Hand blender with internal drive unit

Abstract

The present invention relates to a hand blender (1) with an internal drive unit (3) consisting of a housing (2) with an upper air inlet (2a) and a lower air outlet (2b), in which the drive unit (3) consists of a dedicated lower fan (3a) and a brushless motor of the "brushless" type (3b) partially surrounded by a separation bridge (3c) which is connected to the separation cover (3e) of the drive unit (3) by means of at least one spacer (3e) allowing the circulation of air inside the housing (2) through the air chamber (2d), and above the drive unit (3) there is at least one air dissipator (4) fixed to the support plate (5) of the electronic control board (6). Abstract figure: [Fig.1]

Description

Title of invention: Hand mixer with internal drive unit Field of invention

[0001] The present invention relates to a hand blender having an internal drive unit and a brushless motor of the type used for mixing and / or grinding food, with an arrangement of the elements suitable for working on food. State of the art

[0002] Nowadays, and with reference to the state of the art, hand mixers with internal motor unit, with or without cable, used for mixing and / or grinding food are well known.

[0003] For the application of these hand mixers in sectors such as catering, where the amount of food handled is considerably higher, more powerful hand mixers are required. Compared to a power unit required for domestic applications, the power unit required for catering applications, which requires more power, increases both in size and weight, resulting in very bulky and heavy hand mixers. Over time, there has been a demand for increasingly powerful hand mixers to process larger volumes of food in less time, resulting in a difficult relationship between the weight of the mixer and its power to be considered a "hand" mixer.

[0004] Furthermore, in existing designs, safety problems have been detected when the shredding element, usually in the form of sharp blades, remains in operation for a short time after the motor stop command, due to the inertia of the rotation of the blades. In addition to degradation of the internal elements due to the humid environment in which they work, the control elements do not remain waterproof against moisture. Summary of the invention

[0005] In view of this fact, the present invention relates to a hand mixer provided with an internal power unit comprising a housing with an upper air inlet and a lower air outlet in which the power unit consists of a dedicated lower fan and a brushless motor partially surrounded by a separation bridge which is connected to the separation cover of the power unit by at least one spacer allowing the circulation of air inside the housing through the air chamber, and above the power unit there is at least one air dissipator fixed to the support plate of the electronic control board.

[0006] The use of a brushless motor (of the brushless type) in hand mixers, that is, those that do not rely on a base to operate, allows for the generation of greater torque and a higher number of revolutions, since it is more powerful than a brushed motor, which considerably reduces the weight of the mixer body. However, its use requires more complex specific electronics for its control, since in addition to controlling the transmitted intensity as in a traditional brushed motor, it is necessary to control the polarity that controls the direction of rotation of the shaft.This difference between a traditional motor and a brushless motor requires the addition of an electronic control board exclusively for motor control and independent of the electronic boards generally present in hand mixers, which are responsible for managing the control of the hand mixer (transmission of commands to operate the mixer controls). This electronic control board allows, in addition to a rapid progressive stop, an immediate stop of the motor, by short-circuiting the stator phases and generating a braking force in the opposite direction of rotation, thus eliminating the risk of cut-out due to the fact that the grinding elements remain in motion despite the stop command.The addition of another element inside the box, which must house all the elements in the smallest possible space to be manageable and, in addition, the electronic cards being an element very sensitive to the increase in temperature and humidity, generates the need for a different distribution of the elements, which must take into account the space saving (which induces the grouping of the elements) and the required ventilation (which requires air chambers between the elements), and which is greater the more powerful the motor is and the more complex the control card for the brushless motor is.

