Wire tightener for papermaking machines

Claim 1

APPARATUS FOR MAINTAINING SUBSTANTIALLY CONSTANT TENSION IN THE RETURN RUN OF THE FORMING WIRE OF A FOURDRINIER PAPER MACHINE INCLUDING A DRIVING ROLL FOR THE WIRE LOCATED ADJACENT THE END OF THE MACHINE, COMPRISING A TENSIONING ROLL, COUNTERBALANCING MEANS SUPPORTING SAID TENSIONING ROLL BELOW THE RETURN RUN OF THE WIRE FOR SUBSTANTIALLY WEIGHTLESS GENERALLY VERTICAL MOVEMENT WITH RESPECT TO AND IN CLOSELY SPACED RELATION WITH SAID DRIVING ROLL, THERE BEING NO ROLL BETWEEN SAID TENSIONING ROLL AND SAID DRIVING ROLL IN ORDER TO CAUSE INCREASED WRAPPING OF SAID DRIVING ROLL BY THE WIRE IN RESPONSE TO UPWARD MOVEMENT OF SAID TENSIONING ROLL, FLUID PRESSURE MEANS CONNECTED TO EFFECT CONTROLLED MOVEMENT OF SAID TENSIONING ROLL WITH SAID COUNTERBALANCING MEANS, MEANS FOR SUPPLYING SAID FLUID PRESSURE MEANS WITH PRESSURE FLUID IN THE DIRECTION CAUSING UPWARD MOVEMENT OF SAID TENSIONING ROLL, MEANS FOR MAINTAINING SAID PRESSURE FLUID AT A PREDETERMINED PRESSURE DEVELOPING A CORRESPONDINGLY PREDETERMINED TENSION IN THE WIRE UNDER PREDETERMINED ANGULAR CONDITIONS OF WRAP OF SAID TENSIONING ROLL BY THE WIRE, AND ADJUSTABLE MEANS LOCATED IN SPACED RELATION LENGTHWISE OF THE MACHINE FROM SAID TENSIONING ROLL FOR TAKING UP STRETCHING OF THE WIRE TO CAUSE SAID TENSIONING ROLL NORMALLY TO MAINTAIN AN APPROXIMATELY STEADY VERTICAL POSITION RETAINING SAID ANGULAR CONDITION OF WRAP THEREOF BY THE WIRE.