US 3861187 A
A rolling stand for rolling rod-like stock is provided having at least three interchangeable driven work rolls disposed radially about the longitudinal axis of the stock to be rolled and all of the rolls together with their spindles being jointly adjustable relative to the stock axis by means of a single adjusting spindle.
Description (OCR text may contain errors)
United States Patent Leeuwestein Jan. 21, I975 ROLLING STAND FOR ROLLING 1.899.659 2/:933 Asbeck 72 224 SUBSTANTIALLY RODJJKE STOCK 2,094,920 lO/l937 lnslce M 72/224  Inventor: Kurt Leeuwestein,
Duisburg-Neudorf, Germany Primary ExaminerMilton S. Mehr  Assignee: Firma Friedrich Kooks, Dusseldorf, f fl or firm-Ellen Blcnko and Germany Ztesenhetm  Filed: Nov. 29, 1973 [2l] Appl. No.: 420,235  ABSTRACT  U S Cl 72/224 72/248 72,244 A rolling stand for rolling rod-like stock is provided  "B2", 13710 Bzlb 31/26 having at least three interchangeable driven work rolls  i 72/248 5 237 249 disposed radially about the longitudinal axis of the stock to be rolled and all of the rolls together with their spindles being jointly adjustable relative to the  References Cited stock axis by means of a single adjusting spindle.
UNITED STATES PATENTS 9 Claims, 9 Drawing Figures l,429,3ll 9/1922 Albiez 72/224 5b17 727074 7b 706a J 5 70 15 s 5 72 7 2b 2a 2a 2b 17 s a n PATENTED 3861.187
SHEET 2 [IF 5 WWW I ma SHEU 3 OF 5 Fig. 4
PATENTED W21 SHEU 5 [IF 5 ROLLING STAND FOR ROLLING SUBSTANTIALLY ROD-LIKE STOCK This invention relates to a rolling stand for rolling substantially rod-like stock, such as wire, and particularly to a rolling stand for rolling substantially rod-like stock having at least three interchangeable driven working rollers which are disposed radially about the longitudinal axis of the stock being rolled.
For rolling substantially rod-like stock, such as wire, stands are already known and used in which the pass is formed either by two or by three rollers. The threeroller pass has several basic advantages over the tworoller pass, such as for example better elongation of the stock being rolled in the pass with less spread, thereby improving rolling efficiency. Also with a three-roller pass deformation is more uniform so that there is better stress distribution in the stock. Three-roller passes are therefore able to roll even materials having poor deformation properties. such as for example sintered tungsten and molybdenum, without difficulty. These mate rials, which are only deformable with difficulty, may also be processed using the same sizing gap. Moreover, on account of the improved deformation, the temperature rise of the stock during the rolling process with three-roller passes is less than with two-roller passes so that it is possible to obtain high mean tensile strengths of the rolled stock, higher rolling speeds and thus greater production outputs, and greater economy. The use of three-roller passes also prevents unintentional adverse changes in the properties of the materials, for example as a result of overhigh temperatures during rolling, which is particularly important when rolling high-quality steel. With three-roller stands it is possible to roll without twist, thereby protecting the surface of the stock. Finally, in a three-roller stand the forces arising during rolling are distributed among at least six bearings, whereas there are only four bearings in tworoller stands. Thus, a three-roller stand can withstand and exert higher rolling pressures.
The present invention provides an adjustable stand which has at least three rollers and which apart from having the abovementioned advantages, meet, additional requirements. It is possible to keep within the narrowest tolerances over a longer rolling stand time since the rollers can be adjusted during rolling of a specific dimension several times by the smallest amounts, which are in the order of magnitude of the tolerance. It is also possible to reduce rolling and requipment costs as the rollers may be refinished several times in the same stand.
The adjustability of the working rollers in three-roller studs till now has not been solved structurally to a satisfactory extent because, with radial adjustment of the working rollers and therefore of the roller axes, the driving spindles for the rollers must also be radially movable. This trebles the number of drive shafts and/or compensating couplings to be used between the stand and gears which are not able to cope with the high speeds which are usual especially in wire mills and wear out quickly. These parts also cause vibrations which may leave traces on the rolled stock and which have an adverse effect on the entire machinery.
