Method for producing strip-shaped input stock, especially from metal, which is profiled in subsequent sections, and corresponding device

Description

[0001] The invention relates to a method for producing strip-shaped input stock, especially from metal, which is profiled in subsequent sections, and a corresponding device.

[0002] DE 195 04 711 C2 describes a method for producing strip-shaped input stock from metal using rollers of a roll stand that define a rolling gap in which a metal strip is rolled in two or more than two rolling steps. The operation of the method is such that a metal strip is rolled repeatedly, being continuously guided from its beginning to its end through a roll stand, the working direction of which is then reversed so that thereafter the metal strip is run through the roll stand once again over its full length, but now in reverse direction.

[0003] From DE-PS 104 875 it has been known to profile strip-shaped or plate-shaped workpieces in a single step, for the production of tubes. A similar method is disclosed by DE 197 04 300 A1 for the production of profiled blanks, especially of car body sheets.

[0004] A reciprocating rolling method for the production of thin strips from thick input stock is described in DE-PS 638 195. In the case of this method, the input stock is shaped step by step with a high degree of deformation, being passed through the rolling gap in reverse direction to the usual rolling direction.

[0005] From U.S. Pat. No. 1,106,172 it has been known to convert profiles continuously to a strip using an arrangement of three roll stands arranged one behind the other.

[0006] DE 199 38 966 C1 shows a way of producing strip-shaped input stock, which is profiled in subsequent sections, economically and with a uniform, high surface quality. To this end, the metal strip is rolled always between the same two rollers, in two or more sections each shorter than the circumference of the rollers, for which purpose the metal strip is recalled between every two successive rolling steps, and the recalled section of the metal strip is rolled once again.

[0007] For carrying out that method, DE 199 38 966 C1 discloses a roll stand which has a first coiler for the metal strip to be rolled arranged on the intake end of the rolling gap, and a second coiler for winding up the strip-like input stock arranged on the discharge end of the rolling gap, the coiler arranged on the intake end of the rolling gap being provided with a drive motor, especially a servomotor, for recalling the metal strip by steps of a predetermined length. The length of the steps by which the metal strip is recalled may be adapted to the particular needs by an electronic drive control, especially in programme-controlled fashion. Such a programme control also permits the intermittent drive of the rollers, including forward rotation, stoppage and, if necessary, reverse rotation, to be optimally adapted to the particular rolling task.

[0008] Now, it has been found that when grooving the metal strip by the profiled roller it may happen that the semi-finished product obtained does not exhibit the intended shape and the desired accuracy on its side facing away from the profiled roller. This is true especially when rolling metal strips that are profiled in sections on one side only while the other side should remain flat, but does not actually remain flat with the desired precision.

[0009] Now, it is the object of the present invention to open up a way of producing a strip-shaped semi-finished product, which is to be profiled in sections by a rolling process, so that the desired shape can be realised with higher accuracy on its side facing away from the profiled roller. Especially in the case of a strip-like semi-finished product, which is to be profiled in sections on one of its sides only, the other side is to be kept flat with higher precision.

[0010] This object is achieved by the method having the features defined in Claim 1. A device especially suited for carrying out the method according to the invention is the subject-matter of Claim 51. Advantageous further developments of the invention are the subject-matter of the sub-claims.

[0011] According to the invention, for producing strip-shaped input stock, a metal strip is rolled in a rolling gap defined by a roller and a plate. The rolling process is carried out in one or more rolling steps with the aid of the following process steps:

[0012] (a) Tensioning the metal strip;

[0013] (b) positioning the metal strip in a rolling gap, which is defined by a roller and a movable plate, relative to the roller;

[0014] (c) positioning the plate relative to the roller;

[0015] steps (b) and (c) being carried out either successively or simultaneously or in timely overlapping fashion, or step (c) being carried out before step (a);

[0016] (d) grooving the metal strip with the roller by reducing the distance of the peripheral surface of the roller to the metal strip, the metal strip being maintained steady or being moved only slowly at least during the beginning phase of the grooving step, and the roller being rotated not at all or only very slowly so that the metal strip remains under tensile stress in the rolling gap;

[0017] (e) rolling a section of the metal strip in the rolling gap by rotating the roller and moving the plate in synchronism in a rectilinear manner; and

[0018] (f) releasing the metal strip by opening the rolling gap;

[0019] steps (b) to (f) being repeated for every section of the metal strip to be profiled.

[0020] The term “metal strip” as used herein also includes strips which instead of consisting entirely of metal, include non-metallic components, such as oxidic, carbidic or ceramic components, or a metalloid, such as graphite. Strips made of compound materials such as silver graphite or silver metal oxide, especially materials based on silver tin oxide containing up to 20% by weight of non-metallic components, may serve as examples. Strips made of such materials are used as semi-finished products for the production of electric contacts.

[0021] If in order to achieve higher reductions per pass and/or smaller dimensional deviations, the respective metal strip section to be profiled is rolled in more than one passes, then steps (b) to (f) are repeated after the first pass, for which purpose the metal strip is recalled, after the rolling gap has been opened in step (f), and the recalled strip section is rolled once again in the rolling gap under the action of the same roller. The tensile stress in the strip is conveniently kept constant at a predetermined value during the whole process. This results in higher positioning accuracy of the metal strip in the rolling gap and in improved dimensional accuracy.

[0022] In order to achieve an especially high degree of accuracy and repeatability, the roller is positioned in a predetermined reference position prior to each rolling cycle or to each rolling step, in order to prevent positional errors from summing up. Positioning the rollers in a reference position is effected most conveniently by reversing the roller, and may take place before step (b), after step (b) or after step (c). Simultaneously with the adjustment of the starting angle of the roller, a preliminary adjustment of the size of the roller gap is preferably carried out.

[0023] According to the invention, the metal strip is formed in the rolling gap between a roller and a plate that coacts with the latter. If the rolling gap is to be profiled on one side only, then the plate exhibits a flat shape in the area in which it is in contact with the metal strip during the forming operation. During rolling of a section of the metal strip, the plate is moved linearly in synchronism with the roller with which it cooperates. For recalling the metal strip, it is not absolutely necessary that the plate be moved in synchronism with the roller and/or the metal strip, unless the metal strip is to be rolled also during the recalling motion, which may be the case in one embodiment of the method according to the invention.

[0024] When the metal strip is to be profiled on both sides then, according to the method according to the invention, one initially profiles one side whereafter the metal strip is turned over so that its profiled side faces the plate, and then the other side is profiled, it being especially preferred—depending on the shape of the profile to be produced—that the plate be exchanged against another plate which is profiled, on the side facing the metal strip, in a manner complementary to the profile already rolled so that the profiled side of the metal strip can be optimally supported during profiling of the other side. One thereby obtains the desired profiles with an especially high degree of accuracy. For profiling the meal strip on both sides, one conveniently profiles at first one side of the strip over its full length, whereafter the strip is turned over and profiled on its other side in a further pass in one or more rolling steps. If necessary, the profiling roller is exchanged for that purpose. Instead of exchanging the plate, it may be more favourable—especially if the metal strip is to be profiled on the second side in places that overlie recesses, which have been rolled before into the first side of the strip—to use a profiled back-up roller of the biggest possible diameter as support for the metal strip when the latter is to be profiled on the second side.

[0025] If the plate is exchanged, or if a back-up roller with an especially big diameter is used instead, the register line of the rolled strip should, conveniently, be placed a little above the profile projecting from the plate or the back-up roller. This provides the advantage that stretching of the metal strip during its transport will be excluded and any vertical adjustment of the plate or instead the back-up roller, with the especially big diameter, can be avoided. Otherwise, such vertical adjustment would be necessary when the segment of the back-up roller supporting the metal strip, or the profile of the plate supporting the profiled metal strip, must be returned to its initial position for the next rolling pass to be carried out.

[0026] It has been found that the method according to the invention permits the production of strips that are profiled in sections, preferably on one side only, so that irregularities on one side of the strip, produced by the action of the roller upon the other side of the strip, are clearly reduced or even fully avoided, compared with the previous process.

[0027] During the rolling process, the plate serves as back-up for the roller acting on the metal strip, also known as working roller. It absorbs the rolling forces and transmits them conveniently to the frame of the roll stand, which also supports the working roller and any back-up rollers conveniently provided. Preferably, the plate is supported in floating fashion which allows easy and low-friction motion combined with reliable transmission of forces.

[0028] Conveniently, the arrangement is selected in such a way that the roller defines the roll gap from above and that the plate extends horizontally below the roller and is supported by a back-up roller seated in the roll stand in the usual way. In that case, the rolling forces can be transmitted by the plate to the back-up roller and from the latter, in the usual way, to the frame of the roll stand. In order to guarantee the horizontal alignment of the plate, the latter should be additionally supported beside the back-up roller, preferably on both sides of the roll gap; the carrying capacity of those supporting means may be smaller than that of the back-up roller, the later being arranged directly below the working roller that coacts with the plate.

[0029] A floating arrangement of the plate is achieved with advantage if the plate is supported by rolling elements. The rolling elements may consist of rolls forming a field, conveniently on both sides of the roll gap, that supports the plate at a plurality of points or lines which may be distributed over the entire width and length of the plate. The rolling elements may be driven or may be free-running, instead of being driven. Especially preferred as rolling elements are balls seated in free-running fashion, on which the bottom surface of the plate is supported.

[0030] The plate may be directly driven, for example by means of a spur gear ring, shrunk onto the back-up roller arranged below the plate and transmitting its momentum to the plate via a toothed rod mounted on the plate. This ensures exact positioning of the plate in any phase of its movement, i.e. during the positioning, rolling and recalling phases. Further, there is also the possibility to drive the plate by means of a hydraulic piston-and-cylinder unit or by means of a screw, driven by an electric motor, especially a low-friction and precise recirculating ball screw. Preferably, however, the plate is driven during the rolling process not directly, but indirectly, being entrained by the driving motion of the working roller and/or the metal strip. A locking effect sufficient for this purpose is produced by the rolling pressure acting between the working roll and the plate.

