Roller table apparatus and method of using roller table apparatus

Abstract

Roller table apparatus (200; 300) for transporting a metallic product (P) to or from a mill stand, includes: first and second rolls (202a, 202b; 302a, 302b), outboard ends of the rolls are supported by respective outboard bearings and inboard ends of the rolls are supported by respective inboard bearings, such that each of the rolls is rotatable about its longitudinal axis (X1, X2); and at least one adjuster (216; 316a, 316b), movable in use to displace at least one end of the rolls or the respective bearings of the roll so as to adjust an angle () of inclination of each of the longitudinal axes of the rolls with respect to a datum (D), thereby to adjust a pass-line height (h1, h2) of the product relative to the datum.

Claims

1. A roller table apparatus for transporting a metallic product to or from a mill stand, the roller table apparatus comprising: first and second rolls positioned and configured to transport the metallic product by direct contact with the metallic product, each roll having a respective longitudinal axis, outboard ends of the rolls being supported by respective outboard bearings and inboard ends of the rolls being supported by respective inboard bearings, such that each of the rolls is rotatable about its longitudinal axis, at least one adjuster configured to move in use to displace the rolls so as to adjust an angle of inclination of each of the longitudinal axes of the rolls with respect to a datum, thereby to adjust a pass-line height of the metallic product relative to the datum; wherein the rolls are displaced such that the first rolls extend outward from their respective inboard bearings with axes having a first angle of inclination, while the second rolls extend outward from their respective inboard bearings with axes having a second angle of inclination, the longitudinal axes of the second rolls not being parallel to the longitudinal axes of the first rolls; at least one motor is arranged and configured to rotate the rolls.

2. A roller table apparatus according to claim 1, wherein the first and second rolls are arranged in line such that the respective longitudinal axes of the rolls lie on a common plane.

3. A roller table apparatus according to claim 1, wherein the first and second rolls are spaced apart such that the respective longitudinal axes of the rolls lie in parallel planes.

4. A roller table apparatus according to claim 1, comprising a pivotable support frame which supports the rolls and is arranged to pivot in order to accommodate the displacement of the rolls.

5. A roller table apparatus according to claim 4, wherein the pivotable support frame is connected to the at least one adjuster.

6. A roller table apparatus according to claim 5, wherein the at least one adjuster is located at a central portion of the pivotable support frame so as to displace the inboard ends of the rolls.

7. A roller table apparatus according to claim 5, comprising first and second ones of the adjusters which are located at respective first and second outboard portions of the pivotable support frame so as to displace the outboard ends of the rolls.

8. A roller table apparatus according to claim 5, comprising: a first one of the adjusters, located at a central portion of the pivotable support frame so as to displace the inboard ends of the rolls; and second and third ones of the adjusters, located at respective outboard portions of the pivotable support frame so as to displace the outboard ends of the rolls.

9. A roller table apparatus according to claim 8, wherein the inboard bearings are mounted on respective inboard portions of the pivotable support frame and the at least one adjuster is arranged to accommodate the displacement of the rolls.

10. A roller table apparatus according to claim 4, wherein the motor is located on the pivotable support frame or on an extension thereof.

11. A roller table apparatus according to claim 10, wherein the rolls are connected by a constant velocity joint.

12. A roller table apparatus according to claim 11, further comprising a splined connection between the first and second rolls being configured for accommodating axial movement of the rolls caused by the displacement.

13. A roller table apparatus according to claim 1, comprising a self-aligning bearing housing which houses the inboard bearings and is arranged to accommodate the displacement of the rolls.

14. A roller table apparatus according to claim 1, further comprising at least one actuator for moving the at least one adjuster to displace the rolls.

15. A roller table apparatus according to claim 1, wherein the rolls are of solid construction.

16. A roller table apparatus according to claim 1, wherein the rolls are of hollow construction.

17. A roller table apparatus according to claim 1, wherein the rolls comprise cylindrical rolls.

18. A roller table for use with a mill stand, comprising plural roller table apparatus according to claim 1.

19. The roller table apparatus as claimed in claim 1, wherein when the rolls are displaced the angle of inclination of the longitudinal axes of the first rolls is equal to the angle of inclination of the longitudinal axes of the second rolls.

20. The roller table apparatus as claimed in claim 1, wherein the inboard bearings of a respective roll of the first rolls are positioned adjacent the inboard bearings of a respective roll of the second rolls.

