Description:
CROSS REFERENCE TO RELATED APPLICATION
Barnett U.S. Pat. application Ser. No. 482,196 filed June 24, 1974 is a related application in the sense of commonality of some parts of the oven assembly.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention pertains to the art of ventilating systems for domestic self-cleaning wall ovens.
2. Description of the Prior Art
Various forced air ventilating systems for self-cleaning wall ovens are illustrated in U.S. Pat. Nos. 3,686,476; 3,587,557; 3,485,229; 3,384,067 and 3,310,046. Additionally, U.S. Pat. Nos. 3,659,578 and 3,633,561 disclose ventilating systems for self-cleaning ovens in which a forced air fan is not provided, the passages being arranged to obtain sufficient air movement by convection. With increasingly stringent surface temperature limits being imposed upon range manufacturers, in some installations it is questionable whether the convection ventilating systems will meet the requirements. As to those arrangements which include forced air fans, the airflow paths are not considered to be optimized to obtain the most advantageous results, and in some of the arrangements dampers are provided which are at the least expensive, and in some instances will block convection flow if a fan failure occurs.
The principal object of my invention is to provide a fan-forced ventilating system which channels the airflow in ways which obtain adequate surface temperature cooling and which has inlets and outlets in the most advantageous location.
SUMMARY OF THE INVENTION
In accordance with the invention, the self-cleaning wall oven construction includes side and rear airflow passages in communication with an intermediate airflow passage located above the oven and below an upper control chamber with a forced air fan being disposed to draw air from the intermediate passage into the control chamber space and exhaust it in an upward direction along the upper front edge of the control panel assembly at the front of the control chamber. Air is also introduced into the intermediate passage through an air inlet opening means in the lower portion of the control panel assembly. The fan aperture is in the horizontal plane of the wall between the intermediate passage and the control chamber so that if a fan failure occurs, and in bake and broil operations of the oven, there is convection airflow through the system.
Additional features of the invention will be described in the following description.
DRAWING DESCRIPTION
FIG. 1 is a generally schematic side view of a self-cleaning wall oven incorporating the invention, and illustrating the general flow paths of the air in the system; and
FIG. 2 is a partly broken isometric view of an oven according to the invention, also illustrating flow paths.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing, an oven cavity 10 is generally defined by box-shaped oven liner 12 provided with an open front 14 adapted to be closed by the thermally insulated front door 16, all five sides of the oven liner being surrounded by thermal insulation 18 (FIG. 2) as is conventional in this type of self cleaning oven. In the preferred construction, the outer faces of the thermal insulation surrounding the oven liner are covered by panels with only top panel 20 and side panel 22 being observable in FIG. 2.
An outer shell for the oven assembly as a whole is formed by a top wall 24, opposite side walls 26 (only the right-hand wall being shown in the drawing), a rear wall 28 and a bottom channel-shaped member 30 attached to the bottom of the assembly.
A chamber characterized as the control chamber is formed in the upper part of the outer shell and is bounded at the top by top wall 24, at the rear by rear wall 28, at the sides by the opposite side walls 26, at the front by the control panel assembly generally designated 32 and at the bottom by the control chamber bottom wall 34. The control panel assembly carries operating knobs 36 accessible from the front and connected to operating elements such as switches, timers and oven controls supported immediately behind the control panel assembly.
The control chamber contains partition means 38 extending between the opposite sides of the control chamber adjacent the front of the control chamber to separate the space immediately behind the control chamber front panel assembly from the remainder of the control chamber space. The shape in cross section of the partition means 38 is perhaps best seen in FIG. 1 and includes a vertical wall component having its lower edge connected to the control chamber bottom wall 34, then an upwardly and forwardly inclined part, then a horizontal part, and finally an upwardly and forwardly inclined lip 40 for the purpose of deflecting exhaust air from the control chamber upwardly through the grille-like openings 42 along the top edge of the control panel assembly 32.
The control chamber bottom wall 34 is provided with a circular opening 44, the boundaries thereof serving as a fan ring for fan 46 driven by motor 48 mounted on bottom wall 34.