[0031] Preferably, for entraining the plate, its back-up roller arranged below the plate is likewise driven.

[0032] An important advantage of the invention lies in the fact that it can be transferred to other applications. One such application relates to the production of metal strips with grooves, which instead of extending in longitudinal direction from the beginning to the end of the strip, extend crosswise over the full width of the metal strip, from one longitudinal edge to the other longitudinal edge of the strip, and which reoccur at intervals in the metal strip. Such grooved metal strips can be split, before being used for the production of parts, such as contact springs or commutator segments for electric motors, especially for servomotors. Modern servomotors are getting ever quicker and ever more precise. This places increasing demands on the accuracy to gauge of the commutator segments of such motors. The accuracy to gauge of the groove width should be better than 0.02 mm. If such a groove is to be produced in a metal strip by rolling, one or more passes will be necessary.

[0033] Conventionally, the grooves are produced in a metal strip by milling, but the surface quality achieved in this way is not very high. Milling grooves, which extend crosswise over the metal strip, is difficult. One has also tried to produce grooved, strip-shaped input stock by rolling a longitudinally extending groove into a metal strip by several rolling passes. As a result of this process, lateral lands, delimiting the groove, remain in the metal strips on both sides of the groove. Given the fact that the metal strip is elongated in the area of the groove by a certain dimension, due to the displacement of material during the rolling process, but is not so elongated in the area of the lateral lands, the lateral lands must be correspondingly stretched in compensation, for example by the use of coilers that develop a correspondingly high tensile force. But even if the lateral lands are stretched, it is not possible to roll grooves the depth of which exceeds approximately 10% of the thickness of the metal strip. Moreover, the method is laborious and does not lead to the desired accuracy because the metal strip suffers a certain draught in each pass, with the result that the groove gets wider from one pass to the next, with increasing variation. The ways of proceeding described in DE-PS 104 875 and DE 197 04 300 A1 also do not permit high degrees of accuracy to gauge.

[0034] On the other hand, the method of rolling strips step by step and in sections according to the invention allows, generally, profiled metal strips which have the profile extending over the entire width of the metal strip to be rolled with both a high degree of accuracy to gauge and high surface quality, and this especially when the described multi-pass rolling method according to the invention is improved in such a way that, instead of rolling the metal strip in one step, each of its sections to be profiled is rolled in several steps, for which purpose the metal strip is recalled at the end of one rolling step and the section, which has been rolled before, is rolled once again. Especially high degrees of accuracy can be achieved when, instead of being rolled in the one direction and recalled in the reverse direction, the metal strip is rolled in both directions, i.e. also during the recalling step.

[0035] A particular advantage of the invention lies in the fact that it is now possible, with the aid of the invention, to roll profiles into strips which cannot be produced by cutting processes, for example by milling, namely grooves that extend crosswise to the longitudinal direction of the metal strip and that are provided with edges which, instead of extending along a straight line from one edge to the other edge of the metal strip, open in the longitudinal direction of the metal strip to form pockets or niches whose edges then extend along a straight or curved line. Such grooves, opening into pockets or niches, can be rolled in any case by the method according to the invention if the pockets or niches do not widen the groove to such an extent as to create problems with the resulting displacement of material from the pockets or niches to be formed. Even grooves that extend along a curved or an oblique line can be rolled into a metal strip using the intermittent rolling process according to the invention.

[0036] According to a particular embodiment of the invention it is now possible to provide a metal strip with recesses with a border closed all around, and to simultaneously preserve a flat surface area on the opposite side of the metal strip, in the area of the recess so formed. The contour of such a recess may be square, rectangular, oval, circular, or may follow any other closed line. The edge of the recess may consist of a peripheral wall extending perpendicularly or nearly perpendicularly relative to the plate, or of a peripheral wall extending obliquely relative to the plate and opening from the bottom of the recess toward the outside. Alternatively, however, the edge may gradually merge with the bottom of the recess, as is the case with a flat depression. Recesses of that kind have been produced heretofore in strips by a punching process, for example by deep drawing, in which case a bulging area is formed on the opposite surface of the metal strip which is then removed by milling in order to restore the flatness of the strip surface. The procedure used so far is connected with the following disadvantages:

[0037] Insufficient flatness of the strip surface and of the bottom of the punched recess;

[0038] variation of the strip thickness in the area of the bottom of the recesses, in the order of one or a few tenths of a millimeter;

[0039] irregular roughness of the strip surface in the area of bulging portions that have been removed by milling;

[0040] strips profiled in this way can be reproduced only with tolerances in the order of some tenths of a millimeter, the quality being even deteriorated if more than one recesses formed are distributed over the width of the metal strip. In addition the known process is uneconomical as the recesses are formed by two separate processes, in terms of time and place, namely the process of punching the recess and the process of removing the resulting bulging portions by milling.

[0041] Compared with that situation, forming a profiled metal strip with recesses, which are surrounded by a closed border, using a rolling method according to the invention provides the essential advantage that the recesses need not be produced using separate process steps, in terms of time and place, but can be produced in the roll gap between a roller and a plate simultaneously. This can be achieved by the use of a plate with bumps that are pressed into one side of the metal strip during the rolling process, thereby displacing a corresponding quantity of the metal toward the opposite side of the metal strip, where it is rolled flat by the roller so that the flatness of the strip surface opposite the respective recess is preserved.

[0042] The dimensional accuracy and the flatness of the surfaces that can be achieved according to the invention are better by the power of ten, compared with the conventional method.

[0043] The method according to the invention is particularly advantageous for rolling recesses into a metal strip, if the material that has been displaced by the recess-forming process is rolled flat by the same rolling process on the opposite side, and if simultaneously the overall thickness of the metal strip is moderately reduced, preferably in an order of magnitude of 10% of its thickness. It is then possible to achieve an especially high degree of accuracy.

[0044] Recesses can be formed most easily if they have the shape of flat depressions or are provided with a peripheral wall inclined in such a way that the recess opens from its bottom toward the outside. If a recess with a steeper, especially a vertical peripheral wall is to be formed, it may be of advantage if this process is carried out in two or more than two steps and if in a first step a recess with an inclined peripheral wall, for example a wall inclined at an angle of 45°, is formed and thereafter the inclination of the peripheral wall is increased in a second step, for example to nearly 90°.

[0045] The continuous multi-pass rolling process according to the invention is especially advantageous for the production of such profiled strips. The plate arranged opposite the driven roller can be recalled for this purpose again and again for repeated rolling. In order to prevent scratching of the metal strip during its passage through the rolling gap, and to prevent the back-up roller arranged below the plate from being dislocated, the register line of the metal strip is preferably placed a little above the profile that projects upwardly from the plate and which is to be pressed into the metal strip during the rolling process.

[0046] The invention is particularly well-suited for rolling a regularly recurring profile intermittently into a metal strip; such a metal strip can then be split to produce mutually identical mass parts, such as commutator segments or contact springs for electric purposes, with a high degree of accuracy. Splitting the strip is conveniently effected by stamping. The method according to the invention can be used with advantage also for plated strips and for strips to be plated where the sheets to be applied by plating lie at different levels after the rolling process according to the invention. It is not possible with known roll-plating methods to produce profiled strips with recessed plating by rolling the strip in lengthwise direction since in the case of higher degrees of deformation, especially in the case of a deformation of more than 50%, the resulting displacement of material will become a serious problem.

[0047] Using the discontinuous multi-pass rolling process according to the invention, it is now possible to produce the strip-like input stock with especially high and uniform surface quality and with very low thickness tolerances, or to produce input stock with the quality known from the prior art in greater lengths than was heretofore possible, without having to exchange the rollers. There have already been achieved thickness tolerances of ±1 μm, repetitive accuracy values of ±2 μm, peak-to-value heights of only R1=0.18 μm and centre line average heights (CLA) of only Ra=0.022 μm (DIN 4762).

[0048] In order to permit at least two rolling steps to be carried out on one section of the metal strip with the method according to the invention, the circumference of the rollers should be equal to at least twice the length of the recalled sections, and the recalled section should be a little longer than the dimension of the workpieces to be stamped from the semi-finished product, measured in the longitudinal direction of the strip-shaped semi-finished product, in order to allow for the unavoidable stamping waste. If the metal strip is rolled not only in one direction, but alternately in the one and the other direction, then one may chose to roll the metal strip several times in forward and reverse direction between the same segments of the roller and of the plate and to perform the last rolling step between one circumferential segment of the roller and one section of the plate which had been previously employed for a smaller number of rolling steps and which, therefore, still have a better surface quality so that they will give the metal strip a surface with equally optimum quality in the last rolling step.

[0049] If sections of the metal strip are rolled alternately in one and the other direction, one additionally achieves a more favourable material structure than would be obtained if the metal strip were rolled always in one and the same direction. This gets even more important the more the thickness of the metal strip is reduced by the rolling process, because in the latter case material crowding caused by the rollers is also increased. Another advantage lies in the fact that the favourable effect on the material structure, when rolling individual sections by a reciprocating process, is greater than when conventionally rolling a metal strip alternately in the one and the other direction over its full length.

[0050] The number of rolling steps to be performed on one and the same section of the metal strip is adapted to the desired reduction per pass and the desired surface quality of the input stock to be produced.

[0051] The accuracy and surface quality allowed by the method according to the invention are better than the accuracy and surface quality achievable by milling, and also better than achievable by the conventional method, where a longitudinally extending groove is produced in the metal strip by rolling over the full length which, due to the non-uniform elongation occurring in this case, is possible only up to reductions per pass of maximally 10%.

