Cut-off control apparatus

Claim 1

CUTOFF OR LIKE APPARATUS OF THE CHARACTER DESCRIBED HAVING MEANS FOR PROGRESSIVELY FEEDING THERETO A WEB OF MATERIAL AT SUBSTANTIALLY CONSTANT SPEED, A VARIABLE SPEED TRANSMISSION HAVING OUTPUT AND INPUT SHAFTS AND MECHANISM FOR ADJUSTING THE ROTARY SPEED RATIO OF THE OUTPUT TO THE INPUT SHAFT, MEANS FOR DRIVING THE INPUT SHAFT AT A SUBSTANTIALLY CONSTANT SPEED, A PERIODICALLY OPERATING TOOL IN DRIVEN RELATION TO SAID OUTPUT SHAFT, A PAIR OF TACHOMETERS IN DIRECT DRIVEN RELATION TO SAID WEB AND OUTPUT SHAFT, RESPECTIVELY, MEANS RESPONSIVE TO VARIATIONS IN THE RELATIVE SPEEDS OF ROTATION OF SAID TACHOMETERS FROM A PRESELECTED RATIO FOR ACTUATING SAID ADJUSTING MECHANISM TO RESTORE SAID RATIO, SAID MEANS INCLUDING A CLOSED ELECTRICAL CIRCUIT CONTAINING RESISTANCES IN SERIES WITH THE VOLTAGE OUTPUTS OF SAID TACHOMETERS, RESPECTIVELY, A PAIR OF CONNECTIONS EXTENDING, RESPECTIVELY, FROM A POINT BETWEEN SAID TACHOMETER OUTPUTS AND A POINT OF SAID RESISTANCE, AND ACTUATING MEANS SELECTIVELY RESPONSIVE TO THE POLARITY AND MAGNITUDE OF A DIFFERENCE OF POTENTIAL ARISING BETWEEN SAID CONNECTIONS FOR SO ACTUATING SAID ADJUSTING MECHANISM.