WO2008047397A2

WO2008047397A2 - Oven of the static type for baking food

Info

Publication number: WO2008047397A2
Application number: PCT/IT2007/000725
Authority: WO
Inventors: Gilberto Cattaneo; Vittorio Filippi
Original assignee: Serris Italia S.R.L.
Priority date: 2006-10-17
Filing date: 2007-10-17
Publication date: 2008-04-24
Also published as: ITMO20060333A1; SMAP200900037A; WO2008047397A3

Abstract

An oven of the static type for baking food comprises a baking chamber (3), heating means (6, 7), fan means (9) and a baffle element (30), removably fitted in the interior of the baking chamber (3) and shaped so as to direct a stream of air set in motion by the fan means (9) towards a supporting shelf (15) of the baking chamber (3) in which is positioned the food to be baked and to subdivide the interior of the baking chamber in such a manner as to contain the stream of air in an effective volume which is appreciably reduced relative to volume of the baking chamber. The oven can incorporate humidifying means. It can also incorporate a smaller door (50) inside the access door (4) and a removal carriage associated with one of the doors (4,50) on which the shelf (15) rests.

Description

Oven of the static type for baking food

Description Field of the invention

The present invention relates to an oven of the static type having the features set out in the precharacterising clause of the main claim. Background of the invention

In the relevant technical field of the present invention, ovens for baking food of the "static" type are known in which the food is introduced into and then removed from a baking chamber in batches. In these ovens, the food remains substantially stationary during the baking phase within a closed baking chamber and in this respect they differ from those ovens in which the food is continuously fed into a baking chamber (for example by means of a conveyor belt), and bakes while it is moving through the chamber between the inlet and the outlet. Ovens of the static type typically have a baking chamber of a generally parallelepipedal shape, access to which is provided by a fully opening door and in the interior of which are supported, in removable manner, grills, trays or other surfaces forming the supporting shelf for the food. The baking chamber is normally heated by one or more electrical heating elements, while a fan distributes the heat uniformly in the interior of the baking chamber.

These ovens are widely used in commercial catering or bar establishments and are intended to bake or heat food of various kinds ranging from pizzas to bakery products, from meat to vegetables, from pasta to fish. The high level of operating flexibility required is normally provided by the possibility of varying the baking temperature and/or time. However, varying these parameters is not sufficient to permit ideal baking of all kinds of food, and, in particular, it is found that pizza baking quality is not satisfactory in this type of oven. Description of the invention

The problem underlying the present invention is that of providing an oven of the static type which is structurally and functionally designed to overcome the limitations described above with reference to the cited prior art. In the context of this problem, a first object of the invention is to provide an oven which may generally be used to bake any kind of food, but which allows optimization of process conditions for baking pizza. A second object of the invention is to provide an oven which is straightforward to use and which is configured in such a manner as to restrict energy consumption.

Said problem has been solved and said objects have been achieved by the present invention by means of an oven produced according to the claims stated below. Brief description of the drawings The features and advantages of the present invention will become clear from the following detailed description of a preferred embodiment thereof, which is given purely by way of non-limiting example with reference to the appended drawings in which :

- Figure 1 is a perspective view from above of an oven of the static type produced according to the present invention, - Figure 2 is a longitudinal sectional view of the oven of Figure 1 in a first operational configuration thereof,

- Figure 3 is a partially cut-away front view of the oven of Figure 2,

- Figure 4 is a partially cut-away perspective view from above of the oven of Figure 1,

- Figure 5 is a rear cut-away view of the oven of Figure 1,

- Figure 6 is a longitudinal sectional view of the oven of Figure 1 in a second operational configuration thereof,

- Figure 7 is a partially cut-away front view of the oven of figure 6, - Figure 8 is a schematic sectional view of a variant embodiment of the oven of Figure 1,

- Figure 9 is a perspective view of another variant embodiment of the oven of Figure 1.

Preferred embodiment of the invention In the drawings, 1 denotes overall an oven of the static type, produced according to the present invention.

It should be noted that, in the present context, a static oven is taken to mean an oven in which the food, during baking, is substantially stationary within the oven, apart from optional rotation about a vertical axis. Furthermore, in the present context, the term "baking" will also be used to indicate any generic heat treatment to which the food is subjected, including processes such as heating, thawing etc.

The oven 1 comprises a housing body 2 which provides the frame structure of the oven 1 and in which there is defined a substantially parallelepipedal baking chamber 3 which is accessible through a fully opening door 4 hinged on the housing body 2.

