This invention relates to improvements in stoves, and particularly to an oven construction for combination stoves that are adapted to utilize as fuel either wood, coal, oil, or gas.
One object of the invention is an improved ventilating system for the oven, which is automatically provided when the oven is prepared for gas heating.
Our oven construction is of a type adapted to receive a baffle plate having a gas burner mounted thereon, which baffle plate may be handled as a unit, and is connected to a gas supply by the act of positioning the plate and burner in the oven. Such a construction is described in Field Patent No. 1,989,508, issued January 29, 1935. In addition, as has been suggested heretofore, provision is made for insertion of the same plate unit into a different position in the upper part of the oven, for use as a broiler burner. For this purpose an additional gas supply pipe is provided.
Our invention relates to the provision of improved ventilation in such constructions to secure more perfect combustion of the gas supplied to the burner and to insure a more even and uniform circulation of the products of gas combustion through the oven, for providing an even temperature in all parts of the oven at all times, regardless of the position in which the burner is operated. For this purpose, our ventilating dampers are so positioned that outside air is admitted to the oven at a point remote from the exit of the products of combustion. At the same time, the ventilating system is automatically prepared for operation coincidental with the usual manual operations involved in the preparation of the stove for either gas broiler or gas baking use, and the oven is reconverted into an oven of the usual type, suitable for indirect heating by coal or other fuel, co-incidental with the removal of the gas burner from the oven.
These and further objects of the invention will be more fully understood from the accompanying description, taken in connection with the drawings, in which,Fig. 1 is a cross section of an oven construction, showing our oven prepared for gas baking, and indicating in dotted lines the gas burner broiling position; Fig. 2 is an elevation of the back wall of the oven, showing an exit damper in closed position; Fig. 3 is an elevation of the inside of a door for the oven; Fig. 4 is a plan of the burner in lower baking position, taken along the line 4-4 of Fig. 1, and showing the oven and door in cross-section; Fig. 5 is a plan of the burner in upper broiling position, taken along line 5-5 of Fig. 1, and showing the oven and door in cross-section; and Fig. 6 is a detail of our plate construction.
Referring to Fig. 1, we show an oven construc- a tion provided with suitable flues 10 for heating the oven by circulation therein of products of combustion of fuels such as coal or oil, said flues being located above top wall 12 and beneath bottom wall 14 of the oven, and leading to a chimney flue 1, in accordance with well-known flue construction.
As shown in Fig. 1, the back wall 16 of the oven is provided with two gas supply pipes 18 and 20, each of which is provided with a suitable mixing member 22, and each of which extends as a stub pipe into the interior of the oven.
Back wall 16 is also provided with an aperture 24, preferably in the upper portion thereof, as shown, leading to chimney flue 11. Suitably positioned to close this aperture 24 is a closure member 26, hingedly secured to the back wall 16 as by brackets 28, and shown in closed position in Fig. 2.
The lower portion of this closure member 26 has a suitable extension 30, extending into the path of a vertically slidable cam member 32, mounted on the back wall 16 of the oven, as by loops 34, 34. This cam member 32 is provided with a suitable cam surface 36, adapted with vertical movement to engage the extension 30 to swing closure member 26 away from the aperture 24.
During operation of the oven by indirect heat, this damper 26 remains closed through the influence of gravity on the damper 26 and cam member 32.
For operation of the oven by gas, we provide a suitable gas burner 40, which may be conveniently mounted beneath a baffle plate 42 having any suitable number of perforations 43 (Fig. 4).
This plate may be positioned in the oven, as shown in Fig. 1, guided and supported by lugs 44, 44 on the side walls of the oven. The burner 40 is provided at the rear with a funnel-shaped member 46 adapted to facilitate an operative connection with the stub end of either pipe 18 or 20.
A cam surface 38 is provided on the cam member 32 and is so positioned that it is engaged by the rear edge 48 of the plate 42 as said plate is moved into baking position in the oven, the cooperating surfaces 38 and 48 operating to elevate the cam member 36 and the closure member 26 to open the back damper 26. 55& The cam member 32 is provided with a similar cam surface 37, which is suitably positioned to be engaged by the rear edge 48 of the plate 42 when the plate is moved into broiling position, as shown in dotted lines in Fig. 1, guided and supported by lugs 50, 50, with the funnel-shaped member 46 engaging the supply pipe 20. Thus, when the gas burner is positioned in the oven for either type of operation, the back damper 26 will be automatically opened by the act of positioning the plate 42.
In order to provide a suitable air inlet to allow entrance of outside air to permit gas combustion, a suitable opening may be provided at the front of the oven, which is shown in Fig. 3 as a series of apertures 60 formed in the lower portion of the door 62, where they will not detract from the appearance of the stove on the outside, and where the insulation 63 of the door may be omitted. These apertures are suitably proportioned with relation to the bore of the gas supply pipe 18 to permit the ingress of sufficient air to insure proper combustion of gas supplied at a contemplated pressure.
