Apparatus for regulating the operation of a plant for the making of extruded products

Claim 1

Apparatus for regulating the operation of a plant for making an extruded product, particularly of synthetic plastic material, wherein the product issues from an extruding tool and thereupon passes along a predetermined path toward and through a calibrating tool and wherein the material of the product tends to pile up or swell and has at least one edge in said path, comprising a measuring head for contact-free monitoring of the pileup or swelling of the material in said path, including spaced-apart confronting light emitting and light receiving surfaces at opposite sides of said path; and a plurality of light conducting elements having ends adjacent at least said light receiving surface, said light receiving surface having a plurality of fields each adjacent the end of at least one of said light conducting elements, said fields forming a plurality of substantially parallel rows and the fields of said rows being staggered relative to each other, said head being arranged to generate a first signal indentifying at least one field which is adjacent an edge of the material in said path and a second signal denoting the position of such edge with reference to said at least one field.