GB2389414A

GB2389414A - Single control mechanism for synchronously controlling the movement of dampers over a plurality of air inlets in a stove

Info

Publication number: GB2389414A
Application number: GB0212906A
Authority: GB
Inventors: Paul Wells
Original assignee: A J Wells & Sons
Current assignee: A J Wells & Sons
Priority date: 2002-06-06
Filing date: 2002-06-06
Publication date: 2003-12-10
Anticipated expiration: 2022-06-06
Also published as: FR2841327A1; GB2389414B; FR2841327B1; DE10324634A1; GB0212906D0

Abstract

A stove 1 having a fire box 2, a door 3, to the fire box for fuelling the stove, an exhaust flue 8 from the fire box, a plurality of main air inlets (32, 33, 34, 35, fig 3), each having a damper 322, 332, 342, 352, fig 5) and a single control mechanism 12 and control 14 for synchronising opening of the dampers in accordance with their purpose. The mechanism 12 preferably comprises a ganged set of cams (39, fig 5) acting on the dampers which are hinged to pivot between their open and closed position. The cams (39, fig 5) are preferably provided on a slider and are connected together by a common slide member, connected to a translationally movable control knob 16, or pivotally movable control lever 15. An auxiliary damper (46, fig 4) may be provided, separate from the main control system 12, for tuning the stove to its specific installation, including length and position of the flue. The auxiliary damper is locked in position by a bolt (47, fig 4) after intial set-up. Alternatively, the control mechanism 12 may include a cranked shaft with connecting rods (36, 37, fig 3) to slide the dampers into position. At least one of the dampers may be arranged to remain closed whilst the others are open and vice versa. Two dampers may be provided for controlling air inlets on either side of the fire box.

Description

1 238941 4

STOVE The present invention relates to a stove and in particular but not exclusively a sodba ningstove,, on em- e] ^ i..

5 _ If Traditionall'ood burnti',jstoves essentially comprised a cast iron box, with a door for loading fuel and a hand-wheel damper in the door which could be opened for more combustion air to enter the stove and closed to damp down the fire. Stoves have become increasingly more sophisticated with more air inlets, for instance an "air o wash" air inlet for directing air down the inside of glass in the door, so that soot does not deposit on the inside of the glass. A plethora of air inlets has called for a plethora of air control levers. These lose user- friendliness in that if one is opened so much, another is likely to need to be closed by a different amount.

5 The object of the present invention is to provide a single lever or control for controlling all the air dampers of a multi-airflow stove.

According to the invention there is provided a stove comprising: a fire box; 9''.: ot I'm ' ' 20. > door of the fire box for fuelling the stove; . ' ' '. an exhaust flue from the fire box; ' '. À a plurality of main air inlets to the fire box; . . a damper for each main air inlet; a single control mechanism for controlling the dampers; and 2s À a single control for operating the control mechanism, whereby movement " of the control synchronizes the degree of opening of the dampers in accordance with their purpose.

Whilst it is envisaged that the control mechanism could have a cranked shaft 30 with connecting rods to slide the dampers into their controlled position, in the preferred embodiment the mechanism comprises a ganged set of cams acting on the dampers, which are hinged to pivot between their opened and closed positions. Again the cams could be provided on a rotatable shaft; but preferably they are

translationally slidable and connected together by a common slide member. The latter can be directly connected to a translationally movable control knob or linked to a pivotally movable control lever.

5 In the preferred embodiment, at least one of the dampers is arranged to remain closed whilst the others are open and vice versa. Further, two dampers Carl be provided for controlling air to similar inlets to the fire box, one for one side of the latter and the other for the other side.

0 Also in the preferred embodiment, an auxiliary damper is provided for tuning the stove to its particular installation, e.g. length and position of the flue pipe. The auxiliary damper by-passes the controllable damper(s) and is adapted to be locked in its tuned position.

IS To help understanding of the invention, a specific embodiment thereof will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic side view of a stove according to the invention; Figure 2 is a rear view of the stove; . 20 Figure 3 is a plan view of the air ho x of the stove of Figure 1; ... Figure 4 is a front view of the air b ox and the control box below it; À Figure 5 is a rear view of the air ho x and the control box; .. Figure 6 is a cross-sectional end vi ew of the air box and the control box, on .. the line VI-VT in Figure 3; ,5 Figure 7 shows in scrap views (p), (sit), (b-p) the cam contours ofthe primary, secondary and by-pass dampers.

Referring to the drawings, the stove 1 has a fire box 2 with a Quelling door 3 having glass 4. Internally, a baffle 5 is provided extending at an upwards sloping 30 angle from a back 6 of the firebox, to force circulation of the combustion gases rising from a fire F on a grate 7 around the baffle before entering the exhaust flue connection 8. As is conventional, the baffle in increasing the combustion gas path increases the degree of combustion of the gas leaving the fire box and mitigates against combustion occurring in the flue (not shown) above the connection.

Beneath the fire box is provided an air box 11 and a control box 12 with a main rear inlet 13. A damper controller 14 extends forwards from the control box and is actuated by a lever 15 extending out from one side of the fire box, where the lever 5 has a handle 16. Internally the air box has four compartments 17,18,19, 20.

