BACKFLOW VALVE FOR RECTANGULAR VENTILATION CHANNELS, IN PARTICULAR DISTRIBUTION CHANNELS OR FLAT CHANNELS

摘要

1. A backpressure stop valve for use in rectangular gas-conducting passages, comprising a frame (2) adapted to be inserted into a passage and having substantially flat outer surfaces, and comprising closure means secured to said frame (2) and pivotable in flap-fashion into sealing relationship against said frame (2), characterized in that a) said closure means is formed of two superposed flaps (3, 4) having their pivot axes disposed in the vicinity of the inlet port for a stream of gas within said frame (2), b) the height of each of said flaps (3, 4), which extends transversely to the pivot axis, is smaller than the depth of said frame (2), said frame (2) being of cuboid configuration and being disposed perpendicularly or, respectively, in parallel to the longitudinal extension of said passage, and c) a lower abutment (8) is provided at the bottom (5) of said frame (2) for the lower edge of the lower flap (4) and an upper abutment (9) is provided for the lower edge of the upper flap (3), the upper edge or, respectively, pivotable arrangement of said lower flap (4) simultaneously forming said abutment (9) for said lower edge of said upper flap (3).