Apparatus and method for treating filamentary material

Claim 1

A METHOD OF APPLYING TO A CONTINUOUSLY MOVING WEB OF MATERIAL A PRESCRIBED AMOUNT PER UNIT LENGTH OF A GIVEN SUBSTANCE COMPRISING THE STEPS OF MOVING SAID WEB IN ARCUATE CONTACT WITH PART OF THE SURFACE OF A DRIVEN ROLLER ANOTHER PART OF WHICH DIPS INTO A RESERVOIR NORMALLY CONTAINING A PRESCRIBED AMOUNT OF SAID SUBSTANCE, FEEDING SAID SUBSTANCE IN LIQUID FORM INTO SAID RESERVOIR AT A RATE PREPORTIONAL TO THE SPEED OF THE WEB, SAID RATE BEING CONSTANT AT A CONSTANT SPEED OF THE WEB, SENSING ANY VARIATION IN THE AMOUNT OF SUBSTANCE IN THE RESERVOIR FROM THE PRESCRIBED AMOUNT, AND ALTERING THE SPEED OF SAID DRIVEN ROLLER UPON SENSING ANY VARIATION IN THE AMOUNT OF SAID SUBSTANCE IN THE RESERVOIR FROM THE PRESCRIBED AMOUNT IN ORDER TO COMPSENSATE FOR SUCH VARIATION, SAID ALTERATION BEING AN INCREASE IN THE SPEED OF SAID ROLLER WHEN THE AMOUNT OF SUBSTANCE IN THE RESERVOIR INCREASES ABOVE THE PRESCRIBED AMOUNT AND A DECREASE IN THE SPEED OF SAID ROLLER WHEN THE AMOUNT OF SUBSTANCE IN THE RESERVOIR DECREASES BELOW THE PRESCRIBED AMOUNT.