This invention relates to apparatus for measuring the eccentricity of rolls, particularly rolls in the secondary cooling zone of a continuous casting machine.
In continuous casting, proper confinement of the metal emerging from the mold is necessary for obtaining the best physical and metallurgical characteristics. Rolls spaced precise distances on opposite faces of the partially solidified bar provide the support required. Various devices have been used to measure the separation distance between the rolls, both initially after a rebuild of the machine, and periodically thereafter.
In service the rolls are exposed to high temperatures and may bend, thus becoming eccentric and adversely affecting confinement of the metal and thus the quality of the product. An apparatus for measuring eccentricity of rolls in the cooling zone of casters is shown in U.S. Pat. No. 4,148,145 Holter et al. The main disadvantage of that device is that it must remain stationary while the rolls adjacent to it are rotated, thus obtaining a measure of the bending present. This is a very time-consuming operation. A roll gap sled shown in U.S. Pat. No. Re. 30,075 of common ownership with the application herein can be used to make multiple passes through the cooling zone (because it is guided on a constant reference path) and thus obtain some indication of eccentricity assuming point contact measurements are made at different locations on the roll peripheries. In addition to being time consuming, this does not provide an accurate nor a complete indication of eccentricity.
It is therefore a primary object of this invention to provide an apparatus for measuring roll eccentricity in a single transport pass tangent to the roll face in a direction normal to the roll axis.