US974744A - Method of manufacturing seamless tubes. - Google Patents

Description

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Pantemed Nov. 1, 1910.

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o BBIBDB METHOD OF MANUPAGTURING SEAMLBSS TUBES. y

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O/ l f OTTO BBIEDE, OF .'BEJRATH, NEAR DUSSELDORF, GERMANY.

.- METHOD orilzanarac'rvmne snAmLnss TUBES.

To all 'whom 'it may concern:

Be it known that I, O'i'ro Barnim, residing at Benrath, near Dusseldorf, Province of the Rhine, German Empire, a subject of the German Emperor, liaveinvented or discovered certain new and useful Improvements in Methods of lllanufjacturing Seamless- Tubes, of which improvement the following is a specification.

1o Heretofore in reducing hollow billets to tubes, the billet was made of an internal diameter corresponding approximately to that desired in the finished tube, but the external diameter is made greater than that of the finished tube. And reduction is effected by subjecti the external surface of the billet to reducing surfaces of y progressively reduced caliber. In other werds, during reduction from billet to tube, the internal di- Y ameter of the former remains practically 'unchanged while the external diameter is reduced.

The invention described herein has for its object the reduction of a hollow billet to tube form by increasing the internal diameter ofthe billet, without decreasing the external diameter of the finished tube ma terially beyond the original external diameter of the billet. The invention is hereinafter rr ire fully y. described and claimed.

` In the accompanying drawings forming a part of this specilication Figures 1 and 2 show in side elevation different forms of mandrels, Fig. 3 is' a diagrammatic View illustrati o' m im roved method. Fi 4 nh y p g provided with a suitable coupling member l shows transverse sections in planes indicated respectively by w-a, b-b, {:--c, and Fig. 3; Fig. 5 is a view showing the vposition 40 of the billet and mandrelv at the beginning of a forward or working strokeand after the rolls have been separated ai/id the inandrel and billet turned axially ninety degrees; Fig.- 6 is a transverse section in a lane indicated by the line c-e Fig. 5; Fig.

is a. view partly in section and partly 1n elevation of a forni of apparat.us adapted to the prartice of my invention;-

1g. 8 is a transverse section in a lane indicated by the line VIII-NIH; Fig. 8 is a sectional detail view illustrating a portion of the feed mechanism. Fig. 9 is a diagrammatic view illustrating the employment of u. plu# rality of pairs of rolls and Fig. 10 is asec- 55 tional view of another form of mill adapted Specication of Letters Patent.

Application led February 15, 1910.' Serial No. 544,082.

-Patented Nov. 1, 1910.

tn the practice of the invention and Fig. 11 is a sectional plan of the saine.

In' the practice 'of my invention, the billet is rolled or otherwise reduced to a diameter equal or approximately equal to the external 151)A i diameter desired in the tubeto be formed. After the billet has been pierced, which how ever-is not necessary, it is slipped onto' a mandrel 1 having a portionof theA end enlarged and conical as at 2 and an adjacent 85 Y portion 3V cylindrical and of .a diameter equal to the desired internal diameter of the finished tube. The portion 2, which may be of any suitable form as for example a cone with straight sides 'as s'hown in Fig. 1 or a 70 paraboloid as shown in Fig. 2, connects the stem 4 of the mandrel with the cylindrical portion 3. It is preferredthat the cylinc drical portion should be given a slight taper from or approximately from the plane of junction of the portions 2 and 3, so as to facilitate the movement of the finished p01'-l tions of the tube ofi of the cylindrical fi'nisli-L ing portion of the mandrel.

Afterthe billet has been slipped on the mandrel the stem 4 of the latter is connected to a suitable mechanism for reciprocating it and after each reducing movement, imparting a partial rotation to the mandrel. A suitable form of such mechanism consists of a slide 5 mounted on a bed 6 which is arranged in feed relation to the reduc rolls 7. This slide is connected to a cran arm 8 of the shaft 9 which'can be rotated by any suitable means. A connecting shaft 10 is rotatably mounted on the slide and is 11 whereby it may be connected to the stem of the mandrel as -shown in Fig. 7. Any suitable means may be employedjor rotating the mandrel and billet as for example one end of a clock spring 12 may be attached to the shaft 10 and its opposite end to an externally toothed shell 13 en aging a pinion 14 loosely mounted on a s aft 15, 100

