WO2010030759A1

WO2010030759A1 - Combined steam, conduction and microwave oven

Info

Publication number: WO2010030759A1
Application number: PCT/US2009/056482
Authority: WO
Inventors: Pierluigi Poggi; Gianluca Spaggiari
Original assignee: Premark Feg L.L.C.
Priority date: 2008-09-12
Filing date: 2009-09-10
Publication date: 2010-03-18
Also published as: ITBO20080559A1

Abstract

A combined steam, conduction/convection and microwave oven (10). The oven (10) comprises a casing (CT), in which a cooking cavity (11) is obtained which, in turn, is equipped with a structure (13) adapted to support a plurality of baking tins. The supporting structure (13) is detached from the walls of the cooking cavity (11). Furthermore, insulation devices (PD, ED) of the microwaves with respect to the walls of the cooking cavity (11) itself are included. The insulation devices (PD, ED) comprise feet (PD) and spacer elements (ED) preferably either made of or coated with Teflon®.

Description

COMBINED STEAM, CONDUCTION AND MICROWAVE OVEN

TECHNICAL FIELD

The present invention relates to a combined steam, conduction/convection and microwave oven.

BACKGROUND ART

It is known that in an embodiment of combined steam, conduction/convection and microwave ovens, a plurality of tin-holder guides arranged on two parallel side walls of the oven itself are provided.

In order to support the baking tins, a corresponding tin-holder guide on the left wall obviously corresponds to each tin-holder guide on the right wall.

Before use, the user opens the oven door gate and inserts the side edges of each baking tin (which carries the food to be cooked) into a parallel pair of tin-holder guides; the user thus pushes the tin towards the interior of the oven, making the side edges slide on the respective tin-holder guides.

The main disadvantage of this solution is that the side walls of the oven, subjected to frequent temperature differences, are sometimes considerably deformed; therefore, the side edges of the tins are no longer adequately supported.

The use of self-propelled trolleys provided with metal wheels has been suggested to increase the production in steam and conduction/convection ovens (which thus do not use microwaves).

Two pluralities of tin-holder guides are provided on the side walls of the self- propelled trolleys of this type. In use, each tin-holder guide arranged on a first side wall of the trolley, along with a corresponding tin-holder guide provided on a second side wall of the trolley, supports a baking tin on which the food to be cooked is placed.

Therefore, the baking tins being not supported by guides directly provided on the side walls of the oven but instead by a structure which is independent of the side walls themselves implies that the deformations of the oven walls have no effect on the tin-holder guides.

However, such a trolley, as designed for steam and conduction/convection ovens, may not be used in an oven in which microwaves are also used for cooking.

Indeed, since the metal wheels of the trolley rest on the bottom of the cooking chamber, also made of metal material, any use of microwaves in the oven would cause an annoying, dangerous generation of sparks. In greater detail, we can say that the electromagnetic wave (related to the cooking microwaves) passing at the contact point between the metal wheel and the metal bottom of the cooking cavity leads to the creation of a voltaic arc, which may even cause the wheel to be welded to the bottom itself.

DISCLOSURE OF INVENTION

Therefore, it is the main object of the present invention to provide a combined steam, conduction/convection and microwave oven, which comprises a novel tin- supporting structure in which the aforesaid drawbacks are not found.

According to the present invention, a combined steam, conduction/convection and microwave oven is thus provided as claimed in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to the accompanying drawings, which illustrate a non-limitative embodiment thereof, in which:

- figure 1 shows an assembly view of some coupled elements belonging to an oven of the type object of the present invention;

- figure 2 shows a cooking cavity which is a first element shown in figure 1; and

- figure 3 shows a tin-supporting structure which is a second element shown in figure 1.

BEST MODE FOR CARRYING OUT THE INVENTION

In figure 1, numeral 10 indicates almost as a whole a combined steam, conduction/convection and microwave oven object of the present invention.

Oven 10 comprises a casing CT which accommodates a cooking cavity 11 therein, which is provided in turn with a front frame 12 to which a closing door (not shown) of the cooking cavity 11 itself is attached (by known means).

For completeness of this description, it is worth noting that a rear service space SS is provided in the casing CT, in which the various devices (not shown) providing the cooking cavity 11 with the thermal energy used for cooking the food, are accommodated.

Such a thermal energy may be provided in the form of conductive/convective energy, steam and microwaves.

Furthermore, on its upper wall, the casing CT is provided with an opening EV for evacuating the fumes and vapors and, on the bottom wall, with a drainage sump DR of waste material (e.g. fats, etc.) from the food being cooked.

In use, a supporting structure 13 for baking tins (not shown), illustrated in greater detail in figure 3, is inserted into the cavity 11.

The substantially "cage"-shaped supporting structure 13 occupies the cooking cavity 11 only.

Moreover, the structure 13 is separated from the side walls of the cooking cavity 11 and comprises a pair of portals 14, 15 (shaped as an upside-down U) parallel to each other and mechanically connected by a plurality of tin-holder guides 16.

Each tin-holder guide 16 is C-shaped.

The front portal 14, in turn, comprises two vertical uprights 14a joined by an upper horizontal crossbar 14b, and by a lower horizontal crossbar 14c.

Furthermore, each vertical upright 14a includes a respective sleeve 17 to which a respective handle (not shown) to be used for extracting the structure 13 from the cooking cavity 11 may be secured.