Heating and fan means for the baking chamber 3 are provided in the oven 1, preferably on a back wall 5 thereof opposite the door 4. In particular, the heating means comprise a pair of electrical heating elements 6 and 7 of a generally semicircular shape, which are separately and independently controlled, while the fan means comprise a fan 9 on a horizontal axis X associated with an operating motor 10. The fan 9 preferably has horizontal blading and may be set in both clockwise and anticlockwise rotation. The heating elements 6, 7 and the fan 9 are positioned in the baking chamber 3 in such a manner as to be substantially coaxial, with the two heating elements surrounding the fan 9. A grid 11 attached to the wall 5 provides the necessary protection for these components. The oven 1 has control means, designated 12 overall in the drawings, which may be operated and set by the user by means of front-mounted controls beside the door 4. The control means 12 are programmed to oversee all the operating and safety functions of the oven 1, as described in greater detail below. For example, they may actuate the fan 9, on the basis of preset time cycles, and turn on the heating elements 6, 7, on the basis of the temperatures detected by a pair of temperature sensors 12a, respectively located in the upper half and the lower half of the baking chamber 3. Thanks to the provision of the heating elements 6, 7 and the two sensors 12a, temperature may advantageously be separately and independently controlled in the lower part and the upper part of the oven 1. On the sides 13 of the baking chamber 3, are mounted respective, per se conventional, shelf supports 14, on which may be fitted a supporting shelf 15 for the food to be baked in the oven 1.

The supporting shelf 15 may be of the grill type or of the tray type, depending on the food which is to be baked. The supporting shelf 15, when used to bake pizza, is preferably of the tray type, i.e. a solid sheet of metal which substantially separates the upper part from the lower part of the baking chamber 3. The supporting shelf 15 is furthermore conveniently equipped with a pair of raised portions 16, standing upright therefrom with a generally semicircular profile, to surround the lateral edges of the pizza. In this manner, the pizza being baked is physically contained and the lateral edges are advantageously protected from heat. Beside the baking chamber 3, there is located a separate compartment 17 accommodating means for cooling the housing body 2. Such per se conventional means comprise an electric fan 18 which draws in external air through openings 17a located on the bottom of the compartment 17 and blow it into a gap 19 located in the housing body 2 and the door 4 surrounding the baking chamber 3, so avoiding hazardous overheating of the external surface of the oven 1 during operation. The compartment 17 also accommodates means for humidifying the baking chamber 3, connected to the interior thereof, in order to introduce water in quantities and at times which are predetermined.

To this end, the humidifying means comprise a tank 20, located in the upper part of the compartment 17 and accessible from the outside of the housing body 2 via an inlet 21. A duct 22 runs from the bottom of the tank 20 and opens into the bottom of the baking chamber 3. A metering valve 23, actuated by the control means 12, is fitted in the duct 22 to control the flow rate and time for which water is introduced into the baking chamber 3. The parameters associated with the humidification phase are programmable and typically provide for introduction of water into the interior of the baking chamber in staged opening cycles, in an overall quantity of approx. 0.3-0.7 litres over a period of 20 minutes. In the upper part of baking chamber 3 there is an exhaust 25 open to the outside, through which any fumes produced by the baking process are emitted.

The oven 1 may be used for baking brioches, pasta-based or bakery products, meat, fish and vegetables, and in particular pizza. For the purpose of optimising the baking process depending on the food to be baked, the oven 1 may be provided in two different configurations, the first, in particular shown in Figures 2 and 3, being specifically suitable for baking pizzas, while the second, in particular shown in Figures 6 and 7, is suitable for baking other foods.

In its first configuration, the oven 1 comprises at least one baffle element 30, fitted removably in the interior of the baking chamber 3, and shaped in such a manner as to direct the stream of air set in motion by the fan 9 towards the supporting shelf 15. The oven 1 preferably comprises two baffle elements 30, arranged symmetrically one on each side of the supporting shelf 15 which, when baking pizza, will be placed substantially in the middle of the baking chamber 3. In greater detail, each baffle element 30 is formed from a solid (imperforated) metal sheet of a generally trapezoidal profile, with a first portion 31 inclined against the back wall 5, a second flat portion 32 parallel to the bottom and the top of the baking chamber 3, and an end portion 33 which extends towards the door 4 and is inclined towards the supporting shelf 15. The three portions 31, 32 and 33 are furthermore closed laterally by opposing sides 34.