[0052] The intermittent operation of the method according to the invention contributes essentially to the accuracy to gauge of the profile of profiled metal strips. Due to the intermittent operation, each pass begins from the stopped condition of the metal strip, the roller and the plate, or with a speed so low that any tensile stress prevailing in the metal strip can be preserved as the roller cuts into the metal strip. In the initial phase of each pass, therefore, the elongation of the metal strip resulting from the engagement of the rollers in the metal strip does not begin abruptly, as is the case with continuous profile rolling methods, but sets in so smoothly that a constant tensile stress, which is important for the accuracy to gauge of the profile, is maintained in the metal strip, for example by suitably controlling the drive of the coilers which serve to maintain the tensile stress. To this end, the rollers and the metal strip are accelerated and braked during the rolling process uniformly and synchronously. Conveniently, a constant tensile stress is maintained in the metal strip during cutting-in of the roller and most conveniently also during the rolling process.

[0053] If a profile is to be rolled into a metal strip by sections, the roller may comprise a cylindrical shell, which may be subdivided into segments with identical or different diameters, or a profiled shell. A cylindrical shell enables a profile to be rolled into the metal strip by varying the height of the rolling gap during the rolling process, especially by corresponding relocation of the roller.

[0054] The accuracy to gauge and the surface quality will be the better the shorter the rolling passes are. Advantageously, the rolling passes are selected to be shorter than half the diameter of the rollers. In this case, the profile extends over only part of the circumference of the roller. The remaining part of the shell surface of the roller may be made cylindrical; it is then possible to use the cylindrical section of the roller surface in a first rolling pass for equalising, instead of profiling, the respective section of the metal strip in order to improve the accuracy to gauge of the rolled strip.

[0055] One application, for which the invention was realised with advantage, for producing strip-like input stock from metal, which is profiled in regularly recurring sections, relates to pens for fountain-pens.

[0056] Pens for fountain-pens have a thickness varying over their length. Typically, pens have a thickness of 0.2 mm in the rear region, with their thickness rising toward their point, where the pen finally reaches a thickness of maximally 0.6 mm. It is known to produce pens by rolling a metal strip by sections, i.e. by steps, the length of which corresponds to the length of the pens to be produced, so as to provide it initially with a corresponding longitudinal profile, which extends over the full width of the metal strip. This profiled metal strip serves as input stock from which the pens are then stamped out and thereafter formed to give them the desired bent shape.

[0057] To produce the profiled input stock it has been known to give the upper roller of the two rollers, which define the rolling gap and which are supported in a roll stand, an empirically determined contour in the circumferential direction, complementary to the intended thickness profile of the pens. Outside that complementary contour, the spacing of the outer surface of the roller from its axis is selected to ensure that there will be no engagement with the metal strip in the rolling gap in that area. At the beginning of the circumferential segment, which exhibits the complementary contour, the roller comes to cut into the metal strip, entraining it thereafter for the time of one rolling step, namely so long as it is in engagement with the metal strip, whereby the metal strip is both advanced and profiled. During this process, the metal strip is drawn off the first coiler, and the profiled metal strip exiting the rolling gap is wound up by a second coiler. The motion of the metal strip being effected by the two rollers, a certain loop formation will necessarily occur between the rollers and the second, namely the winding-up coiler, which makes it necessary, according to the prior art, to provide a strip loop with a loop-tensioning device that balances out the intermittent strip transport by the rollers and the continuous winding-up action of the second coiler. This is connected with some apparatus input, which is a disadvantage.

[0058] Pens produced in the known manner exhibit undesirable variations in thickness.

[0059] In contrast, the present invention discloses a way of producing profiled strip-like input stock, for example for pens, with higher accuracy. This is achieved, to a considerable extent, due to the large-surface, flat support for the metal strip, combined with the condition that the roller initially cuts into the static metal strip while still in non-rotating condition. For the cutting-in operation, the roller is shifted toward the plate, with the latter still in its static condition. Another advantageous contribution lies in the fact that the tension of the strip can be maintained throughout all phases of the rolling process. This is different with the known process because in that case the rollers rotate continuously at constant speed so that the cutting-in action of the roller and, thus, feeding of the strip, set in and end abruptly. It is not possible with the known method to maintain a constant tensile force in the metal strip during the profiling operation, which would be an advantage for uniform and high-precision rolling results.

[0060] The metal strip is rolled in one step, or if higher demands are placed on its accuracy or in the case of greater reductions per pass in several rolling steps, until the intended depth of the desired profile of the input stock is reached. If more than one rolling steps are carried out, the metal strip is recalled between every two successive rolling steps, and the recalled section of the metal strip is rolled once again between the roller and the plate. There is, however, also the possibility to roll the respective strip section a second time during the recalling phase. Only when the desired profile has been achieved in a section of the metal strip to be profiled by one or more rolling passes and, if necessary, after one or more recalling steps, is the next strip section fed into the rolling gap, exactly positioned in its longitudinal direction and then processed in the rolling gap, for profiling that next section of the metal strip.

[0061] However, it would likewise be possible to proceed in such a way that following the first rolling pass on a first strip section a similar first rolling pass is performed on the next following strip section, if necessary after having restored the initial position of the rollers, for example by reverse rotation of the roller and, if necessary, reverse movement of the plate, and that the strip is then recalled by two steps, whereafter the second rolling pass is carried out first on the first strip section and then on the second strip section.

[0062] This improvement of the invention, which relates to the production of profiled input stock, offers essential advantages:

[0063] By producing the profile of the metal strip not in one, but rather in two or more rolling passes, a higher accuracy to gauge is achieved than was heretofore possible, which is of significance, in the case of writing pens, especially in the area which later forms the shank.

[0064] Since the desired profile is formed in one section of the metal strip not by one, but by two or more rolling passes, it is possible to profile even harder metal strips, including springy strips.

[0065] The fact that the profile of the metal strip can be produced in more than one rolling passes opens up the possibility to carry out different rolling processes, such as equalising, pre-profiling, plating, pattern rolling and mirror-finishing in succession and in different sequence on the same section of the strip.

[0066] This opens up applications of the invention that go beyond the field of writing pens and that cover a plurality of profiled parts that are formed from a strip-like semi-finished product and can be separated from the strip by punching. Such applications comprise, for example, electric conductive structures, such as contact springs, commutator segments for electric motors, further leadframes and chain links for watch straps and for bracelets.

[0067] Due to the possibility to carry out the profiling operation by several rolling steps, the most diverse profiles can be produced.

[0068] The versatility of the invention is increased by the fact that the metal strip need not be profiled in each rolling pass, but may also be simply and uniformly reduced in thickness in a first rolling step, for which purpose the two rollers must have at least one cylindrical segment, if they are not anyway cylindrical.

[0069] The progress realised by the invention is achieved with a minimum of apparatus input. Starting out from a roll stand known per se, one essentially only has to substitute a plate for one roller and to modify the operating procedure that leads to the desired profile. If the roller is profiled in the circumferential direction, then it is conveniently modified in such a way as to give it successive segments of different contours in the circumferential direction, which segments are separated one from the other, especially by relieved sections, and in combination with the preferred step of recalling the metal strip permit one and the same section of the metal strip to be repeatedly rolled.

[0070] There is also the possibility to make the roller cylindrical and to achieve the variation in height of the rolling gap, required for the profiling operation, during rolling by displacing the roller and/or the plate, preferably the roller, which preferably is located above the plate, in the roll stand. This may be done, for example, with the aid of an electric motor driving screws, which act on the roller to be displaced and which are coupled to an incremental rotary transducer which permits recurring adjustments, and by means of which the electric motor can be controlled. Further, it is also possible to displace the roller and/or the plate hydraulically by locating a hydraulically operated cylinder in each frame, in the head or the lower traverse. The two hydraulic cylinders are integrated in the hydraulically operated roll-adjusting system and are driven by a positioning system comprising a power monitoring system. The positioning system may be equipped with pilot valves as servo components and with displacement sensors and pressure transducers as actual-value sensors. It is thus possible to drive the roller along almost any predefined curve, depending on the profile to be rolled. Compared with the use of an electronically controlled electric drive, a hydraulic servo drive provides the advantage of being quicker and more precise.

[0071] Such a servo drive for the displacement of the roller and/or the plate, serving as its back-up element, permits a profile to be rolled into the metal strip in one or more steps, even with a cylindrical roller. The selection of the diameter of the roller, and the way in which the roller is to be displaced relative to the plate, in response to the strip transport, depends on the desired profile. A corresponding control curve for the drive, derived from the profile to be rolled and intended to displace the roller relative to the plate, may be stored as a control curve in a programmable electronic control unit. By storing a plurality of control curves, it is possible according to the invention to work a corresponding number of profiles in metal strips with a single roll stand and without any exchange of the roller. Moreover, it is also possible to make use of the displacement of the roller during the rolling process in a roll stand having one profiled roller. This combination of two different possibilities of varying the height of the rolling gap during the rolling process, namely by the use of a profiled roller in combination with the displacement of the roller relative to the plate, further increases the versatility of the roll stand in the production of strips that are profiled by sections.

[0072] If a cylindrical roller is employed, it is of advantage if the roller is provided with a notch parallel to its axis, in order to have a reference for the angular position of the roller.

[0073] Exact positioning of the respective roller section relative to the metal strip can be effected with the aid of a regulating system controlling the angle of rotation of the roller.

[0074] In connection with the recalling step for the metal strip, the recalling device, for example a first coiler from which the metal strip is unwound, is of particular importance because it must be capable of reproducing with sufficient accuracy the length of the step by which the metal strip is recalled. To this end, that first coiler, conveniently also the second coiler that pulls the metal strip, is provided with a servomotor comprising an incremental rotary transducer which allows the desired step length to be precisely defined, both for the unwinding and for the coiling process. The step length can be defined with even greater precision if the coilers are provided with strip transfer rollers coupled with an incremental rotary transducer that serves as an actual-value sensor in the strip-position regulating system.

[0075] The width of the metal strip may be selected to permit a single profiled part, for example a single profiled writing pen, to be punched out from each of the successively arranged strip sections. The economy of the process, and of the roll stand operating according to the invention, can easily be multiplied if broader strips are profiled, which are wide enough to permit two or more writing pens or similarly profiled objects, lying one beside the other, to be formed from each profiled section of the input stock.