An intermediate passage generally designated 50 is located above the oven liner top panel 20 and below the control chamber bottom wall 34. It may be observed in FIG. 2 that the side edges and rear edge of the top panel 20 are spaced inwardly from the inner faces of the side walls 26 and rear wall 28, respectively, so that this intermediate passage 50 is in communication with both the side airflow passages 52 (defined between side panel 22 and outer side wall 26), and rear airflow passage 54 (defined between the oven liner rear panel and outer rear wall 28). This intermediate passage 50 also has inlet opening means as at the grille 56 in the lower portion of the control panel assembly 32.
The gases produced within the oven cavity during a heat cleaning cycle are vented back into the room through a vertical conduit 58 (FIG. 1) which extends through the insulation above the oven liner and has its open upper end connected to a relatively shallow horizontal vent duct 60 (FIG. 2 in the lower portion of the intermediate passage 50 and extends forwardly to the outlet 62 at the right lower front of the control panel assembly 32. This arrangement is basically that as disclosed in U.S. Pat. No. 3,633,561.
A front frame assembly 64 serves as a basic structural part at the front of the oven assembly and has a number of side wall parts and the control panel assembly fastened thereto to provide overall structural integrity of the assembly. A series of vertically disposed slots 66 in this front frame assembly at the sides of the oven are aligned with the side air passages 52 to admit air from the room thereinto. It will be understood that there is a gap between the rear facing marginal side portions of the door and the facing front frame so that air can pass through the gap to get to the slots 66.
Referring to FIG. 1, in the installed relation of the oven assembly to the wall cabinet 68 a suitable gap 70 is provided at the bottom front of the oven assembly so that room air can be admitted into the bottom passage formed by the channel 30 to pass to the rear of the oven and thence up the open bottom end of the rear airflow passage 54. This airflow passage 54 contains a temperature responsive switch 72 (FIG. 1) for performing a safety function in the event the temperature in this space exceeds a specified limit due to a stalled or inoperative fan during a heat cleaning cycle. Under normal conditions during a heat cleaning cycle, the airflow through the passage 54 performs a cooling function offsetting radiated heat received from the oven by the switch. If the airflow is interrupted due to a malfunction of the fan the radiated heat and heat conducted from the oven operates the switch which in turn interrupts the self-cleaning cycle to eliminate any impossible hazardous condition. It is noted that other electrical components such as switches and solenoids relating to the locking of the oven door may also be located in the rear airflow passage 54 and receive cooling by the airflow passing thereby.
The door 16 includes vertically extending ventilation air passages 74 in its interior and inlet slots 76 along the bottom edge of the door and outlet slots 78 along the top edge of the door immediately below the lower edge of the control panel assembly. With this arrangement the convected airflow upwardly through the door interior is aided by the induced draft into the intermediate passage through inlet opening 56 in the control panel assembly. The overall airflow upwardly through the door and the airflow into the intermediate passage from the area of the room immediately forwardly of the control panel assembly tends to reduce the temperature of the various parts such as the knobs and vent trim past which the air flows.
Referring to FIG. 2, the part of the control chamber bottom wall 34 underlying the partition means 38 includes one or more apertures 80 which permits a limited draft of air which leaks into the space immediately behind the control panel assembly to be pulled into the intermediate passage 50 to prevent a build-up of heat in the space.
From the foregoing description it will be understood that the control chamber space overlying the fan constitutes the high pressure side of the system, into which all of the air warmed by passing along the sides, bottom, rear and top of the oven liner is admitted, and this warm air is then exhausted out into the room through the slots along the top edge of the top trim of the control panel assembly. The fan will ordinarily be operated only during a heat cleaning cycle, but in case of a fan failure or stall, and during both bake and broil operations, there is a convection airflow through the system with the warm air being exhausted through the slots 42 and the top trim as well as forwardly out of the intermediatie passage front opening 56. This gives a cooler product in all operational modes than those systems which use a damper type switching device for sensing fan failure. The convection airflow under these conditions is also enhanced by the horizontal disposition of the fan ring opening 44.