EP4063747A1

EP4063747A1 - Suction unit for cooking hobs

Info

Publication number: EP4063747A1
Application number: EP22164004.8A
Authority: EP
Inventors: Gabriele Sampaolesi; Riccardo Massili
Original assignee: Emc Fime SRL
Current assignee: Emc Fime SRL
Priority date: 2021-03-26
Filing date: 2022-03-24
Publication date: 2022-09-28

Abstract

A suction unit to be installed underneath a cooktop comprising a casing (40), having a sealed inner compartment (40a), in which is contained an electric fan (10) fixed underneath a tank (30) for collecting water from a cooktop (200), which tank has an inner compartment (30a) intercommunicating with said inner compartment (40a) of the casing (40) by means of windows (37) obtained on the box-like flanks delimiting said inner compartment (30).

Description

The present patent application for industrial invention relates to a suction unit intended to be installed underneath a cooktop.
The invention also extends to the cooktop equipped with the suction unit according to the invention. The peculiarity and advantages of the invention will become more apparent following a brief description of the prior art and the related drawbacks.
The great success recently gained by cooktops equipped with an underlying suction unit replacing the old and conventional extractor hood placed above the burners is known on the market.
Initially, this "suction" technology was applied to cooktops having larger sizes because the area dedicated to suction decreases the useful cooking surface.
The continuous research and development of new suction systems allowed reducing the overall dimensions dedicated to air suction, thus allowing manufacturers to broaden the range of built-in cooktops with more compact solutions.
The commercial success of said cooktops incorporating an underlying fume suction unit is mainly due to being more aesthetically pleasant, but also to being more practical than a conventional extractor hood arranged above the burners.
Indeed, with the implementation of such cooktops, the fumes are drawn downwards, underneath the cooktop itself, rather than going up and therefore getting into the eyes of a person cooking.
The suction unit is arranged underneath the cooktop, on which a suction opening is provided, close to the burners.
Now, such an arrangement of the suction unit immediately gave rise to a problem of protecting the electric motor associated with the suction fan.
Indeed, it is obvious that when cleaning the cooktop or when cooking food, water and liquids in general may accidentally pour into said suction opening and pour into the casing housing the electric fan.
Therefore, there is a risk that water and liquids, precipitated into the suction duct, can also seep into the motor and come into contact with the electrical connections and windings thereof, thus jeopardizing the safety of the apparatus.
In this respect, the solution adopted to date in order to avoid risking user safety has been the use of a watertight motor.
If such a waterproof motor is immune to water infiltration on the one hand, it is very expensive on the other.
Precisely because of this latter consideration, merely economic in nature, a solution has already been suggested on the market to the problem of the possibility of using, in any case with maximum safety, a common electric motor of the non-waterproof type, within the suction unit placed underneath the cooktop.
A cooktop incorporating a suction unit according to the prior art is diagrammatically shown in the accompanying drawings, in which:

Figure 1 is the plan view of a four-burner cooktop with central suction grating;
Figure 2 is the section in Figure 1 with plane II-II;
Figure 3 is the section in Figure 1 with plane III-III.