Similarly, the rear portal 15 comprises two vertical uprights 15a joined by an upper horizontal crossbar 15b, and by a lower horizontal crossbar 15c.

As shown in greater detail in figure 3, each vertical upright 14a and 15a includes a respective foot PD made of a material adapted to insulate the structure 13. Thereby, annoying electric discharges due to the mentioned direct metal-to-metal contact are avoided, which would occur if a trolley or any standard tin-holder of the type normally used in conduction/convection and/or steam cooking was used.

The feet PD may be advantageously but not necessarily made of a TEFLON® type insulating material.

With this regard, it is worth noting that although the supporting structure 13 includes the use of TEFLON® feet instead of wheels, the structure 13 may be easily inserted into and extracted from the cavity 11 by virtue of the fact that TEFLON® allows good sliding on steel.

Moreover, feet PD may be replaced in a possible embodiment, not shown for sake of simplicity, with another type of insulating bearing means, e.g., also in order to further improve sliding, with TEFLON® made (or coated) slides connecting the bottom ends of uprights 14a to bottom ends of uprights 15a and obtained parallel to the guides 16, beneath the same.

As shown again in figure 3, each vertical upright 14a and 15a moreover includes at least a respective outward protruding spacer element ED. Each spacer element ED is in turn made of, or wholly coated with, an insulating material, such as TEFLON®. In particular, front uprights 14a include laterally outstanding spacers ED projecting towards the lateral side walls of cooking cavity 11, while rear uprights 15a include both laterally outstanding spacers ED projecting towards the lateral side walls of cooking cavity 11, and backwards projecting outstanding spacers ED directed towards the rear side wall of cooking cavity 11, such that the supporting structure 13 can contact the lateral walls of cooking cavity 11 through the spacers ED only, leaving the portals 14,15 completely insulated from the lateral walls of cooking cavity 11 via the spacers ED and from the bottom wall of cooking cavity 11 by feed PD.

Like these latter, the spacers ED may be replaced by another kind of outward protruding spacer means, like sliders provided laterally, e.g. placed parallel to guides 16 and laterally protruding outwards towards the lateral side walls of cooking cavity 11, and backwardly, connecting uprights 15a together, placed parallel to crossbar 15c and laterally protruding outwards towards the rear side walls of cooking cavity 11.

Therefore, from the point of view of microwaves, the structure 13 is completely insulated from the cooking cavity 11.

In order the described structure to work properly, however, the Applicant has experimentally found that the insulating thickness provided by feet PD and, above all, by spacers ED, is to be of at least 2 mm for each KW of radio (e.g. microwave) power implemented in the oven.

The main advantages of the combined steam, conduction/convention and microwave oven object of the present invention are the following:

- absolute suppression of electric discharges caused by using microwaves;

- minimization of thermal stresses in the cooking cavity;

- good cooking uniformity of the foods placed in the baking tins; and

- ease of cleaning the side walls of the cooking cavity because the tin-supporting structure may be extracted from the cooking cavity itself.

Claims

1. A combined steam, conduction/convection and microwave oven (10); the oven (10) including: a casing (CT) in which a cooking cavity is obtained (11), said casing (CT) being provided with means for generating cooking heat, and said cooking cavity (11) being equipped with means (13) adapted to support a plurality of baking tins; the oven (10) characterized in that said cooking cavity (11) includes a supporting structure (13) for the baking tins therein; said supporting structure (13) being inserted in the cooking cavity (11) separated from the walls thereof, being provided with outwardly protruding first and second electric insulation means (PD, ED) with respect to all the walls of the cooking cavity (11) itself.

2. An oven (10) as claimed in claim 1, characterized in that said first electric insulation means (PD, ED) include a plurality of feet (PD) integral with the supporting structure (13); said feet (PD) being made of an insulating material and being designed to slide in use on a bottom wall of the cooking cavity (11).

3. An oven (10) as claimed in anyone of the preceding claims, characterized in that said second insulation means (PD, ED) include spacer elements (ED) made of, or wholly coated by, an insulating material, designed to outwardly protruding from the supporting structure (13) towards both the lateral side walls and the rear wall of the cooking cavity (11).

4. An oven (10) as claimed in anyone of the preceding claims, characterized in that said insulation means (PD, ED) are either made of or wholly coated with an insulating material such as TEFLON®.

5. An oven (10) as claimed in anyone of the preceding claims, characterized in that said supporting structure (13) for the baking tins includes a pair of parallel portals (14, 15) which are mechanically connected to each other by a plurality of tin-holder guides (16).

6. An oven (10) as claimed in claim 5, characterized in that said front portal (14), in turn, includes two vertical uprights (14a) joined by at least one horizontal crossbar (14b, 14c); similarly, said rear portal (15) including two vertical uprights (15a) joined by at least one horizontal crossbar (15b, 15c).

7. An oven (10) as claimed in claim 6, characterized in that each vertical upright (14a) includes a respective sleeve (17) to which a corresponding handle is fastened in order to extract said structure (13) from said cooking cavity (11), if desired.

8. An oven (10) as claimed in anyone of the foregoing claims, wherein the insulating thickness provided by said first (PD) and second (ED) insulating means is to be of at least 2 mm for each KW of radio (e.g. microwave) power implemented in the oven.