EP3986091A1

EP3986091A1 - Household appliance and method for assembling a household appliance

Info

Publication number: EP3986091A1
Application number: EP20202356.0A
Authority: EP
Inventors: Gerhard Klein; Ulrich Häutle; Elisabeth REBELEIN; Stefan Bayerlein; Dominik RIEDEL
Original assignee: Electrolux Appliances AB
Current assignee: Electrolux Appliances AB
Priority date: 2020-10-16
Filing date: 2020-10-16
Publication date: 2022-04-20

Abstract

A household appliance (10) comprises a first circuit board (22) and a second circuit board (20) or a first circuit board and a mains connection unit, which are electrically connectable by a connection means comprising at least one connection line (40, 40', 54, 78). Each one of the first (22) and second (20) circuit boards or the first circuit board and the mains connection unit comprises at least one first connector (50) for an electrical connection for power and/or information transmission. The first connector (50) of the first circuit board (22) is of the same or of a different type as the first connector (50) of the second circuit board (20) or of the mains connection unit.

The connection line (40, 40', 54, 78) comprises a second connector (44, 44') at a first line end and a second connector (44, 44') at a second line end. The first connector (50) of the first circuit board (22) is connectable to the second connector (44, 44') at the first line end and the first connector (50) of the second circuit board (20) or of the mains connection unit is connectable to the second connector (44, 44') at the second line end. Each pair of first (50) and second (44, 44') connectors is compatible to one another and comprises a terminal or connection point or a connecting pin or a plug or a socket. The second connector (44, 44') at the first line end and the second connector (44, 44') at the second line end are arranged in a pre-defined first distance from each other at least before performing the electrical connection between the first (22) second (20) circuit boards or between the first circuit board and the mains connection unit.

Further disclosed are a connection device for electrical connection and a method for assembling a household appliance (10).

Description

The present invention relates to household appliance, particularly a cooking appliance, more particularly a cooking hob, even more particularly an induction cooking hob, comprising a first circuit board and a second circuit board or a first circuit board and a mains connection unit, according to claim 1. Further, the present invention relates to a connection device for electrical connection of a first circuit board and a second circuit board or a first circuit board and a mains connection unit, according to claim 21. Finally, the present invention relates to method for assembling a household appliance, according to claim 22.
Generally, household appliances are assembled from modular components, which may be individual parts, e.g. motors, heating elements, pumps, or the like, or systems or subsystems, which themselves may be an assembly of single parts, e.g. printed circuit boards like control units or user interfaces. A relevant number of said modular components is of electrical nature, which modular components have to be supplied with electrical energy and which are electrically connected with other electrical components for information and/or power transfer. In production facilities for household appliances, nowadays, there is already an advanced level of automation, which is reflected in an automated assembly of components, for example arrangeable in a housing of the household appliance. However, there are still manual assembly steps required for establishing electrical contacts, particularly by connecting plug contacts of wiring harnesses.
It is an object of the present invention to provide a household appliance and a connection device, particularly for being used in a household appliance, which are constructed in such a way that the level of automation in production facilities of household appliances can be further increased. It is a further object of the present invention to provide a method for assembling a household appliance, which supports an advanced level of automation during assembly of a household appliance.
The object is achieved by a household appliance comprising

a first circuit board and a second circuit board or
a first circuit board and a mains connection unit,
which are electrically connectable by a connection means comprising at least one connection line. Each one of the first circuit board and the second circuit board or mains connection unit, which may be a mains terminal block, comprises at least one first connector for an electrical connection for power and/or information transmission. Said first connector of the first circuit board is of the same or of a different type as the first connector of the second circuit board or of the mains connection unit. The connection line comprises a second connector at a first line end and a second connector at a second line end. The first connector of the first circuit board is connectable to the second connector at the first line end and the first connector of the second circuit board or of the mains connection unit is connectable to the second connector at the second line end. Each pair of first and second connectors is compatible to one another and comprises a terminal or connection point or a connecting pin or a plug or a socket. The second connector at the first line end and the second connector at the second line end are arranged in a pre-defined first distance from each other at least before performing the electrical connection between
the first circuit board and the second circuit board or
the first circuit board and the mains connection unit.

