Patent ID: 7028742

Claim:
A barrier assembly for sealing off an opening having a top portion, comprising: a housing mountably adjacent to the top portion of the opening; a curtain assembly coupled to the housing, the curtain assembly being movable between a stored position and a deployed position, the curtain assembly in the deployed position covering the opening; a spool coupled to the curtain assembly; a cord coupled to the spool; a drive shaft coupled to the cord and the spool, the drive shaft being rotatable to wind the cord around at least one of the drive shaft and the spool to move the curtain assembly toward the stored position, and to unwind the cord to allow the curtain assembly to move toward the deployed position; a powered drive coupleable to the drive shaft and movable to rotate the drive shaft in one rotational direction to move the curtain assembly toward the stored position and configured to hold the curtain assembly in the stored position; a coupler connected to the drive shaft, the coupler being movable between an engaged position and a released position and configured to couple the drive shaft to the powered drive when in the engaged position and to uncouple the drive shaft from the powered drive when in the released position allowing the cord to unwind and the curtain assembly to move toward the deployed position, wherein the coupler is a clutch that is in the engaged position when power is applied to the clutch, and the clutch moves to the released position when power to the clutch is interrupted; and a deployment governor connected to the drive shaft and positioned to limit a speed at which the drive shaft rotates when the cord unwinds and the curtain assembly moves toward the deployed position, thereby controlling a rate of deployment of the curtain assembly over the opening.