TECHNICAL FIELD

The present invention relates to an oven comprising a cooking cavity and a cooling-air fan, provided outside the cooking cavity, with an inlet opening and an exhaust duct reaching the outer environment.

STATE OF THE ART

A cooking appliance comprises a cooking cavity provided at a housing and a ventilation device located at the top of the cooking cavity closed by a hinged door pane. The ventilation device comprises an exhaust duct with an exhaust opening extending in the form of a strip at the top of the lid and a cooling fan is disposed above so as to provide air flow to an inlet opening. The exhaust duct comprises a plate-like cover disposed at a distance on the cavity upper wall.

EP0897087 discloses an oven with a cooking cavity. A cooling-air fan is provided outside the cooking cavity. An inlet opening leads to the cooling-air fan, and the exhaust duct directs the cooling air to the outside. To reduce installation costs, a holding element with a carrier plate for the motor of the cooling fan is associated with the exhaust duct.

BRIEF DESCRIPTION OF THE INVENTION

The object of the invention is to provide a simple and operationally safe mounting of the cooling-air fan in the exhaust duct of the oven.

In order to achieve the above objective, the invention relates to an oven comprising a cavity delimiting the cooking chamber; an exhaust duct located outside the cavity connecting an air intake opening and an exhaust opening accessing the outside so as to provide fluid transmission; a mounting rim having a support element extending transversely in the air intake opening so as to adapt an electric motor equipped with a cooling-air fan at one end to the exhaust duct in a suspending manner and disposed peripherally from an outer frame to a flat bearing portion surrounding the air intake opening. The oven further comprises a radial holding element provided in the outer frame of the mounting rim and engaging to the collar from the corresponding bearing portion in a manner to block the rotation, and a flexible holding element extending axially from the transverse support element is coupled to the electric motor. The electric motor is fixed to the mounting rim with the help of flexible holding elements. The mounting rim, on the other hand, is disposed from its outer frame, engaging the radial holding element to the bearing portion. In this way, the electric motor rotates the cooling-air fan, and the radial holding element clings to the bearing it passes through and prevents the mounting rim from turning. The flexible holding element and the radial holding element allow the cooling-air fan to be simply mounted to the exhaust duct of the electric motor with the mounting rim.

In a preferred embodiment of the invention, the radial holding element is having a flexible locking tab snap-fits to the corresponding collar in the bearing portion. The flexible tab allows the radial holding element to be mounted to the collar simply by rotating it over the bearing, limiting the air intake opening thereof.

A preferred embodiment of the invention comprises a support wall where the flexible locking tab rests on the collar is set in the opposite direction of a predetermined rotation direction of the electric motor. The support wall can be formed, for example, by cutting or bending the collar. When the cooling-air fan is turned on, the flexible locking tab resists rotation by leaning directly against the support wall, while the electric motor forces the mounting rim to rotate in the opposite direction to the predetermined direction of rotation. In this way, it is ensured that the torque that will occur especially when the electric motor is started is compensated by leaning on the support wall without causing any vibration in the electric motor.

In a preferred embodiment of the invention, a tab is extending perpendicular to the air intake opening and rest from front against the support element to snap-fit a cassette of the electric motor. Afterwards, the electric motor is pushed against the mounting rim and leans against the support element, enabling it to be secured on the mounting rim in the axial direction by the tab. The cassette of the electric motor is preferably a prismatic body obtained by superimposing a large number of lamellas forming the stator part on top of each other. The rotating end of the electric motor with the cooling-air fan mounted lies in the center of the cassette.

In a preferred embodiment of the invention an inner frame is extending radially inwardly circumferentially limiting the air intake opening by means of an intermediate wall bent from the outer frame of the mounting rim, and on which the flexible holding element is erected. The inner frame increases the resistance of the flat mounting rim against the dynamic axial loads that may result from the flexible holding element during the operation of the electric motor and provides an additional mounting surface on the mounting rim.

In a preferred embodiment of the invention, the inner frame comprises a radial inward upward inclination angle. The upward inclination angle has surprisingly improved the airflow characteristics of the cooling-air fan and resulted in less turbulence in the exhaust duct with minimum noise.

