An oven

Abstract

The present invention refers to an oven, in particular an oven where the flow of hot air and / or steam and / or gases from a cooking chamber of the oven is controlled by means of a fan. A heating means (10) covered with a lid (11) is provided in the interior of a cooking chamber (1) in the area of a back wall (5) and spaced therefrom, wherein the said heating means (10) is formed as a cylindrical coil and additional oven ventilating means (12) is provided at the centre thereof and inside the cooking chamber (1). An entry aperture (14) for a fluid connection of the cool environment with the hot interior of the cooking chamber (1) is provided in the back wall (5) behind the oven ventilating means (12), wherein the said entry aperture (14) is designed coaxially with the axis of the oven ventilating means (12) and whereby, spaced from the said back wall (5), an additional bearing wall (5') is provided.

Description

AN OVEN

[0001] The present invention refers to an oven, in particular an oven where the flow of hot air and / or steam and / or gases from a cooking chamber of the oven is controlled by means of a fan.

[0002] Whenever a user opens an oven door after or during the process of cooking, a large amount of hot air, steam or gases is uncontrollably released from the cooking chamber, causing a relatively unpleasant experience for the user or even causing skin burns. Hence, it is more suitable that before opening the said door, the temperature of the hot air and / or the amount of steam and hot gases in the cooking chamber is reduced in a controlled way. In continuation, in the entire description, the term “steam reduction" refers to the reduction of the amount of steam and hot gases in the cooking chamber. Moreover, throughout the entire description, the term "temperature reduction" refers to the reduction of temperature in the cooking chamber. Both terms define the controlled release of hot air with or without steam and hot gases admixture from the cooking chamber, through a fume duct and out of a cooling fan exit section. However, hot air, steam and hot gases can only exit the cooking chamber through the fume duct if the hot and / or possibly moist air is replaced with external air. To this end, an additional aperture in the cooking chamber should allow for an inflow of external air during the process of temperature reduction and / or steam reduction. Controlled steam reduction and / or temperature reduction should not be too slow to avoid unnecessary waiting on the part of the user. Hence, it is necessary to ensure a sufficient air flow through the fume duct and the said additional aperture.

[0003] In addition, to prevent the unpleasant user experience, steam reduction can also be used to reduce steam condensation on the oven door, to dry the air in the cooking chamber if necessary for the cooking process, and for food drying. Similarly, temperature reduction can be used as part of the cooking process, e.g., to relatively quickly reduce the temperature in the cooking chamber.

[0004] Document DE 29914472 111 discloses the air flow through the oven intended to reduce the leakage of steam and / or cooking gases before opening the oven door. ItSUBSTITUTE SHEET (RULE 26)is envisioned to feature a valve-controlled channel, which allows external air to enter the cooking chamber. Also revealed is the possibility of arranging a channel mouth in a sucking area of a circulation oven fan, whereby the circulation oven fan is actively involved in creating the air flow from the exterior of the oven into the cooking chamber. However, the said arrangement does not utilise the full suction capability of the circulation oven fan, constituting a significant shortcoming of the known solution.

[0005] The object of the present invention is to create an oven where the suction capability of the circulation oven fan is utilised to the greatest extent possible.

[0006] The object according to the present invention is achieved by the characteristics set forth in the characterising portion of claim 1. The details of the invention are disclosed in the corresponding sub-claims.

[0007] The invention is further described in detail by way of a non-limiting embodiment and with a reference to the accompanying drawings whereFig. 1 shows an oven according to the invention in a schematic three-dimensional view from the back and in a longitudinal section,Fig. 2 shows the oven according to the invention in a schematic three-dimensional view from the front and in the longitudinal sectionFig. 3 shows the oven of Fig. 1 in a schematic side view and in the longitudinal section, depicting mixing of air in a cooking chamber,Fig. 4 shows the oven of Fig. 3, depicting a supply of external air,Fig. 5 shows detail V of Fig. 4 in a three-dimensional view, andFig. 6 shows a ventilating means in a three-dimensional view.

