US1622744A - Tube-forming mill - Google Patents

Description

rch '29 1927. Ma R. c. STIEFEL TUBE FORMING MILL Filed April 5, 1926 I Ilm 4 Sheets-Sheet l F'LBJ.

l WT/VESLSES March r29, 1927 R, C, sTlEr-'EL TUBE FORMING MILL Filed April 5, 1926 4 Sheets-Sheet 2 FIE.Z..

mandi? 1** Zmfllw 1927. 1,622,744 March 29 R. c. STIEFEL TUBE FORMING MILL Fild April '5, 1926 4 sheets-sheet s 1927. 1,622,744 March 29 R. c. STIEFEL TUBE FORMING MILL Filed April 5, 1926 4 Sheets-Sheet 4 FIELE.

Aam,

laccata! Mm. 29, '1921.

man c. s'rmrnr., or nL'Lwoon ein, PENNSYLVANIA.

Tuna-.romaine .appiieatian'aiednprn 5, 192s. serial ma 99,7%?.

The invention relates to the generaly type of tube-forming .mills in which a heated piercedbillet or' other tubular blank is in-- termittently acted .upon increment-by-increment to elongate it and reduce its wall thickness, the blank bein mounted upon a mandrel which is intermittently moved into andy through the mill to present successive increments of the blank to the action ofthe mill, and the invention has particularly to do with mills of this Atype in which successive increments of a blank are acted upon by a series of uniformly grooved rolls which have orbital movements about central axes.-

The object of the invention is to improve the construction and operation of mills of the type described.

The invention is illustrated in the accompanying drawings, ofwhich Fig. 1 is a vertical central sectional view through a mill in the 'plane of its workin@r pass, this plane being indicated bythe ine I-l, Fig. 2; Fig.` 2 a vertical central sectional' view of the mill taken at right angles to Fig. 1, the

lane of view being indicated by -the line li-II, Fig. 1; Fig. 3 a detail vertical sectional view-taken on the-line III-Ill, Fig. 2; Fi i a detail sectional vievvtaken on the line l -IV, Fig. 3; Fig. 5 a horizontal sectional view taken on the line V--V, Fig. 2;

and Fig. 6 a view corresponding to Fig. 5 illustrating a modication of the mounting of tube-forming rolls.

The mill provided according to this invention comprises a pair of driven shafts rotatably mounted in a suitable housing, around each of which there is arranged a series of grooved forming rolls held in spaced vrelation to each other. Each of the several grooved rolls forming this series has p a peripheral portion in bearing contact with a cylindrical face of the shaft around which the rolls are disposed, the arrangement being such that the shafts'rotate the grooved rolls in ka manner similar to the actionA of a planetary gear. Provision is made for causing the two series of grooved rolls to move at uniform angular rates about the axes of the shafts upon which they bear so .that the rolls forming the two series cooperate in pairs to act upon successive increments of a tubular blank. The mill is intended to be used in coordination with a suitable feeding mechanism adapted tol intermittently advance a mandrel and its supported blank between the functioning of each pair of grooved rolls to 'present successive increments *y ofthe blank to the successive pairs of actin`g rolls, the feeding Amechamsm bein also adapted to rotate the blank on its longitudinal axis through anl angle of 90 between the action of successive pairs of grooved rolls, this turning being el.'-

fected at the saine time the blank is moved forwardly. Because such blank-feeding mechanism iswell known in this art, and because various forms of it may be used in coordination with the' mill provided according tothis invention, no such feeding mechanism is illustrated in the drawings.

Having reference now to the illustrative embodiment of the invention, a pair of shafts indicated as a whole by the letters A and B are suitably supported by a housing 1, the lower shaft B preferably having no provision for vertical movement, and the upper shaft A being mounted for a limited vertical movement, the extent of which may be determined by screws 2. Since beth of these shafts are preferably constructed alike.. and are so shown in the drawings, the explanation of their construction will be limited to a description of shaft A. Adjacent to its ends it is provided with bearing portions 3 which' are rotatably mounted on bearing blocks 4, andat its ends it is provided with angular portions 5 for connection to wahble'rs or other suitable drives. Adjacent to bearing portions 3, this shaft is provided with shoulders 6 surrounding which there is a cage 7 for supporting the ends of a series of grooved tube-forming rolls 8, the cage being rotatable upon the shoulders, but, for a reason presently to be explained, preferably having friction bearing contact with the shoulders. The central portion 9 of shaft A is cylindrical and affords a bearing for peripheral portions of the grooved rolls.

As shown in Fig. 4, cage 7 may comprise a ipair of rings 10, one surrounding each of =the shoulders 6 of shaftA, each of which rings isprovided with al series of inwardly extending arms l5 arranged between rolls 8 and meetin grooved ro ls in bearing blocks 1.9 supported for movements radially of shaft A in suitable radially disposed pockets formed on the inner or a jacent faces of the rings 10 of cage 7.