[0007] Therefore, in addition to the increase in the number of components, on the one hand, the brushless motor requires more ventilation (due to the increase in power) and, on the other hand, the increase in the number of electronic boards by adding the electronic control board requires more cooling and protection against humidity. Thanks to the positioning of an air sink linked to the electronic control board and fixed to the support plate placed above the motor unit, i.e. on the upper part when the hand mixer is in the working position or in the vertical position, the correct cooling of the electronic board is guaranteed. By placing a single dedicated lower fan, it draws air from the upper air inlet and discharges it through the lower air outlet.Thanks to the generation of an air flow contrary to the usual practice of the lower air inlet and the upper outlet, it is possible to work on hot foods that expel steam by absorbing the cooler and less humid air from the upper inlet and cooling first, and with lower humidity, the element most sensitive to the . temperature which would be the electronic control board through the air sink attached to the support plate placed on the power unit, continue the circulation of air inside the housing through the air chamber generated by the geometry of the separation cover, thin spacers and separation bridge around the power unit to cool the brushless motor and, after passing through the dedicated lower fan which changes the direction of the air flow, expel the superheated air through the lower air outlet. The expulsion of superheated air at high speed also creates a barrier around the lower air outlets which diverts the upward flow of steam from the food, creating a less humid space which extends to the upper air inlet located higher (in the vertical or working position) and thus allowing the absorption of cooler and less humid air from the upper air inlet.This arrangement of elements also allows the electronic components to be placed in the area furthest from heat and humidity and closer to the control elements, which improves cooling, protection against the action of humidity and facilitates the connection of the electronic elements.

[0008] An additional advantage is that the brushless motor is firmly anchored thanks to the separation bridge, separation cover and spacer assembly which, thanks to its configuration, positions it in the center of the housing, but without blocking the ventilation thanks to the cantilevered configuration of the separation bridge which surrounds the dedicated lower fan and partially the motor. The usual movements of hand mixers (horizontal position at rest, vertical position during work with possible inclination with respect to the shaft) require that the elements are firmly anchored in order to be able to support the work cycle without displacement.Furthermore, its position in the center of the housing allows, on the one hand, to perfectly position the center of gravity of the motor unit (the heaviest component of the mixer) both horizontally and vertically and, on the other hand, to create an air chamber inside the mixer and around the brushless motor, which allows correct circulation of the air that produces heat dissipation.

[0009] The solid anchoring of the power unit, regardless of the position of the hand mixer, and the creation of the air chamber are ensured by the fact that the separation bridge is provided with at least one transverse support rib, a perimeter support and flow holes which allow it to be cantilevered relative to the inner walls of the housing.

[0010] The position of the support ribs against the housing facilitates the transmission of the weight of the power unit when the hand mixer is positioned horizontally (at rest), thus avoiding stress on the anchors. At the same time, the perimeter support allows the weight of the power unit to be distributed when angular movements are made during work. Furthermore, since these support elements are not fixed to the housing, they can be detached for maintenance, repair or replacement of parts.

[0011] Thanks to the interlaced configuration of the support ribs and the creation of flow holes, an uninterrupted air chamber is created, which allows the brushless motor and the electronic control board to be cooled by a single air flow. This continuous air chamber surrounds the brushless motor through which the ventilation air circulates in a unified manner, thus effectively cooling the brushless motor and allowing the movement of the dedicated lower fan by generating the largest possible volume of air chamber around it. This increase in the volume of the air chamber also allows for a greater flow of ventilation air, which allows for optimal cooling of the electronic control board located above the power unit.

[0012] The separation bridge has at least one perimeter seat in which the embedding hole is located which can incorporate the end of the spacer. It is thus possible to incorporate spacers of different sizes, which allows this configuration to be applied to different modules of varying length, but always ensuring the same location of the brushless motor and the dedicated lower fan in the center of gravity of the hand blender body.

[0013] Thanks to this configuration of the elements, the safe support of the motor unit that supports the weight of the brushless motor and the correct working position are guaranteed and the separation cover is connected by means of the connection of the spacer element, which allows to absorb the forces due to the displacement of the center of gravity of the brushless motor caused by the inclination of the hand mixer during work. In addition, by centering the support and the fixation on a single element, the volume of the air chamber is maximized, allowing greater ventilation and therefore better cooling.

[0014] Furthermore, the separating cover of the power unit has at least one fin and ventilation holes that allow it to be cantilevered relative to the inner walls of the housing. Thanks to the cantilevered support of the fin, the weight of the power unit can be transferred when the hand mixer is positioned horizontally (at rest) and the power unit is stabilized when angular movements are made during work and the configuration of the fin and the ventilation holes allows a smooth and efficient circulation of the ventilation air flow all around the brushless motor, which allows the motor to be perfectly cooled.

