GB683896A - A new or improved apparatus for controlling the draught produced by the chimneys or flues of furnaces, boilers, stoves or kilns - Google Patents

Abstract

683,896. Check draught dampers and explosion fittings for stoves. LANGHAM, A. J. Oct. 25, 1950 [Oct. 25, 1949], No. 27389/49. Class 126 [Also in Group XII] An automatic draught stabilizer for the flues of furnaces, boilers or stoves of the kind in which a counterbalanced valve is pivotally mounted within an opening leading to the flue comprises a frame 1 set in the wall 3 of the flue and the counterbalanced valve 5 so constructed and mounted in the frame that it will open readily either inwardly or outwardly under the influence of a depression or of a positive pressure in the flue as disclosed disclosed in Specification 683,892. The valve 5 comprises an aluminium or like sheet formed with reinforcing side flanges 6 and transverse flutes 8 mounted asymmetrically on a rod or tube 10 pivotally carried by the frame 1 and formed also with a central oblong slot 14 for the passage of a weight and lever assembly. This assembly comprises a bar 11 secured to a segment 13 clamped to the rod 10 having a lower arm disposed inwardly of the valve and carrying weights 22, and an upper arm 15 disposed outwardly of the valve and fitted with a rubber stop 15<SP>1</SP>, cushioning contact of said arm with said valve and! with said frame. When the valve moves inwardly under the influence of a depression in the flue, Fig. 2, the bar 11 is carried with it, but when the valve moves outwardly under the influence of a positive pressure, e.g. an explosion in the flue, Fig. 3, the bar 15 is held against the frame 1 by the stop 15<SP>1</SP> and the valve moves freely. The bar 15 may be locked by a spring or other catch 60 and a counterbalancing weight in the form of a bar 9 is secured to the upper part of the valve, reducing the pendulum-wise movement of the valve. Each end of the rod or tube 10, Fig. 7, is provided with a ball 23 urged axially outwardly by a spring 24 in sockets 25 having ends spun over to be of slightly less diameter than the balls, which seat again screw-threaded members 26 passing through the frame and being provided with lock-nuts 27. Lubricant such as graphited grease may be packed into the sockets 25. Alternatively, the spring-pressed balls 23 may move in sockets formed in the members 26 or may be replaced by pins having rounded ends. Obturator plates 29 formed with V-notches 38 may be fitted below the lower face of the valve as disclosed in Specification 683,922. In a modification, Figs. 5 and 6 (not shown), the valve assembly is mounted on the end wall of the box-like housing attached by straps to a flue pipe.