Greifer zum Oeffnen von Ventilsaecken

The invention relates to a gripper comprising opening elements for opening valve sacks with valves having an oblong shape in their closed state and a circular or oval shape in their open state. The opening elements 3, 3', 4, 5) of the gripper are movable along two axes of motion, whereby one axis of motion in the in the longitudinal extension direction of the closed sack valve (12) runs through two most distant points of the same, and the other axis is perpendicular to the first axis and the intersection of the two axes of motion is located in the centre point of the valve (12). The relationship of the travel paths of the opening elements (3, 3', 4, 5) is adjusted as a function of the required shape of the opened valve (12).