[0015] The fin has an insertion hole that can accommodate the end of the spacer. This modular configuration of the separation bridge and the separation cover makes it possible, thanks to the fact that the spacer element can be supplied in different sizes, to adapt the same configuration to different sizes of brushless motors and hand blenders and use the same parts for different motors, which allows for standardization of components for a range of hand blenders of different power (different motor sizes).

[0016] In addition, the support plate is provided with a heat sink fixed on its ventilated surface and an electronic control board on its sealed surface, as well as a perimeter projection which can be fixed on the interior walls of the housing.

[0017] Thanks to this configuration, the support plate fits securely into the inner walls of the housing, keeping the elements it contains firmly fixed, regardless of the position of the hand blender, insulated and sealed. In addition, by fitting into the inner walls of the housing, the sealed surface containing the most sensitive electronic elements of the electronic control board is isolated from the moisture coming from the water vapor of the food. In this way, the ventilated surface is placed in the most optimal position, near the upper air inlet, when the heatsink is attached to its surface, which guarantees total contact of the surface with the cooler and less humid ventilation air (that received from the outside) and effectively cools the electronic board to which it is connected inside.It is also planned that the electronic elements housed in the ventilated surface will be covered with a layer of protective resin for better protection.

[0018] An additional advantage is that the perimeter projection, due to its increased height, allows a layer of resin to be added up to the edge of the perimeter projection (usually a small amount is applied in the form of varnish), which allows the most moisture-sensitive elements to be completely covered and further protected from the humid atmosphere of the working environment. Figures

[0019] In order to better understand the nature of the invention, the attached drawings show an industrial embodiment which is simply illustrative and not limiting.

[0020] [Fig.l]

[0021] [Fig.l] shows a longitudinal section along the shaft of the hand blender (1) showing the arrangement of the elements which, from top to bottom, in vertical or working position, are the electronic control board (6) located at the top with the other electronic components located on the support plate (5) mounted in the housing (2) from which hangs the heat sink (4) facing the upper air inlets (2a) in an air chamber (2d). Below, in descending order, we can see the separation cover (3e), the spacers (3d), the brushless motor (3b), the separation bridge (3c) and the dedicated lower fan (3a) which make up the power unit (3), the fan dedicated lower (3a) facing the lower air outlets (2b) and which is crossed by the shaft (7) which extends along its lower part.

[0022] [Fig.2]

[0023] [Fig.2] shows a longitudinal section along the perspective shaft of the hand mixer (1) showing the housing (2) and the inner wall of the housing (2d) and the arrangement of the elements which, from top to bottom, in the vertical or working position, would be the electronic control board (6) located at the top with the other electronic components located on the support plate (5) from which the heatsink (4) is suspended in an air chamber (2d) above the power unit (3) consisting of the separation cover (3e), the spacers (3d), the brushless motor (3b), the separation bridge (3c) and the dedicated lower fan (3a).

[0024] [Fig.3]

[0025] [Fig.3] shows an exploded view of the hand mixer (1) showing the housing (2) divided into two parts, of which the inner wall of the housing (2d), the support plate (5) with the electronic control board (6) on its sealed surface (5b), the perimeter projection (5c), the heat sink (4) on its ventilated surface (5a) and the motor unit (3) can be seen.

[0026] [Fig.4]

[0027] [Fig.4] shows an exploded view of the power unit (3), showing the separation cover (3e) with the fin (3el) in which the insertion hole (3el.l) is located, the brushless motor (3b) crossed by the shaft (7), the spacers (3d), the dedicated lower fan (3a) and the separation bridge (3c) composed of the support rib (3c 1), the perimeter seat (3c2) in which the embedding hole (3c2.1) can be seen, the perimeter support (3c3) and the flow holes (3c4).

