US2042832A - Method and apparatus for cross-rolling tubes - Google Patents

Description

June 2, 1936. s. E. DIESCHER METHOD AND APPARATUS FOR CROSS ROLLING TUBES Filed Sept. 2, 1932 4 Sheets-Sheet l METHOD AND APPARATUS FOR CROSS ROLLING TUBES 4 SheetsSheet z Filed Sept. 2, 1932 ir/4742a I II 0 2 3 4. x. s n. a a J I 3 3 V 4. (x a a o z 3 2a 3 a z x u 4. u i A x M J o 3 2 4 m M\ 2 z z 1 a x .J 2 3 M 1 4 FIG. 5

June 2, 1936- s. E. DIESCHER METHOD AND APPARATUS FOR CROSS ROLLING TUBES 4 Sheets-Sheet 3 Filed Sept. 2, 1932 June 2, 1936. s. E. DIESCHER METHOD AND APPARATUS FOR CROSS ROLLING TUBES 4 Sheets-Sheet 4 Filed Sept. 2, 1952 Patented June 2, 1936 amass v nm'rnon ss-aomme mas FGE Samuel E. Diescher, Pittsburgh, Pa, assignor to Diescher Tube b t I corporation of Dware Inc., Pittsburgh, Pa, a

dpplication'september 2, 1932, Serial No. 631,511

My invention relates to apparatus for cross rolling tubular and cylindrical work-pieces,as, for instance, in piercing work-pieces, elongating and reducing wall thickness of tubular workpieces, reducing the diameter of tubes, straightening tubes, etc., by the action of cross-rolls (which term, throughout this application, is in tended to include broadly members which act 'rotatively and helically to apply premure, for one purpose or another, to work-pieces introduced between them).

In apparatus of this character, when constructed in accordance with certain earlier, inventions I have made, apair of discs (or, in some cases, a single disc) is employed. The peripheries of these discs engage the work-piece between the cross-rolls. The discs are positively rotated, in the direction of the longitudinal progression of the work-piece, at a speed in excess of that of rotation of the discs, than has heretofore beenpossible. Another object isto provide such an apparatus in which the operation of the discs will be improved, and made more emcient and convenient for varying settings and characteris- -,tics' of the work-piece and the cross-rolls. Other and further objects of the invention, and special advantages secured thereby, will appear from the following specification and the claims annexed thereto. Y

A cross-roll mill constructed in accordance with my'invention is described, by way of example, in the following specification, and shown in the accompanyingdrawings. The mill thus selected for description and illustration is one suitable for the elongation and reduction of wall thickness of tubular blanks, and, as shown, employs two discs. The invention can, however, be embodied in other constructions'of cross-roll mill than that shown, and, oi. course, can be embodied in cross-roll mills having purposes other than that of elongating and reducing wall thickness of tubular blanks, and a single disc may, in certain circumstances, be employed in place of a plurality of discs, all within the scope of my invention, as defined in the appended claims.

In the drawings: 5

Fig. 1 is a front elevation of the mill, portions being broken away to display interior parts;

Fig. 2 is a sectional side elevation taken on the line 11-11 of Fig. 1;

Fig.3isaplanofthemill; 10

Fig. 4 is a detafl sectional plan showing the means for laterally adjusting the upper disc;

Fig. 5 is a plan of the lower disc and its associated parts;

Fig. 6 is a detail fragmentary view showing 15 view, respectively, showing the discs as disposed in planes inclined with respect to the line of 20 longitudinal movement of the work-piece, such inclination being exaggerated for purposes oi. clearness of illustration; Fig. 9 is an enlarged end view of the crossrolls and discs, looking in the direction oi! the 25 feed of the work-piece through the mill, and showing such worn-piece, and the mandrel, there- I Fig. 10 is a section taken on the line x-x oi! s. a 30 Figs. 11 and 12 are schematic views illustrating diflerent transverse positions occupied by the discs.