The household appliance is particularly a cooking appliance and may be a cooking hob, in particular an electrically driven cooking hob. A specifically selected appliance is an induction cooking hob.
According to a preferred aspect of the present invention, the intended increase of the level of automation is achieved by a configuration of a first and a second module or component, particularly of a printed circuit board and/or of a user interface, in such a way as to be mounted in the housing or the installation case in an assembly movement, the mounting preferably being executed by means of an assembly robot, mainly in a direction at least approximately orthogonally to a base area or a reference area of the housing or of the installation case. On the other hand, also the household appliance may be configured to receive the module or component during an assembly movement, notably by an assembly robot moving and mounting said module or component, which is executed at least approximately orthogonally to a base area or reference area of the household appliance. In particular, the base area or the reference area of the housing or of the installation case is at least approximately horizontally aligned with a mounting surface or an assembly line in a production facility and said assembly movement is executed in a top down assembly movement or any other suitable multidirectional assembly movement with the same or a similar assembling result, which assembly movement is preferably performed until a final position of the module or component has been reached, wherein the assembly movement and/or the mounting is favourably completed by a fixing of the module or component by means of fastening means. In order to perform also an automated electrical connection, it is advantageous to provide exact positions of and/or a defined distance between the connectors that shall be connected to the first and second modules or components, particularly to provide means, which take care of said exact positions and/or the defined distance.
The connection means preferably comprises a plurality of connection lines for electrical connection for power and/or information transmission. Said plurality of connection lines advantageously includes all electrical connections for power and/or information transmission between the first circuit board and the second circuit board or mains connection unit. Each one of the plurality of connection lines comprises second connectors at their first and second line ends and the second connectors are arranged in a pairwise relationship in a pre-defined first distance from each other at least before performing the electrical connection between the first circuit board and the second circuit board or mains connection unit. Pairwise relationship includes not only a pair of a second connector at the first line end and a second connector at the second line end, but also pairs of second connectors at first line ends of two different connection lines and pairs of second connectors at second line ends of two different connection lines. The electrical connection favourably includes a joint connection involving each one of the plurality of connection lines.
The connection line may be designed by following a defined course between the second connectors at the first and second line ends at least before performing the electrical connection between the first circuit board and the second circuit board or mains connection unit. Said defined course is particularly formed by a stiff connection line, which may be a connecting rail, or by a cable that is guided in a defined manner. In particular, the cable is fixed by means of plastic injection moulding.
According to a specific embodiment, the connection means comprises a housing, preferably a plastic housing, enclosing the connection line. The housing particularly comprises fixation means for the connection line and/or completely enclosing the connection line.
One embodiment of the invention is characterized in that the second connector of the first line end and the second connector of the second line end are arranged in a second distance from each other after performing the electrical connection between the first circuit board and the second circuit board or mains connection unit. In that case, the connection means comprises transfer means for transferring the distance between the second connectors at the first and second line ends from the first distance to the second distance during performance of the electrical connection. Particularly, only one second connector of the first and second line ends is moved during performance of the electrical connection and the other one is already fixed at the first or second circuit board or at the mains connection unit, which especially is already positioned in the housing or installation case of the household appliance. During said performance of the electrical connection the movement is executed in only one dimension or in two dimensions, more preferably no movement in horizontal direction is performed.
One preferred embodiment of the present invention provides for at least one first connector, which is or comprises a terminal or connection point and the electrical connection is performed by means of at least one stiff or non-limp connection line, in particular by a conductor rail. Said connection line is resiliently mounted in the connection means and/or is elastically flexible or formable at least in the area of connection to the related terminal or connection point, which may be in the area of the first line end and/or of the second line end. Preferably, at least a section of the connection line next to or around the electrical connection includes a bulge-formed shaping, in particular with an Omega-shaped course and/or cross-section.
An important advantage of the stiff or non-limp connection line is the avoidance of "flying" wiring, i.e. an unstructured arrangement of cables and/or wiring connectors, which need to be connected manually. Further, in case of having always the same installation path of the electrical connection, electromagnetic compatibility can be improvement due to provision of constantly identical or same conditions. Moreover, assembling mistakes during manual connection are avoided and automated connection reduces manual activities.
In particular, the connection line comprises a first line end or end section contacting the terminal or connection point of the first circuit board and a second line end or end section contacting a terminal or connection point of the second circuit board or of the mains connection unit. A contact pressure is provided between at least one of the first and second line ends or end sections and the related terminal or connection point. Said contact pressure is preferably performed by elastic force having a magnitude that is selected to perform a bending of the connection line, in particular of the conductor rail, below the elastic limit of the material of the connection line. Said bending defines the magnitude of the contact force.
According to one embodiment, the terminal or connection point is a contact pad or area, which may comprise a particularly conductive material or surface. The electrical connection is preferably designed to provide an installation condition with a two-dimensional, more preferably a three-dimensional, tolerance compensation. The conductive material or surface of the contact pad may be steel or copper, alternatively or additionally a tin surface for a decreased contact resistance may be provided, e.g. by coating of the contact surface.
A favourable household appliance according to the present invention comprises a first circuit board, a second circuit board, and a mains connection unit. At least one point or section of the connection line is fixedly connected to a support or carrier of the first circuit board and/or of the second circuit board and/or of the mains connection unit. Alternatively, the at least one point or section of the connection line may be fixedly connected to a frame or housing part of the household appliance. Said fixed connection is preferably located at or close to the second line end or end section contacting a terminal or connection point of the mains connection unit.
One specific embodiment provides at least one terminal or connection point of the mains connection unit or of a third circuit board, which is connected with at least one terminal or connection point of the first circuit board and with at least one terminal or connection point of the second circuit board. The connection line that contacts the terminal or connection points of the first and second circuit boards and of the mains connection unit or the third circuit board may be T- or Omega-shaped.
