Abstract: A tensioning device for applying a tensioning force to a component has a cylinder housing having a hydraulic medium filled axial cylinder, a piston rod guided in the cylinder recess telescoping in a longitudinal axis direction, and displaceable back and forth, projecting out of the cylinder housing at one end, a piston guided in an axial piston rod recess, and displaceable, back and forth, by a limited amount, in the longitudinal axis direction, from a moved-in position to a moved-out position, and a spring element connected with the piston driving the piston in an outward piston movement direction parallel to the longitudinal axis. Force is applied to the piston by the spring element and by the hydraulic medium, so that inward movement of the piston rod into the cylinder housing (8), in the inward piston rod movement direction (77), brings about inward movement of the piston into the piston rod.

Abstract: The invention relates to a tensioning device (1) for applying a tensioning force (FX) to a component (2), particularly to a press-down roller or deflection roller (3; 4), having a longitudinal axis (11), a cylinder housing (8) having an axial cylinder recess (20) filled with a hydraulic medium, a piston rod (9) guided in the cylinder recess (20) telescoping in the direction of the longitudinal axis (11), so as to be displaceable back and forth, projecting out of the cylinder housing (8) at one end, wherein the piston rod (9) has an axial rod recess (36), a piston (10) guided in the rod recess (36), so as to be displaceable, back and forth, by a limited amount, in the direction of the longitudinal axis (11), from a moved-in position to a moved-out position, a spring element with which the piston (10) stands in connection, so that it can be driven in an outward piston movement direction (66) parallel to the longitudinal axis (11), wherein the piston has force applied to it on one side by the spring element and