ROLLING MACHINE

Abstract: A rolling machine has two roll carriers (12, 13) rotatable about parallel axes (16, 17) on opposite sides of the passline of the workpiece (15). Each carrier (12, 13) has a sequence of roll assemblies (18A-18E) rotatable about parallel axes (16, 17) spaced round the carrier axis. The barrel length of each roll assembly is less than the width of the workpiece but, when the workpiece has been contacted by all the roll assemblies of the sequence, the whole width of the workpiece has been rolled.

Description: ROLLING MACHINE This invention relates to a planetary-type rolling machine for reducing the thickness ' of a workpiece passed therethrough. In particular, the invention is concerned with a rolling machine having two similar roll carriers which are rotatable about parallel axes on opposite sides of the passline of the workpiece, and, on each carrier, a sequence of roll assemblies rotatable about parallel axes spaced round the respective carrier axis. In use, the carriers are driven in opposite senses in synchronism so that each roll assembly of one carrier approaches the passline simultaneously with the corresponding roll assembly of the other carrier and the workpiece is engaged between corresponding pairs of roll assemblies and rolled thereby. Such a rolling machine will be referred to hereinafter as "a rolling machine of the type described". In the past, numerous rolling machines of the type described have been proposed. In all, each roll assembly has been a single roll having a barrel length at least as great as the width of the workpiece to be rolled. Where the workpiece is a flat product, i.e. one having a width substantially greater than its thickness, the shock loading sustained each time the rolls encounter the workpiece become so large that suitable bearings are almost impossible to be incorporated in the machine which becomes massive with a huge energy requirement. Consequently, for wide machines the cost renders the machine unattractive except possibly when high throughputs are contemplated. Accordingly, the present invention resides in a rolling machine of the type described, characterised in that the barrel length of each roll assembly is chosen so as to be less than the width of the workpiece to be rolled, and, on each carrier, at least two adjacent roll assemblies constitute a sequence whereby the whole width of the workpiece is rolled when it has been contacted by all the roll assemblies of the sequence. Preferably, there are means for urging the workpiece through the machine. The roll assemblies are driven about their own axes and they may be driven in the same direction as the workpiece. Alternatively, the axes of the roll assemblies may be moved in the same direction as the workpiece with the roll assemblies driven in the opposite direction. In one form of the invention, each roll assembly, other than the first of the sequence, has two rolling surfaces, the paths of which partly overlap, and partly extend axially outwardly beyond, the path or paths of the rolling surface or surfaces of the preceding assembly. The two rolling surfaces may be formed by two spaced rolls on a common axis, or by a single roll having a part which is relieved out of contact with the workpiece. In another form of the invention, each roll assembly comprises a single roll, and each such roll, except the first of the sequence, has a barrel length greater than the preceding roll of the sequence, so that its path overlaps that of the preceding roll and extends axially either side thereof. In yet another form of the invention, the roll assemblies on each roll carrier constitute at least two sequences and each sequence may consist of two roll assemblies. Each roll assembly has at least two spaced apart rolling surfaces and a support bearing may be positioned between at least one pair of adjacent rolling surfaces. The workpiece may be moved either continuously or intermittently through the machine; in the latter case, movement is effected between successive sequences of the roll assemblies. Because each intermittent rolling operation between corresponding roll assemblies of the two i carriers is over a part only of the width of the workpi-ece, the torques required and the shock loading are reduced, enabling a lighter and less expensive construction to be adopted. The rolling machine of the invention has the added advantage that width-wise spread of the workpiece may be caused to occur; a feature that is useful, particularly when rolling down a continuously cast metal slab of limited width. In order that the invention may be more readily understood, it will now be described, by way of example only, with reference to the accompanying drawings, in which:- Figure 1 is a side elevation, partly in section, of a rolling machine in accordance with one embodiment of the present invention; Figure 2 is a sectional elevation on the line A-A of Figure 1; Figure 3 shows roll assemblies on successive roll axes of one carrier, the roll assemblies being similar on the other carrier; Figure 4 is an end view of the roll carriers of a machine in accordance with an alternative embodiment of the invention; and Figure 5 is a side elevation, partly in section, of a pair of successive roll assemblies on one of the carriers shown in Figure 4. The rolling machine, as shown in Figures 1 