In particular, the first circuit board and the second circuit board are connected to the mains connection unit by connection lines for power transmission. The mains connection means may include a first phase conductor, a second phase conductor, a neutral conductor and a protective conductor. At least the connection lines for the neutral conductor and for the protective conductor may be T- or Omega-shaped in top down view. This T- or Omega-shaped design may allow a connection of at least two circuit boards with the possibility of a connection to a separate mains power supply. Said mains power supply may be house junction box. The conductor rails may have a dedicated cross-section, depending on the required application. Further, the protective conductor rail may include an electrostatic discharge function, since electromagnetic emissions are in mV range.
The at least one connection line, in particular the conductor rail, is favourably included, preferably embedded, in a housing. Preferably, said housing, which may be a plastic housing, is Tor Omega-shaped and/or comprises pre-centering means in order to achieve a specifically precise positioning. Additionally or alternatively, the housing may comprise fixing means, particularly screw holes, for connecting the housing to a frame or housing part of the household appliance or to a support or carrier of the first circuit board and/or of the second circuit board and/or of the mains connection means.
The pre-centering means may be configured such that damages during the assembly process can be avoided. The arrangement may be at least close to the centre of gravity of the housing and/or of the complete unit. In order to enable a cost efficient fabrication, the housing may be designed symmetrically, particularly by a symmetrical T-shape, and/or it may have a uniform wall thickness. Preferably, clamping elements are arranged at the outer side of the housing as retainer means.
One particularly preferred embodiment of the present invention is characterized by an electrical connection performed by means of at least one connection line, which is enclosed or covered or supported at least partially or in several sections by a rigid block or support element. The block or support element may be non-conductive and preferably a plastic block or support element, or, alternatively, isolation means between the block or support element and the at least one connection line may be included. The block or support element includes or supports the second connectors at the first and second line ends.
The block or support element may be adapted to be connected to the at least one of the first and second circuit boards and/or to the at least one first circuit board and the mains connection unit in an assembly movement mainly in a direction at least approximately orthogonally to a main surface of the first circuit board and/or second circuit board and/or to a main surface of the mains connection means.
Preferably, the block or support element comprises guiding means and/or positioning means and/or engagement means for a precise coupling with the first circuit board and/or with the second circuit board and/or with the mains connection means.
According to one embodiment, the block or support element is adapted to be connected simultaneously to the first circuit board and to the second circuit board or the mains connection unit. The first circuit board on the one hand and the second circuit board or mains connection unit on the other hand are arranged side by side or in an only partially overlapping arrangement, so that their first connectors, in particular their terminal or connection points or connecting pins or plugs or sockets, are arranged side by side or stepped.
The first and second circuit boards or the at least one first circuit board and the mains connection unit may be arranged on the same level or step-like on different levels. A specific embodiment is characterized in that the first circuit board and the second circuit board or mains connection unit are arranged one above the other and the block or support element is arranged or arrangeable at least partially between these two devices.
According to embodiments, the block or support element comprises an upper connector and a lower connector. The upper connector is arranged at the upper or top side of the block or support element for a connection to the upper one of the first circuit board and the second circuit board or mains connection unit. The lower connector is arranged at the lower or bottom side of the block or support element for a connection to the lower one of the first circuit board and the second circuit board or mains connection unit.
The upper one of the first and second circuit boards or of the first circuit board and the mains connection unit may be movable in a direction towards the lower one of the first and second circuit boards or of the first circuit board and the mains connection unit. Said movement is preferably spring-loaded or executable against the force of a spring. More favourably, the movement is guided by means of guiding means, which may be arranged at the upper one of the first and second circuit boards or of the first circuit board and the mains connection unit. Additionally or alternatively, the guiding means may be arranged at a housing of the household appliance or at the block or support element or at the lower one of the first and second circuit boards or of the first circuit board and the mains connection unit.
According to one embodiment, the block or support element comprises a connector carrier carrying the upper connector. Said connector carrier is movably arranged at the block or support element by a limited movement in a direction towards the upper one of the first circuit board and the second circuit board or mains connection unit. Preferably, the plug or socket carrier is movable within a moving compartment, which may be a cage or retainer compartment. The movement of the connector carrier may be spring-loaded or executable against the force of a spring.
A specifically preferred embodiment is characterized in that the upper one of the first and second circuit boards is a user interface, which is pressed against an upper plate of the household appliance, particularly against a worktop of the cooking hob, by means of at least one spring element. Said spring element is arranged between the user interface, particularly a support or carrier of the user interface, and the lower one of the first and second circuit boards, particularly a power board of the household appliance. Alternatively, the spring element may be arranged between the user interface, particularly a support or carrier of the user interface, and a support or carrier of the lower one of the first and second circuit boards. Further alternatively, the spring element may be arranged between the user interface, particularly a support or carrier of the user interface, and a bottom wall of the housing of the household appliance, particularly a protection box of the cooking hob.
The object is also achieved by a connection device for electrical connection of a first circuit board and a second circuit board or of a first circuit board and a mains connection unit. The connection device comprises at least one connection line for transmission of electrical power and/or information signals, second connectors, in particular contacting or connecting elements or surfaces, connected to a first line end and to a second line end of the connection line and allocated or allocatable to first connectors, in particular terminal points or connecting pins or plugs, and support means for the connection line and/or for the second connectors. Said first connectors are arranged at the first and second circuit boards or at the first circuit board and the mains connection unit. Said support means are configured to provide a coupling of at least one of the second connectors with at least one of the first connectors of the first and second circuit boards and/or of the first circuit board and the mains connection unit. Said coupling is executed in an assembly movement mainly in a direction at least approximately orthogonally to the first and second circuit boards and/or to the first circuit board and the mains connection unit. The mains connection unit may be a mains terminal block. The connection device as described before is particularly designed for being used or implemented in a household appliance according to anyone of the afore-described embodiments.
The household appliance is particularly a cooking appliance and may be a cooking hob, in particular an electrically driven cooking hob. A specifically selected appliance is an induction cooking hob.
The object is also achieved by a method for assembling a household appliance, which comprises the steps