In a preferred embodiment of the invention, the inner frame is coaxially aligned with the outer frame in the air intake opening. Therefore, the electric motor and cooling-air fan load from the inner frame can be evenly distributed over the bearing from the outer frame.

In a preferred embodiment of the invention, the support element is aligned from its opposite ends in such a way that it passes through the center of the air intake opening in the inner frame. In this way, the electric motor load can be distributed from the ends to distant positions on the inner ring, so that it can be suspended stably in the support element over the air intake opening. In the preferred embodiment, the support element is in the form of a flat strip. In alternative embodiments, the support element can be mounted to the inner ring with multiple ends on each side of the fork or different constructions.

A preferred embodiment of the invention comprises a support arm is extending radially inwardly from the inner frame diagonal to the support element towards the center of the air intake opening and rest laterally against the electric motor. The support arm helps carrying the electric motor in suspension and alleviate its radial directional vibrations thereof.

In a preferred embodiment of the invention, the support element and the support arm are in a T-like integrated form with the inner frame from their free ends. In this way, the ability of the support element to dampen electric motor-induced vibrations is increased. In an alternative embodiment, the support element can be angled so that the support arm and the support element together can be provided as an equiangular three-legged structure.

In a preferred embodiment of the invention, the flexible holding element is formed extending upwardly on the inner frame against the support element in front of the support arm. In this way, it is possible to lean against the support element from one side of the electric motor, whose vibration is damped with the support element and the support arm, and be held by the flexible holding element from the opposite side. This also facilitates adapting the electric motor to the top mounting rim. Preferably, the operator leans the electric motor on the lower end of the support arm from a lower corner and simply snaps it into place, allowing the flexible holding element to be stretched and locked by taking the electric motor in from the opposite end.

A preferred embodiment of the invention comprises an auxiliary holding element is extending upwards the support element and engages to an upper shaft end of the electric motor in a way to block rotation. The auxiliary holding element increases the operational lifespan of the flexible holding elements by reducing the load via enabling the electric motor to be held with an additional clutch from the top.

In a preferred embodiment of the invention, the mounting rim is made of a plastic material resistant to 200 degrees Celsius. Thus, it is possible to use it on the exhaust duct located adjacent to the cavity.

In a preferred embodiment of the invention, the invention comprises a clip provided on the outer frame and passing over the bearing portion at a predetermined angular position. The clip helps fixingthe mounting rim on the bearing portion in an angular position suitable for mounting. Passing through the top, the clip allows the operator to visually determine whether the mounting rim is in the proper angular position.

A preferred embodiment of the invention comprises a bump and a hole provided in the outer frame, which are mutually adjusted to each other in a predetermined angular position with the bearing portion. When the mounting rim is angularly positioned for mounting on the bearing chamber, the bump fits into the hole and supports the centering.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is a top view of a domestic oven with a representative embodiment of the ventilation device according to the invention.

Figure 2 is a perspective disassembly view of a representative embodiment of a mounting rim and cooling-air fan in a the ventilation device according to the invention.

Figure 3a is a top view of the mounting rim shown in Figure 2.

Figure 3b is the AA sectional view of the mounting rim. Figure 4 is a disassembled perspective view of a cooling motor, mounting rim and exhaust duct on the mounting axis.

Figure 5 is a perspective view of a representative embodiment of the ventilation device according to the invention, mounted on the upper part of the exhaust duct.

DETAILED DESCRIPTION OF THE INVENTION

In this detailed explanation, the development according to the invention is explained only for a better understanding of the subject without any limiting effect.

Figure 1 demonstrates a domestic built-in oven from the front perspective. The oven comprises a cavity (1) surrounding a cooking cavity. The cavity (1) is accessible from the outside with a hinged lid (5) with a display window on it. A flat front panel (2) extends over the lid (5). An exhaust opening (3) in the form of a strip is provided between the cavity (1 ) and the lower part of the front panel (2). The exhaust opening (3) is fluidly connected with an air intake opening (4) through an exhaust channel (50) in the plate structure. The air intake opening (4) has a circular structure and is perpendicular to the exhaust opening (3). An electric motor (10) in an upright position is suspended in the air intake opening (4) with the help of a circular mounting rim (20).