The mill comprises avstand ill in which are mounted, on suitably driven shafts Ii, the cross- 5 rolls II, the same being adjustable to approach or recede from each other in thewell known manner. Upper and lower discs II and M are mounted on shafts l5 and I6 so as to. engage the work-piece intermediate the cross-rolls, the disc 40 shaftsbeing driven, through universal joints l1 and I8 respectively, in such direction thattheir peripheral movement at the points of their engagement with the work-piece is in the same direction, broadly, as the longitudinal movement 45 of the work-piece.

The operation of the cross-rolls and discs will be understoo'dfrom Figs. 9 and 10. In these figures, a tubular work-piece is shown as being elongated, the portion A thereof designating the un- 50.

treated part, having its original shape. the portion A designating the part which is, at the moment, inthe throat of the roll pass, andthe portion A thereof designating the part which has been elongated to produce the tube. B desig- 55 is to bulge into a more pronounced oval than is actually permitted it will be seen that the pressure between the work-piece and the discs is great. The same considerable pressure between the discs and the work-piece occurs in all uses of such discs, whether for elongating and reducing'wall thickness or otherwise, and occasions important friction problems.

Since the work-piece moves helically, the frictional resistance between it and an object engaging it may be regarded as exerted in two di- 'rections,-viz., in a direction circumferential of the work-piece, and in a direction longitudinal of the work-piece. The frictional resistance in a circumferential direction is an important obstacle to successful operation, and is greatly lessened, or may theoretically be obviated entirely, by rotating the discs, in the direction of longitudinal movement of the work-piece, at a speed greater than that of the longitudinal movement of the work-piece. The theoretical formula. for such obviation of the frictional resistance to rotation requires that the peripheral speed of the discs be equal to approximately one-half the speed of rotation of the work-piece divided by the sine of the average angle of. the helix of movement of the work-piece through the cross-rolls. However, to obtain a desired degree of reduction of the frictional resistance of the discs against rotation of the work-piece, it would sometimes become necessary, in previous constructions of cross-roll mills employing such discs, to rotate the discs so rapidly that their friction longitudinally of the work-piece, though taking efiect in a forward direction, would have disadvantageous results.

By the apparatus of the present invention, I am enabled to reduce the frictional resistance exerted by the discs, at any given peripheral speed thereof, against the rotative movement of the' work-piece, thereby being able to obtain a given reduction of such frictional resistance with a less peripheral speed of the discs than would otherwise be necessary. In obtaining this result, the cross-rolling apparatuspf my present invention is constructed in such manner that the discs can be inclined with respect to the line of longitudinal movement of the work-piece, as illus-' trated in Figs. 7 and 8. When so inclined,in such a direction that the planes of the guide discs approach parallelism with the helix of movement of the work-piece, as distinguished from receding from such parallelism,the frictional resistance exerted by the discs against rotative movement of the work-piece is decreased and the peripheral speed of the guide discs need not, therefore, be so great as would otherwise be necessary in order to'obtain a desired result.

In cross-roll mills employing discs of the character herein referred to, it will often be desirable to change the distance separating the discs, or, if only one disc is used, to change the distance between the periphery of the disc and the axis of the pass, or line of pass, between the crossrolls. For example, supposing a tubular workpiece to have been elongated, to produce a tube of a certain diameter and wall thickness, at a given setting of the cross-rolls and guide discs, it would be necessary to separate the discs more widely if it were desired to obtain, with the same mandrel and the same setting of the crossrolls, a tube of the same wall thickness but greater diameter. Similar occasions for varying the distance separating the discs occur in other uses of cross-roll mills employing such discs.