21. A method of using a roller table apparatus for transporting a metallic product to or from a mill stand, the roller table apparatus comprising: first and second rolls positioned and configured to transport the metallic product by direct contact with the metallic product, outboard ends of the rolls being supported by respective outboard bearings and inboard ends of the rolls being supported by respective inboard bearings, such that each of the rolls is rotatable about its longitudinal axis; and at least one adjuster moving in use to displace the rolls so as to adjust an angle of inclination of each of the longitudinal axes of the rolls with respect to a datum thereby to adjust a pass-line height of the product relative to the datum; and the method comprising: moving the adjuster in order to adjust angles of inclination of the longitudinal axes of the first and second rolls according to one or more of the width, thickness, grade and temperature, of the metallic product, such that the first rolls have longitudinal axes at a first angle of inclination, while the second rolls have longitudinal axes at a second angle of inclination, the longitudinal axes of the second rolls not being parallel to the longitudinal axes of the first rolls, wherein at least one motor is arranged to rotate the rolls.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments will now be described, by way of example, with reference to the accompanying figures in which:

(2) FIGS. 1a and 1b show conventional roller table apparatus;

(3) FIG. 2 illustrates the conventional roller table apparatus of FIG. 1a in conjunction with a product;

(4) FIGS. 3a and 3b show embodiments of roller table apparatus in accordance with the present invention;

(5) FIGS. 4a and 4b illustrate an effect of the inventive roller table apparatus; and

(6) FIGS. 5a and 5b show an alternative embodiment of the inventive roller table apparatus.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

(7) Referring to FIG. 3a, a roller table apparatus 200 for transporting a product comprises a pair of half-width cylindrical rolls 202a, 202b. In the condition shown the respective longitudinal axes X1, X2 of the rolls 202a, 202b are parallel with a datum D which represents the horizontal ground on which the roller table apparatus 200 is supported. That is, the angle of inclination, between the ground and the longitudinal axis X1, X2 of each of the half-width cylindrical rolls 202a, 202b, is zero. In this embodiment, the half-width cylindrical rolls 202a, 202b are arranged in line, and the respective longitudinal axes X1, X2 of the rolls 202a, 202b lie in the same plane (i.e. the axes X1, X2 are coplanar). Alternatively, the half-width cylindrical rolls 202a, 202b may be spaced apart (staggered) so that the respective longitudinal axes X1, X2 lie in two different planes which are parallel with each other.

(8) Each of the rolls 202a, 202b has an outboard end which is supported by a conventional outboard bearing 204a, 204b in an outboard bearing housing 206a, 206b that is mounted on a pivotable frame assembly 208. The pivotable frame assembly 208 is located on mounting points 210a, 210b of a foundation mounted fabricated steel frame. Pivot points are located directly above the mounting points 210a, 210b. Alternatively, the pivot points may be offset, either inboard or outboard of the mounting points 210a, 210b, in order to optimize the geometry to minimize the pass-line height variation, as described later herein.

(9) The inboard ends of the half-width rolls 202a, 202b are received by respective inboard bearings 212a, 212b disposed within an inboard self-aligning bearing housing 214. The self-aligning bearing housing 214 is supported on a central adjustable support 216 which is arranged to be moved up and down by an actuator 218. In this embodiment, the inboard bearing housing 214 is fixed to the adjustable central support 216. A connection between the pivotable frame assembly 208 and the adjustable central support 216 comprises slotted holes and pins so that a change of angle (inclination) of the half-width cylindrical rolls 202a, 202b can be accommodated. Alternatively, the slotted holes may be located at the outboard ends and the pivots at the inboard ends. The function of the slotted holes may instead be provided by an alternative component, for example a small link.

(10) The inboard bearings 212a, 212b are arranged to take up a range of angles within the self-aligning bearing housing 214. In this embodiment, the inboard bearings 212a, 212b comprise cylindrical roller bearings which allow for axial movement of the inboard ends of the rolls 202a, 202b to accommodate the range of angles and also thermal expansion of the rolls 202a, 202b. The self-aligning bearing housing 214 includes seals to protect the inboard bearings 212a, 212b and prevent bearing lubricant from escaping and contaminating the product which is to be transported. In an alternative embodiment, the inboard ends of the rolls 202a, 202b are supported by respective self-aligning bearings within a conventional housing.

(11) In order that the two half-width rolls 202a, 202b can be driven by a single motor M and to avoid any cyclical speed variations between the two halves, in this embodiment, they are connected by a constant velocity type joint 220. Preferably, in order to achieve angles which are greater than are normally possible with gear type couplings, this joint is a gear type joint with an over-crowned hub, but other types of constant velocity joint could be used. Preferably, as illustrated, the joint 220 is contained within the same inboard self-aligning bearing housing 214 as the inboard bearings 212a, 212b so that the same lubrication system and seals are common to both. At least one of the rolls 202a, 202b has a splined connection to the joint 220 in order to accommodate the small axial movements caused by the angle change. In an alternative arrangement, the inboard ends of the rolls 202a, 202b are fixed and cylindrical bearings are provided at the outboard ends of the rolls 202a, 202b with a splined coupling to the motor M, to accommodate the axial displacement.