a. providing a housing or an installation case;
b. mounting a first circuit board into or on the housing or the installation case;
c. mounting a second circuit board or a mains connection unit, in particular a mains terminal block, into or on the housing or the installation case; and
d. mounting a connection means comprising or supporting at least one connection line for providing an electrical connection between the
- the first circuit board and the second circuit board or
- the first circuit board and the mains connection unit into or on the housing or the installation case.

The household appliance, to which the method applies or which is designed for the method to be applied on, is particularly a cooking appliance and may be a cooking hob, in particular an electrically driven cooking hob. A specifically selected appliance is an induction cooking hob. Further, it may be a household appliance according to anyone of the afore-described embodiments.
According to a one specific embodiment of the method, the mounting step a. is the first one, the mounting step b. or c. is the second one and the mounting steps d. is the third or fourth one of the mounting steps a. to d..
The mains connection means as described in anyone of the embodiments above, may be used for a connection of the household appliance to the electric power supply. It may be a module or component that is combined with another component or module, i. e. it may be mounted in combination with said other component or module. Preferably however, the mains connection means is a separate component or module, which is mounted during a separate mounting step, notably during an automated mounting step, preferably by means of an assembly robot.
The installation case described in embodiment above may be a receptacle or compartment of the household appliance and it may be included in the housing of the household appliance. In particular, the installation case is a protection box, specifically in the example of a cooking hob.
Novel and inventive features of the present invention are set forth in the appended claims.
The present invention will be described in further detail with reference to the drawing, in which

