Chain tensioner, machine for processing sheet-form elements, and method for tensioning the sets of chains

摘要

The invention relates to a chain tensioner (50; 500) for a transporting device (70) of a machine (1; 1') for processing sheet-form elements (10), said transporting device (70) comprising two lateral sets of chains (80) that are connected to the ends of a plurality of transverse gripper bars (75) that are able to grasp the sheet-form elements (10) and at least one chain guiding device (90) that is configured to guide a respective set of chains (80), characterized in that the chain tensioner (50; 500) comprises: - an actuator (9) configured to be driven by a control unit (8) of the processing machine (1; 1'), - a movable support (11), - a transmission element (12) carried by the movable support (11), - a rotary element (13) configured to be driven in rotation by the actuator (9) and to cooperate with the transmission element (12) in order to exert a pushing force on the movable support (11), the movable element (13) being able to rotate through an angular range (a) of less than 360° between a first extreme angular position and a second extreme angular position, the tension in the set of chains (80) being at a minimum for the first extreme angular position and at a maximum for the second extreme angular position, the actuator (9) being driven in synchrony with the press angle (AM). The invention also relates to a machine (1; 1') for processing sheet-form elements and to a method for tensioning the sets of chains (80) of the transporting device (70).