Rolling plant for rolling billets or blooms

Abstract

A rolling plant for rolling billets or blooms, the plant defining a longitudinal feeding axis X of said billets or blooms and comprising a feeding area for feeding said billets or blooms; a rolling train; a longitudinal roller table to transport the billets or blooms from said feeding area to said rolling train along said longitudinal feeding axis X; a welding machine adapted to move forwards and backwards along said longitudinal roller table to weld billets or blooms to one another when moving from said feeding area to said rolling train; characterized in that said welding machine is slidingly suspended from a bridge and is adapted to translate parallel to said longitudinal feeding axis X, and said bridge is arranged at the longitudinal roller table and is adapted to translate transversely to said longitudinal feeding axis X, whereby in a first operating position of the bridge the welding machine occupies part of the longitudinal roller table and can move forwards and backwards along said longitudinal feeding axis X, whereas in a second operating position of the bridge the welding machine makes said longitudinal roller table clear.

1 . A billet or bloom rolling plant for rolling billets or blooms, the plant defining a longitudinal feeding axis X of said billets or blooms and comprising
 a feeding area for feeding said billets or blooms;   a rolling train;   a longitudinal roller table to transport the billets or blooms from said feeding area to said rolling train along said longitudinal feeding axis X;   a welding machine adapted to move along said longitudinal roller table to weld billets or blooms to one another when moving from said feeding area to said rolling train;   
       characterized in that said welding machine is slidingly suspended from a bridge and is adapted to translate parallel to said longitudinal feeding axis X, and said bridge is arranged at the longitudinal roller table and is adapted to translate transversely to said longitudinal feeding axis X, whereby in a first operating position of the bridge the welding machine occupies part of the longitudinal roller table and can move forwards and backwards along said longitudinal feeding axis X, whereas in a second operating position of the bridge the welding machine makes said longitudinal roller table clear. 
     
     
         2 . The plant according to  claim 1 , wherein said bridge is a bridge suspended on a fixed structure of the plant. 
     
     
         3 . The plant according to  claim 2 , wherein said suspended bridge is a bridge with two beams, parallel to the longitudinal feeding axis X, and the welding machine is adapted to slide on first guides, each first guide being arranged on a respective beam of the bridge. 
     
     
         4 . The plant according to  claim 3 , wherein said suspended bridge is adapted to slide on second guides, orthogonal to the beams and provided on said fixed structure. 
     
     
         5 . The plant according to  claim 1 , wherein a maintenance area of the welding machine is provided at said second operating position of the bridge. 
     
     
         6 . The plant according to  claim 1 , wherein the longitudinal roller table comprises a plurality of first, preferably motorized, rollers, each first roller being mounted on a respective pivoting support, preferably in a number less than or equal to five. 
     
     
         7 . The plant according to  claim 6 , wherein the welding machine is provided at the bottom with at least two second rollers, preferably only two second rollers which are possibly idle, and with at least one cam element adapted to lower at least two first rollers from a supporting position, in which said at least two first rollers support the billets or blooms, to a retractable position during a movement of the welding machine along said longitudinal feeding axis X, so that said at least two second rollers replace said at least two first rollers in said supporting position. 
     
     
         8 . The plant according to  claim 6 , wherein at least some of said first rollers are provided with respective actuation means to lower the corresponding first roller before the bridge passes from the first operating position to the second operating position. 
     
     
         9 . The plant according to  claim 7 , wherein said first rollers are cantilevered with respect to the respective pivoting support and/or said second rollers are cantilevered with respect to a base of the welding machine. 
     
     
         10 . The plant according to  claim 7 , wherein said first rollers and/or said second rollers are provided with side edges for containing the billet or bloom along the longitudinal feeding axis X. 
     
     
         11 . The plant according to  claim 7 , wherein the first rollers are provided with an idle wheel on a side thereof and said at least one cam element is adapted to act on said idle wheel to lower the respective first roller. 
     
     
         12 . The plant according to  claim 1 , wherein the welding machine is suspended from a carriage slidingly fastened to the bridge so as to translate parallel to said longitudinal feeding axis X, preferably wherein said carriage and said bridge are components of a bridge crane or overhead crane. 
     
     
         13 . The plant according to  claim 1 , wherein said feeding area or said billets or blooms comprises a heating furnace and/or a movement bed, or comprises a continuous casting machine. 
     
     
         14 . The plant according to  claim 1 , wherein said welding machine is a flash welding machine entirely suspended from the bridge or from an overhead crane. 
     
     
         15 . The plant according to  claim 14 , wherein said flash welding machine is a welding assembly comprising
 a first fixed structure or frame;   first clamping means, placed on said first structure, for clamping a tail of a first billet or a head of a second billet;   a second sliding structure or frame, connected to said first structure and sliding, parallel to the longitudinal feeding axis X, with respect to the first structure;   second clamping means, placed on said second structure, for clamping the head of the second billet or the tail of the first billet;   at least two upsetting cylinders for adjusting the position of the second structure with respect to the first structure along a direction parallel to the longitudinal feeding axis X, in order to press the head of the second billet on the tail of the first billet, or vice versa, during welding;   
       and wherein the whole welding assembly is slidingly suspended from the bridge or from the overhead crane.