EP4685835A1

EP4685835A1 - Switch arrangement, household appliance and attachment

Info

Publication number: EP4685835A1
Application number: EP24191235.1A
Authority: EP
Inventors: Bostjan KOVACEC; Matej Svara; Gregor Pecnik
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2024-07-26
Filing date: 2024-07-26
Publication date: 2026-01-28

Abstract

Disclosed is a switch arrangement for a household appliance such as a blender, which is adapted to adjust automatically program modes based on the used attachment, a household appliance with such a switch arrangement and an attachment for such a household appliance.

Description

The present invention concerns a switch arrangement for a household appliance. The invention further concerns a household appliance and an attachment for such household appliance.
Modern household (kitchen) appliances such as high-speed blenders have powerful motors up to 2kW with a rotating speed of 20.000 RPM or even more. In order to enable a user to use such household appliance for different kinds of food processing, several attachments are provided which fit the base of the household appliance. For instance, instead of a blender jar, small attachments such as a chopper attachment and a grinder attachment can be used. As, basically, a chopper or a grinder attachment needs less power than a blender jar for preparation, their tools may have different bearing system, for instance a sliding bearing system whereas a blender jar has a ball bearing system. In order to prevent a damage of the small attachments, in particular an overheating of their bearing system, either the sliding bearing system has to be replaced by ball bearing system, or a powerful motor has to be replaced by a less powerful motor. However, replacing the sliding bearing system by a ball bearing system would make the smaller attachments expensive, replacing a powerful motor by a less powerful motor would limit the use of the household appliance to small attachments.
It is an object of the present invention to provide a switch arrangement for a household appliance which enables use of small attachments in combination with a powerful motor, a household appliance that enables a safe use of several attachments on its base, and an attachment for such household appliance.
The object is achieved by a switch arrangement according to claim 1, by a household appliance unit according to claim 5 and by an attachment according to claim 8. Advantageous embodiments are disclosed in the dependent claims, the description and the figures.
A switch arrangement for an electric household appliance comprising an electric main switch, a signal switch, a main actuation element and a signal actuation element. The main actuation element and the signal actuation element are in such an operative connection with each other that the main actuation element can be operated directly by an attachment or indirectly by means of the signal actuation element. If the main actuation element is operated directly by an attachment, the main switch is activated such that some programs of the household appliances are available. If the signal actuation element is operated, the main switch and the signal switch are activated at the same time, wherein via the signal switch a signal is given to a system control that all programs are available.
Preferably, the switch arrangement is adapted to be operated by an attachment of the household appliance. By means of the 2-check-point-positions for attachment detection, the motor control is adapted automatically to the kind of attachment. As a result, small attachments can be used on the base of a high-speed household appliance, as either only programs can be chosen by a user which do not result in a damage of their bearing system, or programs are adapted to the smaller attachments, for instance requiring shorter operating times and lower RPM.
Preferably, the actuation elements are movable in linear direction, in particular in mounting direction of the attachment. By means of this, a robust and easy operation is realised.
In one embodiment, the operative connection of the actuation elements is established by overlapping of body sections. An overlapping is easy to realise and reliable. Alternatively, a kind of hooked or snap and click connection is possible. Important is, that the operative connections enable the operation of the main actuating element without driving the signal actuation element.
Preferably, an elastic element acting on the one actuation element is provided which during non-operation keeps both actuating elements in their initial positions. By using only one elastic element for both actuation elements, the part number is reduced. Preferably, the spring acts on the main actuation element directly. An exemplary spring element is a pressure spring. The elastic element is also used to bring the actuation elements back into their initial positions after operation.
An electric household appliance according to the invention such as a blender has a base housing a motor, a system control and an inventive switch arrangement. The base has a top side which is adapted to receive an attachment. The top side of the base also has areas adapted to enable the actuation elements to be accessible from the top.
By means of this a reliable, robust, multifunctional and due to the easy adaptability of different attachments an easy to use household appliance is realized. Further on, a lid safety function of an attachment can be retained.
Preferably, the main actuation element and the signal actuation element project over adjacent surfaces of the top side. By means of this, the actuation elements are easily accessible.
In order to separate the actuation elements visually, one actuation element is positioned radially inwards with regard to the other actuation element.
An attachment according to the invention is adapted to be placed with its lower side on the top side of the base. It has at least one operating element which is adapted to be in engagement with at least one of the actuation elements. By means of this, a safe operation of the respective actuating element is enabled and a lid safety function of an attachment, in particular a blender jar, can be retained.
If the at least one operating element is rigid, the robustness of the operation is enhanced.
In order to enable a safe positioning of the attachment next the base, for instance on a countertop, the at least one operating element is recessed from the foot of the attachment.
In the following, preferred embodiments of the present invention are explained with respect to the accompanying drawings. As is to be understood, the various elements and components are depicted as examples only, may be facultative and/or combined in a manner different than that illustrated. Reference signs for related elements are used comprehensively and not defined again for each figure. Shown is schematically in

