Device for the control of the tension of an endless belt or screen

Apparatus for controlling both the tension and edge run position of an endless belt or screen in a paper handling machine, comprising a unitary deflecting roller, first and second bearing means at the opposite ends of said roller, said bearing means rotatably supporting said roller, each said bearing means being movably mounted in a slide member, first and second motor means operatively associated with said first and second bearing means, respectively, for individually displacing its associated bearing relative to a said slide, first electronic monitoring control means operatively connected to said first and second motors and responsive to the tension in said belt or screen for activating said motors to shift said bearings in said slides and thereby achieve a desired tension in said belt or screen, and second electronic monitoring control means responsive to the positions of the edges of said belt or screen for activating said motors to shift said bearings in said slides to achieve a desired edge position of said belt or screen, whereby both the position and tension of said belt or screen are controlled by said deflecting roller.