Provision is made for continuously holding the eripheral bearing portions of 8 in contact with the cylindrical portions 9 of shaft A. To such end, the peripheries of cage rings 10 are preferably provided with a plurality of arc-shaped springs 25 each having its ends yieldingly bearing upon the outer faces of an adjacent pair of bearing blocks 19 to urge them toward shaft A. These s rings may be attached to cage 7 by suita le bolts26. Provision is also made for causing cage 7 to rotate with shaft A at such times as the grooved rolls may not be acting upon a bla-nk. This may be done in whole or in part by the frictional contact of the inner bearing Surfaces of caffe rings 10 upon shaft shoulders 6. In addition to this, friction rings 27 may be arranged between the inner faces of cage rings 10 and off-set portions of shaft A, the friction rings being provided with projections 28 which engage the cage rings. These friction rings are yieldingly pressed into engagement with shaft A by means of a plurality of springs 29 so that additional force is applied to cause the cage to rotate with the shaft when pairs of rolls 8 are not in engagement with a blank.

Surrounding shaft B there is a ca e 7 which supports a series of grooved rol s 8, the construction and arrangement of this cage and rollers being the same as the corresponding parts surrounding shaft A. To the end that the several rolls 8 and 8 forming the two Series may be brought into tubeforming positions in pairs, cages 7 and 7a are caused to move at uniform angular rates about the axis of their contained shafts by providing the peripheries of these cages with intermeshing teeth 30 and 308.

In the embodiment of the invention illustrated in Figs. 1-5 forming rolls 8 and 8 are arranged with their axes parallel to each other and to the axes of shafts A and B. If de iied, the forming rolls may be mounted to form pairs of cross-rolls. In other words, they may be so supported in their cages that their axes cross each other when they meet in pairs in tube-forming or reducing positions. To this end, as shown in Fig. 6, rolls 35 surrounding shaft A may have their trunnions 36 mounted in oblique openings 37 in bearing blocks 38 supported by a cage 39, and the second series of rolls 40 surrounding shaft B may be similarly mounted in a cage 41, the axes of the rolls crossing each other as shown. By so mounting the two series of forming rolls, a tubular blank being acted upon by the rolls is turned on its longitudinal axis by the cross roll action of the rolls.`

In the operation of the mill, having reference particularly to the embodiment of the invention illustrated in Figs. 1-5, a tubular blank 45 is supported upon a mandrel rod 46, which, by any suitable form of feeding mechanism, is intermittently advanced to present successive increments of the blank to the action of cooperating pairs of forming rolls 8 and 8, and is turned on its longitudinal axis through an angle of between the operation of each-pair of forming rolls. Shafts A and B are suitably driven in the directions indicated in Fig. 1 by the arrows placed on these shafts with the result that rolls 8 and 8a are caused to roll upon blank 45 in the directions indicated 'by the arrows on the pair of these rolls shown in Fig. 1 as being in contact with the blank. The rotation of the successive pairs of cooperating rolls 8 and 8n causes the cages to rotate in the same directions as shafts A and B, as is indicated by the arrows extending through the rolls'8 and 8a shown in Fi l as being in contact with the blank. T e intermittent rolling action of the pairs of rolls 8 and 8 serves to reduce the wall thickness of the blank and to elongate it as generall indicated. Pressure 1s im arted to the lank through the forming rol by the peripheral bearing of the formin rolls upon shafts A and B which hold t e formin rolls in definite spaced relationship to eac other so that the reduction and elongation of the blank is uniform throughout. During the interval elapsing between the operation of successive series of forming rolls, cages 7 and 7a are rotated to present a succeeding pair of forming rolls to the blank both b the friction of cage rings 10 on shaft sho ders 6 and by the friction drive imparted to the cages by the shafts through friction rings 27. After the tube has been reduced and elongated, such irregularities as may appear on its outer surface, and as usually appear on tubes formed by mills of this type, may be removed in the well known manner by passing the tube through a reeling mill.

According to tlie'provisions of the patent statutes, I have explained the principle and operation of my invention, and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced by other forms of.

mills than that particularly illustrated and described.-

I claim as my invention:

1. A seamless tube-forming mill, comprising a pair of rotary shafts, a series of grooved forming rolls held in spaced relation to each other around and having preipheral ortions in bearing contact with a cylin rical face of each of said shafts for imparting rotation to the rolls, and means for causing said two series of rolls to continuously move at uniform angular `rates about the axes of the shafts upon which they b bear.

2. A seamless tube-forming mill, comprising a pair of driven rotary shafts, a rollsupporting cage mounted for rotation upon each shaft, a series of rotatably mounted in each cage in spaced relation to each other, and having peripheral portions in bearing contact with a cylindrical face of the shaft Within the cage, and means for causing the cages to continuously move at uniform angular rates about the axes of their respective supporting shafts.

3. A seamless tube-forming mill, comprising a pair of driven rotary shafts, a rollsupporting cage mounted for rotation upon each shaft, a series of grooved forming rolls rotatably mounted in each cage in spaced relation to each other, yielding means for grooved forming rolls to operate in pairs' holding peripheral ortions of said rolls in earing contact Wit a cylindrical face of the shaft Within the cage, and means for causing the cages tocontinuously move at uniform angular rates about the axes of their respective su porting shafts.

4. A seamless tu -formingI mill, comprising a pair of driven rotary shafts, a rollsupporting cage mounted for rotation upon each shaft, a series of grooved forming rolls rotatably mounted in bearings arranged in each cage for movements radially; of its contained shaft, means acting through said bearings for holding peripheral portions of said rolls in bearing Contact With a cylindrical face of said shaft Within the cage, and means for causing the cages to continuously move at uniform angular rates about the axes of their respective supporting shafts. In testimony whereof, I sign my name.

RALPH C. STlEFEL.

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