The device for adjusting the amplitude and direction of the feeding of the material to be sewn includes a movable element (15) provided with a set of teeth (17) for feeding. This movable element includes a slideway formed of two tracks (20a, 20b) in the form of arcs of concentric circles, one of which is generated by a cone and the other by a cylinder, both rolling on the trajectory of a shaft (12) providing a link between two levers of the drive mechanism. The two tracks (20a, 20b) of the slideway are formed by a profiled metal foil, attached to the movable element (15).