and 2, has a frame 10, 11 which mounts two carriers 12, 13 located on opposite sides of the passline of a workpiece 15. The carriers 12, 13 are driven in synchronism and in opposite senses about axes 16, 17, respectively, these axes being parallel to the faces of the workpiece to be rolled and at right angles to the movement of the workpiece in the direction of its length. The directions of rotation of the carriers are shown by the arrows 12A and 13A. Each carrier 12, 13 carries a number of roll assemblies (five in the example illustrated), having their axes parallel to the axes 16, 17 of the carriers and spaced round the axis of the respective carrier. The roll assemblies 18A - 18E constitute a sequence. All the roll assemblies have the same diameter and their axes are equally spaced from the carrier axis. The roll assemblies are synchronously driven about their own axes in the directions represented by the arrows 19A, the direction of peripheral motion at the passline due to the rotation about its own axis being opposite to the direction of its peripheral motion due to the rotation of the carrier, and being in the same direction as the movement of the workpiece. The workpiece is thus progressively and intermittently engaged and rolled between successive pairs of corresponding roll assemblies of the two carriers 12 and 13,. Each carrier 12, 13 is rotatably supported in the frame 10, 11 and an extension hollow shaft 20 at one end of each carrier carries a gear 21 and the two gears 21 mesh with a single pinion 22 which is driven by way of a shaft from an electric motor 23. Extending through each hollow shaft 20 there is a shaft 24 and these shafts are driven through a gearbox 25 and a flywheel 26 by an electric motor 27. Each shaft 24 carries a gear 24A which meshes with five other gears positioned symmetrically around it and these gears in turn mesh with gears 28. The gears are mounted in a gearbox 29 and the rolls mounted in each carrier are connected at one end to its appropriate driving gear 28 through a coupling 30. In this way, in operation, the rolls of each carrier are driven in the same direction of rotation and the carriers themselves are rotated about their axes in opposite directions. The roll assemblies on each carrier are of different barrel lengths, the roll assembly 18A having a roll of the shortest barrel length and being situated substantially centrally of the workpiece, and succeeding rolls being of slightly wider barrel length until the last roll 18E of the sequence is substantially the entire width of the workpiece. During rolling of the workpiece, the first rolls of the sequence, when they engage the workpiece, reduce the , workpiece centrally. The subsequent roll assemblies progressively extend the width which is being rolled until the. entire width of the workpiece has been reduced in steps. In an alternative arrangement, shown in Figure 3, each roll assembly, other than the first of the sequence, consists of two rolls which overlap axially with the roll or rolls of the preceding assembly, by which is meant the assembly next ahead of the assembly in the direction of rotation of the carrier. Each roll assembly, except the first of the sequence on axis 1, follows a path during rotation of its carrier which overlaps with, but extends axially, each side of the path of the preceding roll assembly. In the arrangement described, each carrier has a sequence of five roll assemblies and a rolling sequence is accomplished each revolution of the carriers. It is, however, possible to have more than one sequence of roll assemblies on each carrier, the roll assemblies of each sequence being identical with those of every other sequence. For example, there may be two sequences of four roll assemblies carried on each carrier or eight sequences each consisting of a pair of rolls. Each sequence effects a reduction of the workpiece over its entire width. 'During rolling of the workpiece, the first rolls of the sequence, when they engage the workpiece, reduce the workpiece over part of its width. The subsequent assemblies progressively extend the width rolled, until the entire width of the workpiece has been reduced in steps. Because, in each rotation of the carriers, the workpiece is first reduced in the centre and then progressively rolled outwardly from the centre, the reduction in thickness is accompanied by lateral spreading as well as by lengthwise elongation. Accordingly, some of the rolls of each carrier encompass a width in excess of the width of the unreduced workpiece. The lateral spread of the workpiece, as described above, is particularly advantageous when rolling slabs, e.g. from a continuous casting plant, and a wider strip product is desired. The lateral spread achieved by rolling with rolls of constant barrel length is small in comparison. Where lateral spread is not the prime consideration, the rolled pieces may be reduced in thickness effectively across the width of the workpiece but with reduced separating forces and rolling torques from those encountered by full width rolling. Because each roll assembly does not cover the entire width of the workpiece, the length of the roll or rolls and, hence, the separation of the bearings supporting it or them, can be shorter than for full width rolling. Hence, for a given roll deflection, the roll diameter can be