Description

AN OVEN

[0001] The present invention relates to an oven that has a self cleaning feature.

[0002] The self cleaning feature in ovens is a user demanded feature since cleaning the interior of an oven is difficult. The particles like oil that are ejected from food during cooking adhere to the inner walls of the oven and cleaning the dirt becomes hard when the oven is used a couple of times without cleaning. The most widely used self cleaning function in ovens is the pyrolytic cleaning method; however, alternative cleaning methods are developed since there are some safety issues. One of these methods is the ultrasonic cleaning. In the ultrasonic cleaning method, the dirt adhering to the oven surfaces are detached by the sound waves generated from an ultrasonic source; however, water is required for cleaning the surfaces entirely and to discharge the dirt. In the method wherein an ultrasonic device is used together with water, the water in contact with the oven surfaces is vibrated by the ultrasonic source and the liquid is made to move. The main mechanism of the cleaning is the energy generated with the microscopic cavitation bubbles formed in the vibrating liquid. These bubbles maintain the dirt on the surface to be separated from the surface by detaching or by breaking down. During the implementation of cleaning by the ultrasonic device and water method, the necessity for the surfaces to be cleaned contact with water continually makes the application of this method and designing the cleaning system difficult.

[0003] In the state of the art German Patent Application No DE19805276, an oscillating source such as an ultrasonic head is used together with water for cleaning any glass, enamel or steel surface of an oven. In the oven, for cleaning the horizontal surfaces (like the oven bottom surface, tray) water is poured on these surfaces and cleaning process is performed by generating ultrasonic waves by the ultrasonic head. A piezoelectric transducer is used as the ultrasonic head. Water is activated with high frequency oscillations by operating the vibration source. The water poured again on the lower surface is vaporized by means of a heater included in the system for cleaning the non-horizontal surfaces of the oven, and the

vaporized water is made to condense on the oven surfaces.

[0004] In the state of the art German Patent Application No DE10127872, in an oven, the tightly closed work chamber is filled with water and the oven interior is cleaned by ultrasonic waves. After deactivating the ultrasound vibration source, the water is removed and the oven interior is flushed preferably by water with added cleaning chemical agent. The oven door is provided with additional fluid-tight sealing elements to prevent the water in the oven from leaking out. Water used in cleaning is circulated by a circulating device for increasing effectiveness of the cleaning process.

[0005] The aim of the present invention is the realization of an oven that self cleans with the assistance of an ultrasonic device and water.

[0006] The oven realized in order to attain the aim of the present invention is explicated in the claims.

[0007] In the oven of the present invention, an ultrasonic device is used for detaching by vibration the dirt adhering to the walls surrounding the cooking chamber forming the interior volume, for example the vertical surfaces on the side walls, rear wall and the front door, during the cooking process. Besides the ultrasonic device water is used to completely clean the dirt particles detached or the bonds weakened from the surfaces.

[0008] In the oven, a reservoir for storing the water used in the cleaning process by the ultrasonic device is provided that is preferably arranged on the upper side of the body and by means of openings on a water conduit, configured as a pipe or channel connected to the reservoir, water is delivered on the surfaces surrounding the cooking chamber, forming a water film on the surfaces.

[0009] When water is delivered by the water conduit on the surfaces, the ultrasonic device is operated, water on the surfaces is vibrated and cleaning effectiveness is increased. Moreover, elements like the ultrasonic device, reservoir and water conduit used for cleaning do not occupy space in the cooking chamber.

[0010] In the preferred embodiment of the present invention, in order to clean the hard-to-clean vertical surfaces of the side walls and the rear wall in the oven, the water reservoir is emplaced to the back side of the body and the

water conduit extends from the back to the front along the upper sides of the side walls and the rear wall, forming at least a partial frame on the upper portion of the body. The water conduit transmits the water received from the reservoir along the upper sides of the side walls and the rear wall. The water leaking out from the openings arranged along the water conduit, slides downwards from the upper sides of the inner surfaces and wets these surfaces.

[0011] In an embodiment of the present invention, the surfaces surrounding the cooking chamber are covered by hydrophilic material that can transiently bond with water. Thus, the wetting capability of water poured on the surfaces and hence the cleaning effectiveness by the ultrasonic device are increased.

[0012] In an embodiment of the present invention, the water conduit is emplaced on the body sloping from the back to the front so that water can reach easily to the front from the water reservoir at the rear.

[0013] In another embodiment of the present invention, water is controllably delivered from the reservoir to the water conduit by flow control elements such as pump, shutter or valve activated during the cleaning process.

[0014] In another embodiment of the present invention, the user can easily add water into a water drawer on the front side of the body, for example on the front panel, without reaching the reservoir at the rear and water added to the water drawer fills the reservoir by means of a pipe. Moreover, the dirty water flowing from the surfaces of the cooking chamber to the base during cleaning is collected in the dirt water drawer situated under the body and when the dirt water drawer is full, the user removes thereof from the body and discharges by means of a drain conduit.

[0015] In the oven of the present invention, particularly the surfaces of the side walls, rear wall and the interior of the front door can be cleaned easily, application difficulties such as filling the interior volume of the body with water are eliminated and energy savings is provided.

[0016] The oven realized in order to attain the aim of the present invention is illustrated in the attached figures, where:

[0017] Figure 1 - is the schematic view of an oven.

[0018] Figure 2 - is the schematic view of an oven, ultrasonic device, cleaning water reservoir, water drawer, dirty water drawer and water supply conduits.

