Double screen rapid door

A door comprising

• two jambs, a transverse box joining the top ends of the two jambs, and a curtain moveable between a closed position in which it closes an opening formed by the jambs and box and an open position in which it is folded up under the box,
• wherein the curtain comprises two parallel screens that define an air cushion and that are suspended from a top region of the jambs,
• the curtain further comprising at least one lifting strap connecting a bottom part of the curtain to a shaft mounted in the box, and at least one transverse stiffening means fitted to each of the screens, side edges of each screen lying in flat continuous contact with the jambs to form an airtight lateral association between each screen and the jambs,
• wherein said at least one transverse stiffening means includes at least two pairs of stiffening bars, each of said pairs of said stiffening bars being engaged in two mutually opposite sheaths, are connected by at least one spacer disposed between the stiffening bars, said spacer carrying a roller engageable between two tracks that are formed in each of the vertical jambs and a filler endpiece engaged on ends of each of the stiffening bars, and at least one pair of stiffening bars without spacers positioned between two stiffening bars with spacers, in such a way that, during a raising of the curtain alternate folds form symmetrically about a plane in which the door opens, each of the stiffening bars without the spacer having a guide endpiece that is oriented in a plane of the screen in which the bar is oriented, the guide endpiece providing a surface contact against the outside face of the tracks when the curtain in in the closed position, and moving away from the outside surface of the tracks when the curtain is raised in the open position,
• wherein each screen comprises at least two transverse panels of flexible material connected by a sheath, and
• wherein a spacer connects ends of the pair of stiffening bars and carries a roller engageable between two tracks that are formed in each of the vertical jambs.