member is located within an elongate slot in a rubber moulding having additional airfilled elongate slots for cushioning the edge of the door application_number US 83789877 A description according to fig1 a sliding door can be rolled up and down on a steel tube at its upper end this tube being driven by a reversible electric motor 13 via gears 9 the roll down door 12 comprises along its entire longitudinal edge 16 facing the ground 14 a strip shaped signaller 11 of limited electrical conductivity which is connected via an electrical control wire 17 to a control mechanism 18 which stops the drive motor 13 or sets it turning in the opposite direction when the signaller 11 responds during the closing of the roll down door 12 according to fig2 to 6 the signaller 11 consists of an elastically deformable strip 21 of open celled softly elastic foam plastics impregnated with a conductive lacquer the conductive lacquer is introduced into the cellular polymer material preferably by rolling in such a way that the walls of the open cells of the foam plastics are substantially completely and uniformly covered and are connected to one another in electrically conductive manner by the conductive lacquer which adheres to the walls the foam plastics is dried after the conductive lacquer has been rolled.