ROLL REPLACEMENT APPARATUS FOR CANTILEVER ROLLING STANDS

Abstract: Apparatus (10) to replace sets of rolls and relative equipment in rolling stands having rolls supported as cantilevers, which is able to take from the stand the sets of rolls and relative equipment complete and already used and to deliver to the stand new sets of rolls and relative equipment complete and already prepared, positioned and adjusted, the sets of rolls and relative equipment consisting of the rolls, relative equipment, supports and everything else which can be replaced whenever the rolls are changed, the apparatus (10) comprising in reciprocal cooperation a support device (15), at least one positioner assembly (20) and, at least momentarily, at least two support units (21), the positioner assembly (20) being able to move so as to place opposite and position correctly a support unit (21) in relation to the rolling stand (11).

Description: This invention concerns a device according to the preamble of claim 1. The invention aims to improve an apparatus suitable to dismantle and assemble the whole consisting of the rolls supported as cantilevers in a horizontal or vertical rolling stand and also of the sets of equipment, guides for the rolled stock and the means to support such equipment and guides; the above whole forms the set of equipment of such rolling stand having rolls supported as cantilevers. With this apparatus it is possible to position and instal or dismantle the above set of equipment at the same time in one single operation, thus facilitating the operations of maintenance and of changing the rolled section to be produced. Apparatus exists in the state of the art to change the sets of rolls of a rolling stand having its rolls supported as cantilevers; such apparatus performs only the engagement of the two rolls and leaves the relative equipment and supports where they are. The relative equipment and supports are then removed separately by hand or with other known means. GB 1,508,599 discloses a device which is hung on a crane or bridge crane and serves to handle heavy rolls. This device is actuated by hand and comprises claw elements the annular protrusions of which are able to engage each roll at one of the grooves included to shape the bars; this device is actually a large gripper with a plurality of claws. The device is suitable to take and move only one roll at a time. As we said earlier, the state of the art provides for the replacement of the rolls and relative equipment to be carried out in at least two steps with separate removals of the rolls and of the relative equipment, thus entailing a great waste of time. Next, it should be borne in mind that each element to be fitted has to be aligned with the other elements and therefore this operation causes a great waste of the time of the personnel thus employed. FR 1.545.751 comprises a device able to take rolling rolls from stands having their rolls supported as cantilevers and to place the rolls on stationary supports. This device can also carry out the reverse operation. The device includes a hydraulic gripper able to engage the top of the roll to be removed and provides for only one roll to be engaged and carried at a time. Means are not provided which are suitable to engage the whole set consisting of the rolls, relative equipment and the supports of such equipment. The handling is carried out by a bridge crane with a rotary turret. Moreover, the removal of the rolls and relative equipment takes place in an uncoordinated manner in the state of the art, so that the parts are normally deposited at random in the storehouse. In the state of the art the parts have always to be taken one by one from the storehouse so as to be re-fitted to the rolling stands. According to another known embodiment (see BROCHURE DANIELI & C. N⁰ 2000.03.86-"ESC" Rolling Unit) an apparatus is provided which can perform simultaneous withdrawal of the set of rolls complete with the relative equipment from the rolling stand. This apparatus cooperates with suitable means in carrying out correct positioning and reciprocal alignment with the rolling stand. Said apparatus provides in a position near to the rolling stand to be serviced an assembly to position the set of rolls and relative equipment, this assembly employing units to support and reciprocally position the components of such set. This set is prearranged on the support units with its components reciprocally disposed, spaced apart and aligned. By means of this known apparatus it is enough to locate the positioner assembly correctly in relation to the rolling stand so as to have the various components of the set already prepared for working when they have been clamped to the stand. Likewise, the withdrawal of the set of rolls and relative equipment from the rolling stand is carried out by means of the positioner assembly in such a way that after withdrawal the set is properly positioned on the positioner assembly. The apparatus includes also a support device able to support, position and move the positioner assembly. According to this embodiment the sets of rolls and relative equipment to be fitted to the stands to be reequipped are arranged on a support unit and kept ready and waiting. This operation is carried out while rolling is in progress with a set already located on the rolling stand. At the end of the rolling cycle in progress the set of rolls and relative equipment to be replaced is engaged by the other support unit, which has been brought close for this purpose and been positioned in relation to the rolling stand, the set in question being withdrawn by means of a movement axial to the rolls. Steps are then taken to replace one support unit with the other, for instance by rotation of the positioner assembly, and the support unit holding the new required set of rolls and relative equipment is brought up to and aligned with the rolling stand and delivers this new set to the stand itself. The new set is installed on the stand with a suitable