[0019] The elements illustrated in the figures are numbered as follows:

1. Oven

2. Cooking chamber

3. Side wall

4. Rear wall

5. Ultrasonic device

6. Reservoir

7. Water conduit

8. Opening

9. Water drawer

10. Dirty water drawer

[0020] The oven (1) comprises a body, a cooking chamber (2) wherein the cooking process is performed, two side walls (3) a rear wall (4) and a front door (not shown in the figures) forming the surfaces (Y) enclosing the cooking chamber (2), and an ultrasonic device (5) emplaced on the side walls (3) or the rear wall (4), preferably between the body and the walls (3, 4), that provides cleaning the cooking chamber (2) by generating ultrasound vibrations.

[0021] In the oven (1), ejected oil particles adhere to the surfaces (Y) surrounding the cooking chamber (2), for example to the interior surfaces (Y) of the side walls (3), rear wall (4) and the front door. In the cleaning process performed by the ultrasonic device (5), water is used for entirely cleaning the dirt particles that are detached or the bonds weakened from the surfaces (Y).

[0022] The oven (1) of the present invention comprises a reservoir (6) for storing the water used in the cleaning process by the ultrasonic device (5), that is preferably arranged on the upper side of the body and one or more water conduits (7) that deliver the water received from the reservoir (6) to the surfaces (Y) surrounding the cooking chamber (2) and more than one opening (8) situated on the water conduit (7), arranged along the sides of

the surfaces (Y) for pouring the water from the water conduit (7) onto the surfaces (Y) to form a water film on the surfaces (Y).

[0023] The ultrasonic device (5) is operated when water is delivered onto the surfaces (Y) surrounding the cooking chamber (2), the water film on the surfaces (Y) is vibrated and cleaning effectiveness is increased. Moreover, the ultrasonic device (5), reservoir (6) and the water conduit (7) used for the cleaning do not occupy space in the cooking chamber (2).

[0024] In the preferred embodiment of the present invention, in the oven (1) the hard-to-clean inner surfaces (Y) of the side walls (3) and the rear wall (4) are intended to be cleaned. In this embodiment, the reservoir (6) is emplaced at the back side on the body and the water conduit (7), configured as a pipe or channel, extends from the back to the front along the upper sides of the side walls (3) and the rear wall (4) surrounding at least partially the upper portion of the body. The water conduit (7) passes the water received from the reservoir (6) along the upper sides of the inner surfaces (Y) of the side walls (3) and the rear wall (4) and the water leaking out from the openings (8) arranged along the water conduit (7) slides downwards from the upper sides of the surfaces (Y) and wets the surfaces (Y) surrounding the cooking chamber (2) (Figure 2).

[0025] In an embodiment of the present invention, the surfaces (Y) surrounding the cooking chamber (2) are covered by water bond (hydrophilic) material. Thus, the water poured on the surfaces (Y) from the water conduit (7) by means of the openings (8) cling to the surfaces (Y) for a long time and the increasing of the cleaning effectiveness by the ultrasonic device (5) are provided.

[0026] In an embodiment of the present invention, the water conduit (7) is emplaced on the body sloping from the back to the front so that water can reach easily to the front of the body along the upper sides of the side walls (3) from the water reservoir (6) situated at the rear.

[0027] In another embodiment of the present invention, flow control elements such as pump, shutter or valve between the reservoir (6) and the water conduit (7) are used, that are activated during the cleaning process for delivering water and water in the reservoir (6) is delivered controllably to

the water conduit (7) by means of these elements.

[0028] In another embodiment of the present invention, the oven (1) comprises a water drawer (9) situated on the front side of the body, for example on the front panel, enabling the user to easily add water from the front into the reservoir (6) at the rear and the water added flows to the reservoir (6) by means of a pipe (B) filling the reservoir (6) and a dirty water drawer (10) emplaced under the body wherein the dirty water flowing from the surfaces (Y) to the base of the cooking chamber (2) during cleaning is collected.

[0029] When the cleaning mode is selected by e.g. a button on the front panel for performing interior cleaning in the oven (1), the shutters or valves between the reservoir (6) and the water conduit (7) are opened, and the water in the reservoir (6) flows to the water conduit (7). Water proceeding from the water conduit (7) flows from the openings (8) and wets the surfaces (Y). As the water starts to flow from the reservoir (6) to the water conduit (7) and from the openings (8) onto the surfaces (Y), the ultrasonic device (5) emplaced on the rear wall (4) or the side walls (3) operates and vibrates the water flowing on the surfaces (Y). As the water on the surfaces (Y) vibrates, micro bubbles are formed in the water and by the cavitation effect of these bubbles, the dirt separates from the surfaces (Y) and flows together with water. During cleaning, the dirty water flowing from surfaces (Y) to the base of the cooking chamber (2) is collected in a dirty water drawer (10) emplaced under the body and when the dirty water drawer (10) is full, it is removed from the body by the user or discharged by means of a drain conduit.

[0030] In the oven (1) of the present invention, as long as the surfaces (Y) are wet with water, the ultrasonic device (5) is activated and water on the surfaces (Y) is vibrated, the dirt on the surfaces (Y) is removed by means of the formed micro bubbles. Accordingly, application difficulties, for example filling the interior volume of the body with water, are eliminated and energy savings is provided. By means of this embodiment, cleaning particularly the inner surfaces (Y) of the side walls (3) and the rear wall (4) is made easier and since the cleaning system does not occupy space inside the body, the usable space of the cooking chamber (2) does not get

smaller.