US1139957A - Manufacture of seamless tubes. - Google Patents

Description

S. E. DIESCHER.

MANUFACTURE OF SEAMLESS TUBES.

APPLICATION FILED. MAY 22. 1914.

1,139,957. Patented May18, 1915.

2 SHEETSSHEET I.

FIGJ- wL/ITNESSES I A I EN-VENTOR s. E. DIESCHER. MANUFACTURE OF SEAMLESS TUBES. APPLICATION FILED MAY 22, IBM.

1,139,957. Patented May-18, 1915.

2 SHEETSSHEET 2.

F'IG.'4.

MJLKTZZ WITNESSES UNITED STATES PATENT OFFICE.

' ZDII lSCHEB, 0F PITTSBURGH, PENNSYLVANIA MANUFACTURE OF SEAIELESS TUBES.

To all whom it may. concern Be it known that I, SAMUELE. Dmscnnn,

residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, a citizen of the United States, have invented or discovered certainnew and useful Improve ments in the Manufacture of Seamless.

Tubes,.of which improvements the following is aspecification. 4

In all rolling operations the metal will 'flow in the direction of movement of the piece, causing elongation and if not confined will also flow at an angle to the line of feed, and the movement of the metal in these directions will be approximately proportional to the relative dimensions of the area of contact of the rollson the metal. As for example inrolling sheets, the areas of contact of the rolls with the metal in the direction of movement of the sheet isvery narrow, while in the direction transverse of the sheet, the contact area is very wide and is equal to the width of the'sheet. Hence the flow of metal transverse of the feed of the sheet is practically nil, and the entire flow is in the direction the article. In the Mannesmann and other type of of the movement of mills employing reducing surfaces acting at an angle to the axis of the article, for manufacturing seamless tubes and also in reeling machines, the rolls are arranged so thatthe tube is fed through between the rolls b a screw-like motion. In such mills, whet er the reducing surfaces. are convex or approximately flat, the dimension of the area of contact of such-surfaces on the metal isin the direction of feed of the tube or bar' very much greater than its" extent at an angle to the direction of feed, and hence elongation 1s due more to a spiral movement of the metal than to its direct flow in lines parallel with the axis of tube. As will be readily understood the spiral flow of the metal subects the latter to very severe strains which are increased by the flow parallel with the axis. As only the surface metal is displaced 1n the reehng operation, these strainsare negligible, but in reducinghollow billets to.

tubes as in the types of mill referred to the entire mass of metal is displaced as described, and subjected to such severe strains that only a high eglrade of metal can be successfully employ s'ugy the employment of concave reducing aces Specification of Letters Patent. Application filed May 22, 1914. Serial No. 840,190.

feed 0 properly proportioned as regards metal which 7 under some conditions will Patented a 18, 1915.

rolling operations there occurs a gbackward. displacement of cause a swell otvenlargement'in front of the rolls tending to; increase the area of contact of the roll surfaces with the metal. Although the frictional engagement of the reduc-' ing surfaces with the surfaces of the swell or enlargement would be "relatively small, there would be insuch cases a tendency to force in more metal between the rolls. When reducing tubes by surfaces as hereinbefore described, the reducing surfaces will have such an -'efi'ect on the' metal of the swell or enlargement as to icause it to move to points vwhere the metalis unconfined and impart an oval or irregular} cross-sectional sha e to the portion of the billetbeing opera on, and the irregularity thus imparted will appear although to a less degree in the finished tube. By reason of this actionit has been found ractically impossible to control the f the tube and the feed will generally increase as reduction proceeds.

The invention described herein has for its object the reduction of the percentage of metal flowing circumferentially relative to that flowing longitudinally in treating hollow billets and tubes, thereby avoiding the straining of the metal; the regulation of the feed of the billets and tubes between the rollspthe application of a drawing or pulling force durin the reduction thereby improving its qua 'ty; reducing the tendency of such movement of the metal as will imput an oval shape to the metal being worked on, and to insure uniform external and internal surfaces in the finished article.

The invention is hereinafter more fully described and claimed.

;In the accompanying drawings forming a part of this specification, Figure 1 is a sectional view showing concave, reducing surfaces for rolling. down hollow billets and hav ng gny improvement applied thereto;

Fig. 2 is an end elevation of the reducing members, one being shown in section and showing the position of the controlling ring relative to such members; Fig. 3 is an end elevation of the rolls of a reeling machine, and. showing the controlling ring" in posi-- tion; Figs. 4: and 5 are sectional views on planes indicated respectively by the lines IV-TV and V-V Fig. 3. I

While the improvement forming the subject-matter of this case is shown and de scribed. as regards the reduction of hollow billets in connection with the form of reducing surfaces shown and described in Letters Patent No. 1,067,806 dated July 22d, 1913, the improvement is equally applicable to the rolling down of hollow billets by convex surfaces acting at an angle to the axes of the article under reduction, and is also adapted for use in connection with reeling machines.