Fig. 1a:: a perspective view of base of a household appliance according to the invention;
Fig. 1b:: exemplary attachment of the household appliance;
Fig. 2a:: a first sectional drawing of the base showing an internal position of a switch arrangement according the invention:
Fig. 2b:: a second sectional drawing of the base (rotated to the left/clockwise with regard to Fig. 2a) showing an internal position of a switch arrangement according the invention:
Fig. 3a: a first single view of the switch arrangement; and
Fig. 3b:: a second single view of the switch arrangement

In Figure 1a, a base 1 of an inventive household appliance is shown and in Figure 1b an exemplary attachment 6 for the base 1 is shown. The base 1 basically houses an electric motor to drive a tool of the attachment 6, usually a knife with blades, a user interface 2 and at its top side 4 coupling means to attach different attachments 6, such as a blender jar.
At its lower side, the attachment 6 has a counter coupling element (not shown) which enables the operative connection to the base 1, in particular to a motor shaft in order to drive its tool. In order to create a stable positioning of the blender jar 6 adjacent to the base 1, the not shown counter-coupling elements are recessed from an edge region 8 acting as its foot.
Beside the shown blender jar 6, several other attachments can be installed at the base 1. Examples are chopper attachment, grinder attachment and a small blender jar without a lid which can be opened at the bottom by removing a knife holder.
As illustrated in Figures 2a and 2b, in order to adjust the control system, in particular the program diversity that can be chosen by a user, to the installed attachment 6, a switch arrangement 10 is provided inside the base 1 which is operated by not shown operating elements at the lower side of the attachment 6. Preferably, the operating elements are rigid projections at the lower side which are recessed from the foot 8.
The switch arrangement 10 has two actuator elements 12, 14 which in their initial position project over adjacent surfaces of the top side 4 of the base 1. With respect to a rotation axis r of the motor shaft / tool, one actuation element 12 is positioned radially inwardly with regard to the other actuation element 14.
If an attachment 6 is put on the base 1, its operating element touches the respective actuation element 12, 14 and pushes it downwards automatically. If the attachment is lifted up, the respective actuation element 12, 14 goes back into its initial position. A more detailed description follows with reference to Figures 3a and 3b.
Basically, additional to the two actuation elements 12, 14 the switch arrangement 10 has a main switch 16, a signal switch 18, an elastic element 20 and a support structure 22.
The main switch 16 and the signal switch 18 are in electric connection with the motor and the control system, respectively. They are arranged on the support structure 22 which is adapted to position the entire switch arrangement 10 inside the base 1.
Each switch 16, 18 is activated by one of the actuation elements 12, 14 directly. Here, the radial inner actuation element 12 (main actuation element) acts directly on the main switch 16 via a projection (not referenced for the sake of clarity). The radial outer actuation element 14 (signal actuation element) acts directly on the signal switch 18 via a projection 24. The projection 24 acts on an elastic tongue 26 which is configured to close or open the signal switch 18 (exemplary illustrated on the signal switch 18).
In addition, the main actuation element 12 and the signal actuation element 14 are in operative connection which each other, such that the signal actuation element 14 also operates the main actuation element 12. By means of this, the signal actuation element 14 also acts directly on the main switch 16. This operative connection is achieved by overlapping of body sections 28, 30 of the actuation elements 12, 14. The body sections overlap in vertical direction x, whereas the body section 28 of the main actuation element 12 is below the body section 30 of the signal actuation element 14.
The actuation elements 12, 14 are movable linearly in vertical direction x. Here, the actuation elements 12, 14 have cylindrical guiding elements 32, 34 respectively, which are guided vertically in corresponding base holes below the top side 4. In a non-operative state, i. e. the attachment 6 is not attached to the base 1, they are in their initial positions, none of the switches 16, 18 is activated. During operation, i.e. the attachment 6 is attached to the base 1, either only the main actuation element 12 or both, the signal actuation element 14 directly (by the attachment 6) and the main actuation element 12 indirectly (via the signal actuation element 14), are pushed downwards in its working position by the respective operating element of the attachment 6 such that the main switch 16 and/or the signal switch 18 are/is activated. After operation, i. e. the attachment 6 is lifted off, they move upwards back into their initial position.
In order to keep the actuation elements 12, 14 in their initial position during non-operation and in order to bring them back into their initial position after operation, the elastic element 20 is provided. Here, the elastic element 20 is a pressure spring that surrounds partially the cylindrical guiding element 32 of the main actuating element 12. It acts directly on the main actuation element 12 and is positioned below a lever 36 of it. By means of this and in combination with the operative connection of the actuation elements 12, 14, in particular due to the arrangement of their overlapping body sections 28, 30, the elastic element 20 also acts indirectly on the signal actuation element 14 such that the signal actuation element 14 is kept in its initial position and brought back into it after operation by the elastic element 20 as well.
In dependence of the attachment 6, either the main actuation element 12 is operated alone or the signal actuation element 14 and the main actuation element 14 are operated at the same time. If the main actuation element 12 is operated alone, for instance a grinder or a chopper attachment is installed on the base 1, only a limited number of programs are available by the user. For instance, a. soup program and ice crush program are disabled, the rest of the available programs are customized. Additionally, in a manual mode a maximal rotation speed is reduced, for instance. Further on, in the manual mode an operating (processing) time is limited to a maximum of 2 minutes (or less), for instance.
If both actuation elements 12, 14 are activated by the attachment 6 such as a blender jar, i.e. the signal actuation element 14 directly and the main actuation element 12 indirectly, a signal is generated via the closed signal switch resulting in a full program setting mode. All programs are available to the user and in the manual mode the highest rotation speed and the longest processing time are available.
The arrangement enables also a fail-safe function. In case that the signal switch 18 fails, the setting mode(s) for attachments with sliding bearing system will be activated. This means that unfavorable situation (chopper attachment or grinder attachment with high RPM and longer processing time) can never occur.
Disclosed is a switch arrangement for a household appliance such as a blender, which is adapted to adjust automatically program modes based on the used attachment, a household appliance with such a switch arrangement and an attachment for such a household appliance.

