|Title of Invention
AN IMPORVED DEVICE FOR CLAMPING GUIDES DURING ROLLING OF AT LEAST ONE BAR IN A LONG ROLLING MILL STAND
|This invention relates to an improved clamp device for guides for rolling at least one bar in a long roiling mill stand in which the guides (1) are disposed before and after each roll stand, the at least one bar being fed by the guide along the centre line of each roll, the guide being adapted to move lengthwise in both directions within the roll pass, the clamp device having an extended portion (3) at a lower portion for clamping the guide, the extended portion of the clamp device (2) being ceratted to ensure positive grip of the guide to prevent any displacement of the guide.
|This invention relates to an inproved clamping device for guides for roling bar in a rolling mill stand
These guides are fixed just before and after of all the rolling stands. The main purpose of the. guides are to feed the bar at the center of pass/roll and deliver the bar at the successive stands.
FIELD OF THE INVENTION
It is hitherto known that there is waste of metal due to formation of fins on the bar which when passing via rolls become twisted. To obviate these disadvantages guides are provided through which bars may be passed to entert the rolls.It is known in die art so far that the roils are so shaped to produce round bar in such a manner than initial stages or earlier stages or earlier passes of the rolls produce not an oval section but a section two sides of which are rectilinear and the other two sides (or ends) curved in the form. The specially shaped bar is then passed through the final rolls by turning such roll up on to one of its curved ends with the rectilinear sides vertically disposed and running between guides against which these vertical sides can bear in such a manner as to keep them in true linear position for enntering the roll without twisting. Any ordinary square or rectilinear solid type of guide or box like or channel like guide is used and the rolls are cut with curves formed to produce the desired section.
The disadvantage of the prior art is that a continuous continuous control by hand is necessary to adjust tlie guide causing frequent halt of operation of the roiling mill, There is further disadvantage that the through passage of time, the guides are becoming widened while the bar is passed through it, thus resulting tilting which result in sometime twisting of the bar while passing through the cut groove of the rolls.
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An apparatus is also known in the art tor holding down a moving strip while guiding the edges thereof comprising a bottom guide assembly and a top guide assembly between which the strip passes, each said guide assembly includes a plurality of drag, blocks mounted on a plate for moving transeversely of the path of the movement of the strip and an edge guide on each side of one of said guide assemblies said means for moving the drag blocks and edge guides towards and away from one another according, to the width of the strip being guided
There is reference to carriage used need on draw benches for drawing work pieces through dies, the carriages having grippers ro .grip the forward end of work pieces
There is reference in Indian Patent Application No.1 37934 of clamping means for wire guide which generally comprises a set of two or three wedges aftet anchoring of the wires or strands and as a guiding principle should not cany any relative displacement. In other words, all the wedge ends should be located in the same place, The said document discloses means for applying the clumping wedge mean during the application of the apparatus to the wires or stranded wires and during the tensioning thereof against a press-in plate which is located in spaced relation from the anchor piate, said press-in plate being equipped with openings for the trough/passage of the wire or stranded wires, said applying means holding the clamping wedge means oui of their effective damping position and after tensioning of the wires or stranded wire raid press-in piate being displaceable against anchor plate for simultaneously and uniformly bringing the wedges into their clamping position.
Indian Patent No 183531 discloses an equipment holder bar for a roiling null stand in which a holder associated with a rolling mill stand is arranged for positioning and successive clamping in position, a guide base to guide roiled stock, the bar comprising a slider
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able to move lengthwise in both directions by a positioning means on a stationary body fitted on a rolling mill stand, the positioning means comprises an outer sleever associated with a rotary positioner shaft set in rotation by a motor.
None of the said prior art apparatus teaches or suggests about non displacement of guides employed for feeding the bar at center of the roll/pass at successive stand. wherein non displacement of guides is essential requirement for not interrupted production of bar moving through several passes of a roiling mill.
The present invention in the above respectively smims to develop new guides which are positively clamped, irrespective of the force coming on the rolling of bar, such guides will not be displaced. If the guides are displaced the flow of the bar will be disrupted and production will come to a halt. Repositioning the guides in course of the operation is costly and often leads to discarding of the guides and clamps including rejection of rolled product.
According to the invention there is provided an improved clamp device for guides, for rolling at least one bar in a long rolling mill stand in which the guides are disposed before and after each roll stand, the at least one bur being fed by the guide along the centre line of each roll, the guide being adapted to move lengthwise in both directions within the roll pass, the clamp device having an extended portion ata lower portion for clamping the guide, the extended portion of the damp device being ceratted to ensure positive grip of the guide to prevent any displacement of the guide.
DESCRIPTION OF THE INVENTION
The present invention will be better understood from the following description with reference to the accompanying drawings in which
Fig. 1 represents the abnormal condition of the existing guide displaced.
. 4 .
Fig 2 represents the normal condition of the guide be maintained accordingly to the invention.
Fig. 3 represents the photographic view of the clamp guide with plain surface according to the existing art.
Fig. 4 represents the photographic view of the ceratted surface of the clamp guides developed according to the invention.
Fig. 5 represents a further photographic view showing the worn out projected plain par of the guide clamp of the 14th delivery guide.
Fig. 6 represents another photographic view showing the modified ceratted clamping surface of the 14th Delivery guide.
As illustrated in Figures1 and 2 the bar is guided by a guide (i) at the centre of the pass to be rolled in the rolling direction as shown. The guide revives the bar as .soon as it comes out from the pass/roll and deliver the bar at the successive stands the guide is Slidably operated to move lengthwise on roiling mill stand with a clatnping means (2) and farther to position the guide both ways. But problem arises during rolling a long length over a plurality of rolling stands. The fixed guides operable with the clamps frequently get displaced in the production line of wire rod mill generally duiing 14th and 15th stands Such displacement results due to erosion of the clamps holding the guides. As a consequence of such dislocation of the guide, the bar being rolled is not guided through the centre of the pass/roll due to slackening of grip of the damps on the guides. This also aggravates the situation when due to tiit of the bar the through passage through the rolls get widened which subsequently lead to twisting and lapping of the bar while passing through the groove of the bar.
To solve the said problem and to eliminate the possibility any displacement of the guide, the surface of clamp means of the guides are ceratted instead of configuring with a plain surface as maintained in the existing art. In the present invention, projected part (3) at the lower portion of the clamp guide (2) is ceratted.
It is observed that by such maintaining of ceratted surface (3) of the clamp guides, the guides are positively clamped and does not get displaced whatever the force coming on it. Any losses such as cobbles and delays are completely eliminated to ensure continuous production of a long tun of a bar for rolling.
The invention as herein described and illustrated should not be read in a restrictive manner as various adaptations, modifications and changes arc possible as encampused within the scope of appended claim:-
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1. An improved clamp device for guides for rolling at least one bar in a lone rolling
mill stand in which the guides (1) are disposed before and after each roll stand, the at
least one bar being fed by the guide along the centra line of each roll, the guide being
adapted to move lengthwise in both directions within the roll pass, the clamp device
having an extended portion (3) at a lower portion for damping the guide, the extended
portion of the clamp device (2) being ceratted to ensure positive grip of the guide to
prevent any displacement of the guide.
2. An improved clamping for guides for rolling al least one bar in a long rolling mill
stand as herein described and illustrated.
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|Indian Patent Application Number
|PG Journal Number
|Date of Filing
|Name of Patentee
|TATA STEEL LIMITED
|JAMSHEDPUR 831001 INDIA
|PCT International Classification Number
|PCT International Application Number
|PCT International Filing date