[0028] [Fig.5]

[0029] [Fig.5] shows a zenithal view of the separation cover (3e) with the fins (3e 1) and the ventilation holes (3e2). Detailed description

[0030] With reference to the drawings and references listed above, a preferred embodiment of the subject matter of the invention is illustrated in the attached drawings. It is a hand blender (1) with an internal power unit (3) comprising a housing (2) with an upper air inlet (2a) and a lower air outlet (2b) in which the power unit (3) consists of a dedicated lower fan (3a) and a brushless motor (3b) partially surrounded by a separation bridge (3c) which is connected to the separation cover (3e) of the power unit (3) by at least one spacer (3d) allowing air to circulate inside the housing (2) through the air chamber (2d), and above the drive unit (3), there is at least one air dissipator (4) attached to the support plate (5) of the electronic control board (6).

[0031] The use of a brushless motor (3b) in the hand blender (1) allows the incorporation of a more powerful motor (which generates more torque and allows operation at higher speeds), which considerably reduces the weight of the body of the hand blender (1). The brushless motor (3b) requires the addition of a complex electronic control board (6) for motor control, located next to the blender controls, as can be seen in [Fig. 2]. This electronic control board (6) allows the immediate stopping of the motor by generating a force opposite to the direction of rotation at the moment of stopping, so that the residual inertial movement of the shaft is counteracted, thus eliminating the danger of cutting due to the fact that the grinding elements remain in motion despite the stop command.The addition of the electronic control board (6), which is very sensitive to temperature rise and humidity, inside the housing (2) requires repositioning the elements without increasing the internal volume of the housing (2) and providing adequate ventilation for all the elements and protection against humidity for the most sensitive electronic elements.

[0032] On the one hand, the brushless motor (3b) requires more ventilation for adequate cooling (due to the increased power it generates) and, on the other hand, the increase and complexity of the electronic board, with the addition of the electronic control board (6), requires more cooling and protection against moisture. To ensure adequate cooling of the electronic control board (6), it is placed on the sealed surface of the support plate (5), attached to the ventilated surface (5a) of the support plate (5) and a heat sink (4) is attached to the electronic control board (6). The support plate (5) is placed above the motor unit (3), i.e. at the top when the hand mixer is in the working position or in the vertical position. As shown in [Fig.l], at the opposite end, a single dedicated lower fan (3a) is installed, which draws air from the upper air inlet (2a) and exhausts it through the lower air outlet (2b).In this way it is also possible to work on hot foods that expel steam and by absorbing air from the upper inlet (2a) which is colder and less humid, and cooling first, and with less humidity, the most temperature-sensitive element which would be the electronic control board (6) through the air dissipator (4) attached to the support plate (5) placed on the power unit (3), continue the circulation of air inside the housing (2) through the air chamber (2d) generated by the geometry of the separation cover (3e), the spacers (3d) and the separation bridge (3c) around the power unit (3) to cool the brushless motor (3b) and, after passing through the dedicated lower fan (3a), which changes the direction of the air flow, expel the overheated air through the lower air outlet (2b). The expulsion of superheated air at high speed also creates a barrier around the lower air outlets (2b) which diverts the upward flow of food vapor. This arrangement of the elements also allows the electronic components to be placed in the area furthest from heat and humidity, separated from the rest of the elements by the support plate (5) and closer to the control elements.

[0033] The usual movements of hand mixers (1) (horizontal position at rest, vertical position when working with possible inclination with respect to the shaft), require that the elements are firmly anchored to be able to support the work cycle without displacement. For this purpose, the brushless motor (3b), which is the heaviest element, is firmly anchored and positioned thanks to the set of separation bridges (3c), the separation cover (3e) and the spacer (3d). Thanks to the geometry of the elements, they position it in the center of the housing (2), but without blocking the ventilation thanks to the cantilever configuration of the separation bridge (3c) which surrounds the dedicated lower fan (3a) and partially the brushless motor (3b).

[0034] The solid anchoring of the power unit (3) regardless of the position of the hand mixer (1) and the creation of a continuous air chamber (2d) are ensured by the fact that the separation bridge (3c) is intersected by at least one transverse support rib (3c 1) and a perimeter support (3c2) which allow its support in cantilever on the inner walls of the housing, and by the flow orifices (3c4), which allow the volume of the air space (2d) to be increased.