[0076] A particularly advantageous improvement of the invention is defined in claim 22. According to that improvement of the invention, the metal strip is equalised before the profile is rolled. The term equalising is understood to mean that the metal strip is rolled in a roll stand with highly constant rolling gap, whereby any variations in thickness of the metal strip are reduced. Roll stands using two working rollers for equalising purposes are known from DE 25 41 402 C2, to which reference is made for further details. In the case of a roll stand suited for purposes of the invention, a highly constant rolling gap is achieved by the fact that pre-stress forces, acting vertically to the roller axes in a sense away from the material being rolled, are exerted on the roll necks, that extend outwardly beyond the roll neck bearings, by two back-up rolls, which support the plate from below and the other working roller from above, respectively, which pre-stress forces may be oriented perpendicularly and may, preferably, act along a line of action that passes through the incoming metal strip and deviates from the plane of the roller axis by the rolling angle. This reduces the working play of the rollers in the roll neck bearings.

[0077] According to the invention it is, however, not necessary for equalisation purposes to have the roll stand, which serves to profile the metal strip, preceded by an additional roll stand serving the equalisation process. Rather, the equalising and the profiling processes are carried out in one and the same roll stand, for which purpose the metal strip is moved through the rolling gap in the feeding direction not only during the working steps that serve the profiling operation. Instead, the metal strip is first equalised with an only moderate reduction in thickness by steps which—considering the elongation of the equalised section occurring during the subsequent profiling operation—are at least as long as the step for the profiling operation. Thereafter, the strip is recalled by a step of a length at least equal to the length required for the profiling operation and maximally equal to the length by which it has been advanced during the equalisation process, whereafter the profile is rolled into the recalled section of the metal strip. In a roll stand comprising a profiled working roller, where one circumferential segment has the contour adapted to the desired variation in thickness of, for example, a writing pen to be produced from the metal strip, the roller is additionally provided for this purpose with a cylindrical circumferential segment separate from the circumferential segment that is provided with the contour (claim 25). The cylindrical circumferential segment serves to carry out the equalising step. The length of the cylindrical circumferential segment is selected, depending on its function and giving due consideration to the elongation of the metal strip occurring during the rolling process, to ensure that the equalised section of the metal strip will at least have the length of the writing pen, or preferably a somewhat greater length, so that the beginning and/or the end of the profiling step can occur at a certain distance from the beginning and the end of the equalised section.

[0078] Advantageously, the roll stand serving the profiling operation is, therefore, simultaneously designed as equalising roll stand and is equipped with a strip feeding system by which the strip is moved by steps in forward and backward direction.

[0079] The improvement of the invention defined in claim 28 and claim 34 offers essential advantages:

[0080] The variation in thickness by ±20 μm in the input stock and, thus, in the workpieces, for example writing pens, to be produced can be reduced to less than ±2 μm, for example ±1 μm, in a particular pen, especially in the area of the pen that later serves as shank.

[0081] The reproducibility of the thickness profile from one pen to the next can be improved to less than ±4 μm, for example ±2 μm.

[0082] These are accuracy values that could not be reached heretofore in the production of pens by rolling. Corresponding accuracy values can be reached also with strip-like input stock for other profiled products than pens.

[0083] The great progress in accuracy is achieved with a minimum of apparatus input. Starting out from a roll stand known per se the profiling roll of the latter must under certain circumstances be modified insofar as it must be provided with a suitable cylindrical segment, a working roll has to be exchanged against a plate, and the roll necks of the two rollers must be pre-stressed with a view to reducing the bearing play, for example in one of the ways disclosed in DE-25 41 402 C2. In addition, means are required that allow the metal strip to be not only advanced by steps, but also recalled by steps, the steps having approximately a length equal to the length of the equalising steps. As has been mentioned before, this can be achieved simply by providing the first coiler, from which the metal strip to be profiled is unwound, with an electric motor that can be controlled with sufficient accuracy in steps of the desired length and can be reversed in the sense of rotation. This is realised, preferably, with the aid of a servomotor comprising an incremental rotary transducer that allows the desired step length to be exactly predetermined both for the coiling and for the uncoiling process, with the aid of two servo controls with force transducers, provided on guide pulleys for the metal strip, acting as actual-value sensors for coilers that uncoil and wind up the metal strip, respectively, and that create the tensile force in the metal strip, or are, alternatively, controlled with respect to their position by an electronic control system. The actual-value sensors consist, conveniently, of two incremental rotary transducers positioned on the two guide pulleys of the coilers. One servomotor is normally connected to a gearing arranged downstream. Whenever the term servomotor is used hereinafter, it is supposed that the servomotors are normally connected to a gearing arranged downstream.

[0084] Preferably, the second coiler, intended to coil up the profiled metal strip, is also provided with such a servomotor.

[0085] This has the additional advantage that a defined tensile force, which acts toward the achievement of a uniform input stock with little variation in thickness, can be exerted on the metal strip, by the interaction of the servomotors in all phases of the method of the invention, during the cutting-in operation, the equalising step and also when profiling and recalling the metal strip. The tensile force should be as uniform as possible and should not drop below a certain basic tensile force which may be in the order of, for example, 500 N for the production of pens. When recalling the metal strip, the first coiler will, thus, pull the strip with greater force, compared with the smaller coiling force of the second coiler. By maintaining a basic tensile force in the metal strip, that remains as uniform as possible in all working phases of the metal strip, improved uniformity of the rolled input stock is achieved and any off-centre running of the strip is avoided, which means that the metal strip will not get distorted.

[0086] Another advantage of driving the coilers by servomotors lies in the fact that the strip-feeding motion and the drive of the two rollers can be matched so precisely that, contrary to the prior art, the rollers can be driven intermittently, instead of continuously. Specifically, it is then possible to adjust the speed at which the profiled rollers will cut into the metal strip so perfectly to the feeding speed of the strip that no abrupt acceleration of the metal strip will occur at the moment the roller cuts in. Specifically, cutting into the metal strip by the profiled roller may occur initially in stationary condition or at a lower rate of strip feed and at low rotational speed of the roller, whereafter the rate of feed and the rotational speed of the roller may be increased. This is of particular advantage with respect to the achievement of small dimensional tolerances.

[0087] Due to the fact that the metal strip is positioned in the rolling gap relative to the roller by means of a strip-position control system and that the roll is exactly re-positioned for each rolling step by means of a rotary-angle control system, any dimensional deviation in the profile distances will be kept within the order of some hundredths of a millimeter, depending of the particular profile.

[0088] Another advantage of using servomotors for driving the coilers is seen in the fact that special strip-tensioning devices, as required in prior-art devices, are no longer necessary.

[0089] A further advantage of using the servomotors for driving the coilers lies in the fact that using a programmable electronic control unit the strip feed can be adjusted very exactly to the length and the position of the profiled strip sections and to the rotation of the roller, preferably also to the vertical displacement of the roller in order to vary the height of the rolling gap, especially if the latter is defined by a cylindrical roller shell or shell section, and to thereby produce a particular profile.

[0090] Recalling the metal strip can be effected not only by a coiler arranged on the intake end of the rolling gap, but also by a recalling device designed as gripper feed mechanism. This embodiment of the invention is especially well-suited for working shorter or stiffer strips. When the recalling device is a gripper feed device, it may be used additionally to advance the metal strip and to feed it into the rolling gap.

[0091] The sequence control of the process, which combines the control of the strip position, the rotary angle of the roll and the position of the roll, is dependent on the recalling system.

[0092] Instead of using a coiler arranged on the discharge end of the rolling gap, another gripper feed device may be used as pulling device for the strip exiting the rolling gap during the rolling process. This embodiment of the invention is likewise mainly suited for working shorter or stiffer strips.

[0093] The quality of the strip-like input stock produced is increased if a defined tension is maintained in the strip during both, rolling and recalling, especially with the aid of a tensile force control system with two servo controls and force transducers on the guide pulleys as actual-value sensors for the coilers, that favourable influence being the greater the thinner the metal strip is. But it is of advantage also with thicker strips if the strip is kept under tension and is exactly guided between the recalling device and the pulling device by mutually matching the motion of the two devices, and this both during the rolling and the recalling steps.

[0094] The method according to the invention permits the optimum strip tension to be maintained in all phases of a rolling step, especially also in the critical phase when the profiled roller cuts into the metal strip, because the particular nature of the discontinuous multi-step rolling method according to the invention has the effect that each rolling step starts out from the stopped condition of the rollers, the plate and the metal strip so that the engagement of the profiled roller in the metal strip occurs not abruptly but rather so smoothly that the tensile force of the strip-tensioning device, for example the coilers, can be controlled to be maintained at a constant value optimally adapted to the respective strip in the critical phase when the profiled roller cuts into the metal strip and during the entire rolling step. For this purpose, the coilers and the rollers are, advantageously, accelerated and/or braked by their respective drive motors in synchronism and to the same degree when accelerating and braking the metal strip and the rollers.

[0095] The optimum pre-stress for removing the bearing play of the rollers can be determined empirically for the respective application and can then be kept constant for that application. Preferably, the process is optimised by determining the elongation of the roll stand occurring in the particular application during the equalisation process, and compensating it by suitable adjustment of the pre-stress.