The final portion 33 preferably comprises deflectors 35, directed towards the supporting shelf 15 and substantially perpendicular relative to the plane of the end portion 33. Each baffle element 30 is furthermore provided with flanges 36 which extend from the sides 34 and are capable of engaging slidingly into shelf supports 14, in a similar manner to the supporting shelf 15, so permitting particularly straightforward insertion and removal of the baffle elements 30 from the baking chamber 3. This first configuration of the oven 1 is particularly suitable for baking pizzas because the air heated by the heating elements 6 and 7 and set in motion by the fan 9 is directed, thanks to the specific shape of the baffle elements 30, substantially towards the centre of the supporting shelf 15 where the pizza is located. Furthermore, the baffle elements 30 actually subdivide the effective volume of the baking chamber 3, said volume being taken to mean the volume containing the stream of heated air. In this way, for an identical quantity of heat generated by the heating elements, higher temperatures can be achieved at the baking shelf. The reduction in effective volume obtained is of the order of 20%-40% relative to the overall volume of the baking chamber.

The presence of a tray type supporting shelf 15 and the ability to control the two heating elements 6 and 7 separately furthermore makes it possible to maintain different temperatures above and below the pizza. Another advantage of this configuration is a reduction in the quantity of heat which escapes when the door 4 is opened, resulting in a smaller drop in internal temperature and reduced energy waste.

In the second configuration of the oven 1, the baffle elements 30 are removed, while a plate 40 is inserted against the protective grid 11, parallel to the back wall 5.

The plate 40 may easily be fixed in place by being fastened onto suitable screws 43 projecting from the wall 5.

The plate 40 comprises a central opening 41, at the level of the fan 9, and a plurality of openings 42 arranged on the lower part of the plate 40, to direct and distribute the heated air in the interior of the baking chamber 3.

In particular, as shown in Figure 7, the plate 40 is slightly inclined relative to the vertical and the openings 42 are located in such a manner as to direct the outgoing stream of air towards the sides 13 of the baking chamber 3. The oven 1 is preferably provided in this second configuration when foods other than pizza are baked.

It will also be noted that changing between the two configurations is particularly simple.

The baking process involves inserting the supporting shelf 15, on which the food to be baked is positioned, into the baking chamber 3 and starting the appropriate baking program by means of the control means 12, which comprise one or more preset baking cycles associated with specific foods. The control means 12 turn on the fan 9 and the heating elements 6 and 7 depending on the preset nominal temperatures and the actual temperatures detected by the sensors 12a. The fan may be operated in one of the two directions of rotation or in alternating directions depending on the particular baking program.

The route taken by the air in the interior of the baking chamber preferably provides for the air to be drawn in axially by the fan 9, thrust radially along the wall 5, where it is heated by the heating elements 6, 7 and then to continue along the baffle element 30 (in the first configuration, otherwise along the walls of the baking chamber 3) towards the supporting shelf 15 from where it is drawn back in by the fan 9. The fan 9 is preferably deactivated for several tens of seconds before completion of the baking cycle, such that when the door 4 is subsequently opened, the fan is at a complete standstill and the hot air present in the interior of the baking chamber 3 is not blown out of the oven. The oven provided by the present invention lends itself to many modifications and variants, all of which fall within the scope of the patent as defined by the attached claims.

For example, two supporting shelves, each surrounded by respective pairs of baffle elements, may be provided in the interior of a baking chamber, as shown schematically in Figure 8, or each electrical heating element may be associated with a respective fan. According to another variant of the oven provided by invention, shown schematically in Figure 9, the door 4 comprises a supplementary small door 50 with a cross-sectional opening which is reduced relative to that of the door 4 and substantially corresponding to the passage cross-section defined by the ends of the baffle elements 30 facing towards the door 4. In this manner, the baking chamber 3 may be opened only by the amount necessary to insert or remove an appropriately sized supporting shelf 15, so avoiding the wastage of heat which occurs when the whole door 4 is opened. Enablement of opening of the door 4 or of the supplementary small door 50 may furthermore be associated with the presence of at least one of the baffle elements 30 in the baking chamber 3, for example by means of a microswitch which, when activated by the presence of the baffle element, locks the door 4 and enables opening of only the supplementary small door 50. Another variant embodiment of the invention, not shown in the attached drawings, provides for the supporting shelf 15 to be mounted on a removal carriage which is fastened in sliding manner in the interior of the baking chamber 3 to displace the supporting shelf 15 between the inside and outside of the chamber. In particular, the removal carriage may be automatically moved out of the baking chamber 3 by the control means 12 on completion of the baking cycle, once the door 4 or supplementary small door (if present) has been opened.

