GB1126604A - Improvements relating to controlling stresses in rolled metal strip - Google Patents

Abstract

1,126,604. Measuring stress and undulations; measuring stress photo-electrically. LICENTIA PATENT-VERWALTUNGS G. m. b. H. Jan. 2, 1967 [Jan. 24, 1966], No. 111/67. Headings G1A and G1N. [Also in Division G3] In apparatus for minimising variations in tensile stress of rolled steel 1 [Division G3], the tensile stress is measured at a plurality of points situated across the width of the strip, the measured values are compared and their differences are used to control adjustment of the gap between the rolls 2. As shown in Fig. 1, three probes 3 measure the permeability, which is dependent on tensile stress, and a comparison circuit 5 forms a difference signal to control the shape of the roll gap. Indicators 8 register the measured values of the tensile stress and indicators 9 register the differences. In an alternative arrangement, described with reference to Fig. 2 (not shown), a single probe (10) is traversed across the width of the strip. Undulations in the strip, representative of variations in tensile stress, may be measured by using the strip itself as the intermediate electrode of a differential capacitor, by disposing electromagnets above and below the strip, or an incident light beam may be swept over the strip and the varying amount of reflection of this beam resulting from the undulations used to indicated stress variations.