Fig. 1: illustrates the general structure of an induction cooking hob in an exploded perspective view;
Fig. 2: is a perspective top view of an assembled induction cooking hob designed similar to Fig. 1 including component groups;
Fig. 3: is a schematic top view of the induction hob according to Fig. 2 with indications of electrical contacting between component groups;
Fig. 4: is a schematic illustration of two contacting blocks electrically bridging three power boards of the induction cooking hob arranged side-by-side;
Fig. 5: is an enlarged perspective view of a translucently illustrated contacting block comprising contacting rails;
Fig. 6: is a perspective view of a contacting rail similar to the illustration of Fig. 5;
Fig. 7: is a top view of the contacting rail of Fig. 6;
Fig. 8: is a side view of a point of contact according to detail VIII of Fig. 6;
Fig. 9: illustrates a housing part of the contacting block according to Figs. 6 and 7 in a perspective view;
Fig. 10: is a schematic side view of an electrical connection between the power board and a user interface according to a first example;
Fig. 11: is a schematic top view the arrangement according to Fig. 10;
Fig. 12: is a schematic side view of an electrical connection between the power board and a user interface according to a second example;
Fig. 13: is a schematic front view the arrangement according to Fig. 12;
Fig. 14: is a schematic side view of an electrical connection between the power board and a user interface according to a third example;
Fig. 15: is a schematic front view the arrangement according to Fig. 14;
Fig. 16: is a schematic side view of an electrical connection between the power board and a user interface according to a fourth example;
Fig. 17: is a schematic side view of an electrical connection between the power board and a user interface according to a fifth example; and
Fig. 18: is a schematic front view the arrangement according to Fig. 17.