This design solution is characterized in that the suction mouth of the suction unit (G) is not vertically aligned with the suction aperture (F) placed on cooktop (P).
As shown in the drawings, air (A) and water (B) going down through said aperture (F) impact within a water collection tank (V), contained inside a casing (C) where the electric fan (E) is also housed, next to said tank (V), at which a natural separation between the water drops (B) precipitating onto the bottom of tank (V) and the air current (A), which is laterally deflected towards the suction mouth of said electric fan (E), occurs due to the difference in density.
Here, the air current (A) crosses the motor (M) of the electric fan (E) performing an effective cooling thereof, by virtue of which using powerful motors capable of processing large suction flow rates becomes possible.
However, against this advantage there is a major drawback resulting precisely from said misaligned arrangement of the suction unit (G) with respect to the suction aperture (F), which results in increased transversal dimensions underneath the cooktop (P), thus decreasing the useful spaces for the arrangement of the burners.
A further drawback relates to the fluid-dynamic efficiency, since the misaligned arrangement of the suction unit (G) with respect to the suction aperture (F) imposes a path with multiple direction changes and multiple impacts on the intake air current, resulting in the generation of turbulence and efficiency loss.
Finally, it should be noted that the misaligned arrangement of the suction unit (G) with respect to the suction aperture (F) also results in a suction inhomogeneity over the cooktop (P), the suction effect apparently being more intense in the area of aperture (F) facing the arrangement side of the suction unit (G).
The present invention precisely comes from the discussion of the above-indicated and commented prior art, the purpose of which is to provide a cooktop with an subservient suction unit which borrows all the merits of the known design solutions, without however being penalized by the limitations or drawbacks thereof.
Namely, it is the object of the present invention to provide a cooktop with an subservient suction unit, in which the electric fan is placed underneath and in the middle of the suction aperture located on the cooktop, without however putting said electric fan and the related electric system at the risk of water infiltrations.
It is a further object of the present invention to provide a cooktop with subservient suction unit, in which the air drawn by the electric fan effectively cools the motor associated with the suction fan, with the subsequent advantage of being able to adopt motors with high power and large suction flow rate.
It is not the last object of the present invention to provide a cooktop with enslaved suction unit capable of having low nosiness and a homogeneous suction effect over the whole surface extension of the suction aperture located on the cooktop.
These objects are achieved according to the invention by the features listed in appended independent claims 1 and 4.
Advantageous embodiments appear from the dependent claims.
For greater clarity, the description of the suction unit according to the invention continues with reference to the accompanying drawings, having illustrative and non-limiting value only, in which:

Figure 4 is the plan view of a four-burner cooktop with central suction aperture, equipped with a suction unit according to the invention;
Figure 5 is the section in Figure 4 with plane IV-IV;
Figure 6 is the section in Figure 4 with plane VI-VI;
Figure 7 is a three-dimensional exploded depiction of a cooktop with subservient suction unit according to the invention, shown from a first angle;
Figure 8 is a three-dimensional exploded depiction of a cooktop with subservient suction unit according to the invention, shown from a second angle, differing from that in Figure 7;
Figures 9 and 10 are a three-dimensional depiction of a construction variant of the suction unit according to the invention.