The removal carriage may also automatically be moved out of the baking chamber 3 when the door 4 or supplementary small door (if present) is opened. According to another variant embodiment of the invention, the supporting shelf 15 may be set in rotation about a vertical axis. In this case, the supporting shelf 15 will be of a suitable, preferably circular, shape, and drive means suitable for coupling with the supporting shelf and capable of setting it in rotation will be provided. The present invention thus solves the problem described above, at the same time providing numerous further advantages, including considerable optimization of energy consumption, greater operating flexibility and the possibility of influencing the level of humidity in the baking chamber.

Claims

1. An oven of the static type for baking food, comprising:

- a baking chamber (3) in which the food to be baked is positioned,

- heating means (6, 7) for heating the interior of the baking chamber,

- fan means (9) for setting the air in the interior of said baking chamber in motion, characterized in that it comprises a baffle element (30), removably fitted in the interior of said baking chamber and shaped so as to direct a stream of air set in motion by said fan means towards a supporting shelf (15) of the baking chamber on which is positioned said food to be baked and to subdivide the interior of said baking chamber in such a manner as to contain said stream of air in a volume which is appreciably reduced relative to the volume of said baking chamber.

2. An oven according to claim 1, in which said baffle element (30) has a generally trapezoidal profile and comprises an end portion (33) which extends towards a door (4) of said oven and is inclined towards said supporting shelf (15).

3. An oven according to claim 1 or claim 2, in which said baffle element is removably fitted in the interior of said baking chamber by sliding engagement of a pair of flanges (36) in respective shelf supports

(14) fixed to the sides (13) of said baking chamber.

4. An oven according to any one of the preceding claims, in which deflectors (35) facing towards said supporting shelf are provided on said baffle element.

5. An oven according to any one of the preceding claims, in which two baffle elements are arranged on opposite sides of and symmetrically relative to said supporting shelf.

6. An oven according to any one of the preceding claims, in which said fan means comprise at least one fan (9) on a horizontal axis (X) mounted on a vertical wall (5) of said baking chamber.

7. An oven according to claim 6, in which said vertical wall (5) is opposite a door of said oven, through which door food is introduced into and removed from said baking chamber.

8. An oven according to any one of the preceding claims, in which said heating means comprise a first (6) and a second heating element (7), which are separately and independently controlled and are positioned so as to obtain different temperatures above and below said supporting shelf.

9. An oven according to claim 8, in which said first and second heating elements are substantially semicircular in shape and are positioned coaxially around said fan means.

10. An oven according to any one of the preceding claims comprising humidifying means which comprise a water tank (20) connected with the interior of said baking chamber by means of a metering valve (23) for introducing a predetermined quantity of water into said baking chamber with the aim of humidifying the latter.

11. An oven according to claim 10, in which said humidifying means are controlled in such a manner as to introduce from 0.3 to 0.7 litres of water in a baking cycle of approx. 20 minutes.

12. An oven according to any one of the preceding claims comprising an access door (4) to said baking chamber, there being located on said door a supplementary small door (50) having a passage cross- section which is reduced relative to the door, for introducing and removing said food directly from said supporting shelf.

13. An oven according to claim 12, in which said passage cross-section of said small door (50) substantially corresponds to the opening defined by the ends (33) of said baffle elements close to said door.

14. An oven according to claim 12 or claim 13, in which control of the opening of said small door (50) is associated with said baffle element (30), in such a manner that when the baffle element is fitted in the interior of said baking chamber, opening of said door (4) is blocked and opening of said small door is permitted.

15. An oven according to any one of the preceding claims, in which said supporting shelf is mounted on a removal carriage fastened in sliding manner in said baking chamber between a position in which said supporting shelf is inside the baking chamber and a position in which said supporting shelf is outside said baking chamber.

16. An oven according to claim 15, in which control means (12) are provided such that, on completion of a baking cycle, said removal carriage is displaced to move said supporting shelf outside said baking chamber.

17. An oven according to claim 15 or claim 16, in which said removal carriage is associated with said door or said small door such that said supporting shelf is removed from said baking chamber when said door or said small door is opened.

18. An oven according to any one of the preceding claims, in which said supporting shelf is rotatable about a vertical axis.