Abstract: This invention relates to an improvement in a clamping device adapted for use at a gripper head for a shuttleless loom, in which a gripper head pulls a weft thread out of the shed while held between two clamping jaws by a clamping lever of a clamping device subject to spring action while a control means acts upon said clamping lever provided with a clamping jaw, the improvement which comprises means whereby one of said clamping jaws is movable at a part carrying it and is springingly, yieldingly positioned, in the opening direction of the clamping device, in a limited manner, and said control means operates in a two-stage manner such that the first actuating stage is within the limits of movability of said movable clamping jaw, and the second actuating stage lifts the clamping jaws off of each other.