Reference signs

1: base
2: user interface
4: top side
6: attachment (for instance: blender jar)
8: edge region (foot)
10: switch arrangement
12: actuation element (radial inner, main actuation element)
14: actuation element (radial outer, signal actuation element)
16: main switch
18: signal switch
20: elastic element
22: support structure
24: projection
26: tongue
28: body section
30: body section
32: guiding element
34: guiding element
36: lever

r: vertical axis
x: vertical direction

Claims

A switch arrangement (10) for a household appliance, comprising:
- a main switch (16),

- a signal switch (18),

- a main actuation element (12); and

- a signal actuation element (14); and
wherein

- the actuation elements (12, 14) are in such an operative connection with each other that the main actuation element (12) can be operated directly or indirectly by means of the signal actuation element (14);
wherein

- if the main actuation element (12) is operated directly, the main switch (16) is activated such that some programs of the household appliances are available; and

- if the signal actuation element (14) is operated, the main switch (16) and the signal switch (18) are activated at the same time, wherein via the signal switch (18) a signal is given to a system control that all programs are available.
The switch arrangement according to claim 1, wherein the actuation elements (12, 14) are movable in linear direction.
The switch arrangement according to claims 1 or 2, wherein the operative connection of the actuation elements (12, 14) is established by overlapping or hooked body sections (28, 30).
The switch arrangement according to claims 1, 2 or 3, wherein an elastic element (20) acting on the one actuation element (12) is provided which during non-operation keeps both actuating elements (12, 14) in their initial positions.
A household appliance such as a blender having a base, housing
- a motor;

- a system control; and

- a switch arrangement (10) according to any of the preceding claims,
wherein the base (1) has a top side (4) which

- is adapted to receive an attachment (6); and

- has areas adapted to enable the actuation elements (12, 14) to be accessible from the top.
The household appliance according to claim 5, wherein the actuation elements (12, 14) project over adjacent surfaces of the top side (4).
The household appliance according to claims 5 or 6, wherein one actuation element (12) is positioned radially inwards to the other actuation element (14).
An attachment for a household appliance according to claims 7, wherein on its lower side at least one operating element is provided which is adapted to be in engagement with at least one of the actuation elements (12, 14) on the top side (4) of the base (1) of the household appliance.
The attachment (6) according to claim 8, wherein the at least one operating element is rigid.
The attachment according to claims 8 or 9, wherein the at least one operating element is recessed from an edge region (8) of the attachment.