(12) The motor M is mounted on an extension of the pivotable frame assembly 208 and connected to the (in the sense of FIGS. 3a and 3b, left-hand) half-width roll 202a by a conventional shaft coupling. Alternatively, the motor M may be fixedly mounted on the floor or on the foundation mounted fabricated steel frame, although this would require a drive shaft between the motor M and the roll 202a which included constant velocity joints capable of accepting large changes in angle.

(13) Referring now to FIG. 3b, in use the angle of inclination of the half-width cylindrical rolls 202a, 202b (or the longitudinal axes X1, X2 thereof), with respect to the datum D (the ground), is adjusted by changing the height of the central support 216 using the actuator 218. In the condition shown, the rolls 202a, 202b have been displaced by the adjustment such that the angle of inclination is 5 degrees, but it will be understood that the angle may take any appropriate value which allows the support and transport of a product by the roller table apparatus 200.

(14) Turning now to FIGS. 4a and 4b, it will be seen that this adjustment, of the inclination of the rolls 202a, 202b, advantageously provides a reduction in pass-line height variation with product width (the pass-line height being taken as the distance between the bottom surface of the product and floor level). As discussed herein above, the sag of the product is a function of the product width; that is wide products sag more than narrow products. With a conventional fixed angle roller table (see FIG. 4a) a relatively steep angle is required in order to handle the thinnest and widest product. But, with the variable angle roller table apparatus of the present invention (see FIG. 4b) it is possible to choose a relatively shallow angle for narrower products and a steeper angle for wider products.

(15) In principle, by making the angle directly proportional to the width of the product, the pass-line height variation would be zero, but in practice the sag of the material changes the effective pass-line height as well. As discussed herein above, however, the sag can be calculated and so in theory it is possible to virtually eliminate the pass-line height variation. Even if there are other considerations, e.g. the fact that on very thin and wide plate products the material could not support itself from the edges only, it is clear that the variable angle roller table apparatus can at least significantly reduce the pass-height variation for most products.

(16) The adjustment of the table roll angle would take place immediately before rolling a pass and hence the optimum angle can be set dependent on the product thickness, width and strength.

(17) In the case of strip products and the thicker and narrower plate products, the material can be rolled with support at the edges only and with minimal pass-line height variation. In the case of the thinnest and widest plate products, which cannot support themselves from the edges only, the earlier passes and shearing operations can be done with roller angles which support the material at the edges only but the last finishing passes can be done with small or even zero roller angles.

(18) In the case of a 1+1 or similar mill with sections of roller tables having different widths, it is important that there is no change in pass-line height as the material transfers from the wide table to the narrow roller table. If the narrower roller table has a fixed angle, then this can easily be achieved by ensuring that when the variable angle wide roller table is set at this same angle, then the pass-line heights for the two sections are matched. However, if the narrower roller table has adjustable angles, then matching the wide and narrow tables can only be achieved by ensuring that the outboard pivot points for both the narrow and the wide tables are at the same position. This requires either offsetting the pivot points for the wide tables inwards or offsetting the pivot points for the narrow tables outwards or a combination of the two.

(19) Referring to FIGS. 5a and 5b, in an alternative embodiment of the inventive roller table apparatus 300, a central support 314 is set at a fixed height while a pair of adjustable outboard supports 316a, 316b is provided for supporting respective outboard end portions of the pivotable frame assembly 308. Each of the outboard supports 316a, 316b is arranged to be moved up and down by a respective actuator 318a, 318b, in order to raise and lower the outboard ends of the pivotable frame assembly 308 and thereby vary the angle of inclination of the half-width cylindrical rolls 302a, 302b. In the case of a 1+1 mill with both wide and narrow roller tables, it is easy to match the tables when they are at the same angle, so long as the central support is at the same position for the two tables. On the other hand, the pass-line height variation is greater unless very steep roller angles are used on narrow products.

(20) In another embodiment (not shown in the Figures), height adjustment is provided with respect to both the central support and the outboard supports. This has the advantage of allowing independent control of the roller angle and the pass-line height but may make the system more complex and expensive.

(21) In the above-described embodiments, each of the actuators 218; 318a, 318b comprises a screw jack but other means, such as a hydraulic cylinder, could be used. In an embodiment, one single actuator is configured to operate a mechanism which raises and/or lowers (adjusts) central and/or outboard supports in connection with multiple pairs of half-width cylindrical rolls. The supports may also be guided so that the screw-jack or other actuator mechanism does not have to withstand any side loads.

(22) In the above-described embodiments, each of the half-width rolls 202a, 202b; 302a, 302b may be solid, and therefore especially suited to heavier duty areas such as next to the mill stand, or hollow, and therefore especially suited for lighter duty areas such as distant from the mill stand.

(23) While the present invention is particularly appropriate for use with aluminium products, the invention may also be useful in the rolling of products made from other metallic materials.

(24) It will be understood that the invention has been described in relation to its preferred embodiments and may be modified in many different ways without departing from the scope of the invention as defined by the accompanying claims.