Precise web metering device

Claim 1

MECHANISM FOR UNREELING, FEEDING OUT AND PERIODICALLY CUTTING WEB MATERIAL INTO SHEETS OF SUBSTANTIALLY UNIFORM, SELECTED LENGTH, COMPRISING, IN COMBINATION, A WEB REEL, A FLYING CUTTER, WEB FEEDING MEANS INCLUDING A PLURALITY OF POSITIVELY ACTING FEED COUPLES WHICH DIVIDE THE WEB FEED PATH INTO AT LEAST THREE SUCCESSIVE ZONES, THE PENULTIMATE ZONE BEING A CONSTANT TENSION ZONE DISPOSED BETWEEN FEED COUPLES, AND THE FINAL ZONE BEING A TENSION FREE ZONE FOLLOWING THE LAST OF THE FEED COUPLES AND IN WHICH THE CUTTER IS LOCATED AND ACTS PERIODICALLY, A WEB-LOOP-RIDING ROLL DISPOSED IN THE CONSTANT TENSION ZONE, MEANS DRIVING THE FINAL FEED COUPLE AT A CONSTANT FEED RATE SO RELATED TO THE TENSION OF THE CONSTANT TENSION ZONE THAT THE CHOSEN LENGTH OF UNTENSIONED WEB WILL BE FED OUT TO THE CUTTER BY SAID COUPLE IN EACH CUTTER CYCLE, MEANS OPERATIVELY ASSOCIATED WITH SAID WEB RIDING ROLL OF THE CONSTANT TENSION ZONE AND CONTROLLED THEREBY PROGRESSIVELY TO INCREASE THE WEB TENSION AND THE STRETCH IN THE NEXT PRECEDING ZONE AS THE ROLLER CARRYING WEB LOOP OF THE CONSTANT TENSION ZONE INCREASES IN LENGTH, SO TO REDUCE THE QUANTITY RATE AT WHICH THE WEB IS DELIVERED INTO THE CONSTANT TENSION ZONE BY THE CONSTANTLY RUNNING FEED COUPLE AT THE INTRODUCTORY END THEREOF, AND PROGRESSIVELY TO DIMINISH THE WEB TENSION AND STRETCH IN THE NEXT PRECEDING ZONE AS THE ROLL CARRYING LOOP OF THE CONSTANT TENSION ZONE DIMINISHES IN LENGTH, SO TO INCREASE THE QUANTITY RATE AT WHICH THE WEB IS DELIVERED INTO THE CONSTANT TENSION ZONE BY THE CONSTANTLY RUNNING FEED COUPLE AT THE INTRODUCTORY END THEREOF, AND MEANS OVERDRIVING THE FEED COUPLE AT THE INTRODUCTORY END OF THE CONSTANT TENSION ZONE AT A FEED RATE WHICH EXCEEDS THE CHOSEN SHEET LENGTH PER CUTTER CYCLE IN A FIXED RATIO, THE OVERDRIVING RATIO SERVING AUTOMATICALLY TO DETERMINE AND MAINTAIN A PRESCRIBED AVERAGE WEB TENSION AND AVERAGE WEB STRETCH IN THE ZONE WHICH IMMEDIATELY PRECEDES THE CONSTANT TENSION ZONE.