In Figure 2, the cooling fan assembly that is suspended with the help of the exhaust duct (50) and the mounting rim (20) that limits the air intake opening (4) is shown in perspective in disassembled condition. The cooling fan assembly comprises an electric motor (10) and a cooling-air fan (30) fixed to a shaft (12) at its free end from its front perspective. The coolingair fan (30) includes radial blades (32) placed coaxially on a circular curtain (33). The electric motor (10) comprises a stator body in the structure of a prismatic cassette (14) and a shaft (12) extending perpendicular to the air suction opening (4) extending from one end to the other with an upper shaft end (11) extending out from its rear portion. Retaining protrusions (15) are provided on both sides of the upper shaft end (11 ) to facilitate assembly.

The mounting rim (20) comprises an outer frame (21 ) and an inner frame (22) coaxially nested, respectively, in the form of a circular and Z-like cross-section. The outer frame (21) is fixed to the exhaust duct (50) over a bearing portion (40) located on an elevation portion (52) of the exhaust duct (50). The bearing portion (40) has a spring-shaped collar (41) surrounding an opening, between which recesses (43) are provided. The collar (41) is segmented with recesses (43). The outer frame (21) fits into the collar (41) from its lower edge. A radially outward extending end portion (44) of the collar (41 ) protrudes beyond the outer frame (21). The elevation portion (52) of the exhaust duct (50) is mounted on the upper wall of the cavity (1), forming a flange (53) with its base thereof. The flange (53) comprises holes for fixing purposes to the cavity (1 ) with fixing elements such as screws.

A circular overall hole (212) is located on the upper part of the flat circular outer frame (21). A bump (45) in a suitable form is provided on the upper part of the collar (41 ) close to the end portion (44). When the mounting rim (20) is positioned for mounting on the collar (41) in a suitable angular position, the bump (45) passes into the hole (212), allowing the operator to mount the mounting rim (20) to the bearing portion (40) in a suitable manner. The collar (41 ) is comprised of three portions at equal angles, and a radial holding element (24) corresponding to the recesses (43) between the portions is seated by a corresponding flexible locking tab (241) with a snap-fit. An inner edge (221) of the flat circular inner frame (22) coaxial with the outer frame (21) delimits a circular space, forming the air suction opening (4) thereof. The inner frame (22) extends upwardly towards its inner edge (221 ) with an inclination angle (a). A support element (26) in the form of a bridge dividing the air intake opening (4) equally into two is placed on the inner frame (22) over its opposite ends. A support arm (28) in the form of a flat lamella sits on the inner frame (22) from its proximal end, perpendicular to the support element (26) and dividing the support element (26) from its distal end. Thus, the support element (26) together with the torqure rod (28) forms a T-like form. The electric motor (10) rests on the support element (26) from its front portion. The shaft (12) extends down from the center of the air intake opening (4) and comprises a cooling-air fan (30) at its end. The cooling-air fan (30) comprises multiple radial blades (32) on the circular curtain (33) perpendicular to the shaft (12).

In Figure 3a, the mounting rim (20) is shown from its above perspective. The mounting rim (20) is made of one-piece plastic injection molding. The outer frame (21) is arranged narrower than the inner frame (22). A clip (25) is formed on the outer frame (21) in radial distance with the hole (212). The clip (25) is cut from the corresponding part of the outer frame (21 ) and formed to press downwards. A flexible holding element (27) extends perpendicularly to the opening delimited at the inner edge (221) of the inner frame (22) with the support arm (28) facing the support element (26) symmetrically with respect to the extension axis. The free end portion of the flexible holding element (27) comprises a trianglelike tab (271 ). As an adjuvant, an auxiliary holding element (29) facing a central hole (262) through which the shaft (12) located in the middle of the support element (26) is provided perpendicular to the extension direction in a tab-like structure. A mounting hole (261) is located at two opposite ends of the central hole (262), spaced apart. The radial holding elements (24) are formed by cutting the outer frame (21) in an L-like manner from the short edge of the outer frame, radially facing outward.

