polishing. 5 In the installation shown, each of the sets comprises an intermediate idler roll 19, which cooperates in producing tl@e straightening effect. During the finishing operation it is im10 portant that the stock be maintained under a tensioneffecti-ve in the direction of its longitudinal travel. By placing the stock under tension from the point at which it is first gripped by two pairs of rolls, which 15 exert a relatively high degree of pressure on it, there is no point or region in whic.'Ii the stock is subjected to severe pressure without the relief afforded by placing it, under tension. 20 The stock may be placed under tension in seve I ral ways. One such way of producing the tension is the progressively inereiised area of contact surface of succeeding pairs of rolls. This in itself tends to pro25 duce increased speed of longitudinal travel of the stock as it progresses, and thereby places the Aock under tension. Amother way in which the tension to which the stock - is subjected may be produced or increased 30 is to make the rolls (in the installation disclosed'eaeb driven roll of a pair) of pro'gressively increased diameter. That is, the driven rolls 8, 10@ 12@ 14, 16, and 18 are of prog@essively increased diameter. This.pro35 gressive, increase in roll diameter also results in a tendency toward progressi-@ely increased speed of longitudinal travel of th ' e stock, and in the typical installation shown SUI)plements the tendency toward increased Ion-6itudiiial speed resulting from t'.le progre@@sively incr@ased areas of contact with the stock. As illustrated, a ptogressive increase in @ontact area in successi,ve pairs of cross rolls is obtained by graduated roll contour to secure this result. It may, however, be obtained by a progressive adjustment of the angle at which succeeding pairs of cooperating rous are crossed. When the -rolls are contoured t 0 Eive progressively iner easod contact surfac@s, the angular adjustment may still be utilized to effect a final regulation of the areas of contact, and to accommodate for various runs of stock which differ in size. It may be stated generally, that.-I talce rough, unfinished rounds of steel or other material, and op@rating oii the stock while it is cold, so treat the stock that its surface is freed from scale, and it is sized, rounded, straight@ned, and 'polished. In the case: of solid rounds, or bars, the stock is then ready for immediate shipment. In the case of horow rounds, or tubes, the finishing is complete except for possible interior scale; 3 which, if pres6nt, has been broken and is in condition for ready removal. - These results are obtained by an automatic, continuous, and rapid process, and without detriment to the qualities of the material in the rounds so 70 treated. It should be observed that the process eliminates the slow and laborious operations, and repeated handling of stock, encountered iia producing polished, straight, 75 round sections by the methods now in use. For example, iii the cold drawing process, - it is the practice that the stock be subjected to pickling baths for the removal of scale and neutralization of acid, to pointino, in a 80 pointinly machine or in the drawing die, to "slushil@g" 9 th.at is coating wit@ a lubricant for drawinz, and to drawing. After drawing, the st6@k must be cropped, this cropping being a machine, operation which in- 85. volves the discarding of a substantial amount of material. The stock is also straightened, either before or after cropping, and coated for protection against rust. In my method the equivalent of all these OP- 90 erations'is effected auring a single passage of the stock. It is further a fact that the cold drawing step is injurious to the metal, because of the excessive severity of the working in the Ds. drawing die. My method thus in practical effe ct produces finished stock, physically supe rior to cold drawn stock. Th e process may be conducted by various instrumentalities, variously arran ed. 106 For example, application of the pressure in &'sp iral path may be obtain@d by rotating the pairs of cooperating rolls about the axis of the stock, instead of rotating the stock abou t its own axis. 1(5 Fu rther, when the bar is'rotated about its own axis it is possible to obtain the desired resul t by the application of. the prilici@les of the present process to roll installation of various types. For example I may em- 110 ploy a cross roR.. iristallation iii which all ihe rolls are driven, and an installation in whic h all irolls are driven and are E@lso ailgularly adjustable. As concerns the intermediatie@ pressur here@n@ roll 115 illustrated in each set of rofls , this may be replaced by a pair of cooperating rolls. This pair may be both driven, both idle, or one driv6n and one idle. They de-. sirably, but not nee6ssarily are so mounted 120 that they may be angularly adjusted. Thev are, necessarily, so mounted 'that they eioperate with each other, and with the other pa irs of rolls in prbducing a straightening effect. IZ5 It is a further important advantage of the process that the surface compression produced by the cold working of the stock results in a marked increase in the fatigue strength of the metal. This is true not only 130
[4]4 2$9l4i587 for steel, but also in the case -of non-ferFous metals such as copper and bron@e. The improvement in this pliysical quality of the metal is obtained without impairing any othe@ physical quality, of the original rnaterial. I