The fire box 2 has four air ducts 21,22,23,24 up the back of the fire box. The first 21 leads into a grate void 25 beneath the grate 7 for providing primary air P to the grate, i.e. air to flow through the fire on the grate for intense combustion. The second lo and third air ducts 22, 23 lead up either side ofthe first air duct. At their upper ends, they connect with secondary air ducts 26 leading forwards to transverse secondary air outlets 27 Mom which secondary S air flows down the inside face of the glass 4. The upper ends of the ducts 22,23 also connect to the hollow baffle, which has a lateral divider 28 and front outlets 29 for allowing the tertiary air T to flow down with the 5 secondary air S and encourage the combustion air C to flow up the back of the fire box as opposed to up the front, i.e. not up inside the door 3 and its glass 4. The fourth air duct 24 leads up to above the baffle and has an outlet adjacent the exhaust flue connection, to allow non-combustion air to pass up the flue and discourage , condensation there due to stagnation.

. The control box 12 has the rear air inlet 14 and damper controlled outlets 32,33,34,35 to the air box I 1, and specifically to its four compartments 17,18,19, 20.

All the outlets are the same size, except for that 35 for the by-pass air. The control box has corresponding compartments 321,331,341,351. Laterally through these Is extend a pair of guide rods 36,37. Dampers 322, 332,342,352 are pivotally connected to the front rod 36, by means of depending edge flanges 38. Each damper has a centrally depending cam follower 39, by means of which it can be pivoted up to close the corresponding outlet to the air box. A set of four cam plates 323,333,343, 353 is provided, each in its respective control box compartment and having upper cam 30 surfaces 401, 402,403,404 in contact with the cam followers 39 and central slots 41 through which the guide rods pass to limit the forwards and backwards movement of the cans...DTD:

The cams extend through a front wall 121 of the control box and each has a right angle lug 42 via which they are all riveted to a damper control member 43. This has a front tab pinned to the control lever 15 for movement together of the cam.

5 The cam surface 402 of the primary air cam 333 is contoured for: À its damper 332 to be Filly open when the control member is fully withdrawn forwards from the control box, and its damper to be closed once the control member has been halfway returned.

0 The cam surfaces 401,403 of the secondary/tertiarry cams 323,343 (for respective sides of the stove) are contoured for: their dampers 322,342 to be Filly open - and more so than the primary damper 332 - when the control member is Filly withdrawn forwards, and its dampers to be clos'ed once the control member has been fillly returned.

The cam surface 404 of the by-pass cam 353 is contoured for its damper 352 to be fully closed at all positions, except when the control member is fully returned, when the damper is opened, but sufficiently to allow only a relatively small air flow.

. . 20 Above the control member 43, the front wall of the air box i 1 I has a pair of small auxiliary air inlets 44,45 to the secondary/tertiary air compartments 17,19. The orifices of these inlets is controllable by a damper 46, which can be locked in position ' by a bolt 47.

Is For operation of the stove, after laying of the fire, it is lit with the dampers fully open, i.e. with the control member and the control lever 15 pulled fully forward...DTD: This Filly opens the primary air damper 322 and the secondary/tertiary air dampers 322/342. Once the fire is well lit, the lever can be moved back to close reduce the air flow generally. Normal operation requires no primary air and the heat output can be 30 controlled with the dampers 322/342 only open, i.e. with the lever in the rear half of its travel. When the stove is to be shut down for the night, only the by-pass damper 352 is opened with the lever right back. This position opens this damper and closes the others. A small secondary/tertiary air flow is needed to keep the fire alight. This

is provided through the auxiliary inlets 44,45. The damper 46 is set according to the - draw of the chimney and the rate of slow burn required to keep the stove in over-

night. Once the desired position is found, the damper will not require regular adjustment and can be locked by the bolt 47.

The invention is not intended to be restricted to the details of the above described embodiment.

. I l ., 1. . l

Claims

CLAIMS:

1. A stove comprising: À a fire box; at least one door of the fire box for Quelling the stove; 5. an exhaust flue from the fire box; À a plurality of main air inlets to the fire box; a damper for each main air inlet; À a single control mechanism for controlling the dampers; and À a single control for operating the control mechanism, whereby movement lo of the control synchronises the degree of opening of the dampers in accordance with their purpose.

2. A stove as claimed in claim 1, wherein the control mechanism includes a cranked shaft with connecting rods to slide the dampers into their controlled position

3. A stove as claimed in claim 1, wherein the control mechanism comprises a ganged 5 set of cams acting on the dampers, which are hinged to pivot between their opened and closed positions.

4. A stove as claimed in claim 3, wherein cams care provided on a rotatable shaft.

5. A stove as claimed in claim 3, wherein the cams are translationally slidable and connected together by a common slide member.

20

6. A stove as claimed in claim 5, wherein the common slide member is directly connected to a translationally movable control knob.

7. A stove as claimed in claim 5, wherein the common slide member is linked to a pivotally movable control lever.

8. A stove as claimed in any preceding claim, wherein at least one of the dampers is Is arranged to remain closed whilst the others are open and vice versa.

9. A stove as claimed in any preceding claims, wherein two dampers are provided for controlling air to inlets to the fire box, one for one side of the latter and the other for the other side.

10. A stove as claimed in any preceding claim, including an auxiliary damper for 30 tuning the stove to its particular installation.

11. A stove as claimed in claim 10, wherein the auxiliary damper bypasses the controllable damper(s) and is adapted to be locked in its tuned position.

12. A stove substantially as hereinbefore described with reference to Figures lto 7 of the accompanying drawings.