The suction unit (100) according to the invention comprises an electric suction fan (10), a filtration cartridge (20), a water collection and discharge tank (30), a casing (40).
The suction unit (100) mentioned is intended to be installed underneath a cooktop (200).
The electric suction fan (10) has a conventional construction setup and comprises a scroll-shaped housing (112) in which an impeller (13) is housed, practically consisting of a cylindrical paddled drum adapted to draw air and centrifuge it in the snail-shaped diffuser duct (18), which surrounds the impeller (13) and ends with a delivery mouth (14).
In the preferred embodiment, said scroll-shaped housing (112) comprises a pair of half-shells, one being the upper half-shell (11), the other being the lower half-shell (12), interfaced and connected to each other by means of screws.
Said diffuser duct (18) is defined by the side walls of said half-shells (11 and 12), on the bottom walls of which respective circular mouths (11a and 12a) are provided instead, being coaxial to each other and to the vertical rotation axis (Y) of said impeller (13).
Said impeller (13) is mounted to the vertical shaft of an electric motor (15) housed inside the impeller (13) and supported by a U-bolt fastened in the middle of the circular mouth (12a) of the lower half-shell (12), closed by a grating cover (16), which shields said motor (15) without hindering the flow of air drawn by the impeller (13).
The suction unit (100) according to the invention comprises a collection and discharge tank (30) for any water accidentally fallen onto the cooktop (200), and from the latter poured into the underlying compartment, passing through the aperture (201) obtained on the cooktop (200), in order to allow the suction of the air and fumes by the electric fan (10) placed underneath the cooktop (200).
Said tank (30), preferably having a rectangular shape in top view, has a bottom wall (31) and four lateral flanks (32, 33, 34, 35) adapted to delimit a watertight compartment (30a).
Three (32, 33 and 34) of these lateral flanks are characterized by the box-like structure thereof, meaning that their section with a transverse plane has an upside-down "U"-shaped profile.
In other words, these three box-like flanks (32, 33 and 34) have respective inner gaps (36), all intercommunicating with one another, where each gap (36) is laterally delimited by the opposing and parallel pair of two vertical segments of said upside-down U-shaped section, while it is closed at the top by the horizontal wing joining said pair of vertical segments.
A further feature of said tank (30) is that the three box-like flanks (32, 33 and 34) thereof have a series of windows (37) placed side-by-side, through which said gaps (36) are intercommunicated with said inner compartment (30a) of tank (30).
As shown in Figures 6 and 7, the lower edge (37a) of each window (37) is at a higher height than the bottom plane (31) of tank (30), whereby the water poured into the compartment (30a) cannot overflow from said windows (37), at least as long as the level thereof does not exceed the height at which lies said lower edge (37a).
The electric fan (10) is fixed underneath the tank (30) so that the bottom wall (31) of tank (30) overlaps/covers the circular mouth (11a) of the upper half-shell (11), as shown in Figures 5 and 6. When fixing the electric fan (10) underneath the tank (30), attention is to be paid so that the non-box-like flank (34) of tank (30) is placed towards and above the aforesaid delivery mouth (14) of the electric fan (10), as shown in Figure 7.
The suction unit (100) according to the invention also comprises an airtight casing (40) practically shaped like a parallelepiped box, the side walls (41) of which enclose said electric fan (10) therein, the delivery mouth (14) of which is centered in a suitable and alike opening (42) obtained at one of said side walls (41), as shown in Figure 8.
Said casing (40) is fixed underneath said tank (30), which has a peripheral baseboard (30b) having shape and size such as to be coupled to the upper mouth of said casing (40) in a perfect manner, the inner compartment (40a) of which remains intercommunicating only with the three overlying gaps (36) of the three box-like flanks (32, 33 and 34).
Finally, it should be mentioned that said tank (30) is fixed underneath the cooktop (200) so that said aperture (201) is centered with respect to the inner compartment (30a) of tank (30), where a filtering cartridge (20) is housed, which can be removed from such a compartment (30a) by passing it through the same aperture (201) after the removal of the related closing grating (202).
The arrows (F1) in Figure 4 indicate the trajectory of the path followed by the intake air current, which from cooktop (200) reaches and crosses the electric fan (10), while the arrows (F2) indicate the trajectory of the path followed by the water which could accidentally precipitate from cooktop (200) into the aperture (201).
As indicated by arrows (F1), the intake air current pours through the aperture (201) into the compartment (30a) of tank (30), from where it exits, after passing the filtering cartridge (20), through the windows (37), pouring into the gaps (36) and from the latter into the underlying compartment (40a) of casing (40), where the suction mouth of the electric fan (10) is located, i.e., the circular mouth (12a) of the lower half-shell (12).
After having crossed said circular mouth (12a), the air current hits the electric motor (15) and is centrifuged by the impeller (13) within said snail-shaped diffuser duct (18), to finally be ejected from the delivery mouth (14), on which the delivery duct responsible for conveying the air to the outside is engaged.
Instead, as indicated by the arrows (F2), the water poured through the aperture (201) is collected on the bottom of tank (30), where a discharge hole with related external discharge tube is provided (not shown in the accompanying drawings).
Therefore, it is apparent that there is no risk that water could dangerously reach the motor (15) placed underneath the tank (30).
Even in case of accidental obstruction of said discharge hole, the water, by overflowing through the windows (37), could at most be collected on the bottom (43) of the compartment (40a) of casing (40), but never reach the electric motor (15), the latter being at a higher height than said bottom (43).
At the same time, the idea of setting up the filtering cartridge (20), the collection tank (30) and the electric fan (10) one on top of the other in a column allows limiting as much as possible the transverse dimensions of the suction unit (100) according to the invention, with the advantage of also installing it underneath small cooktops (200), while having a wide useful space for the arrangement of the burners straddling the central aperture (201).
Figures 9 and 10 show a construction variant of tank (30) differing from that shown in Figures 7 and 8 only in that the bottom wall (31) comprises a transverse partition (38), placed close to the aforesaid lateral flank (33) and adapted to separate two compartments, the first (VI) being larger, the second (V2) being smaller.
The bottom wall (31) has some slots (39) at said second compartment (V2), which open into the underlying casing (40) and intercommunicate the inner compartment (30a) of tank (30) with the inner compartment (40a) of casing (40).
Therefore, in this construction variant of tank (30), not only may the intake air current (F1) reach the inner compartment (40a) of casing (40) through said windows (37), but also through said slots (39), by following a less winding path, and therefore with less load losses.
It is apparent that the first larger compartment (VI) is provided to collect and discharge any water dripping from the aperture (201).

