ANNULAR UNIT FOR UPPER CHIMNEY PART Russian patent published in 2006 - IPC E04F17/02 

FIELD: vertical ducts, channels, particularly for carrying away waste gases, for instance flue gases.

SUBSTANCE: annular unit 10 comprises outer faces 12, 14, 16, 18 having brick masonry appearance and inner cylindrical surface 20. Upper edge 22 of each outer plane 14 is provided with depression 24. Lower edge of each outer plane 14 has ledge extending from lower side 28 so that ledge of upper annular unit 10 passes into depression 24 of lower unit. Ledge 24 has base of greater width in comparison with that of free ledge end. Depression 24 depth increases from outer surface 14 to upper side 34 of annular unit 10 and depression height exceeds ledge height so that groove is viewed on outer surface between two stacked annular units 10. Outer plane 12, 14, 16, 18 is provided with at least one depression 36, 38, 40, 42 and 44, 46 extending in parallel to axis 32 of annular unit 10 to simulate brick masonry joint. Outer unit faces have brick masonry appearance. At least two opposite outer surfaces 14, 18 are provided with two depressions 38, 40 and 44, 46 formed from the right and the left of central axis defined in corresponding face. Depressions 36, 42 made on another opposite outer surfaces 12, 16 extend in center of corresponding face along central axis thereof.

EFFECT: possibility to handle the units at building site by unskilled workers without moisture penetration into the units.

3 cl, 3 dwg