Patent GB-681258-A (GB)
Abstract: 681,258. Operating gear for stove dampers. BAINES, R. July 6, 1950 [July 7, 1949], No. 17938/49. Class 126. A common control for two or more flue dampers of a heating installation is provided with an indexing device which causes the common control to operate different combinations of dampers or different dampers or to operate the dampers in different ways according to the setting of the device. The front flue, hotplate flue and boiler flue of a heating installation are controlled by dampers 4, 5, 6 respectively. The flues lie on one side of a partition 7 whilst the control rod 8 is-located in a chamber on the opposite side of the partition 7 so as to be isolated from the flues. The control rod is mounted in flanges 9, 10 of a bracket and is longitudinally movable to displace the dampers and angularly movable to index it in relation to the dampers. The right-hand end of the control rod 8 extends through the stove casing and carries a knob 12 having a pointer marking which may be brought into register with markings on the casing. The dampers are mounted on spindles 15 extending into the control chamber, and the spindles of dampers 5 and 6 are provided with weighted lever arms 16, 17 so that the dampers tend to return to a closed position. The spindle of the front flue damper 4 carries a lever 18 having a pin 19 which engages between spaced discs 20 in the control rod 8 so that any longitudinal movement of the control rod displaces the damper 4. The control rod 8 carries pins 21, 22 and 23 which engage the levers 16, 17 respectively, according to the setting of the control rod. As shown, the pins 21, 23 engaging levers 16, 17 operate dampers 5, 6 respectively when the pointer is vertically upwards, while the discs 20 operate the front flue damper 4. With the pointer horizontal, pin 23 engages lever 17 so that only the front flue and boiler flue dampers 4, 6 are operated. With the pointer vertically downwards the hotplate flue and front flue dampers 5, 4 are operated. With the control rod 8 fully in, the pins 21. 22, 23 are some distance to the left of levers 16, 17 so that the control rod can move through part of its travel to operate front flue damper 4 without operating dampers 5, 6. The damper 4 is so formed that it is fully open at an intermediate position, and is partly closed at either of its terminal positions, so that the front flue damper 4 may be fully opened while dampers 5, 6 remained closed. The left-hand end of control rod 8 is provided with an axial fin 24 adapted to engage flanges 25, 26 to limit rotation of the control rod to 180 degrees. The flange 9 has three perpendicular slots 27, and the fin 24 is spaced from the flange 9 so that it enters one of the slots 27 as the pins 21, 22 engage the levers 16, 17 so as to prevent resetting the control rod after either of the dampers 6, 7 have been opened. The control rod 8, at its right-hand end is provided with notches which engage the aperture in flange 10 to fix the rod in any position of longitudinal adjustment. A block 28 prevents the notches engaging the upper edge of the aperture in the flange 10. The longitudinal movement of the rod 8 is limited by the knob 12 and a stop 29. Opposed springs, Fig. 4 (not shown), may be provided to engage the notches in the control rod. The lever arms 16, 17 may be of cam profile, and may-operate sliding dampers through rack and pinion gearing. The Specification also describes an arrangement with an indexing device separate from the common control.