ROLLING STAND OF THE TYPE WITH TIE-RODS WITH OSCILLATING SUPPORTS WITH INTERCHANGEABLE INTERMEDIATE HOLDER BASES

Abstract: The present invention relates to a rolling stand (17) of the type with tie-rods (15) so designed that, in addition to being suitable to be easily replaced, dismantled and reassembled, it is also capable of being transformed within reduced times and at a low cost, from a two-high stand, having only a pair of parallel and motor-driven rolls (13), into a "universal" stand, composed, in addition to the pair of parallel rolls, by a further two idle rolls, opposed to each other, and perpendicular to the previously mentioned cylinders, commonly known as vertical cylinders.

Description: The present invention relates to a convertible rolling stand of the type defined in the preamble of claim 1. Rolling stands are known, which essentially comprise rolls rotatably supported by roll supporting means mutually tightened through a set of tie-rods, each one of said tie-rods reacting on two pins rotatably assembled within one of said roll supporting means. Stands having such a structure do not allow a great flexibility in production, in that they require long times for the replacement of the rolling rolls, when the profile to be produced is varied. Their structure moreover does not always allow such a production diversification, in that it is not possible to produce by means of such a stand, e.g. parallel-flange beams, if the same stand is not provided with particular supports for pairs of additional, so-called vertical rolls. From EP-A-0 103 989 a rolling stand is known, in which the intermediate holder structure arranged between the roll supports and the bed frame of the rolling stand comprises a single rectangular frame with feet integral therewith for fastening to the bed frame, and with integral blocks for housing the tie rods. This intermediate frame includes four tie rods with opposite threaded portions and threaded nuts, which latter are so arranged that they engage cross portions to the roll supports respectively above and below the tie rods, the cross portions conferring to the roll supports a T-like shape. Further, tensioning bolts are provided which extend from a crosshead through the roll supports and which in cooperation with a piston and cylinder device maintain engagement of the opposite roll supports with the nuts by urging the roll supports toward each other. A conversion of this rolling stand, however, requires that the whole frame with blocks, tie rods, eye, and with adjusting screw means is replaced upon having removed the tensioning bolts. and this represents a complex and time consuming operation. DE-A-2 506 449 discloses a rolling stand which is similar to that of EP-A-0 103 989 in respect of roll support configuration and intermediate frame, and so substantially the same drawbacks pointed out for the rolling stand of EP-A-0 103 989 are present in the rolling stand of DE-A-2 506 449. DE-A-2 515 651 relates to a rolling stand of the type defined in the preamble of claim 1. The structure of this rolling stand provides a single holder base which is disposed horizontally and embraces from opposite sides the rolls. The intermediate holder base can be subdivided in axial direction of the horizontal rolls and so said intermediate holder base is of separable type. It is an object of the present invention to provide a rolling stand of the type above specified which is much more easy and very quick to be converted from a two-roll stand into a four or universal roll stand, whereby production diversification can be carried out by means of quick and simple replacements. This object is achieved by a convertible rolling stand as claimed in claim 1. The structural and functional chracteristics and the advantages of a rolling stand having the structure according to the present invention shall be better understood from the following disclosure relating to exemplifying but not limitative embodiments referring to the schematic drawings, wherein: Figure 1 is a general schematic sectional elevation side view of a convertible two roll stand according to the present invention, Figure 2 is a sectional plan view according to line II-II of Figure 1, Figure 3 is a schematic front elevation view of the stand of Figure 1, Figure 4 is a sectional side elevation view of a convertible universal stand according to the invention, Figure 5 is a sectional plan view according to line V-V of Figure 4, and Figure 6 is a schematic front elevation view of the stand of Figure 4. Referring to the drawings, a convertible rolling stand comprises essentially a bed frame 11 holding by means of an intermediate holder structure, opposite roll supports and/or packings 12, by which horizontal rolling rolls 13, 14 are rotatably supported. The intermediate holder structure comprises four vertical tie-rods 15 which are rotatable for the relative positioning of the upper roll 13 and the lower roll 14, by adjustment and synchronization drive means 16 supported atop the tie-rods of the stand. More precisely, Figures 1, 2 and 3 show a two-roll stand, generally indicated with 17, provided, above its bed frame 11, with four intermediate holder bases or holder feet 18 which each house a respective tie-rod 15 and which are removably constrained to the bed frame 11 by means of four eye pressure bolts 19 and four related nuts 20, the bolts 19 being pivoted to the frame 11 and entering open seats 21 of protruding portions of the holder base 18. Two sleeve portions 22, provided on each holder base 18 and protruding therefrom, contain and support a respective tie-rod 15, each of the tie-rods 15 having two threaded portions 23, provided on opposite sides relatively to the holder base 18 and engaging respective threaded nuts 24 irrotatably connected to the roll supports 12. The nuts 24 are housed in seats of the roll supports 12 and the seats define shoulders 25 in the roll supports 12 for holding rings 26 having rounded surfaces 27 in an inner intermediate position, whereby they engage slidingly the outer surface of the sleeve portions 22. The rings 26 are each provided with protruding sectors 28, having a rounded cup-like shape, provided on diametrically opposite positions on the transversal face where they interact with the associated threaded nut 24, thus allowing the roll supports 12 to oscillate together with their related rolls 13 and 14 relatively to the holder bases 18. Between the roll supports 12 of the upper roll 13 and the roll supports 12 of the lower roll 14 within related seats 29 four jacks 30 determining the pre-load of the stand are provided. As shown in the drawings, the jacks 30 engage the roll supports 12 and urge them away from each other against opposite pairs of threaded nuts 24. The rolls 13, 14 are removed from the stand and replaced in a very quick way, by means of suitable toolings, by removing axial locking screws 31 and horizontally opening the shoulders of the rolling stand. Figures 4, 5 and 6 show how a two-roll stand according to the invention of the type just described can be quickly transformed into a convertible universal stand by removing the four intermediate holder bases 18 and replacing them with two wide intermediate holder bases 32, such bases 32 too being fastened to the bed frame 11 by means of pressure bolts 19. Each base 32 houses a pair of the rods 15 with related threaded nuts 24. The holder bases 32 include support portions for a pair of vertical idle rolls 33, whose position can be adjusted relatively to a protruding profile 34 of two horizontal rolls 35 and 36, by means of a related drive unit 38. Moreover, each one of the two holder bases 32 is provided with four half-seats 37 for the positioning of four upper jacks 30 and four lower jacks 30, so that the jacks 30 become positioned between the holder bases 32 and the roll supports 12 for urging the roll supports 12 away from each other against opposite pairs of threaded nuts 24. The advantage and the usefulness results thus clear of the present invention, which allows, in a rolling stand essentially of the type wherein the relative vertical adjustment of the rolls is carried out by means of threaded tie-rods rotatably and centrally housed in replaceable intermediate holder bases, to transform it in a quick and simple way from a "normal" two-roll stand into a "universal" stand for complex profiles, by replacing the individual holder bases with the associated tie-rods. It should be noted that thanks to the positioning of the pressure bolts 19, the replacement of the roll supports 12 and the holder bases 18 or 32 is particularly easy, because it is sufficient to that purpose to loosen the nuts 20 of the pressure bolts 19 and turn the same pressure bolts around their eye, so as to set the holder bases 18 or 32 free. Once that the adapters, not shown, between the rolls and their drive means have been disconnected, the roll supports 12 can be replaced, by raising them up by means of suitable connections. Re-positioning of the roll supports 12 can be carried out in an equivalent opposite way, it resulting therefore very quick and easy. It is thus clear that each type of intervention, both for the replacement of the rolls and for the transformation of the stand is extremely fast and simple, because a structure which is lighter and more compact that the known structures of the prior art is to be manipulated. Moreover, convertible rolling stands with intermediate holder bases according to the invention are suitable to be opened horizontally, i.e. by spacing wide apart the shoulders containing the roll supporting elements and the supports, in order to remove the rolls, which remain in their position, and replace them with a new pair, both the old and the new rolls being supported on a suitable maintenance unit.