Furthermore, detaching and dismantling the three couplings and/or drive shafts when changing stands is complex and time-consuming. lf, instead of a distributor gear, stands are used for the roller drive whose rollers are driven in the stand by way of bevel gears by a drive shaft, adjustment of the rollers was still thought to be impossible because the bevel gears disposed on the roller axes then also move radially so that they either become disengaged and not all the working rollers are driven or the driving bevel gears are pushed firmly against one another and are thus damaged. Other known means of transmitting the driving torque from a directly driven roller spindle to the spindles of the other two working rollers are either incapable of being housed in the little space available in such a rolling stand or they have to be so weakly dimensioned that they cannot meet requirements, especially those im posed when rolling relatively solid material.
With non-adjustable three-roller stands it is impossible to alter the first pass cross-sections as much as is desirable in many cases. Recently, however, this has become a necessity from the point of view of economic and versatile running of rolling mills.
Moreover, with non-adjustable stands, one is basically tied to a specific rolling program for which the individual working rollers and passes have been designed so that it is impossible to depart from the original rolling program without changing or refinishing rollers. Departures from the prescribed rolling program simply by correspondingly adjusting the rollers has an adverse effect upon the accuracy of shape.
The aim of the invention is to provide an adjustable rolling stand having three interchangeable driven working rollers disposed radially round the longitudinal axis of the rolling stock and which overcomes the problems of the prior art discussed above.
in accordance with the invention all the working rollers together with their spindles are jointly and centrally adjustable radially relative to the longitudinal axis of the stock being rolled by means of a single adjusting spindle. if required, the working rollers may also be individually adjustable.
Besides the initially mentioned advantages of a threeroller stand, the adjustability according to the invention of the three working rollers of the stand has the added advantage that, as regards dimensions, it is possible to keep within even narrower tolerance limits than before and to improve the accuracy of shape of the rolled stock. The adjustability, in particular of the last rolling stands of a rolling-mill line, makes it possible to regulate the quantity of material running into the last passes so that filling of the passes can be regulated within specifie limits while retaining optimum tension conditions. By adjusting the rollers, in particular in the last pass of a preliminary or intermediate line, it is also possible to alter the first pass cross-sections for the subsequent lines. The siight opening of the pass, which is conditioned by the natural play in the roller bearings and is caused by the stock running through, can moreover be compensated by suitably adjusting the working rollers after they have been ground to size.
It is even possible to remove used but not completely worn rollers and use them again later without having to regrind them. The differences arising during installation and removal can be compensated by adjustment. This makes it easier and less expensive to convert the rolling mill when the rolling program is changed.
The construction according to the invention also substantially reduces rolling costs since the rollers of a rolling stand can be reground ten to fifteen times in their installed state and can be used again after grinding at the same point of the rolling-mill line. Only after the working rollers of a stand have been reground ten to fifteen times is it necessary to change the location of the stand relative to the stock being rolled. a process which. in a non-adjustable stand. is required after the very first re-grind. The expensive process of changing the rollers is therefore undertaken much less frequently so that the cost of this process maybe reduced by as much as 60%. There is significantly better use made of even the expensive working rollers. It is also possible using the rolling stands according to the invention to obtain rolled stock dimensions which differ slightly from the gauges for which the rolling pass is actually designed. These intermediate dimensions can be obtained by suitably adjusting the working rollers without having to alter the rolling pass though this affects the accuracy of shape. Thus. almost every cross-sectional dimension in the dimension range of the rolling stand can be rolled continuously. For this purpose it is particularly advantageous if the drive of the rolling stand according to the invention is constructed so that the driving speeds may be regulated over an adequately wide range. If the dimension of the rolled stock is to be retained and only the natural wear of the rollers is to be compensated. it is usually sufficient simply to regrind and adjust the last stand. Thus, in many cases only one or two adjustable stands are required per rolling-mill line.
In a preferred embodiment of the invention. to obtain the radial adjusting movement of the working rollers. the spindles of the latter are supported in radial bearings. preferably radial roller bearings, which are in turn located in bearing bores in adjusting bushes and the bearing bores are placed eccentrically relative to the outer peripheral surfaces of the adjusting bushes and the adjusting bushes are rotatably journalled by their peripheral surfaces in housing bores in the rolling stand. In this manner. an adjusting range is obtained which is dimensioned according to the degree of eccentricity of the bearing bores and is in the region of, for example, 2 to mm. this being dependent in particular upon the diameter of the rollers. This adjusting range is quite sufficient to achieve the abovementioned advantages.