[0008] An oven according to the invention comprises a cooking chamber 1 surrounded by walls comprising a bottom wall 2, top wall 3, side walls 4, and a back wall 5. The said walls are surrounded by heat insulation and an outer oven housing. Spaced from the said back wall, an additional bearing wall 5’ is provided, which preferably comprises smaller dimensions than the back wall 5, intended for the fixationof a driving motor of a ventilating means. The cooking chamber 1 can be closed by means of a door 6 intended to allow for the loading of foodstuffs for thermal processing into the cooking chamber 1. For optimal ventilation, the oven according to the invention comprises a first cooling ventilating means 7, which in the preferred embodiment is selected as a radial and tangential fan, whereby the said cooling ventilating means 7 is arranged in the oven outside the cooking chamber 1 in the area of the back wall 5 and above the top wall 3 of the oven. Furthermore, the oven according to the invention comprises a cooling channel 8, which is arranged outside the cooking chamber 1 in the area directly above the said top wall 3, and an air vent 9, which connects the said cooking chamber 1 to the said cooling channel 8. In the interior of the cooking chamber 1, in particular in the area of the bottom wall 2 and / or top wall 3, at least one heating means known perse can be arranged, not shown in the Fig.

[0009] In the interior of the cooking chamber 1, in the area of the back wall 5, in the specific embodiment in the central area of the back wall 5 and spaced therefrom, the heating means 10 is provided, which can optionally be covered with a lid 11 formed with a set of through holes for the passage of air. The said heating means 10 is formed as a cylindrical coil with at least one winding, whereby at the centre of the heating means 10 and inside the cooking chamber 1 additional oven ventilating means 12 is arranged. The said oven ventilating means 12 is formed, in the specific embodiment, as a radial fan, which is driven in a manner known per se by a driving means 13, such as an electric motor, arranged outside the cooking chamber 1. In the presented embodiment, the said driving means 13 is attached to the said bearing wall 5’. The said oven ventilating means 12 draws air from the cooking chamber 1 through the central area 11a of the said lid 11, which covers both the heating means 10 as well as the oven ventilating means 12 arranged around it and pushes the air in the radial direction towards the said heating means 10. The heated air returns to the cooking chamber through a peripheral area of the said lid lib (see the arrows in Fig. 3).

[0010] The electronic components of the oven and the oven door can be cooled by means of an air flow created by the said cooling ventilating means 7, which forces cool surrounding air through the said cooling channel 8. The latter can optionally be connected to the cooking chamber via an air vent 9, whereby in this case, the air is drawn through the said air vent 9 into the cooling channel 8 whenever the coolingventilating means 7 is active. The air, which consequently exits the cooling channel 8 above the oven door 6, is thus a mixture of cool surrounding air and hot air from the cooking chamber 1.

[0011] The air, which exits the cooking chamber 1, has to be substituted with external air to prevent a pressure drop in the cooking chamber 1 that would prevent further air flow through the said air vent 9. In order to enable air flow through the air vent 9, it is necessary to open at least one additional aperture in the oven walls to substitute the air in the cooking chamber with external air, which is particularly useful for temperature reduction and / or steam reduction. Most of the moist air exiting the air vent 9 is substituted in the cooking chamber 1 with dry surrounding air.

[0012] The time required for sufficient temperature reduction and / or steam reduction should not be too long for the user. The speed of temperature reduction and / or steam reduction is proportional to the flow through the air vent 9, which depends on the power of the Venturi effect. As a result, the said speed of reduction is increased, for example, by increasing the flow through the cooling channel 8 by means of increasing the rotational speed of the cooling ventilating means 7. Alternatively, it is possible to increase the cross-section of the air vent 9, which increases the level of noise, or the said additional aperture for air in the walls of the oven, which has a negative effect on the heat loss in the oven.

[0013] According to the present invention, in order to increase the flow of external air into the cooking chamber 1, the said oven ventilating means 12 is used, which is achieved by arrangement of the entry aperture 14 in the back wall 5 of the oven walls behind the oven ventilating means 12 near or in the vicinity of the latter’s rotational axis, preferably coaxially to the said rotational axis of the oven ventilating means 12. The said entry aperture 14 is provided for the fluidly connection of the cool surroundings to the hot interior of the cooking chamber 1 (see the arrow in Fig. 5). This way, it is achieved that the said oven ventilating means 12, which draws primary air from the cooking chamber 1 through the apertures in the central area 11a of the lid 11, draws secondary air from the surroundings through the said entry aperture 14. As a result, the said oven ventilating means 12 forces the mixture of the said primary air and the said secondary air into the cooking chamber 1 through the peripheral area of thesaid lid lib (see the arrows in Fig. 4).

