US20100101556A1

US20100101556A1 - Food baking oven, with airflow control devices of the heat dispersion from the baking chamber through the access span, and with integrated ventilation system for the thermal insulation with thermal barrier of the access span

Info

Publication number: US20100101556A1
Application number: US12/561,508
Authority: US
Inventors: Fabio DELL'OGLIO; Andrea Faedo; Giorgio Zanchetta; Gianluca Salamon
Original assignee: UNIELDOM GROUP s cons arl
Current assignee: UNIELDOM GROUP SCONSARL; UNIELDOM GROUP s cons arl
Priority date: 2008-10-27
Filing date: 2009-09-17
Publication date: 2010-04-29
Also published as: ITTV20080136A1; EP2180259A1

Abstract

Domestic use food baking oven to be embedded is provided with a ventilation system for the thermal insulation of the baking chamber, an airflow control device of the heat dispersion from the baking chamber, and integrated ventilation system for the thermal insulation of the baking chamber. At the baking chamber access span, and in an operative baking condition with the baking chamber access door in an open condition, the forced airflow is generated by the ventilation system for the thermal insulation of the baking chamber, which is in a diverted condition at the baking chamber access span. The airflow is diverted by a flow diverter, being of the type which can be shut down as soon as the access door of the oven, in a closed condition, is arranged in abutment with the flow diverter or with a part of it.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

Not applicable.