To permit the varying separation of the discs above referred to, the apparatus according to my present invention is made so that the discs can be shifted both towards and away from each other and also in a transverse direction,-and the discs are made so as to engage the work-piece chiefly w the side at which the engagement with the workpiece chiefly occurs, as shown particularly in Figs. 9, 11 and 12. This reduces the necessary total thickness of the discs and permits them to be shifted towards each other without coming into engagement with the surfaces of the cross-rolls, the distance between which latter narrows, of course, as the axis of the pass is neared. The engagement of each disc with the work is predominantly on the side of the work-piece nearest to that cross roll, of the two, which is causing the metal to move towards the disc, or, in other words, is rotating towards the disc, and by the apparatus of my present invention the discs can be placed in close proximity with the crossrolls at the sides of the discs where they thus engage. This avoids spaces, between the edges of the discs and the surfaces of the cross-rolls, into which the metal might tend to flow to the detriment or destruction of the product.

The shape of the guide discs, and the manner of difierently positioning them, will be readily understood from Figs. 11 and 12. Fig. 11 shows the cross-rolls l2 as set, with respect to the mandrel B, for producing an elongated tube of a given wall thickness. The diameter of the elongated tube for any setting of the cross-rolls will be controlled by the position of the discs l3, l4, which are shown as widely separated, so as to produce a tube of relatively large diameter. The separation of the discs is somewhat exaggerated, however, in the figure, for ease of comparison with Fig. 12. It will be noted from the arrows showing the direction of revolution that the cross roll on the right is causing the metal to move towards the upper disc, that such disc engages the work-pieoe on an area nearer to that cross-roll than to the cross-roll on the left, and tha the right-hand edge I 3a, of the disc is disposed in close proximity with the adjacent crossroll, so that the disc immediately intercepts and deflects the metal as it moves from the cross-roll.

cross-roll on the left. This provides room for the disc to be moved further in towards the axis of the pass, and for the disc to be moved to the ameter.

left (so as to avoid contact of its right-hand edge l3a with the adjacent cross-roll when the disc is thus moved further in towards the axis of the pass), without the right-hand side ofthe disc coming into contact with the surface of the adjacent cross-roll. Figure 12 shows the same setting of the cross-rolls with respect to the mandrel B, giving a tube of the same wall-thickness as before. However, the discs are placed more closely together, to produce a tube of smaller di- To bring the discs into the closer position, they are moved so as to approach each other, and also transversely, as is indicated by the dotted lines a continuing the edge I3a of the disc I3 in the two figures, and the dotted lines b continuing the edge Ma of the disc Hi.

In Fig. 10, the discs are shown as placed centrally of the length of the pass,that is, so that the line a: joining the closest points on their peripheries intersects a line joining the closest points on the surfaces of the cross-rolls. Varying circumstances of operation may require that the discs be thus positioned with respect to the length of the pass, or that they be positioned to a greateror less extent on either the entry or the exit side of the center of the pass.

The constructional details of that form of my apparatus which has been herein selected for description and illustration, by which the foregoing results are obtained, are as follows:

The shaft I5 of the upper disc, I3, is carried by bearing blocks l9 (Figs. 1, 2 and 4) which are mounted to slide in guide hangers 20 depending from a support cap 2| mounted on the top of the stand H). The bearing blocks are sustained vertically by suspension rods 22 connected with the blocks at their lower ends and mounted at their upper ends in a bridge member 23 disposed above the cap 2|. The bridge member is supported upon collars close to the upper ends of screws 24, the lower ends of these screws engaging against the tops of the bearing blocks. The

adjustment of the parts is such that the suspension rods hold the bearing blocks in close engagement with the ends of the screws 24, it being understood that the screws 24 resist the upward pressure of the disc shaft l5 during the operation of the disc. Upon the upper ends of the screws are mounted bevel pinions 25 with which mesh other bevel pinions, 26, mounted upon a shaft 21 supported in bearings carried by the bridge member. The shaft 21 can be rotated by means of a handwheel 28, thereby to effect an adjustment of the screws 24. By such adjustment any desired vertical position of the disc [3 can be obtained, the upward pressure,

imparted to such disc in the operation of the mill, being resisted by the screws 24.

The bearing blocks l9 are provided with flanges 29 adapted to be engaged by horizontal screws 30 threaded into the guide hangers 20; so

that the position of the disc, transversely of the cross-rolls, can be adjusted by loosening the screws 30 on one side of the disc, and correspondingly tightening such screws on the other side of the disc.