[0014] Due to the increased flow of air into the cooking chamber 1, the air flow through the air vent 9 consequently increases, reducing the time of temperature reduction and / or steam reduction. Furthermore, the air flow through the said entry aperture 14 can further be increased with the design of the oven ventilating means 12 comprising either identical or different blades 12a, 12b on each side of a rotor plate 12c of the ventilating means 12.

[0015] The cooking chamber 1 is, via the said entry aperture 14 in the back wall 5 of the oven walls, fluidly connected to the surroundings of the oven according to the invention, for instance by means of a duct 15, which is arranged between the said back wall 5 and the said bearing wall 5’, and which entirely surrounds the said entry aperture 14 and extends from the latter along the back wall 5 in the direction facing away from the rotational axis of the oven ventilating means 12.

[0016] The first end of the said duct 15 thus fits tightly to the said entry aperture 14, while the other, free end of the duct 15 can be closed and opened by means of a locking means 16. The said locking means 16 is, for example, designed as a flap, which can be switched from a closed to an open position by means of an actuator not shown. Whenever the flap 16 is in the closed position (Fig. 3), the entry of cool surrounding air into the cooking chamber 1 is disabled, whereby the ventilating means 12 performs its primary function, i.e., forced convection in the cooking chamber 1. Whenever the flap 16 is in the open position (Fig. 4), the entry of cool surrounding air into the cooking chamber 1 is enabled, whereby the ventilating means 12 mixes the hot and moisture-saturated air in the interior of the cooking chamber 1 with fresh, cool surrounding air, entering via the said duct 15 and through the said entry aperture 14, and forcibly pushes the cooled mixture of air through the said air vent 9 and into the cooling channel 8.

[0017] Of course, it is understood that the said duct 15 is, at the connection point with the entry aperture 14, designed with a through hole suitable for receiving the axis of the ventilating means 12.

Claims

Claims1. An oven comprising a cooking chamber surrounded by walls, which comprise a bottom wall, top wall, side walls and a back wall, whereby the cooking chamber can be closed by means of a door; a first cooling ventilating means, which is arranged outside the cooking chamber in the area of the back wall and above the top wall; a cooling channel, which is arranged outside the cooking chamber in the area directly above the said top wall; an air vent, which connects the said cooking chamber with the said cooling channel; and a second ventilating means, which is arranged in the cooking chamber in the area of the back wall, whereby in the interior of the cooking chamber, at least one heating means can be arranged, characterised in that a heating means (10) covered with a lid (11) is provided in the interior of a cooking chamber (1) in the area of a back wall (5) and spaced therefrom, wherein the said heating means (10) is formed as a cylindrical coil and additional oven ventilating means (12) is provided at the centre thereof and inside the cooking chamber (1), wherein an entry aperture (14) for a fluid connection of the cool environment with the hot interior of the cooking chamber (1) is provided in the back wall (5) behind the oven ventilating means (12), wherein the said entry aperture (14) is designed coaxially with the axis of the oven ventilating means (12) and whereby, spaced from the said back wall (5), an additional bearing wall (5’) is provided.

2. The oven according to claim 1, characterised in that the said fluid connection of the interior of the cooking chamber (1) with the surroundings is formed by means of a duct (15), which fully surrounds the said entry aperture (14) and extends from the latter along the back wall (5) in the direction facing away from the rotational axis of the oven ventilating means (12), wherein the said duct (15) is arranged between the back wall (5) and the said bearing wall (5’).

3. The oven according to claim 2, characterised in that the first end of the said duct (15) fits tightly to the said entry aperture (14), while the second free end of the duct (15) can be closed and opened by a locking means (16).

4. The oven according to claim 3, characterised in that the said locking means (16)is formed as a flap, which can be moved from the closed to the open position by means of an actuator.

5. The oven according to any of the preceding claims, characterised in that the said lid (11) is formed with a set of through holes for the passage of air.

6. The oven according to any of the preceding claims, characterised in that the entry aperture (14) in the back wall (5) of the walls behind the oven ventilating means (12) is formed in the vicinity of the rotational axis of the latter.

7. The oven according to any of the preceding claims, characterised in that the air flow through the said entry aperture (14) can further be increased with the design of the oven ventilating means (12) comprising either identical or different blades (12a, 12b) on each side of a rotor plate (12c) of the ventilating means (12).

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