Claims

A suction unit to be installed underneath a cooktop, comprising:
- a casing (40), having a sealed inner compartment (40a) laterally delimited by walls (41);

- an electric fan (10) contained inside said compartment (40a) and comprising a scroll-shaped housing (112) in which an impeller (13) is housed, fixed to the shaft of an electric motor (15), having a rotation axis thereof oriented in a vertical direction, as well as surrounded by a snail-shaped diffuser duct ending with a delivery mouth (14);

- a tank (30) for collecting water from a cooktop (200) and having an inner compartment (30a) delimited at the bottom by a bottom wall (31) and laterally by flanks (32, 33, 34, 35);
a suction unit (100) characterized in that:
- one or more of said flanks (32, 33, 34, 35) has a box-like structure, meaning that their section with a transverse plane has the profile of an upside-down "U", which coincides with the cross section of respective inner gaps (36) which intercommunicate said compartment (40a) with said inner compartment (30a) by virtue of the provision of a series of windows (37) placed side-by-side obtained on said box-like flanks;

- the lower edge (37a) of each window (37) is at a higher height than the bottom plane (31) of the tank (30);

- said casing (40) is fixed underneath said tank (30), which has a peripheral baseboard (30b) having shape and size such as to be coupled to the upper mouth of said casing (40) in a perfect manner, the inner compartment (40a) of which remains intercommunicating only with the overlying gaps (36) of the box-like flanks;

- said electric fan (10) is fixed underneath the bottom wall (31) of the tank (30).
A suction unit according to the preceding claim, wherein the bottom wall (31) of the tank (30) comprises a transverse partition (38) placed close to one of said flanks (32, 33, 34, 35) and adapted to separate two compartments, the first (VI) being larger, the second (V2) being smaller, at which the bottom wall (31) has some slots (39), which open into the underlying casing (40) and intercommunicate the inner compartment (30a) of the tank (30) with the inner compartment (40a) of the casing (40).
A suction unit according to one of the preceding claims, wherein said tank (30) accommodates a filtering cartridge (20) inside the compartment (30a) thereof.
A suction unit according to one of the preceding claims, wherein said scroll-shaped housing (112) consists of two half-shells (11 and 12) bearing, on the bottom walls thereof, respective circular mouths (11a and 12a) being coaxial with each other and with the vertical rotation axis (Y) of said impeller (13), and wherein said upper circular mouth (11a) is overlapped/covered by the bottom wall (31) of the overlying tank (30) while the lower circular mouth (12a) is overlapped/covered by a grating cover (16).
A cooktop equipped with a suction unit (100) according to one of the preceding claims, wherein said cooktop (200) has an aperture (201) centered with respect to the inner compartment (30a) of said tank (30), which is fixed underneath the cooktop (200).