INCORPORATION-BY-REFERENCE OF MATERIALS SUBMITTED ON A COMPACT DISC

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention
This invention relates to a food baking oven with an airflow thermal barrier device and baking system, particularly for embedded ovens and ovens for domestic use.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
Freely installable domestic use kitchen ovens and embedded ovens for domestic use are known. Conventionally, they are devices which, in order to reduce the thermal flow exchanged between two different temperature environments, such as the baking chamber of the oven and the external environment, are insulated with a thermal insulation, mostly made of glass wool, applied on all the sides. In many other types of ovens and embedded kitchen ovens, an insulation air-casing is provided surrounding the baking chamber, which constitutes a cooling ventilation duct with an entry mouth obtained along the lower border of the access span of the baking chamber and a corresponding exit mouth obtained along the upper border of the same. Said air-casing is passed through by a one-way airflow also pushed by a fan, with the purpose to accelerate the cooling in such a way as to limit the heat dispersion and, improving at the same time the total performance of the baking chamber, for example as described in U.S. Pat. No. 3,659,578 (Davis et al.) and EP1028290 (Autin et al.) relative to ovens of the pyrolytic type.
Among the critical moments of any baking cycle, the opening phase of the door must be considered. It is an operation, which occurs each time one needs to stir the food, to relocate the food, to perform an inspection, or to sprinkle the food with liquids useful for baking. These sequences are particularly recurrent, repeated during even short intervals and which are necessary for the user in order to obtain good food baking quality. Therefore, the door opening operation itself is a circumstance, which is common to all the types of ovens, including the ones intended for domestic use. The constant opening is a necessary situation, yet causes various problems. More in detail, contextually with the door opening operation, at the baking chamber, an immediate and progressive heat exit occurs which is proportional to the time the door itself remains in the open condition and to the room temperature. This phenomenon, mainly due to the re-establishment of the equilibrium of the two pressures, the one inside the baking chamber and the external environment one, very often causes some known drawbacks, such as for example heat blasts, lengthening of the baking time, loss of the uniformity and of the coloring of the baking surface of the food and especially an increase in the power consumption due to the fact that once the door has been closed, the temperature set by the user should be re-established again by the control and heating devices of the oven.
At the same time, airflow thermal barriers are known to control the microclimate inside rooms. Conventionally, it is an airflow, confined as far as possible within certain spaces, which is generated by a convenient fan means, and conveyed near the access opening to the environment in such a way as to achieve a sort of vertically oriented air curtain, mainly with a continuous flow but also temperature controlled, which, being thermostated, is originated and interposed between two different areas, each with its own ambient temperature.
It is widely used in trade centers, at high latitudes as well, and it allows limiting of the bilateral migration, through an opening, of the natural convective air motion due to the different temperatures of the two relative air masses. From a practical point of view, a slit is obtained corresponding to the opening, along the lintel, developing for about the whole length, before or after a conventional door, through which an airflow exits oriented in such a way as to be substantially perpendicular to the floor, like a barrier. In this way, notwithstanding the frequent opening of the doors to allow the transit of people, e.g. in correspondence of the access to a department store, or means as at the entry of an industrial shed, the air, for example hot air, circulating inside the heated environment, does not exit through the opening, even if it is attracted by the external cold mass and vice-versa.
Solutions of this type are well known, in literature also in more than one configuration, and they find application in different sectors. For instance, in U.S. Pat. No. 6,234,892 (Geyer et al.), a device is described for producing hot air barriers for door openings in the local transit of vehicles. It is a device for producing airflows corresponding to door openings, to allow the passage of people where vehicles transit, having a unit for forming an airflow, which forms a barrier against the cold air penetration into a space, located adjacent to the door opening. The unit is structured in such a way as to be located at the lower end of the door, and it is limited in height between a minimum of a third to a maximum of the half of the total height of the door opening in such a way as to prevent the penetration of the hot air only in the lower zone of the door opening.
In the field of ovens in general, in particular to perform braising, U.S. Pat. No. 4,898,319 (Williams) is known. It is an oven comprising a device, which generates an airflow or barrier involving the area of the door of the oven opening when the door is in an open condition. The barrier or air curtain consists of a fluid localized portion directed through the opening. The air barrier prevents the gas exit from inside the oven when the door of the oven is in an open condition, and furthermore it is used to relocate or to fill with the conditioned air in the internal part of the oven when it exits from the oven itself. The barrier is generated through an opening and by means of load-bearing and generation means, located on the outside and adjacent to the opening or in the internal housing of the oven and adjacent to the opening.
The solutions relative to the prior art are surely significant, in substance, if on the one hand they suggest the use of an air barrier, which encumbers the migration of the airflow, which corresponds to an opening dividing two rooms, and which remains in a temporarily open condition. On the other hand, it is also true that they are not solutions, which are optimized for many other sectors. In this case, of particular relevance is the fact that so far said solutions have not been applied to food baking ovens, and consequently the problem relative to the heat exit, and therefore to the sudden lowering of the temperature in the baking chamber, due to the opening of the door/hatch in an operative condition of the oven, was noticeably an unsolved problem.
Moreover, it is interesting that the position of the channel or of the emission mouth of the air blast originated by corresponding generation means, is obtained, based on the prior art, on the outside or on the inside with respect to the wall defining the opening towards the heating chamber. The applications listed in the prior art refer to solutions, which noticeably can find application only in specific intended uses, which are not similar and appropriate for food baking ovens. In most of the cases, in fact, said applications could not find use in the latter equipments also because in any case they need the door occluding the access and in a condition which, when it is an operative condition, must remain as closed as possible and which does not need the use of the air barrier. The presence of the door or of the hatch, mainly in the cases in which it is hinged along the upper side of the access mouth to the baking chamber or along the lower side of the same, therefore constitutes an objective limit to the translation of said techniques in food ovens, substantially having a structural origin, the prior art being de facto inapplicable.
Prior Art Closest to the Invention

- D1: JP9119643 (Kurokawa)
- D2: ITTV2005U000029 (Ferretti)
- D3: U.S. Pat. No. 3,659,578 (Davis et al.)

In D1, a baking apparatus is described, intended to reduce the hot air consumption and the steam discharged out of the heating chamber, when the door is opened during the baking, by providing an air barrier which is formed at the opening surface of the door of the heating chamber for baking food. A door is provided at the front surface of a baking chamber in an oven. An air outlet port is provided at the upper border of the opening surface of the door so as to be extended horizontally along the whole border. The air is supplied to the air outlet port by a fan through a ventilation passage and a header so as to blow the air flow through the air outlet port. An air suction port is provided at the lower border of the door opening surface so as to be extended along the whole length of said lower border. In this way, the air located at the door opening surface is sucked into the air suction port by means of a suction device, which disposes the discharged air into a collecting hood through a ventilation passage and a duct at the door opening surface where the air barrier is formed.
D2 discloses an improved pizza baking electrical oven, comprising an airflow thermal barrier for controlling the environment temperature in the baking chamber with, in correspondence with the front of the oven, a control board, which provides means for maintaining the preset temperature controlling the heat supply, the automatic and/or a traditional type programming of the oven ignition. The oven consists of a parallelepiped metal covering structure, which integrates the plant design, and a baking chamber with relative heating means, said baking chamber having at least one surface coated with a refractory material, located in correspondence of the bedplate. The baking chamber is enlightened, and it is provided with an access opening closed by a respective tiltable door hinged along the lower or along the upper side. The access opening has means to generate a thermal barrier consisting of an airflow which is channeled in correspondence of the access opening of the oven in such a way that the airflow is perpendicular to the profile defining the opening itself. The airflow is generated only contextually to the opening of the door of the oven and in a substantially operative condition of the oven which requires the presence of a certain baking temperature inside the baking chamber.
D3 discloses a vent structure for venting an air space around the cavity of a self-cleaning food oven with the vent structure including a damper located at the airflow exit mouth along the upper border of the access span of the baking chamber of said oven.
It is therefore reasonable to consider as known:

- a baking oven for domestic use or to be embedded;
- a baking oven for domestic use or to be embedded provided with a cooling system of the baking chamber by means of ventilation through a duct surrounding the baking chamber;
- a thermal barrier consisting of a forced airflow which is generated by fan means and induced through a duct with at least one exit mouth, which thermal barrier precludes the heat exit from a heating chamber;
- a food baking oven provided with means intended to generate a thermal barrier consisting of an airflow, wherein airflow exits through some openings located in correspondence with the upper border of a baking chamber access span, which is closed by a door through which one can access the baking chamber, and wherein said thermal barrier is active with the door in an open position and in a baking operative condition of the food oven.

BRIEF SUMMARY OF THE INVENTION

The invention is a domestic use food baking oven to be embedded, of the type provided with a ventilation system for the thermal insulation of the baking chamber, with an airflow control device of the heat dispersion from the baking chamber, and with an integrated ventilation system for the thermal insulation of the baking chamber. The oven, at the baking chamber access span, in an operative baking condition of said oven and with the baking chamber access door in an open condition, has a forced airflow generated by the ventilation system for the thermal insulation of the baking chamber, which is in a diverted condition at the baking chamber access span. The airflow is diverted by means of a flow diverter, said flow diverter being of the type which can be shut down as soon as the access door of the oven, in a closed condition, and is arranged in abutment with said flow diverter or with a part of it.
Aims
In this way, by the considerable creative contribution the effect of which constitutes an immediate and non-negligible technical progress, different and important aims are achieved.
A first aim is to retain inside the oven the heat produced during the baking of the food, whenever the condition in which the user opens the oven door occurs, to stir, to inspect or to sprinkle cooking liquids, by means of the airflow barrier generated by the hot airflow produced by the insulation ventilation of the baking chamber.
A second aim is to eliminate, by means of the airflow barrier, the blasts, making the intervention of the user more comfortable, easier and safer.
A third aim is to reduce by means of the airflow barrier, the baking time in the usual baking cycle, which considers the conventional periods with the door in an open/closed condition, due to the fact that the temperature detectable inside the baking chamber of the oven is not subject to relevant variations. In this way, a greater rapidity is also allowed in restoring the steady state temperature originally set in the baking chamber, because the fluctuations of temperature in the baking chamber are minimum. Finally, also due to the fact that the changes of temperature in the baking chamber are minimum, an improvement of the food baking cycle is achieved, with an optimal coloring and uniformity of the food.
A fourth aim is to reduce, by means of the airflow barrier, power consumption because the temperature inside the oven baking chamber is less subject to significant changes and, as a result, less power is required to restore the original condition.
In conclusion, these aims and advantages have the value to obtain a food baking oven for domestic use or to be embedded with a good technological content.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

These and other advantages will appear from the following detailed description of a preferred solution with the aid of the enclosed schematic drawings whose execution details are not to be considered limitative but only and exclusively illustrative.

FIG. 1 is a schematic view of the original path of the airflow of the cooling ventilation system for the thermal insulation of the baking chamber.

FIG. 2 is a schematic view of the path of the airflow of the cooling ventilation system for the thermal insulation of the baking chamber in a deviated condition of the flow to obtain the thermal barrier function.

FIG. 3 is a schematic view of the position of the flow diverter with the baking chamber access door in an open condition.

FIG. 4 is a detailed sectional view of the position of the flow diverter with the baking chamber access door in a condition close to the closed condition.

FIG. 5 is a schematic view of the position of the flow diverter with the baking chamber access door in a closed condition.

FIG. 6 is a perspective view of the position of the flow diverter only in a closed condition.

FIG. 7 is a perspective view of the position of the flow diverter only in an open condition.

FIG. 8 is an exploded perspective view of the flow diverter only.