By reference to Fig. 1, it will be seen that the reducing surfaces ofthe' annuli l and 2 are divided into what may well be termed preliminary surfaces extending from a to Z), and final or finishing surfaces extending from b to 0.. As described and shown in said patent the annuli are so'con-.

structed and adjusted relative to each other and to the axis of the tube while passing through, that the surfaces between 6 and c which receive the metal from the surfaces between a. and b and efiect the final reduction are substantially parallel with or at a very acute angle to the axis of the tube. The initial or preliminary surfaces a b have an inclination to the axis of the tube much less .acute than that of the surfaces b ,0. These surfaces are made of such a length that the mouth of the bell which they form for the reception of the billet has a diameter greater than that of the billet to be reduced. When the billet is fed into' the bell, its end will strike the surfaces 11 b at the points a: approm'mately midway of the length ofthese surfaces. It will be understood however that the points of contact of j the billets on these surfaces will depend for a given size of annuli, on the external diameter of thebillet the larger the billet the farther forward will be the points of conv pered so that the billet can be readily intact and vice versa.

As the billet. is? drawn in by the screwlike action of the annuli, there will be a gradual reduction of the billet until it passes between the surfaces 6 0, when the rate of reduction becomes small. By the action of the surfaces between a h and l) 0, 5b a portion of the metal will flow longitudipendent as before stated on the relative dimensions (circumferential and longitudinal) of the areas of contact of these surfaces with the metal. I By reference to Fig. 1 it will be seen that there is also a dis- 7 stated.

nally and a portion circumferentially deplacement of the metal forwardly from the points of contact w. This forward displacement increases the area of contact be tween the annuli and the metal both circumferentially and longitudinally. The feed of the billet tends to crowd this forwardly displaced metal between and through the contracting walls of the bell formed by the annuli, but as movement of more metal longitudinally is practically impossible, there will be an increased flow circumferentially due in part to' frictional engagement with the revolving annuli and partly because there will be less resistance to flow in that direction. In this circumferential movement the metal will pass beyond the confining surfaces of the annuli and will therefore move outwardly from contact with the mandrel producing an oval shape. This added circumferential flow due as stated to. the crowding into the bell of the forwardly displaced metal, also produces irregularities of feed. v

As the irregularity of feed and the 1mparting of an oval shape are due to the so crowding of more metal into the bell formed by the annuli than the reducing surfaces ,can properly treat, provision is made for so retarding the onward movement of the billet that. metal will be presented to the reducing surfaces only as they are designed to properly treat it in the normal operation of the annuli. This retardation should be capable of automatic adaptation to variations of reductions, and should not prevent the movement of such quantityv of metal as the reducing surfaces can properly care for. A convenient means for retarding the movement ofthe billet and consequent crowding of too much metal, into the bell formed by the annuli consists of a floating ring 3 of any suitable length and having such an internal-diameter relative to the external diameter of the billet as to permit of the insertion of the billet therethrough and inno sure that thering will so engage thebillet as to retard the flow of metal as hereinafter stated. The ring is externally tapered so that its rear end will project as far into the bell as the size of the billet will permit. M5 The bore of the ring should .be slightly taserted into and slide without material friction through the ring except as hereinafter I The billet after passing through the ring encounters the reducing surfaces of the annuli, and by these surfaces the metal is caused to flow longitudinally and circumferentially as beforestated. There is also a forward displacement of metal which will extend forward into the floating ring, thereby causing such a frictional engagement betweenthering and billet as to retard the onward movement of the billet, the ring 139 aim? offeedby its bearing against the annuli.

The frictional engagement between the ring and billet will be, roughly stated, proportional to the metal crowded forward mto the ring, and during the early stages of reduction the retardingaction of the ring'increases progressively until the onward movement of theunreduced portions of the bil-' .let is checked. But as the reducing surfaces of the "annuli are constantly .pushin the metal along, they must when the bi] et 'is checked draw their supply from the metal within the bell formed by the annuli and crowded forward as before stated, thereby reducing the congestion in the bell and in the rear end of the floating ring. As soon as the pressure of the metal within the ring is reduced the billet is free to move forward bore of the ring through the ring until the metal between the surfaces 0' b and in the rear end of the ring becomes congested thereby increasing the grip of the ring on thevbillet and checking its onward movement. 1 It 'has been found that in a very short time a balance is established and the billet will move uninterruptedly forward; 1

When the onward movement of the billet is checked the continued flow of they metal ,will reduce th effectiveness of the surfaces so that in the practice of the improvement i described herein the metal is simultaneously reduced by pressure and tension thereby greatly improving the quality of the finished tube. 4

As 'the'ring rotates with the 'annuli, there will not be any material resistance to the rotation of thebillet by the annuli. In order. to avoidthe forward shifting of the ring by the metal when crowded forward by the reducing action of the annuli, the ring may be held inoperative relation to the annuli by rollers 4 carried by shafts longi-' tudinally movable in bearings 5 in the hous= ing of the mill. By properly adapting the to the external diameter of the billet arate of feed of the billet can be maintained at the center of the reducing area as it will be at the beginning of the reducing action before the forward displacement occurs. This will naturally cause a slippage of the reducin faces which tend to feed faster than the b' et travel throughout reduction of billets.

the entire length of the portion oi the am operated-on; and this slippage hasin turn a pronounced tendency to move the material longitudinally.

