Apparatus for scanning a material for detection of flaws and having material axis deviation detection

DETAILED DESCRIPTION It is an object of the invention to provide a flaw detector whereby a material is inspected for flaws with a constant distance maintained between the circumference of the material and probes.
Another object of the invention is to provide a flaw detector of the type stated whereby the distance between the circumference of the material and probes is not subjected to variation, but can be maintained constant even if the actual axis of the material has been deviated from its predetermined one by a warped portion thereof passing into an inspection or detection space.
A still another object of the invention is to provide a flaw detector having a relatively-simple construction to keep constant the distance between the circumference of the material and probes even in the event of deviation of the axis of the material from its predetermined one.
According to the invention, if the material axis has deviated, the center of revolution of the probes can be instantly made re-coincident with the material axis simply by displacing a means supporting a rotator means in accordance with the amount of deviation of the material.
In most cases, since the degree of its deviation caused by its warped portion is very small (of several millimeters, for example) compared with the length of the material, the degree of deviation per time for a unit length of the material to pass is very small; in other words, the material axis may deviate gradually.
Hence the support means may be displaced slowly to compensate the deviation, thus requiring no complicated technique in order to keep constant the distance between the circumference of the material and the probes.
Other objects and advantages of the invention will become apparent during the following discussion of the accompanying drawings.