a jet loom with a weft yarn insertion brake contains a braking element that is movable from a position of rest , on one side of the weft yarn , across the path of the weft yarn to a braking position . an electric motor , which drives the braking element , can be actuated during each insertion process of the loom . the electric motor preferably constitutes a fast response step or d . c . motor , whose direction of displacement can be switched and whose stroke can be individually adjusted for each set position of the braking element during the insertion process . operation of the electric motor is controlled by an electronic control device . programming within the control device can be modified between varying insertion processes so as to adapt the timing , stroke and driving direction of the electric motor . the driving force of the electric motor is transferred to the braking element by a constrained , inelastic link connecting the two . the electric motor is controlled so that the driving force exerted on the braking element is always greater in magnitude than the greatest possible reaction force of the deflected weft yarn .