movement, and then the positioner assembly bearing the replaced set of rolls and relative equipment is distanced and disposed as desired on the support device. The present invention aims to improve the performances of an apparatus as described above, in that it comprises a device which is able to raise and to lower the sets of rolls, as placed on the support unit, in order to greatly simplify the replacing operations. This is achieved by a device having the features disclosed in the characterising part of claim 1. By means of the invention the times for changing the sets of rolls and relative equipment are greatly reduced since the new sets are pre-arranged and pre-positioned during the preceding rolling step; moreover, the times required to engage and withdraw a set to be replaced are very short. According to the invention, therefore, the apparatus includes a specially equipped support unit for raising and lowering the set of rolls and relative equipment. The specially equipped support unit comprises a device to support, position and handle the support units. The support unit includes means for swift clamping and positioning of the various components and also means for positioning and alignment in relation to the rolling stand. We shall describe hereinafter preferred embodiments of the invention as a non-restrictive example with the help of the attached figures, in which: Fig. 1 gives a side view of the apparatus according to the prior art for a stand having its rolls supported as cantilevers with horizontal axes; Fig. 2 shows a side view of the apparatus according to the prior art for a stand having its rolls supported as cantilevers with vertical axes; Fig. 3 shows a side view of the device according to the invention for a stand having its rolls supported as cantilevers with horizontal axes in a variant of Fig. 1; Fig. 4 shows a three-dimensional diagram of embodiment of Fig. 1. The attached figures show a rolling stand 11 with rolls 12 supported as cantilevers, possible adapters 13 and a motor 14. The rolling stand 11 may include rolls 12 supported as cantilevers with a horizontal axis (Figs. 1 and 3) or with a vertical axis (Fig. 2). A support device 15 with which there cooperates at least one positioner assembly 20 that comprises at least one support unit 21 is included in cooperation with the stand 11. The positioner assembly 20 is able to move so as to take up a position of direct cooperation with a set of rolls and relative equipment 22 already positioned on, or to be positioned on, the rolling stand 11, and also to take up an inactive position. While the rolling stand 11 is at work, the set of rolls and relative equipment 22 to process the next rolled section is pre-arranged on a support unit 21. The support unit 21 may be integrally fixed to the positioner assembly 20 or be capable of being dismantled and installed elsewhere for the better pre-arrangement of a set of rolls and relative equipment 22, already complete and geometrically coordinated and positioned, on that support unit 21. If the support unit 21 is arranged elsewhere, it is fitted to the positioner assembly 20 as soon as it has been completed with its set 22. When the rolling stand 11 has finished its working cycle with the set of rolls and relative equipment 22 then fitted to the stand, a support unit 21 which does not hold such a set 22 is positioned in cooperation with the set already present on the rolling stand 11. This support unit 21 may be positioned in relation to the rolling stand 11 by positioner pins and abutments (not show here) and proceeds to connect itself to the rolling stand 11 so as to cooperate directly with the set of rolls and relative equipment 22 present on the stand 11. When the support unit 21 has been connected to the set of rolls and relative equipment 22 on the stand 11, that set is disconnected from the stand 11 and the support unit 21 can be removed. The removal of the support unit 21 is performed by the positioner assembly 20 which bears that unit 21 and which arranges to position and align in front of the rolling stand 11 another support unit 21 complete with a new set of rolls and relative equipment 22. When the new support unit 21 has been positioned and aligned, the new set 22 can be fitted to the stand 11, which is thus ready at once for the next rolling cycle. The support device 15 in Fig. 1 cooperates with the base of the rolling stand 11 and extends parallel to the axes of the rolls 12. The positioner assembly 20 is located on the support device 15 and can move therealong and comprises at its two sides two support units 21 respectively. The positioner assembly 20 is installed on a rotary platform 16 and can be moved in front of the rolls 12 by a displacement ram 19. For the removal of the set of rolls and relative equipment 22 positioned on the stand 11 the positioner assembly 20 brings to the stand 11 a support unit 21 not containing a set 22 by moving from position 20 to position 220 and by employing suitable positioner pins and abutments for accurate alignment and positioning. When the support unit 21 has been firmly secured to the set 22 located on the stand 11, the positioner assembly 20 retires by a suitable distance from the stand 11 and is then rotated substantially by 180° by the rotary platform 16; the assembly 20 thus takes a new support unit 21 complete with a new set of rolls and relative equipment 22 to the stand 11 and is brought close to the latter by the displacement ram 19. When the set 22 has been transferred onto the stand 11, the positioner assembly 20 withdraws to its inactive position. The positioner assembly 20 can be left in its inactive position or be dismantled and taken elsewhere. Likewise, the support units 21 can be integrally fixed to the positioner assembly 20 or be capable of being dismantled and re-installed as required. Fig. 2 shows a rolling stand 11 having rolls 12 with a vertical axis. A support device 15 is included with the rolling stand 11 and comprises a rotation pivot 24 