less, and the loads and torques are consequently smaller. For the control of shape of the reduced material, small differences in roll diameter and/or the addition of camber may be used. Referring now to Figures 4 and 5, an arrangement of roll carriers 12A, 13A is shown where a sequence comprises two roll assemblies on each carrier. Figure 4 shows the arrangement where there are eight sequences on each roll carrier, that is, each sequence consists of two rolls making a total of sixteen rolls on each carrier. Figure 5 shows a typical pair of rolls, roll 50 preceding roll 51 on the carrier. The width of the workpiece to be rolled is indicated by the lines 52 and it will be seen that roll 50 consist of four rolls 53 separated by roll necks 54. The roll is supported at its ends by way of bearings 55 and an additional bearing 56 is positioned within the width of the workpiece on roll neck 54 substantially centrally of the ends of the roll. Roll 51 has three rolls 57 separated by roll necks 58 and the rolls 57 are aligned and overlap the roll necks 54 on the roll 50. In the same way, the rolls 53 on roll assembly 50 are aligned with a d overlap the roll necks 58 on roll 51. The rolls are driven from one end in the manner indicated in Figure 1. A support bearing may be provided on each roll neck. When a workpiece has passed between the roll carriers and has been acted upon by a pair of rolls 50, 51 on each carrier, the two rolls together contact and • roll the workpiece over its entire width. In all the arrangements, the work feeding mechanism may comprise a set of pinch rolls, as indicated by reference 60 in Figure 2, where the forces applied by the roll assemblies to the workpiece is relatively small. Otherwise, .a suitable alternative mechanism is employed, such as one comprising clamps which alternatively clamp on to the workpiece and move it forward.

Claims: Claims : 1. A rolling machine for reducing the thickness of a workpiece, said machine having two similar roll carriers (12, 13) rotatable about parallel axes located on opposite sides of the passline (15) of a workpiece passed through the machine and on each carrier a plurality of roll assemblies (18) rotatable about respective parallel axes spaced round the carrier axis, characterised in that the barrel length of each roll assembly is chosen so as to be less that the width of the workpiece to be rolled, and, on each carrier, at least two adjacent roll assemblies (18) constitute a sequence whereby the whole width of the workpiece is rolled when it has been contacted by all the roll assemblies of the sequence. • 2. A rolling machine as claimed in claim 1, characterised in that all the roll assemblies (18A - 18E) on each carrier constitute a sequence and so the whole width of the workpiece-is rolled on completion of one revolution of the carriers. 3. A rolling machine as claimed in claim 1, characterised in that the roll assemblies (50, 51) on each roll carrier constitute at least two sequences. 4. - A rolling machine as claimed in claim 2, characterised in that each roll assembly, other than the first of the sequence, has two rolling surfaces, the paths_of which partly overlap and extend outwardly beyond the path or paths of the rolling surface or surfaces of the preceding assembly in the sequence. 5. A rolling machine as claimed in claim 4, characterised in that the two rolling surfaces are provided by two spaced apart rolls on a common axis. 6. A rolling machine as claimed in claim 2, characterised in that each roll assembly comprises a single roll and each roll, apart from the first of the sequence, has a barrel length greater than that of the preceding roll, so that its path overlaps that of the preceding roll and extends axially either side thereof. 7. A rolling machine as claimed in claim 3, characterised in that two roll assemblies (50, 51) constitute a sequence. 8. A rolling machine as claimed in claim 1, 2, 3 or 7, characterised in that each roll assembly has at least two spaced apart rolling surfaces with a support bearing positioned between at least one pair of adjacent rolling surfaces. 9. A rolling machine as claimed in any preceding claim, characterised in the provision of means for urging the workpiece in the direction of its length through the machine. 10. A rolling machine as claimed in claim 9, characterised in that said means urge the workpiece continuously through the machine, 11. A rolling machine as claimed in claim 9, characterised in that said means urge the workpiece intermittently through the machine, the movement being effected between successive cycles of rotation of the roll, carriers. 12. A rolling machine as claimed in any preceding claim, characterised in that the roll carriers and the roll assemblies are moved in opposite directions. 13. A rolling machine as claimed in claim 11, characterised in that the axes of the roll assemblies are moved in the same direction as the direction of the workpiece through the machine. 14. » A rolling machine as claimed in claim 12, characterised in that the axes of the roll assemblies are moved in the opposite direction to the direction of the workpiece through the machine.

Inventors: WILSON ALEXANDER IAN, WILSON, ALEXANDER, IAN
Applicants: HILLE ENG CO LTD, HILLE ENGINEERING COMPANY LIMITED
Application year: 1985
Main classification: B21B13
IPC codes: B21B13