Figure 3b shows the AA sectional view of the mounting rim (20). As can be seen, the outer frame (21) lies flat with the collar (41) where it is placed and is connected to the inner frame (22) which has an inclination angle (a) with an inclined intermediate wall (23). In order to achieve this, the intermediate wall (23) is formed by bending from an upper corner (231) at an obtuse angle and from a lower corner (232) at an acute angle. The support element (26) extends vertically upwards from the inner frame (22).

In Figure 4, the cooling-air fan assembly is shown disassembled on the exhaust duct (50). The cooling-air fan (30) has a narrower diameter curtain (33) than the diameter of the air intake opening (4) partially limited by the collar (41 ). The curtain (33) comprises radial blades (32) at the shaft (12) end, providing a vacuum in the rotation axis thereof. The electric motor (10) is based on the cassette (14) and the support element (26) from above in a block structure. The shaft (12) is connected to the cooling-air fan (30) in a torque-transmitting manner through the corresponding central hole (262). Meanwhile, the two protrusions adjacent to the shaft (12) extend from the cassette (14) into the corresponding mounting holes (261). The mounting hole (261) extends in line with the central hole (262) along the support element (26). The extensions of the electric motor (10) that pass into the mounting holes (261 ) prevent the cassette (14) from turning during the operation of the electric motor (10). The electric motor (10) cassette (14) abuts against the corresponding edge of the support arm (28) from one side wall. From the opposite side, the flexible holding elements (27) are fixed to the mounting rim (20) by passing the tab (271) from the top, close to their opposite corners, at a distance from each other. Meanwhile, the auxiliary holding element (29) passes into the protrusion surrounding the shaft (12).

The electric motor (10) is fixed on the upper part of the mounting rim (20), and the cooling-air fan (30) is located on the lower part, rotating on the shaft (12) axis. The electric motor (10) is arranged to rotate in a single rotational direction (R) by providing vacuum to the cooling-air fan (30) and the air intake opening (4). When the axial cooling fan (30) operates, the air from the air intake opening (4) enters through the exhaust duct (50) from the outer portion of the cavity (1) with the low pressure formed in the inner frame (22) with an upwardly radially inclined portion in the inclination angle (a). Mentioned low pressure is provided by the radial blade (32) at the elevation portion (52) of the exhaust duct (50) by passing through the air flow opening (4), with the rotation direction and suitable angle of attack adjusted appropriately for the vacuum. In Figure 5, the position of the cooling-air fan assembly on the exhaust duct (50) is provided in perspective in the assembled condition as zoomed. After the run-up, the electric motor (10) forces the mounting rim (20) to rotate against the rotation direction (R) with a torque in the opposite direction to the rotation direction (R), abutting against a support wall (42) with a flexible holding element (27) and with the support element

(26) to which it is attached through the mounting holes (261) from the front portion. Radial holding elements (24) that fit into the recesses (43) between the collar (41) parts on the bearing portion (40) block the mounting rim (20) against a momentum in the rotation direction. Thus, the electric motor (10) remains motionless on the mounting rim (20) in the radial direction. Vibrations in the axial direction are damped by the flexible holding element

(27).

REFERENCE NUMBERS

1 cavity 26 Support element

2 Front panel 261 mounting hole

3 Exhaust opening 262 Center hole

4 Air intake opening 27 Flexible holding element

5 Lid 271 Tab

10 Electric motor 28 Support arm

11 Upper shaft end 29 Auxiliary holding element

12 Shaft 30 Cooling-air fan

14 Cassettes 32 Radial blades

15 Retaining protrusion 33 Curtain

20 Mounting rim 40 Bearing portion

21 Outer frame 41 Collar

212 Holes 42 Support wall

22 Inner frame 43 Inlet

221 Inner edge 44 end portion

23 Intermediate wall 45 Bump

231 Upper corner portion 50 Exhaust duct

232 Bottom corner portion 52 Elevation portion

24 Radial holding element 53 Flange

241 Flexible locking tab a Inclination angle

25 Clip R rotation direction