Abstract: A roll-up door assembly including a flexible curtain made of synthetic rubber or fabric, a curtain winding mechanism and two guide members which extend vertically on opposite sides of the doorway. Side edge sections of the curtain are movable in respective guide members. Each guide has inner and outer wall sections with each wall section having an inwardly projecting, longitudinal rib. The two ribs of each guide form an elongate slot that receives a side edge section of the curtain. Spaced-apart pairs of curtain lock members are mounted on and distributed along each side edge section of the curtain. The lock members of each pair are positioned opposite one another on front and rear surfaces of the curtain respectively. The combined thickness of each pair of lock members and the curtain exceeds the width of the elongate slot.

Abstract: A rolling door assembly including a flexible curtain having an inner end, an outer end and side edges. The inner end of this curtain is mounted to a rotatable curtain roll. The assembly includes a sprocket mounted on the curtain roll and a continuous chain loop that extends around this sprocket and is connected to a motor drive to form a curtain winding and unwinding mechanism. Two drive loop members are in operable engagement with the curtain roll for purposes of loop travel during rotation of the roll. The bottom end of the curtain is secured to the two drive members so that the bottom end and the drive loop members travel together. There are also two adjusting mechanisms connected between the bottom end of the curtain and the two loop members to accommodate a difference in speed of travel between the loop members and the bottom end of the curtain, the latter moving at a variable speed as the curtain is wound or unwound.