[0035] The position of the support ribs (3c 1) against the inner wall of the housing (2d) allows the weight of the power unit (3) to be transmitted when the hand mixer (1) is positioned horizontally (at rest), avoiding tensions in the anchors, which prevents the generation of clearances that would produce vibrations and therefore prolongs the life of the hand mixer (1). In turn, the perimeter support (3c3) allows the weight of the power unit (3) to be distributed when angular movements are made during work. On the other hand, as they are support elements, they are not linked to the housing (2), which can be detached for maintenance, repair or replacement of parts.

[0036] Thanks to the interlaced configuration of the support ribs (3c 1) and the creation of flow holes (3c4), a continuous and barrier-free air chamber (2d) is created around the brushless motor (3b), through which the ventilation air circulates in a unified manner and can, thanks to a single air flow, effectively cool the electronic control board (6) and the brushless motor (3b). This increase in the volume of the air chamber (2d) also allows a greater flow of ventilation air, improving the cooling of the electronic control board (6) located on the power unit (3) (improves the dissipation of heat by the heat sink (4) linked to the electronic control board (6)).

[0037] The separation bridge (3c) comprises at least one perimeter seat (3c2) in which the embedding hole (3c2.1) is located, capable of incorporating one end of the spacer (3d). This allows the incorporation of spacers (3d) of different sizes, which makes it possible to apply the same configuration to different modules of greater or lesser length, but always ensuring the same location of the brushless motor (3b).

[0038] The brushless motor (3b) is placed on the separation bridge (3c) and partially surrounded by it, which ensures a secure support of the brushless motor (3b) and a correct working position. The separation bridge (3c) is connected to the separation cover (3e) by means of four spacer elements (3d), preferably, containing the brushless motor (3b) and forming the drive unit (3), thus capable of absorbing the forces due to the displacement of the center of gravity of the brushless motor (3b) and compensating them.Furthermore, by centering the support and fixation on a single element (the separation bridge element (3c)), the volume of the air chamber is maximized, allowing for greater ventilation flow and therefore better cooling by being able to separate the power unit (3) comprising the separation bridge (3c), the separation cover (3e), the spacers (3d), the brushless motor (3b) and the dedicated bottom fan (3a) from the inner walls of the housing (2c).

[0039] This independence of the inner walls of the housing (2c) from the separating cover (3e) of the power unit (3) is possible because the separator cover (3e) has at least one fin (3e 1) which allows it to be cantilevered from the inner walls of the housing (2c). Thanks to the cantilevered support of the fin (3el), this allows the balanced transmission of the weight of the power unit (3) when the hand mixer (1) is positioned horizontally (at rest) and the stabilization of the power unit (3) when angular movements are made during work. Furthermore, as can be seen in [Fig.5], the separation cover (3e) has several ventilation holes (3e2) which, together with the separation of the inner walls of the housing (2c) generated by the fins (3e 1), allow the smooth and efficient circulation of the ventilation air around the brushless motor (3b), and therefore optimal cooling of the motor, as well as its passage to the lower part of the interior of the housing after cooling of the support plate (5).

[0040] Individually, each fin (3e 1) has an insertion hole (3e 1.1) which can accommodate the end of a spacer (3d) which connects the separation cover (3e) to the separation bridge (3c). This modular configuration of the separation bridge (3c) and the separation cover (3e) allows, thanks to the fact that the spacer element (3d) can be supplied in different sizes, to adapt the configuration to the different sizes of brushless motor (3b), and required for the different hand mixers (1). This adaptability allows to standardize the components for a range of hand mixers of different powers (different motor sizes) using the same separation bridge elements (3c) and the same separation cover (3e) for different brushless motors (3b) with the modification of the spacer element (3d) adapted to the distance of the brushless motor (3b) which integrates the motor unit (3).

[0041] [Fig.3] shows how the support plate (5), located on the power unit (3) in the vertical or working position, has on its ventilated surface (5a) a heat sink (4) fixed to the electronic control board (6) located on its sealed surface (5b) and has a perimeter projection (5c) which can be mounted on the inner walls of the housing (2c).