and cooperates with a lifter jack 17. A movable door 18 is also included and closes the space left free by the support device 15 when the latter is rotated substantially by 90° to become positioned substantially parallel to the axis of the rolls 12. When the support device 15 reaches position 115 where it is substantially parallel to the axis of the rolls 12, the positioner assembly 20 reaches position 120, whereas position 220 is that for removal and delivery of a set of rolls and relative equipment 22 from and to the rolling stand 11. The positioner assembly 20 can be rotated about its axis with the support device 15 in a vertical position 115 or with the support device 15 rotated momentarily into a horizontal position. The choice between these two positions for rotation of the positioner assembly 20 to bring a new support unit 21 in front of the rolling stand 11 will depend on the strength of the structure of the support device 15 and the power of the lifter jack 17 and rotary platform 16. Fig. 3 shows a support device according to the invention 15 able to move in front of the rolling stand 11 and comprising a positioner assembly 20 with two support units 21. In this example the positioner assembly 20 is able to rotate by 180° about its vertical axis and comprises support units 21 which are not only replaceable but also have two vertical positions. These vertical positions are respectively a position for installing and pre-arranging a set of rolls and relative equipment 22 and a position for removing and delivering a set 22 from and to the rolling stand 11. A jack 25 cooperating with an abutment 27 and with sliders 26 able to slide in suitable guides provided in the positioner assembly 20 enables these two vertical positions to be reached so that the horizontal axis of the support unit 21 can be lowered as much as possible, as indeed is necessary with such rolling stands 11 having such rolls 12. The two vertical positions are made necessary so as to provide enough strength for the base of the apparatus. The support device 15 may be fed through a suitable electrical cable and may include within itself all the controls needed for its positioning and displacement. Fig. 4 shows an example of the positioner assembly as applied to the embodiment of Fig. 1. The positioner assembly 20 comprises two support units 21, each of them equipped with two jaws 29 suitable to position and secure not only the two rolls 32 but also the relative equipment 33 and the support 44 of that equipment 33. The jaws 29 slide in guides 31 and can be actuated by anchorage screws 28. The jaws 29 clamp and position the rolls 32 in cooperation with appropriate grooves provided in the rolls. Thus they clamp and position the relative equipment 33 and the support 40 of that equipment by acting on appropriate seatings in the elements forming the set of rolls and relative equipment 22. When the whole set 22 has been clamped by the jaws 29 to the support unit 21, it is possible to place the other support unit 21 against the rolling stand 11 by rotating the positioner assembly 20. The positioner assembly 20 is positioned in relation to the stand 11 by means of positioner pins 30; to achieve this, the positioner pins 30 cooperate with positioner holes 36 and possibly with a positioner abutment 38. Next, securing screws 28 are employed to clamp the jaws 29 to the set of rolls and relative equipment 22 located on the stand and, when clamping catches 35 which are anchored to projecting feet 34 of the support 40 of the equipment and which clamp those feet to a support surface 37 have been disengaged, it is possible to withdraw the whole set of rolls and relative equipment 22. The positioner assembly 20 is moved backwards according to the arrows 43, is rotated according to the arrow 42 and positions opposite the stand 11 the other support unit 21 complete with the new set of rolls and relative equipment 22. The positioner assembly 20 may comprise appropriate attachements 41 for removal and positioning purposes by means of a hoist, crane or another means. The rolls 32 are inserted directly onto shafts 39 and are clamped with known rapid clamping means. The word "equipment" 33 is to be understood as meaning the entry and exit guides, oval turners, other guides and all the means in general which are auxiliary to the rolls 32 for proper rolling.

Claims: Device (25-27) for raising and lowering sets of rolls (22) and relative equipment (33) such as entry and exit guides, oval turners, guides and auxiliary means, said device (25-27) being assembled on a positioner assembly (20) belonging to an apparatus (10) for replacing said sets of rolls (22) in rolling stands having rolls supported as cantilevers with vertical axes, said apparatus (10) comprising a support device (15) movable from a first position, which is relatively remote from the rolling stand, to a second position, which is relatively close to the rolling stand, said support device (15) carrying a rotatable platform (16) bearing said positioner assembly (20), said positioner assembly (20) comprising a first and a second support unit (21) for respectively delivering and withdrawing a set of rolls to and from said rolling stand, characterised in that said first and second support units (21) are movable on rectilinear guides (26) between a position where the axes of the shafts carrying the rolls to be delivered are aligned to the corresponding axes of the rolling stand, and another, raised, position where said axes are not aligned to each other. Device (25-27) as claimed in claim 1, characterised in that said support units (21) are movable by means of jacks (25) carried by said support units (21), and in that said another, raised, position being defined by an abutment (27) which is present on said support units (21) and which limits the raising movement of the same.

Inventors: DRIGANI, FAUSTO
Applicants: DANIELI & C. OFFICINE MECCANICHE S.P.A.
Application year: 1988
Main classification: B21B31
IPC codes: B21B13, B21B31