[0096] The device, as defined in claim 51, for producing strip-shaped input stock from metal by rolling a metal strip by the method according to the invention comprises a roll stand in which a roller and a plate, that can be moved linearly and that faces the plate, define a rolling gap, and a recalling device for the metal strip arranged on the intake side of the rolling gap, for which device a drive motor, especially a servomotor, is provided with permits the metal strip to be recalled in steps of pre-determinable length, the plate being adapted for being driven, in synchronism with the roller and/or with the metal strip, in the predetermined direction of movement of the metal strip in the rolling gap, and for being driven and recalled independently of the metal strip as well. The possibility to move the plate in synchronism with the roller and/or the metal strip guarantees that the metal strip will not slip on the plate in the rolling gap as such during rolling of the metal strip. Moreover, the metal strip can be driven and recalled independently of the plate in order to permit the plate to be recalled upon completion of a rolling pass in a selected section of the metal strip, without however being forced to recall the metal strip, so that a next section of the metal strip can be rolled. The drive of the plate may be realised directly, but is preferably realised indirectly in that the plate is entrained during the rolling operation by the driven roller and by the driven metal strip, preferably also by a driven back-up roller arranged below the plate and supporting the plate. Likewise, the back-up roller can recall the plate between two successive rolling steps, for which purpose the frictional lock between the back-up roller and the plate resting on it will be sufficient although, if necessary, the friction force generated by the dead load of the plate can be increased by pressure elements that additionally urge the plate against the back-up roller. Such pressure elements may consist, for example, of rollers that are pressed upon the plate by pneumatic cylinders.

[0097] Profiled metal parts, which are obtained by splitting metal strips and which are formed by sections in a single rolling pass of the intermittent rolling process, are employed for example in the automotive industry where they can be used to replace metal parts that heretofore had to be produced laboriously by welding processes.

[0098] The invention is suited not only for rolling strips from metal in the sense in which the term “metal strip” is used in this description, but also for rolling strips from plastic materials and also for strips made from plastic-based compound materials, for example a plastic material with metallic or mineral or ceramic fillers, or metallised plastic strips as well as metal strips coated with a plastic material.

[0099] Further features and advantages of the invention will become apparent from the appended diagrammatic drawings showing certain embodiments of the invention in which:

[0100]
FIG. 1 shows a side view, sectioned in part, of a machine according to the invention;

[0101]
FIG. 2 shows a front view of the machine, sectioned in part;

[0102]
FIG. 3 shows a detail of the machine, namely the main part of the roll stand of the machine, in an enlarged scale compared with FIG. 1;

[0103]

FIG. 3

a
shows the detail marked “X” in FIG. 3;

[0104]
FIG. 4 shows a detail of the machine, namely the roll stand, in an enlarged scale compared with FIG. 2;

[0105]

FIG. 4

a
shows the detail marked “Y” in FIG. 4;

[0106]
FIGS. 5-10 show a flow diagram of a first working method that can be carried out with the machine;

[0107]
FIGS. 11-16 show a flow diagram of a second working method that can be carried out with the machine;

[0108]
FIG. 17 shows a diagrammatic view of a method for carrying out the invention using two cylindrical rollers;

[0109]
FIG. 18 shows a modified machine according to the invention, in a representation similar to FIG. 1;

[0110]
FIG. 19 shows a metal strip that can be produced using the invention, comprising grooves that widen to form rectangular niches;

[0111]
FIG. 20 shows a metal strip that can be produced using the invention, comprising grooves that widen to form a curved niche; and

[0112]
FIG. 21 shows a metal strip that can be produced using the invention, comprising grooves that widen to form rectangular niches, and comprising recesses that are defined by a closed border.

[0113] Parts corresponding one to the other are identified in the examples by the same reference numerals.

[0114] The machine shown in FIGS. 1 and 2 comprises a machine bed 1 with a roll stand 2 erected in its middle and with one mounting device 3 and 4, respectively, for a coiler 5 and 6, respectively, mounted before and behind the roll stand, which coilers can be driven by a drive motor 7, 8 designed as electric servomotor.

[0115] Seated in lateral mounting elements 9 of the roll stand is a working roller 12, hereinafter simply referred to as roller, which coacts with a flat plate 67, arranged below the roller, to define a rolling gap 13. Supporting rollers 14 and 15, respectively, of larger diameter than the roller 12 are mounted in mounting elements 10 and 10a, respectively, above the upper roller 12 and below the plate 67. The mounting elements 9, 9a of the working roller 12 are each arranged in a recessed portion of the mounting elements 10, 10a of the supporting rollers 14, 15.

[0116] A metal strip 16 to be worked runs from the coiler 5 over a transfer roller 17 into the rolling gap 13, passes the latter and reaches the second coiler 6, via a further transfer roller 18, where the metal strip 16, having been worked in the roll stand 2, is coiled up. Between the rolling gap 13 and the second transfer roller 18, there is further provided a device 19 for exhausting rolling oil, in which the metal strip is cleaned from rolling oil.

[0117] The structure of the roll stand 2 is shown more fully in FIGS. 3 and 4. There it can be seen that the roller 12, the diameter of which is only ⅓ of the diameter of the supporting rollers 14 and 15, is seated with its roll necks 20 and 21 in roll neck bearings 22 designed as roller bearings. One roll neck 21 of the roller 12 is extended beyond the respective roll neck bearing 22 and designed as part of a gimbal suspension 23, which allows the roller 12 to be driven using a cardan shaft 24. An electric motor 41, driving the roller 12 in synchronism via the cardan shaft 24, is shown in FIG. 2. It drives the roller 12 and the lower back-up roller 15 via a branched gearing 48, although it is likewise possible to have the roller 12 and the back-up roller 15 driven by two separate motors.

[0118] The supporting rollers 14 and 15 have roll necks 25 seated in roll neck bearings 26, designed as roller bearings, in the lateral mounting elements 10 and 10a. The roll necks 25 are extended beyond the roll neck bearings 26 and fitted in bushes 27, the bushes of the lower supporting roller 14 being braced with the machine bed 1, whereas the bushes 27 of the upper supporting roller 15 are braced with a crosshead 28 arranged above it. Bracing is effected in each case using a threaded rod 29, projecting from the bushing 27, on which a set of cup springs 30 is tensioned by a nut 31. This is shown only above the crosshead 28, but the arrangement at the machine bed 1 is the same. The pre-stress so created reduces the bearing play of the supporting rollers 14 and 15 and, thus, its influence on the thickness deviations of the rolled metal strip, compared with the intended thickness. The roller 12 and the back-up rollers 14 and 15 thereby reach a degree of concentricity of ±1 μm.

[0119] The plate 67 is supported not only by the lower back-up roller 15, but additionally by two fields of ball-bearings 65, one of such fields being arranged on the intake side of the rolling gap 13, the other field being arranged on the discharge side of the rolling gap 13. Each of the ball-bearings consists of a cup 69, firmly closed by a spherical cover 70. The cover 70 comprises a central, circular opening, and a ball 71, arranged below the cover and having a diameter larger than the diameter of the central hole, projects with part of its surface through that hole. The ball 71 is urged against the spherical cover by a spring 72 arranged in the cup 69. The ball 71 is, thus, seated resiliently and besides in freely moving fashion between the edge of the central opening in the cover 70 and the spring 72. The ball-bearings 65 are arranged in the two fields in such a way that their upper surfaces lie in a common plane in which they support the bottom surface of the plate 67 resiliently and in easy-moving, i.e. low-friction fashion. The ball-bearings are arranged in holders 66 that are mounted on the roll stand 2 in a vertically adjustable way. The vertical position of the ball-bearings 65 is adjusted to ensure that during rolling, i.e. when the plate 67 is urged against the lower back-up roller 15, the plate urges the balls 71 in downward direction and slightly away from the edge of the central opening in the cover 70.

[0120] The lower back-up roller 15 can be vertically adjusted with the aid of adjusting means 73 using wedges, as indicated between the two beds of the roll frame window and the two lower bearing blocks of the lower back-up roller 15. Accordingly, the plate 67 is likewise adjustable in vertical direction.

[0121] Mounted on the bottom surface of the plate 67, via cup springs 84, are two mutually parallel toothed rods 82 which extend in a direction indicated by the double arrow (FIG. 3), namely the-rolling direction. The toothed rods 82 mesh with two ring gears 83, which are mounted laterally, especially by shrinking, on the lower back-up roller 15. This permits the plate 67 to be driven very precisely by the lower back-up roller 15, which in turn is driven by the electric motor 41 (FIG. 2). The cup springs 84 act in this connection to compensate any possible flattening of the back-up roller 15 that may be caused by the rolling forces.

[0122] Alternatively, the plate 67 may not have a drive of its own, but may be entrained, by a frictional locking effect, by the synchronously driven roller 12, the metal strip 16 and the lower back-up roller 15. If the plate 67 is to be recalled between two rolling steps, this is effected by driving the lower back-up roller 15 in the corresponding direction, the necessary frictional locking effect between the back-up roller 15 and the plate 67 being generated in this case by the dead load of the plate 67. Should that dead load be insufficient to achieve a reliable frictional locking effect, then the plate 67 may be additionally urged against the back-up roller 15 by rollers—not shown in the drawing—that are urged against the upper surface of the plate 67 by pneumatic cylinders.

[0123] The required pre-stress on the roll stand 2 is produced by means of two screws 32 and 33, that press on the crosshead 28 and the bearing shells 27 from above and that are each driven by a separate electric motor 34 (see FIG. 1) arranged on top of the roll stand 2. Both electric motors 34 are provided for this purpose with a driving shaft 49, configured as pinion, whose teeth mate with a gear 50. The two gears 50 are fixed against rotation on the one screw 32 and on the other screw 33. The suitable pre-stress on the roll stand is determined empirically, based on the elongation of the roll stand in the particular application, and is adjusted so as to compensate for the elongation. After that preliminary adjustment, the machine according to the invention works as follows:

[0124] The metal strip 16 to be worked is drawn off the first coiler 5, passed through the rolling gap 13, pulled to the second coiler 26 and fixed on the latter.

[0125] The plate 67 has a flat upper surface. The roller 12 has a shell surface (FIG. 5) with a profiled circumferential segment 35 of a length L1, measured in the circumferential direction of the roller 12, and a cylindrical circumferential segment 36 of a length L2, measured in the circumferential direction of the roller 12, the two segments being separated by two relieved portions 37 and 38. The cylindrical circumferential segment 36 of the surface is spaced the largest distance from the axis of the second roller 12, the relieved portions 37 and 38 are spaced the smallest distance from the axis of the second roller 12. The profiled circumferential segment 35 of the surface has a contour the shape of which, viewed in the circumferential direction, is matched to the longitudinal development of the thickness of the workpiece, for example a writing pen, finally produced from the metal strip 16.

