Abstract: A device for controlling weft carrying grippers on a continuous weft feed loom has a connecting rod-crank mechanism that controls rectilinear translation of a slide along a fixed guide. The slide has an internal nut screw that engages a worm that is mounted in idleable manner on a fixed support that is integral with the guide and fitted with a pinion for controlling the gripper strap. The nut screw is made up of at least two elements having respective worm followers. The elements are movable relative to each other along the worm axis by a cam but angularly fixed relative to the slide or to another element mounted on the slide so that the angular position of the elements is controlled by a cam as a function of the axial position of the slide.