GB1260450A - Improvements in or relating to a method for bending and straightening a cast bar and plant for carrying out such method - Google Patents

Abstract

1,260,450. Straightening. VEREINIGTE OSTERREICHISCHE EISEN - UND STAHLWERKE A.G. 23 July, 1970 [25 July, 1969], No. 35814/70. Headings B3E and B3M. A method for bending and straightening a cast bar 1 comprises feeding the bar through a curved pass of stationary guiding rolls 2, then through a bending and straightening apparatus 3 including an adjustable reaction roll 4 and at least two bending rolls 5, 8, the steps of readjusting one of said bending rolls following said reaction roll when a pressure gauge 28 senses a deviation from a desired value and if said re-adjustment is ineffective, slewing said bending rolls around a horizontal axis in a direction contrary to the re-adjustment to keep said cast bar free from bending moments. The bending and straightening rolls 5, 8 cooperate with pulling rolls 6, 7 the rolls being mounted in insert pieces 10 to 14 in a roll frame 15. Spacers 32, 33 support the insert pieces and maintain equal spacing between the rolls during operation. The rolls 5, 6 and 8 are tightened by hydraulic units 21, 22 and 23. The roll frame is slewable as a unit about a horizontal axis in bearing assemblies 24, 25 and a projection 27 on the delivery side of the frame engages a slewing device 29 through the interposed pressure gauge 28. Adjustable guide pads 31 engage the bar as its enters the rolls. In operation, the roll 5 is adjusted to co-operate with rolls 4 and 8 to remove the curvature R from the cast bar and the bar is passed to a roller table 9. Any bending moment acting on the bar by the rigid guide rolls 2 and from the bar via the rolls upon the roll stand is registered by the gauge 28 and an automatic control at first adjusts the roll 5 to remove the bending moment. If this fails to straighten the bar because the bending moment is in front of the roll 4 the automatic control actuates the slewing device 29 which rotates the roll frame in a direction contrary to that on which the roll 5 has been displaced and the bending moment is removed. The rolls 5, 6, 7 and 8 are designed as shaping rolls to shape the cast bar immediately after its solidification.