[0126] In FIGS. 5 to 16, the plate 67, which supports the metal strip 16 during the rolling process, is shown only in part.

[0127] Working the metal strip 16 commences by causing the cylindrical circumferential segment 36 of the second roller 12 to cut into the metal strip stretched between the two coilers 5 and 6, and this smoothly with the metal strip 16 in static condition and the roller 12 not rotating, or at best at a low feeding speed of the metal strip 16 adapted to the circumferential speed of the cylindrical circumferential segment 36. The cutting-in phase is shown in FIG. 5, although not true to scale but with the metal strip 16 shown in exaggerated thickness. The further FIGS. 6 to 16 also show exaggerated reductions per pass, produced by the rolling process on the metal strip, in order to illustrate the rolling process more clearly. The cylindrical circumferential segment 36 rolls on the metal strip 16, thereby reducing the latter's thickness typically from 0.66 mm to 0.60 mm, while simultaneously equalising the thickness. The end of the equalising step is shown in FIG. 6. Now, the metal strip 16 gets out of engagement with the cylindrical circumferential segment 36 of the roller 12, which continues to rotate over an additional small angle until the relieved portion 37 faces the metal strip 16. By reversing the two drive motors 7 and 8, designed as servomotors, the metal strip 16 is now recalled, preferably with the roller 12 and the plate 67 stopped, by a length greater than L1 but smaller than L2, L2 being the length over which the metal strip 16 had been equalised. The length by which the metal strip 16 is recalled is selected in such a way that in the next step (FIG. 7), when the movement of the roller 12 and the feeding movement of the metal strip 16 are re-started, the profiled circumferential segment 35 of the roller 12, with the contour adapted to the workpieces to be produced, will smoothly cut into the equalised section of the metal strip 16 directly after its beginning (FIG. 7) or at a small distance, for example 2 mm, behind it. With the relieved portion 37 facing the metal strip 16, the screws 32 and 33 are rotated to lower the roller 12 far enough to ensure that the desired cutting depth will be reached with the profiled circumferential segment 35 of the roller 12, which is the next to cut into the metal strip 16. As the second roller 12 continues to rotate and the metal strip 16 is correspondingly advanced by the second coiler 6, the profiled circumferential segment 35 rolls the intended profile into the equalised section of the metal strip 16, over its entire width (FIGS. 7 and 8). FIG. 8 shows the final point of the profiling step. It ends a small distance before the end of the equalised section, at the latter's level. As the upper roller 12 continues to rotate, its relieved portion 38 faces the metal strip 16. In this phase, the upper roller 12 is returned to its upper position, by rotating the screws 32 and 33, so as to adjust the height of the rolling gap 13 as necessary for the following equalising step. The position of the relieved portion 38 between the profiled circumferential segment 35 and the cylindrical circumferential segment 36 of the roller 12, and the action of positioning the metal strip 16 in the rolling gap 13 by means of the servomotors 7 and 8 of the coilers 5 and 6, are matched in such a way that the next time the cylindrical circumferential segment 36 cuts into the material, this occurs at a small distance, approximately 2 mm, behind the end of the previously equalised section of the metal strip 16 (FIG. 9), whereby another equalising step is initiated, as shown in FIGS. 9 and 10.

[0128] During the equalising, profiling and recalling processes, the servomotors 8 and 9 ensure that the tensile stress in the metal strip 16 is kept as uniform as possible.

[0129] If the higher degree of accuracy that can be achieved by the equalising step is not of importance that step may be omitted, and the respective sections of the metal strip may be processed by a single rolling pass, namely the one by which the section is profiled.

[0130] The practical embodiment shown in FIGS. 11 to 16 differs from the embodiment shown in FIGS. 5 to 10 in that the upper roller 12 acts on the metal strip 16 which is to be worked with three, instead of two, circumferential segments 35, 36 and 40, separated by relieved portions 37, 38 and 39. The roll stand 2 provided for this purpose has the same structure as the one shown in FIGS. 1 to 4, with the proviso that the roller 12 illustrated in FIGS. 11 to 16 is used as roller 12, the profile of the roller 12 being exaggerated in the drawing. Here again, the equalising step is not absolutely necessary in that example.

[0131] The circumferential segment 36 is cylindrical, whereas the two circumferential segments 35 and 40 have a non-cylindrical profile. Similar to the example shown in FIGS. 5 to 10, the cylindrical circumferential segment 36 has the largest spacing from the axis of the roller 12 over its full length, which is of advantage under the aspect that the cylindrical circumferential segment, which serves to carry out the equalising step, must be reground as necessary.

[0132] The working method illustrated in FIGS. 11 to 16 corresponds to that illustrated in FIGS. 5 to 10, with the exception that following the equalisation of the respective section of the metal strip 16, the profiling step is carried out in two successive, instead of one, rolling steps between which the metal strip is recalled once more.

[0133]
FIG. 11 shows, similar to FIG. 5, the moment when the cylindrical circumferential segment 36 of the roller 12 cuts into the metal strip 16. Similar to FIG. 6, FIG. 12 shows the end of the equalising step. By continued rotation of the roller 12, the metal strip 16 is brought out of engagement with the roller 12 and can be recalled by the coiler 5. During that phase, the roller 12 is lowered by means of the screws 32 and 33 in order to adjust the height of the rolling gap 13 for the subsequent first profiling pass, the beginning of which is illustrated in FIG. 13. FIG. 13 corresponds to FIG. 7 and shows the cutting-in phase for the first non-cylindrical, profiled circumferential segment 35 of the roller 12. FIG. 14 corresponds to FIG. 8 and shows the end of the first profiling step.

[0134] As the roller 12 continues to rotate, the metal strip 16 is again brought out of engagement with the roller 12, and in this phase, with the relieved portion 39 facing the metal strip 16, the metal strip is recalled another time and the rolling gap is adjusted, by operation of the screws 32 and 33, for the second profiling step, the beginning of which is shown in FIG. 15 which illustrates the cutting-in phase of the profiled circumferential segment 40.

[0135]
FIG. 16 shows the end of the second profiling step. By further rotating the roller 12, the metal strip 16 is once more disengaged and can be positioned for the equalising step in the next following strip section, while the height of the rolling gap 13 is simultaneously, or subsequently, adjusted for the equalising step. Thereafter, the sequence of the steps illustrated in FIGS. 11 to 16 is repeated. In order to achieve a high degree of reproducibility of the rotary angle of the roller 12, it is most convenient if the roller 12 is reversed to a predetermined starting position (for example the 0° position) at the end of every process cycle, in order to prevent any inaccuracies from summing up by continuous full revolutions of the roller 12.

[0136] This method of operation is especially well-suited for the production of profiled sections in strips where the desired reduction per pass cannot be reached, or can be reached only with difficulty, with the desired accuracy in a single profiling step.

[0137] The invention may be carried out also with more than two profiling steps. In order to permit the required number of circumferential segments participating in the rolling process to be accommodated, the diameter of the roller 12 may be increased as desired.

[0138] Further, there is the possibility to provide, either additionally to or instead of an equalising step, a reducing step by which the thickness of the metal strip 16 is initially uniformly reduced in sections before these are profiled in a later rolling step.

[0139] The invention finds its application not only in the production of input stock for writing pens, but also in the production of other input stock which is profiled, in a sequence of regularly recurring sections, over the entire width of the metal strip 16, for example for the production of a strip-like input stock for the production of electric conductive structures, such as contact springs or leadframes, or for the production of grooved strips where the grooves, with or without pockets or niches, extend crosswise to the longitudinal direction of the metal strip 16, in parallel or not in parallel to the axis of the roller, and continuously from one longitudinal edge to the other longitudinal edge of the metal strip, for example for the production of commutator segments, electric plug-in connectors or other electric contact elements. Even sheet metal parts for the automotive industry, which are stiffened by a corresponding profiling, can be produced at low cost and with a high degree of precision. The method according to the invention permits the production of any profiled shape that can be produced by means of rollers, if necessary profiled rollers.

[0140]
FIG. 17. shows, in a schematic diagram, how the servomotors 7 and 8 of the two coilers 5 and 6, preferably also electric motors 41 and 42 designed as servomotors for driving the roller 12 and the back-up roller 15, and the two electric motors 34, which preferably also consist of servomotors with a gearing 34a connected downstream, by which the roller 12 can be displaced using the screws 33 and 32, are linked via a common electric control unit 43. It is thus possible, by controlling the servomotors 7 and 8 in response to a profile shape to be rolled into the metal strip 16, which is input into the control unit 43 and, preferably, stored in digital form, to control the feeding motion of the metal strip 16 during the rolling and recalling phases, to rotate, stop and, if necessary, reverse the roller 12 and the back-up roller 15 correspondingly, and to displace the roller 12 by actuation of the electric motors 34, in response to the feeding motion of the metal strip 16 and the profile shape input to the control unit 43. To this end, the actual positions are each fed back to the control unit 43 by incremental rotary transducers. These rotary transducers are integrated in the servomotors 7, 8, 41 and 42. In the drawing, one incremental rotary transducer 44 is shown by way of example between the screws 32 and 33 and two servomotors 34, respectively.

[0141]
FIG. 17 shows a cylindrical roller 12, which has a radial notch 45 parallel to its axis in order to provide a reference for its rotary position. If the roller 12 has a non-cylindrical circumferential segment, as in the example previously discussed, displacement of the roller 12 will not take place during the rolling process, but can be carried out only between the individual rolling steps, as necessary.

[0142] The curve according to which the roller 12 is displaced cannot only be stored in the control unit in the form of suitable software. Rather, a mechanical control using a cam running in synchronism with the strip feed is, generally, likewise possible.

