Wet end drainage system for paper machines

Claim 1

IN A PAPER MACHINE HAVING AN ENDLESS FORMING WIRE, ROLLS SUPPORTING SAID WIRE, SAID WIRE HAVING UPPER AND LOWER PATHS OF TRAVELLING MOVEMENT, AND A SLICE FOR DELIVERING LIQUID SUSPENSION ONTO SAID WIRE DURING SAID UPPER PATH OF MOVEMENT, APPARATUS FOR EFFECTING DRAINAGE OF SAID SUSPENSION COMPRISING, IN COMBINATION WITH A PAIR OF SAID ROLLS DEFINING THEREBETWEEN A SECTION OF SAID UPPER PATH EXTENDING FROM ONE TO THE OTHER OF SAID PAIR OF ROLLS, A SUCTION BOX LOCATED BENEATH SAID SECTION OF TRAVEL OF SAID WIRE AND HAVING A SINGLE UNINTERRUPTED SUCTION AREA EXTENDING THROUGHOUT THE MAJOR LONGITUDINAL EXTENT OF SAID SECTION OF TRAVEL, SAID WIRE HAVING AN ARCUATE PORTION IN ITS UPPER PATH OF MOVEMENT DEPENDING BETWEEN SAID PAIR OF ROLLS INTO SAID SUCTION AREA, SAID ARCUATE PORTION OF SAID WIRE BEING OF UNINTERRUPTED CONTOUR AND HAVING AN UNDER SURFACE FREE FROM BEARING CONTACT THROUGHOUT SAID SUCTION AREA AND AN UNCONSTRAINED UPPER SURFACE FREELY EXPOSED TO ATMOSPHERIC PRESSURE, MEANS FOR APPLYING SUCTION TO SAID BOX TO CAUSE FORMATION OF SAID ARCUATE PORTION OF SAID WIRE, AND MEANS FOR APPLYING TENSION TO SAID WIRE TO ADJUST THE RADIUS OF CURVATURE OF SAID ARCUATE PORTION.