[0042] The support plate (5) securely engages with the inner walls of the housing (2c) along its entire perimeter, keeping the elements it contains firmly fixed regardless of the position of the hand mixer (1). Furthermore, by inserting itself into the inner walls of the housing (2), the sealed surface (5b) on which the electronic control board (6) is located (containing electronic components sensitive to the humidity of food vapors) is isolated from the ventilated surface (5a), so that the humidity does not reach the sealed surface (5b). Furthermore, the ventilated surface (5a), on which the heat sink (4) is positioned, is located in the most suitable position for heat dissipation, close to the upper air inlet (2a).By placing the heat sink (4) fixed to the ventilated surface (5a), contact is ensured over the entire surface of the heat sink (4) with the cooler and less humid ventilation air (that received from outside through the upper air inlet (2a)) and effectively cools the electronic control board (6) to which it is connected inside. In addition, this ventilated surface, as well as the elements housed there, will be protected by a layer of resin for greater safety.

[0043] The perimeter projection (5c), due to its increased height, allows the addition of a layer of resin up to the edge of the perimeter projection (usually a small amount is applied in the form of varnish), which allows even the most moisture-sensitive elements of the electronic control board (6) located on the sealed surface (5b) of the support plate (5) to be completely covered and protected from the humid atmosphere of the working environment.

[0044] The variations in materials, shape, size and arrangement of the constituent elements, described in a non-limiting manner, do not alter the essential character of the present invention and are sufficient to be reproduced by a person skilled in the art.

[0045] Nomenclature

[0046] The following references are indicated in Figures 1 to 5:

[0047] L- Hand mixer.

[0048] 2.- Housing.

[0049] 2a- Upper air inlet

[0050] 2b- Lower air outlet

[0051] 2c- Inner wall of the housing

[0052] 2d- Inner tube

[0053] 3.- Motor unit.

[0054] 3 a- Dedicated lower fan

[0055] 3b- Brushless type brushless motor

[0056] 3c- Separation bridge

[0057] 3c 1- Supporting rib

[0058] 3c2- Perimeter seat

[0059] 3c2.1 embedding hole

[0060] 3c3- Perimeter support

[0061] 3c4- Flow orifice

[0062] 3d- Spacer

[0063] 3rd- Separation cover

[0064] 3rd 1- Fin

[0065] 3el. 1.1 insertion port

[0066] 3e2- Ventilation holes

[0067] 4.- Dissipator

[0068] 5.- Support plate:

[0069] 5a- Ventilated surface

[0070] 5b- Waterproof surface

[0071] 5c-Perimeter projection

[0072] 6.- Electronic control card

[0073] 7.- Tree

Claims

Claims

1. Hand blender (1) with an internal drive unit (3) consisting of a housing (2) with an upper air inlet (2a) and a lower air outlet (2b), characterized in that the drive unit (3) consists of a dedicated lower fan (3a) and a brushless motor (3b) partially surrounded by a separation bridge (3c) which is connected to the separation cover (3e) of the drive unit (3) by means of at least one spacer (3e) allowing the circulation of air inside the housing (2) through the air chamber (2d), and above the drive unit (3) there is at least one air dissipator (4) fixed to the support plate (5) of the electronic control board (6).

2. Hand mixer (1) according to claim 1, characterized in that the separating bridge (3c) has flow orifices (3c4) interspersed with at least one transverse support rib (3c 1) and a perimeter support (3c3) capable of being supported on the inner walls of the housing (2d).

3. Hand mixer (1) according to the preceding claims, characterized in that the separation bridge (3c) has at least one perimeter seat (3c2) in which the embedding orifice (3c2.1) is located, capable of incorporating one end of the spacer (3d).

4. Hand blender (1) according to the preceding claims, characterized in that the separating cover (3e) of the drive unit (3) has ventilation holes (3e2) and at least one fin (3e1) which allow it to be cantilevered on the inner walls of the housing (2c).

5. Hand mixer (1) according to the preceding claims, characterized in that the fin (3el) has an insertion hole (3el.l) capable of housing one end of the spacer (3d).

6. Hand mixer (1) according to the preceding claims, characterized in that the support plate (5) has on its ventilated surface (5a) a fixed heat sink (4) and on its sealed surface (5b) an electronic control card (6) and is bordered by a perimeter projection (5c) capable of adapting to the interior walls of the housing (2c).

Images