The adjusting movement is effected by a corresponding rotational movement of the adjusting bushes. At least one adjusting bush of each roller spindle is advantageously provided with a bevel gear by means of which the bush meshes with a corresponding bevel gear of an adjusting bush of an adjacent roller spindle with this embodiment of the invention it is sufficient to rotate one of the adjusting bushes to displace all the adjusting bushes of all the roller spindles in a similar manner. A precondition of this is. of course. a transmission ratio of l:l between the bevel gears of the adjacent adjusting bushes. This in turn ensures that all the working rollers are at a constant distance from the longitudinal axis of the stock being rolled. it is also advisable to connect the adjusting bushes for each roller spindle to one another by means of. for example. one or more yokes straddling the rollers. bushes or the like so that they are relatively non-rotatable and are spaced axially relative to one another. Thus, all the adjusting bushes are synchronously adjustable without having to provide all the adjusting bushes with bevel gears.
In a rolling stand wherein all the working rollers are driven by means of a common drive shaft and by means of drive bevel gears. which are disposed on the roller spindles and are in direct mesh with one another. compensating means may. according to a preferred feature of the invention. be provided for effecting relative movements between the roller spindles and the respective associated drive bevel gears. these means maintaining their predetermined position relative to one another when the rollers are adjusted. Only by maintain ing the drive bevel gears in their predetermined position relative to one another can they function efficiently and enable all the working rollers of the stand to be driven in synchronism. By means of the compensating means the roller spindles can nevertheless be adjusted independently of the drive bevel gears.
in one preferred embodiment of the invention. the drive bevel gears as well as the roller spindles are advantageously radially. journalled in the eccentric hearing bores of the adjusting bushes preferably the drive bevel gears are axially displaceable with the adjusting bushes relative to the roller axes. Here it is advisable to coordinate the extent of eccentricity of the hearing bores of the adjusting bushes with the axial feed of the adjusting bushes and the drive bevel gears during a rotational movement of the adjusting bushes. so as to keep the pairs of intermeshed drive bevel gears prop erly in mesh despite the displacements of their axes of rotation due to the adjustment. At least one adjusting bush of each roller spindle is advantageously provided in the region of its peripheral surface with a longitudinal portion having an external screw thread which is in engagement with at least one fixed internal screw thread or internal thread portion. Rotation of the ad justing bush then also effects a suitably dimensioned axiai feed by means of which the associated drive bevel gear is moved along the common cone generatrix.
It is however alternatively possible to rotatably journal the drive bevel gears in bearing bores of their adjusting bushes in fixed positions. these bearing bores being placed coaxially relative to the peripheral surface of the adjusting bushes, and only the roller spindles are journalled in eccentrically disposed bearing bores of the associated adjusting bushes. In this embodiment of the invention, the drive bevel gears remain. independently of the radial adjusting movement of the roller spindles permanently on the same point of the stand and thus remain permanently and easily intermeshed. it has proved advantageous to make the internal diameter of the central bores of the drive bevel gears. which eccentrically accommodate the roller spindles. substantially larger than the external diameter of the roller spindles and to provide transmission means for transmitting the torque. preferably an external or internal toothing. between each roller spindle and the respective drive bevel gear. The required play between the drive bevel gears and the associated roller spindles is thereby achieved. In principle other torquetransmitting means are possible as alternatives.
in a further embodiment according to the invention. the working rollers together with their spindles are individually adjustable also in an axial direction. This embodiment makes it possible to re-install used but not worn rollers and use them again without refinishing because the slight axial displacements arising during reinstallation may be compensated by axially adjusting the roller spindles. This not only economizes on the expense of refinishing but also avoids additional grinding down of the rollers so that. in this case too. rolling costs are considerably reduced especially if the rolling program is frequently changed. This last embodiment is consequently particularly suitable for rolling smaller quantities of stock, such as for example occur when rolling high-quality steel, whereas an embodiment of the invention not having axial adjustment is particularly suitable for rolling bulk produced steel when as a rule such a large quantity is rolled that the passes are used extensively, are worn out after rolling and so require regrinding anyway.
In order to obtain axial adjustability of the working rollers and their spindles it is advisable to make the bearings of the spindles in the adjusting bushes steplessly axially displaceable and lockable relative to these adjusting bushes. It is also advantageous to divide the bearings of the roller spindles into radial bearings and separate axial bearings. Such a subdivision enables substantially play-free journalling to be obtained which produces a satisfactory surface on the rolling stock.
Although the rolling stand according to the invention is primarily intended for steel wire and rods and its advantages are evident in this particular field, it is basically quite possible to use such a rolling stand for roll ing tubular stock. The rolling stand can process cold and hot stock.