The support cap 2| rests upon the top of the stand I0, and is secured in any position of adjustment thereon'by means of bolts 3| passing through clearance slots 32 in the cap and carrying washers 33 adapted to be held down, in firm engagement with the support cap, by means of wedges 34. The support cap has secured thereto a pair of guide blocks 35 disposed at the front and rear thereof respectively, and a second pair of guide blocks 36 disposed at the sides thereof, the outer faces of all these guide blocks being shaped to the arcs of concentric circles described about the center of the cap. The guide blocks 35 are engaged by bearing blocks 31 curved to conform therewith and slidably mounted upon the top of the stand I0. The guide blocks 36 are likewise engaged by hearing blocks 38, these bearing blocks being mounted to slide longitudinally in guides 39 carried by the stand I0. Adjusting screws 40, carried by lugs 4| extending upward from the stand, engage the bearing blocks 31, and adjusting screws 42, threaded in lugs 43 extending upward from the stand, engage the support cap 2|. From this it will be seen that, upon,loosening of the wedges 34, the support cap 2|, and the disc which it carriesjis adjustable both in the way of rotation about a vertical axis and in the way of movement in a direction longitudinal of the cross-rolls. As to the former, if the bearing blocks 31 are held stationary, the support cap can be turned about a vertical axis by tightening certain of the screws 42 and loosening others. I As to the latter, the support cap can be moved bodily lengthwise of the cross-rolls by tightening the screws 40 and 42 on one side of the machine and loosening the corresponding screws on the other side of the machine.

The shaft I6 of the lower disc (Figs. 2, 5 and 6) is carried by bearing blocks 44 mounted for longitudinal sliding movement in a head 45 which is mounted to rotate, about a vertical axis, upon a support table 46. Stud bolts 47 extend from the head 45 and pass through flanges with which the bearing blocks are provided, so that by adjustmsnt of the nuts upon these stud bolts the bearing blocks can be moved longitudinally in the head, so as to give an adjustment of the disc, transversely of the cross-rolls, which corresponds with the adjustment of the upper disc by means of the screws 30. Lugs 48 (Fig. 6) on the head are disposed above corresponding slotted lugs, 49, on the table, 45, and bolts 55 passing through such lugs are provided for locking the head in any angular position to which it may be adjusted relatively to the table.

The support table 46 rests upon a wedge member 5| which is guided, for longitudinal movement, in the stand ID and is adapted to be moved lengthwise by means of a screw shaft 52. The head 45 is provided with guide portions or members 53 (Figs. 1 and 5), the outer faces of which are shaped to arcs having their centers in the axis about which the head is adjustable. These guide portions are engaged by correspondingly shaped guide. blocks 54 mounted in the stand II] for longitudinal movement with respect thereto and engaged by screws 55 adapted to be operated by hand-wheels 55. It will be seen that the blocks 54 guide the head 45 vertically, regardless of any adjustment of the said head either around its axis, or in a direction longitudinal of the cross-rolls, and, further, that these blocks support the head firmly against any tendency of the same to cant which may result from such lateral forces as may be applied to the disc during the operation of the mill. Lengthwise adjustment of the wedge 5|, therefore, results solely in an adjustment of the vertical position of the lower disc, corresponding to that which is obtained in the case of the upper disc by the adjustment of the screws 24.

To rock the head 45 about its axis, screws 51 threaded into bosses 58 carries by the stand I0 are provided] These screws engage the head (Fig. 5), and-by loosening certain of them and tightening others the head can be adjusted about its axis and locked in its adjusted position. For

adjusting the lower disc longitudinally of the cross-rolls, screws 59, threaded into the stand l0 and engaging the table 46, are provided. By tightening the screw 59 and screws 51 at one side of the stand and loosening the corresponding screws at the other side of the stand, :the table 46, and the head 45 carried thereby, can be ad-. justed ,in one direction or another lengthwise of the cross-rolls.

