ROLLING MILL STAND WHICH CAN BE CONVERTED INTO A FOUR-HIGH STAND OR UNIVERSAL STAND

Abstract: Rolling stand which can be converted into a four-high stand or universal stand, comprising one pair of housing standards (13) mounted on a base plate (11). The housing standards are able to support a universal roll assembly (24) or a four-high roll assembly (25). The housing standards (13) are longitudinally movable and able to be reciprocally positioned at least in their working position on said base plate (11). The pair of housing standards permanently bears two main roll chocks (14) together with their devices (15) for adjusting the distance between the centres of the rolls. The adjusting devices (15) cooperate with inwardly projecting supports (16) being a part of the housing standards (13). The main chocks (14) support either the horizontal rolls (26) of the universal roll assembly (24) or the back-up rolls (35) of the four-high roll assembly (25). Either the vertical rolls (28) belonging to an universal roll assembly (24) or the horizontal work rolls (36) of a four-high roll assembly (25) are located within the interspace comprised between two main roll chocks (14) in the housing standards (13).

Description: This invention concerns according to the precharacterising part of claim 1 a rolling stand which can be converted, if so required, into a four-high stand or a universal stand. To be more exact, the invention concerns a stand which employs standardized housing standards suitable for the positioning and anchorage of the specific rolls of four-high stands or of universal stands, and also concerns a rolling line which employs such rolling stand which can be converted into a four-high stand or a universal stand. At the present time four-high stands have been designed, structured and made to process only wide flat products and cannot be employed, when so required, as universal stands too. Likewise, universal stands have been designed, structured and made to process sections, such as I-beams and sections with a normal or wide flange or other sections such as H-beams, but cannot be suitable to process wide flat products and therefore to perform the functions of a universal stand. The need to have not two separate rolling lines but to be able to have in the same line and with the same stands both four-high stands and universal stands and viceversa has been felt for some time now. This need is mainly felt on economical grounds and is linked firstly to the processing of small lots, where the need to obtain swift changes of the product to be manufactured has become urgent, and secondly to the instability of the market with its high and low points of demand, now for one type of product and now for another type. Each of these plants involves requirements of investment, space occupied and embodiment of plants, and it is unthinkable that two specialized plants should be set up, one for one type of product and the other for another type of product, and should then be underemployed and used only part-time. On the other hand, considerable technical problems are involved in embodying a rolling stand which can process both wide flat products and also I-beam sections or the like. It is enough to think of the substantial differences in the rolling rolls and in their composition so as to understand the technical, technological and conceptual problems which hinder such an embodiment. Documents FR-A-2.541.600, JP-A-54139866, DE-A-1, 937, 368, US-A-3, 319, 450 and EP-A-0, 166, 478 refer to rolling stands which can be converted from universal stand into two-high stand and vice-versa. None of said documents provides for the possibility of converting an universal stand into a four-high stand. Furthermore, the rolling stands disclosed in said documents are of relatively complicated use, owing to the plurality of elements which they comprise; the substitution of the rolls is always a slow and difficult operation. Document JP-A-62114706 discloses a rolling stand which can be converted from an universal stand into a two-high and/or a four-high stand and vice-versa, according to the preamble of claim 1. This kind of stand is provided with fixed roll housings forming, by pairs, a frame into which the different rolls are laterally inserted. Said rolls are inserted in the spaces comprised between the housings by means of a laterally movable carriage, causing a remarkably large lateral bulk of the whole roll stand. Furthermore, all the rolls must necessarily be provided of their roll chocks and of the elements for journaling them to the housings, prior to the insertion into the housings. Owing to the fixed spatial disposition of the housing standards, only rolls having particular dimensions may be used, and in the case of a stand converted into a four-high stand, the wide flat strips which are produced may obviously not have a width which goes beyond the distance between the roll standards. It is a purpose of the present invention to obviate such difficulties and to enable one and the same rolling line to perform the rolling of wide flat products and of I-beams, H-beams, H-beams with a wide flange, etc. This is obtained by a convertible rolling stand of the kind mentioned above, and having the features disclosed in the characterising part of claim 1. The dependent claims illustrate advantageous forms of embodiment of the invention. According to the invention a stand body comprises four roll standards which can be positioned either in their working position or in a position for conversion and which cooperate in a stable manner with the main roll chocks and relative tie rods. The lengthwise positioning of the housing standards can be carried out by hand or automatically. Such housing standards with their relative main roll chocks cooperate with the rolls and with the accessory roll chocks suited to the purpose. The main roll chocks have standardized overall dimensions for cooperation with their respective rolls, and the intermediate distances too are standardized. Additional accessories such as fixture plates, reinforcing bars, stiffening bars, etc. may be comprised so as to make possible the maximum usage of the stands according to the invention as momentarily equipped according to the examples in the figures. According to the invention the rolls which cooperate with the main roll chocks have the same dimensions in relation to their seatings. Processing rolls for four-high stands, or rolling rings with a vertical axis for universal stands, may be fitted in an intermediate position in cooperation with the roll chocks and rolls. The invention is therefore embodied with a stand body able to bear rolls for a four-high stand or rolls for a universal stand. The attached figures, which are given as a non-restrictive example, show the following: Fig. 1 gives a three-dimensional view of a stand body according to the invention; Fig. 2 shows a stand for a universal rolling stand; Fig. 3 gives a three-dimensional view of a stand for a four-high rolling stand; Fig. 4 gives a breakaway view of the basic components required to convert a stand equipped for four-high rolling into a universal stand according to the invention. The various components are shown diagrammatically in the figures so as to clarify the concept of embodiment according to the invention as much as possible. According to the invention a standardized stand body 10 comprises mainly a base plate 11 with lengthwise guides 12, housing standards 13 and main roll chocks 14 with adjusting devices 15 to adjust the distance between centres of rolls. The housing standards 13 are coupled together two by two and can move lengthwise along the base plate 11 in the guides 12. The housing standards 13 comprise supports 16 that cooperate with main screws 17 of the adjustment devices 15. Lengthwise displacement of the housing standards 13 can be carried out by hand or may be actuated by a motor 18. An assembly of two housing standards 13, two main roll chocks 14 and of the adjustment devices 15 for the distance between centres of the rolls constitutes an end frame 34. The housing standards 13 comprise advantageously a plurality of holes 19 for fixture of the components and accessories needed for correct employment of the stands according to their specific purposes. The housing standards 13 comprise seatings 21 at their lower end 20 for stationary or movable anchorage bolts 22 comprised in the base plate 11. According to the invention the seatings 23 of the rolls in the main housings are standardized, as also are the other overall dimensions. An assembly 24 for conversion into a universal stand and an assembly 25 for conversion into a four-high stand cooperate respectively with the end frames 34, which, as we said, can move lengthwise along the base plate 11. By using the conversion assemblies 24-25 it is possible to provide specific, differentiated usages for the resulting stands. The assembly 24 for conversion to a universal stand comprises essentially two horizontal rolling rings 26 and two vertical rolling rings 28, the vertical rings 28 being fitted to auxiliary housings 27 and suitable to roll the flange of a section. The auxiliary housings 27 are positioned correctly between the main roll chocks 14 and between the supports 16. The assembly 25 for conversion to a four-high stand comprises back-up rolls 35 cooperating with the main roll chocks 14 integrally fixed to the stand body 10 and also work rolls 36 cooperating with specific housings 37. The specific housings 37 are positioned correctly between the main roll chocks 14 and between the supports 16. The specific housings 37 of the work rolls 36 comprise fixture lugs 29 which cooperate with retention plates 30-31. The method of conversion of a rolling mill of one type into a rolling mill of another type according to the invention is simple. With the rolling train pre-arranged with the relative stand bodies 10 perfectly positioned reciprocally, the end frames 34 of each stand body 10 are positioned spaced apart lengthwise along the stand body 10, the end frames 34 being equipped in a stable manner with the main roll chocks 14, as we said earlier. If it is desired to equip the rolling train with a four-high stand, the various components of the assembly 25 for conversion to a four-high stand are positioned and the end frames 34 are brought towards each other and positioned. If it is desired to convert the four-high stand thus obtained into a universal stand, the end frames 34 are distanced further from each other, the rolls 35-36 and specific housings 37 are removed, and in their place are positioned the horizontal rolling rings 26 and vertical rolling rings 28 with the relative auxiliary housing 27; a stiffening bar may be included. In any event, bars 33 to stiffen the end frames 34 may be comprised. Thus the replacement times are very short and the ability to work either as a four-high stand (Fig. 3) or as a universal stand (Fig. 2) in the same rolling line is quite feasible.

