Proportional edge alignment control system

Claim 1

THE METHOD OF SENSING WEB ALIGNMENT WHICH COMPRISES (A) ESTABLISHING FIRST AND SECOND SETS OF OPPOSED FLUID JETS AT SPACED LOCATIONS TO DEFINE A NEUTRAL RANGE OF POSITIONS OF THE EDGE OF A WEB TRAVELLING IN A PLANE LOCATED BETWEEN THE RESPECTIVE JETS OF EACH SET, (B) SENSING THE CHANGE IN THE RELATIVE INTERNAL PRESSURES IN THE PRESSURE SUPPLY LINES TO THE FIRST SET OF JETS BY MEANS OF SENSING FLUID CIRCUITS COUPLED THEREWITH WHEN THE FIRST SET OF JETS HAS NO WEB THEREBETWEEN TO GENERATE A FIRST ACTUATING SIGNAL AND SENSING THE CHANGE IN RELATIVE INTERNAL PRESSURES IN THE PRESSURE SUPPLY LINES TO THE SECOND SET OF JETS BY MEANS OF SENSING FLUID CIRCUITS COUPLED THEREWITH WHEN THE SECOND SET OF JETS HAS THE WEB THEREBETWEEN TO GENERATE A SECOND ACTUATING SIGNAL, (C) APPLYING CORRECTIVE FORCES TO THE WEB IN RESPONSE TO THE FIRST AND SECOND ACTUATING SIGNALS TO TEND TO RESTORE THE EDGE OF THE WEB TO THE NEUTRAL RANGE OF POSITIONS, AND (D) ADJUSTING THE FLUID PRESSURE TRANSMISSION CHARACTERISTICS OF THE SENSING FLUID CIRCUITS CONNECTED WITH THE PRESSURE SUPPLY LINES OF THE FIRST AND SECOND SETS OF JETS OF ADJUST THE TIME REQUIRED TO GENERATE AN ACTUATING SIGNAL IN RESPONSE TO A DEVIATION OF THE EDGE OF THE WEB FROM SAID NEUTRAL RANGE OF POSITIONS.