The invention is further described, by way of exam ple, with reference to the accompanying drawings, in which:
FIG. 1 is a cross-section of a rolling stand having individually driven roller spindles;
FIG. 2 is a section along the line IIII of FIG. 1;
FIG. 3 is a cross-section of a rolling stand having jointly driven roller spindles and axially and radially displaceable drive bevel gears;
FIG. 4 is a section along the line IV-IV of FIG. 3;
FIG. 5 is a section along the line VV of FIG. 3;
FIG. 6 is a diagrammatic illustration of the movement of two drive bevel gears;
FIG. 7 is a cross-section of a rolling stand having jointly driven roller spindles but fixed drive bevel gears;
FIG. 8 is a section along the line VIIIVIII of FIG. 7; and
FIG. 9 is a section along the line IX-IX of FIG. 7.
Referring to FIG. 1, the column 1 of a rolling stand supports three working rollers 2 disposed radially round the longitudinal axis 3 of the stock to be rolled. Each working roller 2 comprises a rolling annulus 211 made of a wear-resistant material and two clamping discs 2b which hold the rolling annulus 2a and form the hub of the working roller 2. Each of the working rollers 2 is journalled by a roller spindle 4 which is likewise made up of two parts, a main part 4a and a clamping part 4b. The two parts of each roller spindle 4 are drawn towards one another by means of a drawn bolt 5. This is effected by screwing the treaded end 50 of the bolt into the clamping part 4b so that the clamping disc 2b and the rolling annulus 2a are clamped firmly via the inner races of roller bearings 6. In its clamped state the drawn bolt 5 acts by way of a nut 5b on the main part 4a of the roller spindle 4.
The working rollers 2 are journalled by their spindles 4 in the roller bearings 6 which are radial bearings and which are supported in the rolling stand I. The outer races of the roller bearings 6 are located not directly in housing bores in the rolling stand I but in bearing bores in adjusting bushes 7. The exception to this is a radial roller bearing 6a in an outerlying adjusting bush 70 because an axial bearing 8 is adjacent to this radial hearing 6a and both bearings are inserted in an adjusting bush 9 which is screwed into the adjusting bush 7a. By rotating the adjusting bush 9 in and out. the roller spindle 4 with the working roller 2 can be axially displaced by a limited amount.
The adjusting bushes 7 and 7a are journalled in rotatable but axially fixed manner in the rolling stand I. The bearing bores of the adjusting bushes 7 and 7a. which serve to accommodate the radial bearings 6 or the adjusting bush 9, are placed eccentrically relative to the peripheral surfaces of the adjusting bushes 7 and 7a which serve as bearing surfaces. Rotation of the adjusting bushes 7 and 70 therefore enables radial adjustment of the roller spindles 4 and the working rollers 2.
For transmitting the rotational movement. the two adjusting bushes 7 of each roller spindle 4, disposed at opposite sides of the other 2 are connected to one another by means of yokes Ill. The adjusting bushes 7a are also connected non-rotatably by means of their bush-like extension 7b to the adjacent adjusting bush 7. At least one adjusting bush 7 or 70 of each roller spindle 4 has a bevel gear 11 by means of which the adjusting bushes 7 or 70 of the various roller spindles 4 are coupled to one another. It is therefore sufficient to rotate one of the adjusting bushes 7 or 7a to rotate all of the adjusting bushes of the rolling stand I through the same angle and thus to displace all of the radial bearings 6 or 60, the roller spindles 4 and the working rollers 2 radially by the same amount, this naturally presupposing a transmission ratio of l:l and identical eccentricity of all the bearing bores in all of the adjusting bushes 7 or 7a.
The working rollers 2 are adjusted manually by means ofa key (not shown) which is placed on one end of an adjusting rod I2. FIG. 2 shows that rotation of the adjusting rod l2 causes its screw-threaded spindle 12a to be screwed in or out of a threaded bush [3. The adjusting rod 12 is journalled in an axially fixed manner so that the threaded bush I3 is moved substantially in an axial direction with respect to the adjusting rod l2. The threaded bush 13 is connected by a hinge pin 14 to an adjusting ring I5 which in turn encloses the bushlike shoulder 7b of the adjusting bush 7a and is connected by means ofa key 16 in a non-rotatable manner to the adjusting bush 7a.