It is characterlstic of the reduction by sur faces moving in a direction forming an acute angle with the axis of the article; operated on, that as the metal is gripped and confined only'at two diametrically opposite points, the" metal in its circumferential flow will at points intermediate the reducing surfaces move away from the mandrel and the resulting tube will be irregular in crosssection. But as in the improved method herein described, the metal tendingto move transversely awayfrom the mandrel is subjectedto a. longitudinal pull as 'before described, such movement away from the mandrel is reduced and by properly adapting the boreof the ring so as to'obtain a maximum stretching actlon, the inner wall of the hereinafter stated the reducin surfaces (1 b are so constructed that there w' be a greater flow ofithe metal acted upon by said surfaces,

longitudinally than circumferentially, and as the stretching action occurs mtermediate the surfaces Z2.v 0., and the ring, the resulting tube will be practically round.

The floating-ring can be used in connection with convex reducing surfaces whether 'used for reducing a hollow billet to a tube or adjusted merely for straightening and truing tubes as shown in the reeling machine illustrated in Figs. 3, 4and '5.

The reeling machine shown in Figs. 3, 4

and 5 consists ofrolls 6 having their axes tube may be held close to the mandrel. As

at an angletotlie direction of feed .of the tube so that the latter is moved forward by a screw-like action of the rolls on the tube. A mandrel 7 is so arranged between the rolls thatthe tube as it is drawn between the rolls will be forced over the'mandrel. In feeding, the tube passes through the ring 3 before enterin'g'the bite of the rolls, and although the .metal displaced in reeling is small comparedtothe displacement eifected in reducing. hollow billets, the action of the ring does not differ in kind from that explained in connection with the herein, will in most cases render sizingand,

subsequent operations unnecessary.

\ In the form of reeling machine herein shown the main rolls 6 are so arran ed that the axis of the tube when. passing tween the rolls is slightly above the narrowest space between; the rolls, and order to avoid an upward movement of the tube and mandrel due to such an arrangement-of the g antenna rolls 6,5a3third roll dis'em ployedi- It will be understood that the improved method is not dependent for its practice on any particular form or construction of reeling machine.

I claim herein as my invention: 1. As an improvement in the art of manufacturing tubes, the method herein described, which consists in' subjecting-the hollow articles to the action of reducing surfaces rotating on axes at an angle less than a right angle to the axis of such articles and subjecting the metal while acted on by the reducing surfaces to longitudinal tension governed by the circumferential flow of the metal.

2. As an improvement in the art of manufacturing tubes, the method herein described which consists in applying reducing pressure to a hollow article at an angle less than a right angle to the axis of the article andprogressively around the article and longitudinally stretching the metal while beingreduced, and governing the stretching by the circumferential flow of the metal. n

3. As an improvement in the art of manufacturing tubes, the method herein described which consists in subjecting a hollow article to concave reducing surfaces rotating in planes at acute angles to the axis of the articles, longitudinally stretching the metal while being acted on by such surfaces and governing the stretching action by the circumferential flow of the metal.

4. As an improvement in the art of manufacturing tubes, the method herein described which. consists in applying reducing pressure to a hollow article at an angle less than a right angleitothe axis of the article and progressively around the article, and diverting the circumferential flow of metal induced by the. reducing surfaces by retarding the-onward movementof the billet.

5. As an improvement in the art of manufacturing tubes, the method herein described which consists in applying reducing pressure to ahollow article'at -an angle less than a right angle to the axis of the article and progressively around the article, ap-

plying a retarding pressure to the billet and automatically varying such pressure.

6. In a machine for reducing hollow billets,the combination oftwo rotating members arranged to operate on the billet in direction at an angle less than a rightangle to the axes of the billet, and a ring arranged in front of the rotating members and having an internal diameter slightly greater than the external diameter of the-billet.

7. In a machine for reducing hollow billets, the combination of two rotating members arranged to operate onthe billet in direction at an angle less than a right angle to the axis of the billet, and a ring arranged 5 in front of the rotating members and having such an internal diameter relative to the external diameter of the billet, that while permitting the insertion of the billet it will, during the reducing operation, af-

feet a retardation in the onward flow of the metal.

8. In a machine for reducing hollow bil- I lets, the combination of two rotating members arranged to operate on the billet in directions at an angle less than a right angle to the. axes of the billet, a ring arranged in front of and adapted to be rotated by the said members and having an internal diameter slightly greater than the external diameter of the billet.

9. Ina machine :for reducing hollow billets, the combination of two rotating members having concave reducing surfaces and arranged to operate on the billet in directions at an angle less than a right angle to the axis of the billet, and. a ring, arranged in front of the rotating members and having an internal diameter slightly greater no hand. I

y SAMUEL E. DIESCHER.

Witnesses:

Mien A. 'IRILL, 'Inos. B. Joron.

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