von which is loosely mounted a pinion 16 having angularly arranged teeth adapted to engage inclined teeth on a stationary rack bar 17. The shaft 15 is mounted in suitable brackets depending from the slide 5, and it reciprocates with the latter. l'lherefore when the slide is reciprocated corresponding back-and forth rotation will be imparted to the pinion 16. When the pinion is rotated in one direction z'. e. during a 110 thereby rotating the toothed shell 13 and v placing the spring under tension, which will become operative to rotate the mandrel and billet as soon as the latter is released from the grip of the rolls at the end of the working stroke.' During the return stroke of the slide the toothed shell will not be rotated. Provision is made for forcing the billet farther in the mandrel at the end of the `reducing stroke of the latter. A. convenient means to this end consists of a ratchet dish 18 keyed to a screw threaded spindle 51 mounted for rotation in suitable bearings of the frame of the machine. The awl b of the said ratchet disk is dispose on a rocker arm 52 mounted on the spindle 5l. A finger of the said rocker arm is adapted to be engaged and to be rocked by a cam face 53 provided on the slide 5 whenever the latter reaches the end of its return stroke. By the pawlv b such rocking movement is transmitted to the ratchet disk 18 and the vspindle 51. When released from the said cam the rocker arm is retracted into its normal position by a spring. The shaft 51 is threaded and engages a threaded opening through a downwardly projecting lug21 on a slide 19 which is provided with a wall or abutment 20, adapted to bear against the rear end of the. billet. In order that the whole of the billet may be reduced, a sleeve 23 is interposed between the rear end of the billet and the abutment, said sleeve being preferably integral with the abutment 20 and made of a length a little greater than that of the conical ortion of the mandrel and of such interna shape and dimensions that such conical portion may enter the sleeve. The abutment 20 is advanced toward the mandrel whenever the slide reaches the end cf its return stroke. In order that the billet may be turned axially after each forward movement, provision is v made for relieving the exterior surface of the billet of any retarding J rictional resistance of the rolls. This can be accomplished in many ways, as by using recessed or sectional rolls or swages, well known in this art, or by separat-ing the rolls a sutlicient distance to permit of the free movement of the billet axially and longitudinally.

As shown in Fig.'7 provision is made for shifting one of the rolls toward and fromk the other by means of wedges 24 movable under the journal boxes of the lower roll. These wedges should be shifted to drop the lower roll at or about the time the billet and mandrel reach the limit of their forward or reducing movement. At. or about the time the mandrel reaches the limit of its return or non-working movement. the lower roll is again raised to its operative or reducing position. These movements of the wedges to raise the roll are effected hy any suitable means, as for example by a cam 25 on the shaft 9 acting von an arm 25l on a counter shaft 26 which is provided with arms 27 connected by rods 28 to thewedges, which are shifted in the opposite direction to drop the lower roll by springs 29 or other suitable means.

In describing the method as carried out by the construction shown in Figs. 3 to 8 inclusive, it will be understood that a reduction has been completed by the rolls and that the latter and the billet and mandrel are in the position shown in Fig. 3. During such reduction the billet has been caused to assume the transverse relations to the mandrel shown in Fig. 4, by the rolls which are provided with grooves forming an oval pass, so as to avoid tinning of the metal. As soon as the several parts reach the position shown in Fig. 3 the billet is released from the bite of the rolls by dropping the lower roll, and the rear end of the billet strikes against the shiftable abutment 23, so that it is slipped farther on the mandrel. This action is facilitated by the oval shape of the billet imparted thereto by the previous reducing operation. By this movement of the mandrel into the billet the latter is enlarged peripherally along that portion in contact with the conical portion of the mandrel as indicated in Fig. Furthermore the turning mechanism is thrown into operation, and turns the billet at an angle of 90 degrees, whereupon the mandrel and bil# let perform their return movement to the left. At the end of their return movement Y the billet and mandrel are moved forward or in a direction to cause a reduction of the portionof the billet enlarged by the mandrel, the metal displaced in such reductions causing an elongationv along the portion operated on. As before stated the grooves in the rolls are so shaped as to form an approximately oval pass or of such shape and dimensions relative to the tube to be roduced that the upper and lower walls o.. the pass will act reduetively on about'one quarter of the perimeter of the billet; and as the billet at the beginning of each reduction is circular or approximately so in cross-section the pressure of the rolls will cause not only a longitudinal ow of the metal but also and to a limited extent a lateral flow so that the side ortions of the billet will be forced away from the mandrel. After a reducing movementvof the billet and ninndrel or one to the right in Figs. 5 and 7, the billet is relieved of the pressure of the rolls, the billet and mandrel are turned through an are of 90 to the position shown in Fig.