In the embodiment of FIGS. 1 and 2, the working rollers 2 are driven by .way of coupling I7, only half of which are shown, separately but synchronously by a gear (not shown). The working rollers 2, in particular the rolling annuli 2a, are interchanged after loosening the nut 5b by rotating the draw bolts 5 so that their threaded ends are screwed out of the clamping part 4b. The clamping part 4!) can be axially displaced away from the main part 4a of the roller spindle 4 by means of the draw bolt 5. By suitably rotating the adjusting bushes 9, the main part 4a of the roller spindle 4 is also axially displaceable on the opposite side so that, after the draw bolt 5 has been screwed out completely, the rolling annulus 2a can then be withdrawn from the now sufficiently large gap between the two clamping discs 2b. After installation of a new rolling annulus 20, assembly is effected by reversing the process.
In the embodiment of FIG. 3, in which parts like those of FIG. I are denoted by like reference numerals, radial adjustment of the working rollers 2 is basically the same as in the embodiment of FIG. I. In this case too, the radial bearings 6 are eccentrically journalled in adjusting bushes 7. The adjusting bushes 7 of each roller spindle 4 are again connected to one another by yokes 10 or a bushlike extension 711 and are coupled to one another by means of bevel gears 11. The adjusting movement is effected manually by means of an adjusting rod 12 and an adjusting spindle 18, 180. A worn gear 19 rotates an adjusting shaft 20 whose rotational movement is transmitted to the adjusting bushes 7 by way of an adjusting ring 150 and a connecting rod 21, which is pivoted to the adjusting ring a and to the bushlike extension 7b of an adjusting bush 7. This can also be seen in FIG. 4. The adjusting shaft has a second adjusting ring 150 and a further connecting rod 21 so that the two lefthand adjusting bushes 7 can also be pivoted.
The embodiment of FIG. 3 differs basically from the rolling stand of FIG. 1 in that in this case only a single common drive shaft 22 serving simultaneously as one of the roller spindles 4 is provided. The driving torque, which is transmitted by a gear (not shown) by way of a coupling (also not shown) to the lefthand end portion of the common drive shaft 22, is passed on by drive bevel gears 23 to the other two roller spindles 4. The roller spindles 4 are tapered in the region of their working rollers 2 and the hubs of the working rollers 2 have a tapered bore so that the rollers 2 are non-rotatably and in an axially fixed manner fitted onto the roller spindles 4. Oil or some other suitable pressure fluid can be urged, by way ofa system of bores (not shown) preferably in the hubs of the working rollers 2, under high pressure between the tapered surfaces of the working rollers 2 and the roller spindles 4 so that the latter, if required, may be separated from one another. This is necessary for changing the working rollers 2 when the roller spindles 4 must also be axially withdrawn after the working rollers 2 have been detached in the previously described manner. The roller spindles 4 are withdrawn by suitably rotating the draw bolts 5 whose threaded ends 5a are thereby withdrawn from the axial bearing 8. Once a roller spindle 4 has been disengaged in this way, it can be removed sufficiently for the working roller 2 to be interchanged. Otherwise, the bearings remain unaffected.
Like the roller spindles 4, the drive bevel gears 23 are journalled in the radial bearings 6 and therefore effect the same radial adjusting movement as the working roller 2 and its roller spindle 4. So that this does not lead to damage of the drive bevel gears 23 or to their coming out of mesh, the radial adjusting movement is superimposed by an axial displacement of the drive bevel gears 23, as is illustrated diagrammatically in FIG. 6. The pitch circle cones 23a of two drive bevel gears 23 are shown before and after adjustment. It can be seen that the drive bevel gears 23 are displaced along the common cone generatrix 31. This necessitates the exact dimensional co-ordination of the radial adjusting movement and the axial displacement. Axial displacement of the drive bevel gears 23 is effected by axially displacing the adjusting bushes 7 in which the drive bevel gears 23 are journalled in an axially fixed manner. FIG. 5 shows how the axial movement of the adjusting bushes 7 is effected. The latter have, in the region of their peripheral surface. a circumferential portion 24 having an external screw thread which receives an internal thread cut into the end faces of two fixed pins 25. A rotational movement ofthe adjusting bushes 7 therefore also causes them to be axially displaced. lt is not necessary for every adjusting bush 7 to have such an external thread 24 if their axial feed movement is transmitted by a bushlike extension 7b or a yoke 10.