Fig. 1 illustrates an exploded perspective view of the general structure of a cooking hob 10.
The cooking hob 10 comprises a casing 12 and a panel 14. The casing 12 includes a bottom wall 12a, four sidewalls 12b and an open top side. Preferably, the casing 12 is made of metal, e.g. steel. Alternatively, the casing 12 may be made of plastics. The panel 14 covers the top side of the casing 12. For example, the panel 14 is a glass ceramic panel.
The cooking hob 10 comprises four circular cooking zones 15, two thereof with a smaller diameter, while the diameter of the other two cooking zones 15 are larger. The contours of the cooking zones are indicated by respective circles on the top surface of the glass panel 14. Each cooking zone 15 receives its heating power from a heating element 16 arranged beneath the panel 14.
A carrier 18 supports the heating element 16. Said carrier 18 is arranged beneath the heating elements 16. The carrier 18 is a metallic plate, preferably made of an aluminium material, and may be of an extension adapted to carry all four heating elements 16, in that having dimensions close to the dimensions of the glass panel 14. Alternatively, four carriers 18 may be provided, each carrier 18 supporting merely one dedicated heating element 16.
The cooking hob 10 further comprises a user interface 20 for enabling user inputs including also a control panel for controlling the cooking hob functions. The user interface 20 includes touch sensors and display means corresponding with a user interface zone 21 arranged at the front edge of the glass panel 14.
Preferably, the heating element 16 is an electric heating element. At least one printed circuit board 22 is arranged above the bottom wall 12a of the casing 12. A plurality of electric and/or electronic elements 24, 26 is attached on the printed circuit board 22. The printed circuit board 22 including the electric and/or electronic elements 24, 26 forms a power board of the cooking hob 10. Power electronic elements 26 for supplying the heating elements 16 with electrical power are attached to a cooling channel 28, which extends horizontally through the cooking hob 10. An air stream driven by at least one fan 30 passes the cooling channel 28 and cools down the power electronic elements 26.
In this example, the cooking hob 10 is an induction cooking hob, wherein the heating element 16 is a heating coil unit 16 comprising an induction coil and the carrier 18 is a coil carrier.
Fig. 2 illustrates schematically an assembled induction cooking hob 10 designed similar to Fig. 1. The assembly of Fig. 2 mainly differs from the solution of Fig. 1 in that the single power board 22 of Fig. 1, which is configured to supply all four cooking zones 15, is split into two power boards 22, each one thereof supplying two cooking zones 15 arranged one behind the other. Further, for the sake of clarity, Fig. 2 only shows the electrical components of the induction cooking hob 10 in the form of two power boards 22 and the user interface 20 arranged in the casing 12. Further components arranged above the power boards 22 and the user interface 20, e. g. heating coils units 16 and glass panel 14 are left out. Also the power boards 22 are illustrated only schematically, particularly without any electric and electronic parts, except their cooling channels 28 and associated fan. Moreover, the user interface 20 is also shown without any details, but it is indicated as being arranged in a user interface carrier that is supported by a pedestal 20a against the bottom wall 12a of the casing 12.
As already indicated in Fig. 2 by 32, the schematic illustration of Fig. 3 shows more precisely the way of electrically connecting the two power boards 22 with other as well as each one of the two power boards 22 with one user interface 20. The provision of two elongated user interface devices in a side-by-side arrangement according to Fig. 3 is a different solution to the option of Fig. 2 with implementing all user input fields in a single device, what also represents a different induction cooking hob model.
Nowadays the electrical connection, in particular the information communication as well as the power connection, of two power boards 22 among each other and/or with the related user interface modules 20 is executed in manufacturing facilities by manual connection of respective wirings and cables, particularly cable harnesses. In order to facilitate the electrical connection, the solution according to Fig. 3, but also further solutions represented by the following figures, turns away from this principle of manual cable connection and illustrates an electrical connection free of flexible cables.
