Patent ID: 8127584

Claim:
A cluster mill housing assembly for a rolling operation to reduce a gauge of a flat metal strip, the assembly comprising: a. a first housing, having a plurality of corners, wherein said first housing has a roll cavity configured to receive a first plurality of rolls, b. a second housing, wherein said second housing has a roll cavity configured to receive a second plurality of rolls, c. a plurality of vertical prestress rods, wherein at least one of said vertical prestress rods is located at each of the plurality of corners of said first housing and at each of the corresponding corner of said second housing, wherein said first housing moves vertically relative to said vertical prestress rods, wherein each of said plurality of vertical prestress rods is rigidly attached to said second housing, d. a hydraulic tensioning and positioning control system that includes a first plurality of hydraulic cylinders, each including a piston, each said piston being connected to one of said plurality of vertical prestress rods, wherein said first plurality of hydraulic cylinders is connected to said first housing, wherein said first plurality of hydraulic cylinders is used to create a respective predetermined tensile load in each one of said plurality of vertical prestress rods, wherein said predetermined tensile loads are at least large enough to create a compression stress in both said first housing and said second housing during said rolling operation, wherein said hydraulic tensioning and positioning control system is operable to increase a vertical separation between said first housing and said second housing in the event of a break in said flat metal strip during said rolling operation, wherein said hydraulic tensioning and positioning control system further includes a second plurality of hydraulic cylinders operatively connected to the cluster mill housing assembly, wherein each one of said second plurality of hydraulic cylinders includes a piston, wherein said hydraulic tensioning and positioning control system includes a hydraulic position control system operatively coupled to said second plurality of hydraulic cylinders and configured to vertically position and maintain said first housing relative to said second housing during said rolling operation to set a predetermined gap between said first housing and said second housing, and e. a distance sensor system operatively coupled to said cluster mill housing assembly, wherein said distance sensor system measures a distance between said first housing and said second housing at each one of two selected points.