[0143] The device illustrated in FIG. 17 also permits metal strips with grooves that extend crosswise to their longitudinal direction, or metal strips with another profile extending continuously over the full width of the metal strip 16, to be produced if the roller 12 is provided with a corresponding profile extending in the circumferential direction.

[0144]
FIG. 18 shows an embodiment modified as compared with FIGS. 1 to 4. It differs from the embodiments illustrated in FIGS. 1 to 4 insofar as gripper feed mechanisms 52 and 53 are provided instead of coilers 5 and 6. This embodiment is suited especially for shorter or thicker metal strips 16 that cannot be coiled so easily.

[0145] The gripper feed devices 52 and 53 comprise a carriage 56, 67 that can be approached to and withdrawn from the rolling gap 13 in horizontal direction, by means of a servomotor 54, 55. A dovetail spring 58 is provided for this purpose on the bottom surface of the carriage 56, 57, which spring engages a matching dovetail groove 59, 60 formed in an element 61, 62 attached to the roll stand 2. The engagement between the groove 59, 60 and the spring 58 ensures perfect horizontal guidance for the carriages 56, 57. Other types of guides are also possible. Each carriage 56, 57 is equipped with a lower jaw 63 and an upper jaw 64, fixed rigidly on the carriage, the distance of the upper jaw from the lower jaw being variable, preferably by means of a pneumatic cylinder. The metal strip 16 is passed, and clamped if necessary, between the two jaws 63 and 64, which form a pair of grippers or a clamp. The gripper feed mechanisms 52 and 53 can be actuated and displaced individually, but also jointly in matched fashion. In the latter case it is also possible, during both the rolling and the recalling action, to maintain a defined tensile stress in the section of the metal strip 16 that is tensioned between the two gripper feed mechanisms 52 and 53.

[0146] The two gripper feed mechanisms 52 and 53 are arranged adjacent the rolling gap 13, as shown in FIG. 18. The device 19 for exhausting rolling oil is arranged at the discharge end of the rolling gap 13, after the gripper feed mechanism 53 in the rolling direction, followed by a thickness gauge 51 for picking up and signalling the thickness of the rolled metal strip 16, either by means of a probe or in no-contact fashion, so that suitable controlling or regulating action can be taken to vary the height of the roller 13 in a suitable manner if deviations from the desired thickness should occur.

[0147]
FIG. 19 shows a metal strip 16, which can be produced according to the invention and which has been profiled on both sides, with grooves 74 extending in crosswise direction in the bottom surface of the metal strip 16 and grooves 75 and 76 extending in crosswise direction in the upper surface of the metal strip 16, the grooves 74 in the bottom surface having been formed in a first pass, the grooves 75 and 76 in the upper surface of the metal strip 16 having been formed in a second pass, after the metal strip has been turned over. That sequence of process steps is, however, not compulsory. In the illustrated example, the grooves 74 are narrower than the overlying grooves 75, which alternate in the upper surface of the metal strip 16 with the narrower grooves 76. It is a particularity of that example that the wider grooves 75 open up to form rectangular niches 77 of a relatively small depth, measured in the longitudinal direction 79 of the strip 16 so that the displacement of material from the niches can be kept under control.

[0148] The metal strip illustrated in FIG. 20, which can be produced according to the invention, differs from the metal strip illustrated in FIG. 19 in that niches 78 with curved borders have been produced instead of rectangular niches 77.

[0149] The invention not only allows the production of metal strips with grooves that open up to form rectangular or curved niches, as shown in FIGS. 19 and 20, but also provides the possibility to provide a metal strip 16 with recesses 80, arranged one behind and/or one beside the other, which recesses are enclosed by a closed border, for example of triangular, rectangular or circular shape, as illustrated in FIG. 21. Other outline shapes are likewise possible. In the example illustrated in FIG. 20, the recesses 80 are delimited by circumferential walls that extend at a right angle or nearly a right angle relative to the plate 67. However, the circumferential walls of the recesses 80 may also extend obliquely to the plate 67, i.e. so that the recesses widen from their bottom toward the upper surface of the metal strip 16.

[0150] Recesses 80 of that kind can be formed by moving the metal strip 16 through the gap between the working roller 12 and a plate 67, which is provided on its upper surface with bumps 81 of a shape complementary to the recesses 80, as shown diagrammatically in FIGS. 3a and 4a.