DETAILED DESCRIPTION OF THE INVENTION

The present innovation refers to a food baking oven (10) of the type to be embedded or for domestic use, with an airflow control device (100) of the heat dispersion from the baking chamber (20) through the access span (200) and with integrated ventilation system for the thermal insulation by means of a thermal barrier of the access span (FIGS. 1 and 2). In particular, the oven (10) includes a baking chamber (20) surrounded by a frame (11) to which one can frontally access through the access span (200), which is closable by means of a door (300) of the type which is hinged to the frame (11) of the oven (10). The door (300) closing the access span (200) of the baking chamber (20) can be of the type hinged along the lower border (12) of the frame (11) of the oven (10), as represented in FIG. 3, or as in other solutions not shown, along the upper border (13) of the frame (11) of the oven (10), or moreover with an arrangement of the hinges allowing a folding opening of the door (30), such as for example along the vertical border of the frame (11) of the oven (10), or sideways with respect to the access span (200).
The oven (10) is of the type provided with a cooling ventilation system for the thermal insulation of the baking chamber (20) by generating an airflow (f1) licking the external surface of the baking chamber (20) along a path which is defined inside the frame (11) of the oven. Therefore, said cooling ventilation system consists of at least one environment air input vent (30) obtained in correspondence with the lower border (12) of the frame (11) of the oven (10) on the front side, followed by a duct (40) externally surrounding the baking chamber (20). Along the duct (40), a tangential fan (50) is present which pushes the cold air sucked through the environment air input vent (30) towards a hot air exit vent (60), which is located near the access span (200), along the upper border of the frame (11) of the oven (10) at the side of the access span (200) and which in this case is located on the front.
At the air exit vent (60) through which the cooling ventilation airflow (f1) flows outside the oven (10) for the thermal insulation of the baking chamber (20), the airflow (f2) control device (100) is present which controls the heat dispersion from the baking chamber (20) (FIGS. 2, 3, 4 and 5). More in detail, along the upper and horizontal profile (61) of the air exit vent (60) the control device (100) is joined, which essentially consists of an anchor plate (101) fixed by means of screws to said upper and horizontal profile (61) of the exit vent (60). The anchor plate (101) at the upper face (101 a) is provided with supports (102, 103, 104), each of which consists of two spaced symmetrical and parallel walls (110, 111) and which face one another. Each support has a central hole (112), in such a way as to interpose a rotational shaft (113) engaged inside said holes (112). The purpose of each rotational shaft (113) is to support in a hinged way the flow diverter (120). Even in more detail, said flow diverter (120), consists of a rectilinear wing-shaped deflector, obtained from a plastic material, which in correspondence with the greater side (121) is provided with three overhanging hooks (122, 123, 124) with a semicircular section, each of which is engaged to the corresponding rotational shaft (113) of each support (102, 103, 104). In this way, the flow diverter (120) is dynamic, being able to rotate with respect to the anchor plate (101), which is static, because it is fixed at the air exit vent (60) through which the cooling ventilation airflow (f1) for the thermal insulation of the baking chamber (20) flows outside the oven (10). The flow diverter (120) is elastically hinged with respect to the anchor plate (101) due to the fact that spiral springs (130) are provided, at least one for each support (102, 103, 104). Each spiral spring (130) is joined to the relative rotational shaft (113) and with a first end (131) presses the flow diverter (120) while the second end (132) is located at the anchor plate (101) between the latter and the upper and horizontal profile (61) of the exit vent (60).
Operatively, (FIGS. 2, 4 and 5), the oven (10) in a conventional condition corresponding to the baking of the food contained in the baking chamber (20), has a ventilation airflow (f1) for the thermal insulation, which is sucked through the environment air input vent (30) and runs along the peripheral duct (40) with respect to said baking chamber (20), to be sent towards the air exit vent (60) by means of the tangential fan (50). With the door (300) in an open condition (FIGS. 2 and 3), the flow diverter (120) is directed towards the bottom in such a way as to intercept the flow (f1) and deviate the airflow (f1) generating an airflow (f2) acting as an air blade barrier parallel to the access span (200) in such a way as to involve at least all the width of said access span (200). In this condition, the flow diverter (120) is maintained in an open position due to the tension applied by the springs (130) pushing downwards and in a predetermined position said flow diverter (120). Vice-versa, by closing the door (300) occluding the access span (200) of the baking chamber (20) of the oven (10), the tooth (301) along the upper border of the door (300) goes in abutment with the outwardly directed surface of the flow diverter (120), in such a way as to counteract the elastic effect of the springs (130) (v. FIG. 4). By further pushing the door (300) until reaching its closed condition (FIG. 5), the flow diverter (120) is caused to rotate towards the baking chamber (20) and therefore to remain in an upwardly rotated position until the door (300) is opened again. In this case, when one opens the door (300) again, the progressive contextual elastic release of the flow diverter (120) occurs in the condition shown in FIGS. 2 and 3.

