Abstract: In order to achieve, in a device for welding of a foil tube comprising two welding jaws, which can be moved against one another and clamp the foil tube between one another, a relatively low building height of the device and a high welding force, it is suggested that a gearing has four rods, of which two inner rods are pivotally fastened through a stationary joint, and two outer rods are each connected through one joint to an inner rod and a further joint to a jaw carrier, and that a movable part of a linear drive is connected to the inner rods through a connecting member in order to pivot the inner rods and thus the jaw carriers away from one another or toward one another during a movement of the movable part along its active line.