Claims

1. Method for producing strip-like input stock from metal, which is profiled in subsequent sections on one or both sides, by rolling a metal strip in one or more rolling steps, comprising the following process steps: (a) Tensioning the metal strip (16); (b) positioning the metal strip (16) in a rolling gap (13), which is defined by a roller (12) and a movable plate (67), relative to the roller (12); (c) positioning the plate (67) relative to the roller (12); steps (b) and (c) being carried out either successively or simultaneously or in timely overlapping fashion or in a successive inverse order, or step (c) being carried out before step (a); (d) grooving the metal strip (16) with the roller (12) by reducing the distance of the shell surface of the roller (12) to the metal strip (16), the metal strip (16) being maintained steady or being moved only slowly at least during the beginning phase of the grooving step, and the roller (12) being rotated not at all or only very slowly so that the metal strip (16) remains under tensile stress in the rolling gap (13); (e) rolling a section of the metal strip (16) in the rolling gap (13) by rotating the roller (12) and moving the plate (67) in a rectilinear manner in synchronism with the rotation of the roller (12); and (f) releasing the metal strip (16) by opening the rolling gap (13); steps (b) to (f) being repeated for every section to be profiled of the metal strip (16).
2. The method as defined in claim 1, characterised in that the metal strip (16) is profiled on one side only.
3. The method as defined in claim 1, characterised in that the metal strip (16) is at first profiled on one side only and is then turned over so that its profiled side faces the plate (67), and that the metal strip (16) is then profiled on its other side.
4. The method as defined in claim 3, characterised in that following profiling of the one side of the metal strip (16) the plate (67) is exchanged against another plate provided with a profile complementary to the profile previously rolled into the metal strip (16).
5. The method as defined in any of the preceding claims, characterised in that a flat plate (67) is used if the metal strip (16) is profiled only on one side or initially only on one side.
6. The method as defined in any of the preceding claims, characterised in that recesses (80) with closed borders are formed in the metal strip (16), for which purpose the plate (67) used is one provided with bumps (81) complementary to the recesses (80).
7. The method as defined in claim 6, characterised in that a moderate reduction of the overall thickness of the metal strip (16) is effected by having the roller (12), arranged opposite the plate (67), acting on the metal strip (16) at the same time the recesses (80) are formed.
8. The method as defined in claim 7, characterised in that the moderate reduction in thickness of the metal strip (16) is equal to approximately 10% of its previous thickness.
9. The method as defined in claim 6, 7 or 8, characterised in that the recesses (80) are formed in several steps and that the steepness of the circumferential wall of the recesses (80) increases from one step to the next.
10. The method as defined in any of the preceding claims, characterised in that the tensile stress in the metal strip (16) is kept constant during the grooving and the rolling phases.
11. The method as defined in any of the preceding claims, characterised in that when several rolling steps are carried out for profiling the metal strip (16) in the respective sections, the process steps (b) to (e) are repeated, for which purpose the metal strip (16) is recalled after opening the rolling gap (13), and the recalled section of the metal strip (16) is rolled once again in the rolling gap (13) under the action of the same roller (12).
12. The method as defined in any of the preceding claims, characterised in that the metal strip (16) is not rolled during the recalling phase.
13. The method as defined in any of claims 1 to 11, characterised in that the metal strip (16) is rolled also during the recalling phase.
14. The method as defined in any of the preceding claims, characterised in that plate (67) is floatingly supported.
15. The method as defined in any of the preceding claims, characterised in that the roller (12) defines the rolling gap (13) from above, and that the plate (67) is arranged in horizontal position and is supported by a back-up roller (15).
16. The method as defined in any of the preceding claims, characterised in that the plate (67) is supported on both sides of the rolling gap (13).
17. The method as defined in claim 15 or claim 16, characterised in that the plate (67) is supported on both sides of the rolling gap (13) by rolling elements.
18. The method as defined in any of the preceding claims, characterised in that the surface of the plate (67), facing the roller (12), is configured to be flat.
19. The method as defined in any of the preceding claims, characterised in that the plate (67) is moved during the rolling process by being entrained by the driven roller (12) and/or the metal strip (16).
20. The method as defined in any of claims 13 to 17, characterised in that the plate (67) is moved by its back-up roller (15), which is driven for that purpose.
21. The method as defined in any of the preceding claims, characterised in that the metal strip (16) is recalled by a length shorter than the circumference of the roller (12).
22. The method as defined in any of the preceding claims, characterised in that the metal strip (16) is simultaneously equalised by the rolling process.
23. The method as defined in any of the preceding claims, characterised in that using the roller (12) a profile is rolled, into the sections of the metal strip (16), the profile extending over the full width of the metal strip (16), so that the metal strip (16) exhibits a thickness that varies over its length.
24. The method as defined in claim 23, characterised in that a periodically recurring profile is rolled into the metal strip (16).
25. The method as defined in any of the preceding claims, characterised in that the roller (12), the plate (67) and the metal strip (16) are accelerated and braked, resp., in synchronism and to the same degree during the rolling steps.
26. The method as defined in any of the preceding claims, characterised in that for producing strip-shaped input stock with a selected profile, which recurs in successive sections of the input stock, the sections to be profiled of the metal strip (16) are guided through the rolling gap (13) in steps of predetermined lengths, and the height of the rolling gap (13) is reduced from one rolling step to the next until the desired depth of the selected profile of the input stock is obtained in the respective sections of the metal strip (16).
27. The method as defined in any of the preceding claims in combination with claim 14, characterised in that in the first rolling step the metal strip (16) is only reduced in thickness, but is not yet profiled.
28. The method as defined in claim 27, characterised in that the metal strip (16) is equalised in the first rolling step.
29. The method as defined in claim 27 or claim 28, characterised in that the reducing rolling step is followed by one or more profiling rolling steps in one and the same rolling gap (13).
30. The method as defined in claim 27, 28 or 29, characterised in that the length (L2) of the reducing rolling step, during which the metal strip may also be equalised, is longer than the length (L1) of the next following profiling rolling step, taking into account the elongation of the reduced section occurring in the next following profiling step.
31. The method as defined in any of claims 27 to 30, characterised in that following the reducing rolling step the metal strip (16) is recalled by a length shorter than the length (L2) of the reducing rolling step and longer than the length (L1) of the next following profiling rolling step to be performed on the same section of the metal strip (16).
32. The method as defined in any of the preceding claims in combination with claim 14, characterised in that it is performed in a roll stand (2), in which the surface of the roller (12) includes a profiled section (35, 40) having a contour which together with the plate (67) defines the rolling gap (13).
33. The method as defined in any of the preceding claims, characterised in that the roller (12) has a cylindrical shell which is preferably subdivided into segments of equal or different diameter.
34. The method as defined in any of claims 1 to 32 in combination with claim 19, characterised in that prior to rolling a profile the metal strip (16) is initially equalised in the rolling gap (13), with moderate reduction of its thickness, between the roller (12) and the plate (67) in steps having a length (L2) not shorter than the length (L1) of the first profiling rolling step, and is then recalled by a step at least equal to the length (L1) of the first profiling rolling step and maximally equal to the second length (L2), whereafter the profile is rolled into the recalled section of the metal strip (16), and that for equalising the metal strip (16) the shell of the roller (12) has a cylindrical circumferential section (36) separate from those one or more profiled circumferential sections (35, 40) that exhibit a non-cylindrical contour.
35. The method as defined in any of the preceding claims, characterised in that during rolling of the metal strip (16) the roller (12) of the roll stand (2) is displaced for varying the height of the rolling gap (13).
36. The method as defined in claim 35, characterised in that the roller (12) is displaced by a servo drive (32, 34, 44).
37. The method as defined in claim 36, characterised in that one or two electric motors (34) or one or two short hydraulic cylinders are used for the servo drive.
38. The method as defined in any of claims 35 to 37, characterised in that the displacement of the roller (12) is effected with the aid of a program-controlled drive (32, 33, 34, 44), the profile to be produced in the respective rolling step being stored in a programmable control unit (43) as control curve for the drive (32, 33, 34, 44) effecting the displacement of the roller (12).
39. The method as defined in any of claims 35 to 38, characterised in that the roller (2) has a notch (45), which is parallel to the axis of the roller (2).
40. The method as defined in any of the preceding claims, characterised in that the roller (12) is driven in synchronism with the feeding motion of the metal strip (16).
41. The method as defined in any of the preceding claims in combination with claim 18, characterised in that a relieved portion (37, 38, 39) is provided in the shell surface of the roller (12) between the circumferential sections (35, 38, 40) which are active during the rolling process, which relieved portion extends over a circumferential angle sufficient to ensure that the circumferential section (35, 36, 40), which is active during the rolling process, will groove the metal strip (16) only after the metal strip (16) has been released by the circumferential section active during the preceding rolling step.
42. The method as defined in any of the preceding claims, characterised in that the metal strip (16) to be rolled is uncoiled from a first coiler (5) and the rolled metal strip (16) is wound up on a second coiler (6), and that the rotary speed of the roller (12) and the circumferential speed of the coilers (5, 6) are matched, especially during the phase when the roller (12) grooves the metal strip (16).
43. The method as defined in any of the preceding claims, characterised in that grooving by the roller (12) is effected at reduced rotary speed of the roller (12) and, correspondingly, at reduced feeding speed of the metal strip (16), and that the movements are then accelerated.
44. The method as defined in any of claims 1 to 40, characterised in that the metal strip (16) is recalled by means of a first gripper mechanism (52).
45. The method as defined in claim 44, characterised in that by means of the first gripper mechanism (52) the metal strip (16) is also advanced for rolling.
46. The method as defined in claim 43 or claim 44, characterised in that the metal strip (16) is pulled during the rolling process with the aid of a second gripper mechanism (53) which engages that section of the metal strip (16) that leaves the rolling gap (13).
47. The method as defined in any of the preceding claims, characterised in that a tensile stress is continuously maintained in the metal strip (16) during rolling and also during recalling of the strip.
48. The method as defined in any of the preceding claims, characterised in that a tensile stress is continuously maintained in the metal strip (16) during the grooving of the metal strip (16) by the roller (12).
49. The method as defined in any of the preceding claims characterised in that the width of the metal strip (16) is so selected to allow two or more of the objects, which are intended to be punched out from the input stock formed by the rolling process, can be punched out one beside the other across the width of the metal strip (16).
50. The method according to any of the preceding claims as applied to strips consisting of a plastic material and to strips consisting of a compound material based on a plastic material or including a plastic material as substantial component.
51. Device for producing strip-shaped input stock, especially from metal, by rolling a strip (16), especially for performing the method defined in claim 1 or claim 46, having a roll stand (2) in which a roller (12) defines a rolling gap (13), and having recalling means (5, 52) for the strip (16) arranged on the intake side of the rolling gap (13), characterised in that a drive motor (7, 54), especially a servomotor, is provided for the recalling means (5, 52), which drive motor permits the strip (16) to be recalled in steps of a predeterminable length, and that the rolling gap (13) is additionally defined by a plate (67) that faces the roller (12) and can be linearly displaced, and can be driven in synchronism with the roller (12) and/or with the strip (16) in the predetermined direction of movement of the strip (16) in the rolling gap (13), and can also be driven and recalled independently of the strip (16).
52. The device as defined in claim 51, characterised in that the plate (67) is arranged below the roller (12).
53. The device as defined in claim 51 or claim 52, characterised in that the height of the rolling gap (13) is variable.
54. The device as defined in claim 51 for producing strip-shaped input stock, having a selected profile which recurs in successive sections of the input stock, characterised in that the roller (12) and/or the plate (67) can be displaced during the rolling operation in upward and downward direction in the roll stand (2) in controlled fashion, namely by a distance determined by the selected profile and in response to the feeding motion of the strip (16).
55. The device as defined in any of the preceding claims 51 to 54, characterised in that the roller (12) has a cylindrical shell surface.
56. The device as defined in claim 53 for producing strip-shaped input stock, having a profile which recurs in successive sections of the input stock characterised in that the shell surface of the roller (12) has two or more separate circumferential sections (35, 36, 40), that follow each other in the circumferential direction and that do not all exhibit the same contour.
57. The device as defined in any of claims 51 to 56, wherein the recalling means for the strip (16) is a first coiler (5).
58. The device as defined in any of claims 51 to 56, wherein the recalling means for the strip (16) is a first gripper mechanism (52).
59. The device as defined in any of claims 51 to 58, wherein a pulling device (6, 53) for the strip-shaped input stock is provided on a discharge side of the rolling gap (13).
60. The device as defined in claim 59, wherein the pulling device is a second coiler (6) intended to wind up the strip-shaped input stock.
61. The device as defined in claim 59, wherein the pulling device is a second gripper mechanism (53).
62. The device as defined in claim 56, wherein the roller (12) has a cylindrical circumferential section (36).
63. The device as defined in any of claims 51 to 62, wherein the roll stand (2) is designed as an equalising rolling mill.
64. The device as defined in any of claims 51 to 63, wherein the drive motor (7, 52) for the recalling device (5, 52) provided on the intake side of the rolling gap (13) is an electric servomotor.
65. The device as defined in any of claims 51 to 64, wherein the pulling device (6, 53) provided on the discharge side of the rolling gap (13) is driven by an electric servomotor (8, 55).
66. The device as defined in any of the preceding claims, characterised in that a roller coupled to an incremental rotary transducer, which can be rotated by the strip (16) running over it, is associated to the recalling device (5, 52) and/or the pulling device (6, 53).
67. The device as defined in any of claims 51 to 66, wherein the roller (12) and the plate (67), respectively, are engaged on their sides facing away from the rolling gap (13) by a back-up roller (14, 15), respectively, whose roller necks (25) preferably can be prestressed in their roller neck bearings (26) in order to reduce their bearing play.
68. The device as defined in any of claims 51 to 67, wherein the roller (12) is driven intermittently so that during the advance motion of the strip (16) it is driven in synchronism with the pulling device (6, 53) provided on the discharge side of the rolling gap (13), whereas when the recalling device (5, 52) provided on the intake side of the rolling gap (13) is driven in reverse direction for the purpose of maintaining the strip tension and for recalling the strip (16), it is temporarily stopped and/or repositioned by rotating it in forward or in reverse direction.
69. The device as defined in any of claims 51 to 68, wherein the circumferential speed of the roller (12) and the speed of the pulling device (6, 53), and preferably also the speed of the recalling device (5, 52) can be controlled at desire.
70. The device as defined in claim 53 or claim 54, wherein one or more servo drives (32, 33, 34, 44) are provided for displacing the roller (12).
71. The device as defined in claim 70, wherein each of the servo drives (32, 33, 34, 44) comprises an electric motor (34) or one or two short hydraulic cylinders.
72. The device as defined in claim 65, wherein an electronic control unit (43) is provided in which the displacement of the roller (12) required for an envisaged profile is stored as curve, preferably digitally, and wherein the servomotors (7, 8; 54, 55) of the recalling device (5, 52) and the pulling device (6, 53), a servomotor (42) for rotation of the roller (12) and one or more setting drives (32, 33, 34) with an incremental rotary transducer (44) for the roller (12) are connected with that control unit (13), and wherein preferably a servomotor is also provided for the back-up roller (15) that may be provided for the plate (67).
73. The device as defined in any of claims 51 to 72, wherein the sense of rotation of the roller (12) and of the coilers (5, 6) can be reversed for rolling in both directions.
74. The device as defined in any of claims 51 to 73, wherein the roller (12) has a notch (45) parallel to its axis.

Method for producing strip-shaped input stock, especially from metal, which is profiled in subsequent sections, and corresponding device

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Description

Claims