EINRICHTUNG ZUM ABSPERREN EINER OEFFNUNG

摘要

The invention relates to an improved shuttering device for preventing back-flow in air conduits or the like. The device includes an attachment section and a frame section, the latter being provided with a series of elastic lamellae shiftable between blocking and unblocking positions within the frame, the frame having in addition guide plates extending axially of the conduit to prevent transverse currents.