As regards the roller drive, the embodiment of FIG. 7 basically corresponds to the embodiment of FIG. 3 apart from the additional lay gearing arrangement 26. The working rollers 2 are also adjusted again by means of the radial bearings 6 placed eccentrically in adjusting bushes 7. The rotational movement of the adjusting bushes 7 is effected from the adjusting spindle l8!) by way of a worm gear 27 to the first adjusting bush, the rotational movement being transmitted in the manner already described to the other adjusting bushes 7 by way of the bevel gears ll, the yokes l0 and the bush like extension 7!). Axial adjustment and interchanging of the working rollers 2 is effected in the same manner as in the embodiment of FIG. 1 or 3.
The embodiment of FIG. 7 differs from the previ ously described embodiment mainly in that the drive bevel gears 23 are journalled, not with the roller spin dles 4 and with these eccentrically relative to the peripheral surfaces of the adjusting bushes 7, but in sepa rate radial bearings 28 concentrically relative to the peripheral surfaces of the adjusting bushes 7 and in an axially fixed manner, In contrast to this (see FIG. 8) the radial bearings 6 for the roller spindles 4 are again inserted eccentrically into the adjusting bushes 7. The drive bevel gears 23 therefore maintain, independently of the adjusting movement of the working rollers 2 and the roller spindles 4, their position and not only relative to one another but also within the rolling stand I. The drive bevel gears 23 however have an internal bore 29 which is substantially greater than the external diameter of the roller spindles 4. This is particularly evident from FIG. 9. Thus, the roller spindle 4 and with it the working roller 2 can effect a radial adjusting movement independently of the drive bevel gear 23 owing to the eccentric bearing. For transmitting the torque from the roller spindle 4 to the drive bevel gear 23 or vice versa, the clamping part 4b of the roller spindle 4 has an external toothing and a corresponding internal toothing is provided in the bore 29 of the drive bevel gear 23. This toothing, designated 30 in FIG. 9, can if desired be replaced by other torque-transmitting means.
In the foregoing specification l have set out certain presently preferred embodiments of this invention. It will be understood, however, that this invention may be otherwise embodied within the scope of the following claims.
1. A rolling stand for rolling rod-like stock, such as wire, having at least three interchangeable driven working rollers which are disposed radially about the longitudinal axis of the stock to be rolled, an axial spindle in each said working roller all said spindles being journalled on each side of the roller in radial bearings which are in turn located in bearing bores in adjusting bushes eccentrically relative to the outer peripheral surfaces of the adjusting bushes which are rotatably journalled by their outer peripheral surfaces in housing bores in the rolling stand, all the adjusting bushes of each spindle being spaced axially from one another and connected together to be rotatable in synchronism as a unit whereby all the working rollers together with their spindles are jointly adjustable relative to the stock axis by means of a single adjusting spindle.
2. A rolling stand as claimed in claim I, in which at least one adjusting bush of each roller spindle has a bevel gear by means of which it engages in a corresponding gear of an adjusting bush of an adjacent roller spindle.
3. A rolling stand as claimed in claim 2, in which the drive bevel gears are radially journalled by their spindles in the eccentric hearing bore in the adjusting bushes. and the drive bevel gears and the adjusting bushes are axially displaceable relative to the roller spindles.
4. A rolling stand as claimed in claim 3, in which the extent of eccentricity of the bearing bores in the adjusting bushes and of the axial feed of the adjusting bushes and the drive bevel gears during a rotational movement of the adjusting bushes are co-ordinated so that a respective pair of intermeshed drive bevel gears are displaced along the common cone generatrix.
5. A rolling stand as claimed in claim 3, in which at least one adjusting bush of each roller spindle has, in the region of its peripheral surface. a circumferential portion having an external screw thread which is in engagement with at least one fixed internal screw thread or thread portion.
6. A rolling stand as claimed in claim 2, in which the drive bevel gears are journalled in a fixed but rotatable manner in bearing bores in their adjusting bushes. these bearing bores being placed concentrically relative to the peripheral surface. of the adjusting bushes. and only the roller spindles are journalled in eccentrically disposed bearing bores in the associated adjusting bushes.
7. A rolling stand as claimed in claim 6. in which the internal diameter of the central bores of the drive bevel gears which accommodate the roller spindles eccentrically is substantially greater than the external diameter of the roller spindles where accommodated. and transmission means for transmitting the torque, are provided between each roller spindle and the respective drive bevel gear.
8. A rolling stand as claimed in claim 7 in which said transmission means compress internal toothing in said central bore meshing with external toothingin the respective roller spindles.
9. A rolling stand as claimed in claim I, in which the bearings for the roller spindles comprise radial bearings and separate axial bearings.
a s a a a