REFERENCE

(10) oven
(100) airflow control device
(20) baking chamber
(200) access span
(11) frame
(300) door
(12) lower border of the frame (11)
(13) upper border of the frame (11)
(f1) ventilation airflow
(30) environment air input vent
(40) duct
(50) tangential fan
(60) hot air exit vent
(f2) airflow thermal barrier
(101) anchor plate
(61) horizontal and upper profile of the air exit vent (60)
(101 a) upper face
(102, 103, 104) supports
(110, 111) symmetrical and parallel walls
(112) central hole
(113) rotational shaft
(120) flow diverter
(121) greater side
(122, 123, 124) overhanging hooks
(130) spiral springs
(131) first end
(132) second end
(301) tooth of the door (300)

Claims

1. Food baking oven, with airflow control for heat dispersion and integrated ventilation, the oven comprising:

a baking chamber being comprised of a frame with an access span, said chamber being frontally accessible through the access span, and a door for closing said baking chamber;

a cooling ventilation system for thermal insulation of the baking chamber, having an airflow licking an external surface of the baking chamber, the ventilation system being comprised of at least one environment air input vent corresponding to a lower border of the frame and a duct with a tangential fan, pushing sucked cold air towards at least one hot air exit vent located near the access span;

an airflow control device, corresponding to the hot air exit vent and controlling the heat dispersion from the baking chamber through the access span, wherein the control device comprises a flow diverter.

2. Food baking oven, with airflow control, according to claim 1, wherein said flow diverter is elastically yielding.

3. Food baking oven, with airflow control, according to claim 1, wherein the control device comprises an anchor plate joined in correspondence with the exit vent, said anchor plate being provided along a face with supports, each support being comprised of symmetrical and parallel walls spaced from and facing each other, in such a way as to interpose a rotational shaft, said flow diverter being hinged to each support.

4. Food baking oven, with airflow control, according to claim 1, wherein said flow diverter is comprised of a rectilinear wing shaped deflector, having overhanging hooks corresponding to a side, each hook being engaged to the corresponding rotational shaft of each support, said flow diverter being of the dynamic type with respect to the static anchor plate.

5. Food baking oven, with airflow control, according to claim 1, wherein said flow diverter is elastically hinged with respect to the anchor plate, due to the provision of springs, at least one spring being provided for each support.

6. Food baking oven, with airflow control, according to claim 5, wherein each spiral spring is joined to the respective rotational shaft and with a first end acts on the flow diverter while a second end is located corresponding to the anchor plate.

7. Integrated ventilation system for thermal insulation as a thermal barrier of an access span for food baking ovens, each oven having a baking chamber and an airflow control device controlling the heat dispersion from the baking chamber, according to claim 1, wherein the oven in a conventional condition of the food contained in the baking chamber is comprised of a ventilation airflow for the thermal insulation, being sucked through the environment air input vent, the airflow flowing along the duct peripheral with respect to said baking chamber, the airflow being sent by a tangential fan towards the air exit vent, when the door is in an open condition, the flow diverter being directed towards the bottom in such a way as to intercept the flow and deviate the airflow generating an airflow acting as an air blade barrier parallel to the access span in such a way as to involve at least all the wideness of said access span.

8. Integrated ventilation system, according to claim 7, further comprising a door being closed and occluding the access span of the baking chamber of the oven, a tooth along a top edge of the door being in abutment with the outwardly directed surface of the flow diverter, in such a way as to counteract the elastic effect of the springs, wherein further pushing the door until reaching a closed condition, the flow diverter rotating towards the baking chamber and therefore to remain in an upwardly rotated position until the door is opened again, when the door opens, the progressive contextual elastic release of the flow diverter occurs.

9. Integrated ventilation system according to claim 7, wherein said flow diverter, in an open door condition, is maintained in an open position due to the tension applied by the springs pushing downwards and in a predetermined position.