Abstract A photoelectric apparatus for determining the boundary between areas giving off different amounts of light, e.g. the fusion line on a tinplate strip moving through a fusion furnace where unfused matte surfaced tinplate becomes fused bright surface tinplate. The apparatus contains several photoelectric cells and the boundary''s position is indicated where a difference occurs in the outputs of adjacent cells. The cells are aligned with the output ends of light-conveying conduits whose input ends face portions of the areas on both sides of the boundary. Only light rays parallel to the axes of the conduits are allowed to pass through them, so that only light from those portions of the area directly in line with the conduits stimulates the cells. The apparatus may include gates adapted to adjust the size of the openings at the input ends of the conduits, and which are preset to regulate the amount of light impinging on each of the cells. In this manner, the gates may compensate for differences in cell sensitivity or provide a desired pattern of cell outputs.
In an apparatus for fusing a strip of tinplate comprising heating means adapted to fuse said tinplate as it passes therethrough, the improvement comprising: a. a source of light directing light toward said strip; b. a plurality of light-conveying conduits disposed longitudinally of said strip and facing said strip at an angle such that light from said source is reflected from said strip in a direction substantially parallel to the longitudinal axes of said conduits; c. means, disposed within said conduits, for allowing only light substantially parallel to the axes of said conduits to pass therethrough; d. a plurality of photoelectric cells, each of said cells being adapted to receive light which passes through one of said conduits; e. means connected to each said cells for determining the electrical output thereof; and f. means for varying the location of the line of fusion of the tinplate whereby the strip is maintained at a predetermined temperature above that of fusion as it leaves said heating means.
Claim 2
Dependent Claim
165 words
In an apparatus for fusing a strip of tinplate comprising heating means adapted to fuse said tinplate as it passes therethrough, the improvement comprising: a. a source of light directing light toward said strip; b. a plurality of light-conveying conduits disposed longitudinally of said strip and facing said strip at an angle such that light from said source is reflected from said strip in a direction substantially parallel to the longitudinal axes of said conduits; c. means, disposed within said conduits, for allowing only light substantially parallel to the axes of said conduits to pass therethrough; d. a plurality of photoelectric cells, each of said cells being adapted to receive light which passes through one of said conduits; e. means connected to each said cells for determining the electrical output thereof; and f. means for varying the location of the line of fusion of the tinplate whereby the strip is maintained at a predetermined temperature above that of fusion as it leaves said heating means.
Claim 3
Dependent Claim
23 words
The improvement as recited in claim 1, further comprising g. means to vary the amount of light passing through each of said conduits.