Device for changing the work rolls and the back-up rolls of a strip-mill

Abstract

The invention relates to a method and a device for changing the work rolls and the back-up rolls ( 8, 9 ) of a strip mill, by means of a roll-changing carriage ( 2 ) which can be transversally displaced in relation to the roll stand ( 1 ). Said roll-changing carriage receives the old sets of rolls removed, enabling them to be exchanged for new sets of rolls.

1 .- 3 . (canceled)  
   
   
       4 . An apparatus for changing the work rolls and backup rolls of a roll stand in a strip mill, the strip mill defining a longitudinal path therethrough, said apparatus comprising: 
 a roll-changing carriage movable transversely to the longitudinal path of the strip mill, said roll-changing carriage being movable from a distal standby position to a proximal position relative to the roll stand;    a stationary changing cylinder mounted proximate a floor level of the strip mill and a piston movably inserted in said changing cylinder and having a forward end projecting out of said changing cylinder, said piston being movable in said changing cylinder transverse to the longitudinal path of the strip mill;    an extraction carriage connected to said piston rod at said forward end and movable with said piston rod on said roll-changing carriage, said extraction carriage being selectively connectable with said roll-changing carriage such that said extraction carriage and said roll-changing carriage are movable together by said piston rod of said changing cylinder transversely to the longitudinal path of said strip mill when said extraction carriage is connected with said roll-changing carriage;    a transverse shift table installed on said roll-changing carriage and movable approximately parallel to the longitudinal path of the strip mill; and    a shift cylinder movable approximately parallel to the longitudinal path of said strip mill and selectively engageable with said transverse shift table for moving said transverse shift table into and out of a changing position aligned with the roll stand.    
   
   
       5 . A process for changing work rolls in a roll stand of a strip mill using the apparatus of claim  1 , comprising the steps of: 
 arranging the roll-changing carriage at the distal standby position, wherein the transverse table holds a new set of work rolls;    coupling the extraction carriage to the roll-changing carriage and moving, by the changing cylinder, the extraction carriage and the roll-changing carriage to the proximal position relative to the roll stand;    connecting the extraction carriage with an old set of work rolls in the roll stand to be changed;    uncoupling the extraction carriage from the roll-changing carriage and engaging the transverse shift table with the shift cylinder, which causes the roll-changing carriage to be locked in the proximal position relative to the roll stand;    moving, by the changing cylinder and the extraction carriage, the old set of work rolls from the roll stand to a changing position on the transverse shift table;    disconnecting the extraction carriage from the old set of work rolls;    shifting the transverse shift table, by the shift cylinder, so that the old set of work rolls is moved out of the changing position and the new set of work rolls is moved into the changing position, which is aligned with the roll stand;    connecting the extraction carriage with the new set of work rolls and moving, by the changing cylinder, the extraction carriage and the new set of work rolls such that the new set of work rolls are moved into the roll stand;    disconnecting the extraction carriage from the new set of work rolls;    disengaging the shift cylinder from the transverse shift table and coupling the extraction carriage to the roll-changing carriage; and    moving the roll-changing carriage with the old set of work rolls located on the transverse shift table into the distal standby position, where the old set of work rolls is removeable.    
   
   
       6 . A process for changing the backup rolls in a roll stand of a strip mill after removal of the work rolls using the apparatus of claim  1 , comprising the steps: 
 arranging the roll-changing carriage at the distal standby position;    coupling the extraction carriage to the roll-changing carriage and moving, by the changing cylinder, the extraction carriage and the roll-changing carriage to the proximal position relative to the roll stand;    connecting the extraction carriage with a lower backup roll of the old set of backup rolls in the roll stand to be changed;    moving, by the changing cylinder, the extraction carriage and the roll-changing carriage together away from the roll stand such that the lower backup roll of the old set of backup rolls connected to the extraction carriage is brought into a changing position to the side of the roll stand;    placing a dummy on the lower backup roll;    moving, by the changing cylinder, the roll-changing carriage with the extraction carriage and the lower backup roll of the old set of backup rolls with the dummy back into the roll stand;    placing the upper backup roll of the old set of backup rolls on the dummy;    moving, by the changing cylinder, the roll-changing carriage with the extraction carriage and the old set of backup rolls out of the roll stand and into the changing position;    disconnecting the extraction carriage from the lower backup roll of the old set of backup rolls;    replacing the old set of backup rolls with a new set of backup rolls including a dummy;    connecting the extraction carriage with a lower backup roll of the new set of backup rolls;    moving, by the changing cylinder, the roll-changing carriage with the extraction carriage and the new set of backup rolls into the roll stand;    removing the upper backup roll of the new set of backup rolls from the dummy and installing the upper backup roll of the new set of backup rolls in the roll stand;    moving, by the changing cylinder, the roll-changing carriage with the extraction carriage and the lower backup roll of the new set of backup rolls with the dummy from the roll stand to the changing position;    removing the dummy from the lower backup roll of the new set of backup rolls;    moving, by the changing cylinder, the roll-changing carriage with the extraction carriage and the lower backup roll of the new set of backup rolls into the roll stand;    disconnecting the extraction carriage from the lower backup roll of the new set of backup rolls; and    moving, by the changing cylinder, the extraction carriage and the roll-changing carriage to the distal standby position.