Oven structure, mainly for cooking of natural and/or deep-frozen and/or pre-cooked food

The present invention is drawn to a combination microwave/infrared oven heating a box-like structure in which a plurality of chambers are defined. A microwave heating source is associated with at least one of the chambers for generating microwaves therein, an infrared short-wave radiation source is associated with at least another one of the chambers for generating short-wave infrared radiation therein, and a medium-wave infrared radiation source is associated with at least yet another one of the chambers for generating medium-wave infrared radiation therein. A rotary conveyor is rotatably supported in the oven within the box-like structure and conveys foodstuffs in the oven successively through the chambers. An electronic circuit including a central logic system controls the operation of the rotary conveyor to set the time periods during the foodstuffs conveyed in the oven remain in respective ones of the chambers. The central logic system may also control the operation of the microwave heating source, the short-wave infrared radiation source and the medium-wave infrared radiation source.

BACKGROUND OF THE INVENTION 
The invention relates to oven structure mainly useful for cooking natural, 
deep-frozen and/or pre-cooked food. 
Nowadays many types of ovens are known using gas combustion, resistance 
heating or microwaves to cook food. 
All of these types of ovens, whether they provide a natural internal 
ventilation or a forced one, present a problem of not allowing optimum 
cooking of the food in very short times as the cooking time required can 
be different. 
In fact, the microwave oven, although it can quickly defrost deep-frozen 
food, can only cook food uniformly without varying the degree of the 
cooking and humidity from the inside to the outside of the food, for 
example, to make the food surface baked and crusty. 
SUMMARY OF THE INVENTION 
Therefore, the main object of the invention is to eliminate the 
above-mentioned problem in known ovens by providing an oven in which food 
that is differentiated is cooked appropriately in very short times. 
Another important object is to provide a structurally simple oven having 
small dimensions that can cook a large number of single portions of food, 
even of different quality, in a short time. Another object is to provide a 
structurally simple oven that is compact and usable with vending machines 
for cooking deep-frozen and/or pre-cooked and/or natural-state food. 
The above-mentioned objects, as well as others that will appear more 
clearly hereinafter, are achieved by an oven of the invention, mainly for 
cooking natural and/or deep-frozen and/or pre-cooked food, characterized 
by a container defining a fixed box-like structure subdivided into radial 
sectors and inside of which is operatively disposed a rotary conveyor 
having radially extending elements, seats for a plate of natural and/or 
pre-cooked and/or deep-frozen food, at least one source for microwave 
heating, at least one source for infrared radiation microwave cooking and 
at least one medium-wave radiation source for baking and crusting the 
surface of food. The conveyor and sources are controlled by an electronic 
circuit including a centralized logic system. Further, the oven includes 
means for allowing the introduction and removal of said plates.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
With reference to the figures, the oven 1 includes a container 2 inside of 
which a box structure 3 is fixed, the box structure being mainly 
cylindrical with an upper closing wall 4 and open at the bottom. 
Extending axially to the structure 3 is a cylindrical shaft 5 from which 
some radial sectors 6 branch off. Four adjacent sectors are equally spaced 
by angular intervals of about sixty degrees and the remaining ones by an 
angular interval of about one hundred and twenty degrees. 
Each one of such radial sectors 6 is connected to the side 7 of the box 
structure 3 and extends, similarly to the shaft 5, a distance beyond the 
side 7. 
In fact, below the shaft 5 and coaxial to the longitudinal axis thereof is 
a rotary conveyor 8 rotatably connected with the structure 3 and driven by 
a suitable motor. 
The conveyor has a central body 9 that is circular and from which some 
radial elements 10 branch off, are equally spaced by an angular interval 
of about 60 degrees, and the free ends of which skim over the inside 
surface of the side 7 of the box structure 3. 
Connected to the wall 4 inside the box structure 3 are two first sources 11 
and 12 for microwave heating disposed over the space interposed between 
the two radial sectors 6 spaced by the angle of one hundred and twenty 
degrees. Anticlockwise in FIG. 5 and below the closing wall 4 are 
positioned, each in correspondence with the space interposed between two 
adjacent radial sectors spaced by sixty degrees, two second sources 13 and 
14 for infrared radiation shortwave cooking and two third sources 15 and 
16 capable of producing infrared medium-wave radiations for the surface 
baking and crusting of the food. The food is contained in plates 17 
positioned between adjacent ones of the radial elements 10. 
Such plates are moved inside the box structure 3 by means of the radial 
elements 10 of the rotary conveyor 8. All such sources 11, 12, 13, 14, 15 
and 16 and the rotary conveyor 8 are controlled by an electronic circuit 
20 including a centralized logic system 21 which sets, according to a 
predetermined and selected program, for example, the wavelengths of the 
sources and the operating times that shall be lower than the pace of the 
rotary conveyor 8. 
In this way, the times during which each plate 17 remains below one of the 
sources are set according to the type of food to be cooked. 
The containers 17 are put in the box structure 3 in the space associated 
with the source 11 and are carried outside the container 2 from the space 
associated with the source 16. 
Concerning such a last stage, a rotary part 18 is provided to support the 
plate 17 and which part 18, by rotating ninety degrees, carries plate 17 
through an opening 19 in the container 2. 
The operation of the oven is as follows: after putting in the box structure 
3 a plate 17, the centralized logic system sets, according to whether the 
oven contains natural-state, pre-cooked or deep-frozen food, the times 
during which the plate 17 will remain at the various stations by 
controlling the rotation of the rotary conveyor 8 and the operating times 
of the various sources. In this way, the oven can facilitate the optimum 
cooking of any kind of food, a considerable reduction in the cooking times 
and the possibility of cooking, for a longer or shorter time, the inside 
part of food compared with the outside part of the food. 
Furthermore, the invention allows, considering the cooking speed and the 
contemporaneous number of plates that can be positioned inside the box 
structure 3, a considerable increase in the production rate of cooked 
food. Furthermore, the oven structure is particularly advantageous in 
cooking plates of natural, pre-cooked and deep-frozen food in very short 
times. Also, the structure of the oven is compact. Of course the materials 
and dimensions of the component parts of the oven such as the radial 
sectors, the radial elements and the sources, can be of any kind, 
according to specific requirements.