In order to close these apertures 69 to permit proper indirect heating of the oven from the flues 10, 10, a closure member 64 is provided, which normally covers the apertures 60, but which may, as hereinafter described, be moved into a position exposing the apertures 60, for gas operation. For this purpose, the closure member 64 may be conveniently mounted on the door 62, as shown in Fig. 3, in the following manner: Door 62 is formed with an insulation-free portion 65 provided with bosses S5, 6S, having bores 63, 60, adapted to receive hinging means including pins 70, 70 integral with connecting links 72, 72.
After the pins 70 are mounted in the bores 68, 68, the closure member 64 may be attached to the connecting links 72, 72 as by bolts 74, 74. It will be noted that by this construction we provide a closure member 64 which may be hingedly moved away from the apertures 60. The construction described is especially suitable, because the closure member 64 and its attached hinging means is completely balanced to allow perfect operation, and there is no metal connecting the pins 70, 10 along the pivot line, thereby avoiding operation difficulties due to expansion from prox.50 imity to the high temperatures of the oven, which expansion might, with some constructions, result in binding of the hinging means.
The closure member 64 is adapted to be swung from the dotted line position shown in Fig. 1 to the full line position shown in Fig. 1, through the cooperation of a stop member 80 (Fig. 4), provided at the front edge of the plate 42, with a cam ýextension member 82 associated with one of the connecting members 72. For the purpose of maintaining the balanced effect, we provide a similar extension member 82a on the other connecting link 72.
As shown in Figs. 1 and 4, when the oven door 62 is moved into closed position, the cam extension member 82 engages the stop 80 to swing the closure member 64 away from the apertures 60, to permit ingress of air through the apertures.
At the same time, as shown in Fig. 1, the exten70 sion members 82, 82 strike against the insulation 63 of door 62, as shown in Fig. 1, which acts as a stop for retaining the closure member 64 in a position in the path of incoming air to act as a baffle member both to direct the incoming air towards the bottom of the oven, and to preheat the air after the closure member has become heated by the high temperature of the oven.
As will be understood, when the door 62 is opened, the closure member 64 will hingedly swing into a closed position over the apertures 60 under the influence of gravity.
In order to provide air ingress when the plate 42 is in upper or broiling position, we provide a stop 84 at the outer side edge of door 62, which is adapted to engage a cooperating stop 86 at the front edge of the plate 42. As illustrated in Fig. 5, these cooperating stops 84 and 86 act to prevent closure of the door when the plate 42 is in upper or broiling position. However, as shown in Fig. 4, when the plate is in lower position, the stop 86 is received in the concavity of the door 62, and allows latching of the door in closed position.
As thus described, our oven construction provides a ventilating system supplying an adequate air ingress for proper combustion of a gas burner in its baking position, together with a damper exit into the chimney flue, such ventilating system automatically closing upon the removal of the gas burner from the oven, to convert the oven to a form suitable for indirect coal or oil heating.
Likewise, upon positioning of the gas burner for broiling operation, the oven is placed in suitable condition to allow the exit of products of combustion into the chimney flue through opening of the damper, and the broiler is operated with the door open to allow ingress of an adequate amount of air to insure proper combustion of the gas; and, upon removal of the broiler unit, the oven is again converted to a form suitable for indirect coal or oil heating.
Our construction thus is simple in form, and may be incorporated in a usual type of oven by the attachment of a minimum number of suitable parts, and is conveniently operated with high combustion efficiency, and uniform gas oven heating without in any way affecting the indirect heating of the oven by other fuels.
We claim: 1. In a stove, an oven, a door for said oven, a plate having a gas burner mounted thereon and movable into a lower baking position and into an upper broiling position in said oven, a damper disposed at the front of said oven, and means associated with said damper and cooperating with said plate when said plate is in said lower position to operate said damper by the act of closing said door, and means to prevent closing of said door when said plate is in said upper position.
2. In a stove, an oven having a back wall, a door for said oven, a plate having a gas burner mounted thereon and movable into a lower baking position and into an upper broiling position in said oven, inlet and exhaust dampers for said oven, one of said dampers being disposed at the front of said oven, the other of said dampers being disposed in the back wall of said oven, means cooperating with said plate to open said back wall damper by the act of positioning said plate in either of said positions, and means cooperating with said plate to open said other damper when said plate is in said lower position, by the act of closing said door.
3. In a stove, an oven having a back wall, a door for said oven, a plate having a gas burner mounted thereon and movable into a lower baking position and into an upper broiling position in said oven, inlet and exhaust dampers for said oven, one of said dampers being disposed at the front of said oven, the other of said dampers being disposed in the back wall of said oven, means cooperating with said plate to open said back wall damper by the act of positioning said plate in either of said positions, and means cooperating with said plate to open said other damper when said plate is in said lower position, by the act of closing said door, and means to prevent closing of said door when said plate is in said upper position.
4. In a stove, an oven having a back and side walls, a door for said oven, a plate having a gas burner mounted thereon and selectively movable into two positions in said oven, an exhaust damper in said back wall, means associated with said damper and actuated by the act of positioning said plate in either of said positions to open said damper, apertures in said oven door, closure means for said apertures normally held in closed position, and means associated with said closure means to cooperate with said plate when said plate is in said lower position to actuate said closure means in the act of closing said door, to ex