6.. and the mandrel and billet moved relative to each other so as to Ycause an enlargement of a portion of the billet for a distance ap-A cal portionk of the mandrel. f

It will. be observed that two reducin e1ements are employed z'. e. tliemandre and the grooved rolls or sw'aging or reducing members.v It is immaterial which of these, .the mandrel or rolls, is moved relative to proximatelv equal to the length of the conithe other. Inaddition to the reducing elements, a feeding movement'of the billet relativeto the mandrel is effected intermediate of billet Vreducing operations. The rolls f while reducing the billet should have a. peripheral movementcorresponding to the rec- Y rolls.

tilinear movement of the billet and this movement of the rolls may be eilected in any suitable manner, as for instance by contact with the surface of the billet. As shown in Fig. 9 a plurality of pairs of rolls may be I employed, successive pairs of rolls being arranged with their axes at an angle to the axes of adjacentl rclls. When using a plu..

rality of pairs of rolls the billet need not be turned axially and if a sulicient number of pairs be employed a billet may be reduced to tube form by acontinuous movement through a single train of rolls.

In Fig. 10 is shown a mill adapted to the practice of the improved method and having the rolls rotatin in a plane at an acute angle to the axis o the mandrel, whereby the path of the rolls on the billet can be of any desired length by changing the angular relation of the rolls to the axis of the billet. In this construction the rolls are positively driven in such direction as to travel in a spiral path from a point ad'acent to the point of the conical portion o the mandrel j to the cylindrical portion thereof, and `to` this end provision is made permitting a. movement of the mandrel carrying the billet and the rolls relative one to the other. In the construction shown, the housing 30 in which the rolls 31 are mounted with .their axes at an angle to each other and to the axes of the mandrel '1, is stationary while the bed 32 carrying the mandrel and the billet feeding means is movable relative to the In the construction 4shown the bed 32 is provided at its ends with vertical abutments 33 and 34 which carry fluid pressure cylinders so arranged that their rams or pistons 35 and 36 bear against o posite sides of the housing 30. By means ci) suitable valve mechanism such as is well known in the art the low ofv fluid pressure to and from said cylinders is regulated to eifect any desired movement of the bed and parts carried thereby relative tothe rolls. A fluid pressure cylinder and piston 37. are so mounted onV the abutment 33 as to be capable of forcing the billet into the mandre which is held as ings 38-and 39 are interposed between the piston rod and billet, and between the mantion shown wedges 40 are employed for shifting the lower roll. The end 43 of one of the Wedges strikes against and is shifted by a stop 44 at the end of the working stroke thereby permit-ting the lower roll to drop and at the end of the return or dead stroke or movement the face 41 will strike the abutment 42 and shift the wedges in a direction to cause the rolls to assume normal or operative relation to the billet.

In the mill shown in Fig. 10 the rolls will cause a reduction of the portion of the wall of the billet forced by the action of the mandrel substantially as before stated. By arranging the rolls as in Fig. 10 the conical,

portion ofthe mandrel may be made of considerablelength without unduly increasing.

the size of the rolls. After the completion of a working or reducing stroke the billet is released from the grip of the rolls, and Vthe mandrel and billet are returned to initial position and during this movement the `billet is advanced on the mandrel by means of the cylinder and piston 37. As is Well ilmcwn in the art the axial rolling of the billet has a tendency to open up the metal adjacent to and along its axis thereby facilitating the penetration of the mandrel into the billet at each feed movement.

While for convenience of illustration and description it has been set forth with some nal and external dimensions of the billet and then as a. part of the same operation reducing the external dimensions of the S8 me.

2. The method of manufacturing seamlessv tubes-which consists in alternately and successively increasing the internal and external dimensionsof a billet and reducing the external dimensions thereof.

3. The method of manufacturinff seamless.

tubes which consists in progressively increasing the internal and external dimensions of a billet and progressively as a part of the same operation reducing its external dimensions.

4. The method of manufacturing seamless tubes which consists in enlarging the external dimensions of a billet by a radially acting force and then as a part of the same operation reducing the external dimensions.

' The method of manufacturing seamless 5 tubes which consists in progressively step by stepy increasing the internal dimensions of a hollow billet and then step by step reducing the thickness of the wall of the billet while maintaining the increased internal di- 1.0 mensions.

' my hand.

' OTTO BRIEDE.

Witnesses:

'HENRY HASPER,

WoLneMAn HAUPT. Y

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