The solution according to Fig. 3 provides an electrical connection of the power boards 22 among each other as well as of each power board 22 with one related user interface 20 by means of at least one connection block 32, 34, which includes not only the wiring but also the connection means that are connectable to the related terminal element of the printed circuit board, i. e. power board 22 or user interface 20. Said connection block may comprises either connection lines for power connection or power transfer, indicated by 32, or connection lines for information transmission, indicated by 34. Depending on the design of the power boards 22 to be connected, the connection block for power transfer 32 and the connection block for information transmission may be arranged adjacently (see Fig. 2) or they may be arranged distant from each other (see Fig. 3). However, even more advanced solution includes the functionalities of power transfer and information transmission in a combined connection block unit 32, 34, particularly a "multifunctional mains and communication connector", as will be described more in detail further down below with reference to Fig. 4. Moreover, two UI connector blocks are illustrated in Fig. 3, which is configured to carry out information transmission between one power board 22 and the user interface 20, preferably also a power supply of the user interface 20 is instituted.
Fig. 4 illustrates schematically the electrical connection of three power boards 22 of an extensive induction cooking hob 10, particularly with a width of 90 cm and comprising five or six cooking zones 15, by means of two combined connection block units 32, 34. A first one of the combined connection block units 32, 34 is positioned on the border of left and centre power boards 22, transferring power and information between these power boards 22, and a second one is positioned on the border of centre and right power boards 22 for their power and information transfer. Both combined connection block units 32, 34 comprise connection means on their bottom side and they are configured to be mounted from above. Preferably by one single plug movement, all wiring connection between the involved two power boards 22 is performable.
Each one of the combined connection block units 32, 34 may comprise guiding means, positioning means and/or engagement means (not shown), particularly latching elements, in order to correctly position and fix it on the pair of power boards 22.
The information transmission realized with a combined connection block unit 32, 34 is realized by means of a communication bus. While the combined connection block unit 32, 34 connecting the centre and the right power boards 22 is designed for mere power and information transfer between these two power boards 22, the combined connection block unit 32, 34 coupling the centre and the left power boards 22 also comprises connection lines and connection means for a power connection to a mains terminal unit, which may be a separate unit on a separate circuit board or, as realized in the present example according to Fig. 4, the connection of the centre power board to the mains supply may be performed directly by the combined connection block unit 32, 34 for connecting the centre and the left power boards 22, which also includes a section 32' for directly connecting a mains power cord (not shown). A channel 38 for a guided introduction of the mains power cord is comprised as well.
As also indicated with the designation of the connecting pins of the combined connection block units 32, 34, each one of the three power boards 22 is configured to be supplied by one phase L1, L2, L3 of a three-phase network. The neutral and ground conductors are distributed for common connection. The protection phase is also connected to the metallic casing, but only once, rather than from each one of the three power boards 22.
The connection of the connection lines included in the connection blocks 32, 34 may be of any type known in the art, in particular plug and socket connections. In such solution, connecting plugs may be included for example in the connection block 32, 34 pluggable to related sockets implemented as terminal points on the circuit board, e. g. the power board 22. One preferred solution, however, is illustrated by Figs. 5 to 9 and provides conductor rails 40, 40' for performing connection between a contact point on a first one of the power boards 22 with a related contact point on a second one of the power boards 22. Fig. 5 schematically illustrates said first and second power boards 22 arranged side-by-side within related support frames 42, which are preferably made of plastic in order to provide electric isolation to the power board 22 from the metallic casing 12. A first group of conductor rails 40 is configured for transferring power and a second group of conductor rails is configured for transferring information between the interconnected power boards 22. The metallic conductor rails 40, 40' are configured to touch the related contact points with their first and second end sections 44, 44' from above, which contact points may be uncoated surfaces of conductive tracks on the circuits of the power boards 22. Each one of the groups of conductor rails 40, 40' is covered by a rail housing 46, 46', which rail housings 46, 46' are translucently illustrated in Fig. 5. Due to adjacent arrangement, the separate rail housings 46, 46' are mechanically interconnected at one longitudinal side and hold-down clamps 48, which are formed integrally with the support frames 42, press down the rail housings 46, 46, and insofar the respective conductor rails 40, 40', against the power boards 22, what establishes contact between the conductor rails 40, 40' and the related contact points on the circuits of the power boards 22, as explained below.