Claims: 1. Rolling stand which can be converted into a four-high stand or universal stand, comprising one pair of housing standards (13) mounted on a base plate (11), said housing standards being able to support a universal roll assembly (24) or a four-high roll assembly (25), characterised in that said housing standards (13) are longitudinally movable and able to be reciprocally positioned at least in their working position on said base plate (11); the pair of housing standards permanently bearing two main roll chocks (14) together with their devices (15) for adjusting the distance between the centres of the rolls, said adjusting devices (15) cooperating with inwardly projecting supports (16) being a part of the housing standards (13); said main chocks (14) supporting either the horizontal rolls (26) of the universal roll assembly (24) or the back-up rolls (35) of the four-high roll assembly (25); either the vertical rolls (28) belonging to an universal roll assembly (24) or the horizontal work rolls (36) of a four-high roll assembly (25) being located within the interspace comprised between two main roll chocks (14) in the housing standards (13). 2. Rolling stand as claimed in Claim 1, in which the geometric dimensions relating to overall volume and cooperation of the conversion assemblies (24-25) with end frames (34) of the stand are standardized. 3. Rolling line which comprises a plurality of stand bodies (10) as claimed in claim 1 with end frames (34), characterized in that on the end frames (34) are installed assemblies (24) for conversion of the stands into universal stands able to roll I-beams, H-beams and like sections. 4. Rolling line which comprises a plurality of stand bodies (10) as claimed in claim 1 with end frames (34), characterized in that on the end frames (34) are installed assemblies (25) for conversion of the stands into four-high stands able to roll wide flat products.

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