' By means of the screws 42, adapted tomove the cap 2| about its axis, and the screws 51 adapted to move the head 45 about its axis, the

' upper and lower discs can be moved about versuchnarrowest part;

tical axes so as to occupy positions which are inclined with respect to the plane (indicated by the line. a-a Fig. 7) bisecting the space ,be-. tween the cross-rolls. By thus inclining the discs, in the direction in which their planes approach towards parallelism with the helix of movement of the work-piece'the greatest reduction of frictional resistance of the discs to .i'rotation of the work-piece, for'any givenperipheral speed of the discs, is obtained, or, conversely, the required peripheral speed of thediscs is, minimized" for any given" reduction of the frictional resistance of the-discs to rotation of the work-piece,

Means are provided for indicating the extent of the-inclination .of the discs, suchmeanscon sisting of index, marks 60 (Fig; 3) upon one of.

the guide blocks 38, for the upper disc, and index marks 6| (Fig. 6) upon one of the lugs 49, for the lower disc. The amount-of the inclination will vary in accordance withthe conditions incident to the work being done and will, in any case, generally be subject to limitations'connected with the space available between the cross-rolls A comparatively small inclination (for instance, about 2). has markedly advantageous effects, especially where the-anglefof the feed helix of the work-piece is also small. The

inclination is shown in Fig. 7 as somewhat great-1 er than it would usually be in' practice, this being. for clcarness of illustration. .j

'By means of 'the screws 24 and the'wedge 5|,- respectively, the discs may be made to approach or recede from each'other, and by means of the screws 30 and'thexnuts on the studs 41, respec-.

tively, the discs may be moved transversely of the cross-rolls. This permitsfthe changing of the positions bf'the discs; withfrespect to dispass, can be changed by manipulating the screws 40,.for the upper disc, and the screws 59 for the lower disc, thereby permitting the discs to be. set

either at the narrowest part'of the pass or at various positions on the entrance or exit side 'of- I claim: I

*1. In a cross-rolling mill, a frame,- a pair of cross-rolls rotatablysupported thereby, a disc between the cross-rolls positioned to have its periphery engage a workpiece as' it passes through the working pass of the cross-rolls, means borne by said'frame' for supporting said disc with its axis of rotation more nearly transverse than longitudinal of the line of pass through the cross rolls, said disc-supporting means being rotatable about an axis substantially perpendicular to said' .line of pass and lying in the plane o f r'otation of the disc whereby to variably inclinesaid disc .with'respect to said line of pass, and means for rotating said disc at a peripheral speed materially in excess of the longitudinal progression of a workpiece effected by the cross-rolls.

2. In a cross-rolling mill, a frame, a pair of oross-rollsrotatablysupported thereby, a pair of discs between the cross-rolls positioned to have their peripheries engage the opposite sides of a workpiece as it passes through the working pass of the cross-rolls, means borne by said frame for independently supporting each of said discs with its axis of rotation more nearly transverse than longitudinal of the lineof pass through the crossrolls and withsaid axes inclined to each other, said disc supportinglnearg being rotatable about axes substantially perpendicular to said line of pass and lying in the planes of rotation of the discs whereby to variably incline said discs withrespect to said'line of pass and toy each other,

. and means for rotating said discs at peripheral speeds materially in excess of the longitudinal progression of a workpiece eifected by the cross- 25 rolls. I

'3. In a cross-rolling mill,-a frame, a pair of cross-rolls rotatably supported thereby, a disc between the cross-rollspositioned to have its periphery engage a work-piece as it passes through 30 the working pass of the cross-rolls, means borne by said'frame for-supporting said disc in a plane substantially parallel with the line of pass a through the cross-rolls and with the periphery of the disc nearer to the cross-roll which-rotates a workpiece towards the disc than to the other cross-roll, means for rotating'said disc at-a peripheral speed materially in excess of thelon gitudinal. progression of a workpiece effected by the cross-rolls, and means for adjusting said disc supporting means toward and from said line of pass and also transversely thereof.' I