Claims: A convertible rolling stand having two opposite roll supports (12) for each roll rotatably supporting respective horizontal rolls (13,14; 35,36) above a bed frame (11) of the rolling stand, and an intermediate holder structure (15,18,24; 32) arranged between the roll support (12) and the bed frame (11) and removably fastened to the bed frame (11), the structure comprising four vertical tie rods (15) each having two opposite threaded portions with which threaded nuts (24) engage, the tie rods (15) being rotatable in the structure and the threaded nuts (24) being non-rotatably connected to the roll supports (12), whereby rotation of the tie rods (15) causes axial displacement of the threaded nuts (24) along the tie rods (15) and vertical adjustment of the horizontal rolls (13,14; 35,36) relative to one another, and means for holding the roll supports (12) in engagement with the threaded nuts (24), characterised in that said intermediate holder structure comprises at least two intermediate holder bases (18,32) which are positioned separated each from the other normally to opposed ends of said horizontal rolls (13,14; 35,36) and which house said tie rods (15), and in that said threaded nuts (24) are received into seats of said roll supports (12), which define shoulders (25) for receiving holding rings (26) having rounded inner surfaces (27) slidably engaging sleeve portions (22) of the holder bases (18), so that the threaded nuts (24) are loosely inserted within said seats and said roll supports are allowed to oscillate together with their rolls (13,14) relatively to said holder bases (18,32), whereby said means for holding the roll supports (12) in engagement with the threaded nuts (24) comprise jacks (30) engaging the roll supports (12) and urging opposite roll supports (12) away from each other against opposite pairs of threaded nuts (24) positioned in the above manner. A convertible rolling stand as claimed in claim 1, characterised in that said holding rings (26) are further each provided with protruding sectors (28) having a rounded cup-like shape, provided on diametrically opposite positions on the transversal face where they interact with the associated threaded nuts (24). A convertible rolling stand as claimed in claim 1, characterised in that the intermediate holder bases (18,32) are secured to the bed frame (11) by pressure bolts (19) pivoted to the bed frame (11) and insertable into outwardly open seats (21) of protruding portions of the intermediate holder bases (18,32) for clamping said protruding portions to the bed frame (11). A convertible rolling stand as claimed in claim 1, characterised in that each tie rod (15) is arranged in a respective one of the intermediate holder bases (18). A convertible rolling stand as claimed in claim 1, characterised in that it comprises two intermediate holder bases (32) each housing a pair of said tie rods (15). A convertible rolling stand as claimed in claim 5, characterised in that the intermediate holder bases (32) include support portions for one pair of rotatable vertical rolls (33). A convertible rolling stand as claimed in claim 1, characterised in that the jacks (30) are disposed between the roll supports (12). A convertible rolling stand as claimed in claim 6, characterised in that the jacks (30) are disposed between the intermediate holder bases (32) and the roll supports (12). A convertible rolling stand as claimed in claim 1, characterised in that drive means (16) for rotating the tie rods (15) are supported atop the tie rods (15).

Inventors: FORNI, LUIGI
Applicants: POMINI FARREL S.P.A.
Application year: 1985
Main classification: B21B31
IPC codes: B21B31, B21B13