4. In a cross-rolling mill, a frame, a pair 0 cross-rolls rotatably supported thereby, a pair of discs between the cross-rolls positioned to have their'peripheries engage the opposite sides of a workpiece as it-passes through the-working pass of the cross-rolls, means borne by'said frame-for independently supporting said discs in planes substantially parallel with the line of pass through the cross-rolls and with the periphery of each disc-nearer to the cross-roll which rotates the workpiece towards the disc than to the other I cross-roll, means for rotatingsaid discs at pe-.

ripheral speeds materially in excess of the longitudinal progression of a workpiece 'eifected by the cross-rolls, and means for adjusting said disc- .supporting means toward and from said line of pass and also transversely thereof.

5. In a cross-rolling mill, a frame, a pair of cross-rolls rotatably supported thereby, a disc arranged'between said cross-rolls with its periphery disposed to engage a work-piece as it jpasses through the working pass of the crossrolls, means borne by said frame supporting said disc for rotation inxa plane substantially parallel with the line of pass between the cross-rolls; means for rotating said disc, and means for canting the disc relative to said plane of rotation about an axis perpendicular to the lineof pass. 6, In a cross-rolling mill, a frame, a pair of cross-rolls'rotatablysupported thereby, a pair of discs arranged between said cross-rolls with their peripheries disposed to engage the opposite sides of a work-pieceas it passes through the working pass of the cross-rolls, means borne by said frame supporting each disc for rotation in a plane substantially parallel with the line of pass between the cross-rolls, means for rotating said discs, and means for canting said discs relative to said plane and relative to each other about an axis perpendicular to the line of pass.

7. A cross-rolling mill comprising a supporting frame, cross rolls mountedfor lateral adjustment in said frame, a pair of driven guide discs disposed for operation between said cross rolls and about axes extending substantially transversely of the axes of said cross rolls, shafts for supporting said guide discs, hangers adjustable toward and from the pass-line of the mill for supporting said shafts, frames mounted for both angular and sidewise movement on said supporting frame for supporting said hangers, means for adjusting said hangers in said hangersupporting frames toward and from the passline of the mill, means for adjusting said hangersupporting frames sidewise, means for angularly adjusting said hanger-supporting frames, and

means for locking said hanger-supporting frames in a selected position.

8. The method of treating work-pieces in a cross-rolling mill, comprising subjecting a workpiece to the action of a pair of opposed cross rolls positioned to impart a, helical movement to the work-piece, and applying to the work-piece in the pass zone of the cross rolls the resisting pressure of a guide member engaging the work-piece and moving, at a speed materially in excess of the speed of longitudinal progression of the work-piece through the cross rolls, in a direction which is generally that of such longitudinal progression but inclined from the line of such progression toward parallelism with the feed helix of the work-piece. I 5

9. In a cross-rolling mill for the manufacture of seamless tubular articles, the combination of a pair of oppositely rotating cross-rolls, and a pair of guide discs positioned between the crossrolls on the opposite sides of the pass line through them and rotatable in the direction of travel of a blank through the mill, each guide disc being of greater diameter at its side adjacent .to that one of said cross-rolls whose working face is rotating towards it than it is at its other side, and each guide disc being provided with a peripheral concave curved surface between its said different diameter sides.

10. In a cross rolling mill, a frame, a pair of cross rolls rotatably supported thereby, a disc between the cross mils positioned to have its periphery engage a work-piece as it passes through the working pass of the cross-rolls, means borne by said frame for supporting said disc in a plane substantially parallel with the line of pass through the cross rolls, means for adjusting said disc transversely of said line of pass, means for adjusting said disc toward and from the line of pass, means for adjusting the disc axially of the line of pass and means for rotating said disc at peripheral speeds in excess of the longitudinal progression of a workpiece effected by the cross-rolls.

SAMUEL E. DIESCHER.

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