The conductor rails 40, 40', which are generally applicable to a number of different applications, are characterized by dedicated cross-sections and layouts depending on the respective application. The embodiment of Fig. 5 provides only two, or three respectively, rails 40, 40' arranged in parallel. If, however, an electric power supply with connection to the mains supply shall be integrated, as outlined in Fig. 4, a cross-section and layout of the conductor rails 40 arrangement is illustrated in detail by Figs. 6 to 8.
Figs. 6 and 7 represent a perspective view and a top view of a conductor rails 40 arrangement for power supply and power transfer. When looking from above, the overall layout is similar to a T-shaped design. A neutral conductor rail N thereof is T-shaped and comprises terminal or contacting points to be connected to first and second power boards 22 as well as to a neutral conductor of a power supply cable. A protective conductor rail PE is Omega-shaped and also comprises terminal or contacting points to be connected to first and second power boards 22 and, respectively, to a protective conductor of a power supply cable. Naturally, above-described T- and Omega-shapes depend on the structure of the respective contacting block and any other suitable design of an arrangement of conducting rails may be considered. Finally, phase conductors L1, L2 for a two-phase power supply for two power boards 22 are also included with a direct connection between each one of the two phase conductors L1, L2 to the related one of the two power boards 22. The PE conductor rail also includes an electrostatic discharge function ESD, which is possible since the electromagnetic emissions are in the millivolt range only. The system according to Figs. 6 and 7 preferably transfers up to 32 A current, more preferably up to 16 A current. If applied to information transmission, the system may be operable at 10 mA, more preferably at 5 mA or even less.
As illustrated by Fig. 8, which is a detail view of the detail VIII indicated in Fig. 6, the contact between a conductor rail 40, 40' and the related contact point is executed by an elastic form of an end section 44, 44', wherein the end section 44, 44' is pressed against the contact point in a spring-loaded manner. In a side view the end section 44, 44' is designed with an upside down Omega-shape, with the lowest point of the Omega constituting the contact point on the conductor rail 40, 40'. Insofar, the end section 44 shown in Fig. 8 constitutes a spring element, which generates a spring force F_c in the direction towards the contact point, which is formed as a contact pad 50. The spring force F_c is equivalent to a contact force F_k for this connection. The contact pad 50 is connected to the power board 22, in particular to the conducting path thereon. The material of the contact pad 50 is characterized by specific electrical conductivity and may be of steel or, preferably, of copper. It may also have a tin surface coating, further decreasing the contact resistance. The point of clamping significantly defines the bending of the connection and, insofar, the magnitude of the amount of force. The characteristics of the way of clamping are chosen in that no plastic deformation will occur, so that a permanent electrical connection is guaranteed.
With the illustrated contacting by means of the upside down Omega and the related contact pad 50 a three-dimensional tolerance elimination area is provided. In correspondence with the size of the contact pad 50, the position tolerance in horizontal directions can be eliminated, while the altitude tolerance is eliminated by the elasticity of the end section 44, 44' of the conductor rail 40, 40'.
Finally, a specific plastic rail housing 46" for the conductor rails assembly of Figs. 6 to 8 is illustrated in Fig. 9. The outer dimensions of the rail housing 46'' follow the outer dimensions of the conductor rails assembly. Further, channel 38 for a guided introduction and a strain relief clamp 52 for the mains power cord are included.
With reference to the Figs. 10 to 19, different examples of electrical connections between a power board 22 and a user interface 20 will be described. Said electrical connection includes both power transfers from the power board 22 to the user interface 20 and information communication, particularly in a bi-directional manner.
As already illustrated by Fig. 2, the user interface 20, notably a circuit board comprising the user interface functionality, is arranged on top of a pedestal 20a, preferably made of plastics, in that establishing an elevated arrangement level compared to that one of the power board 22. Said pedestal 20a is supported by the bottom wall 12a of the casing 12.
Similar as with the interconnection of power boards 22, also a power board 22 and a related user interface 20 are interconnected by means of flexible wiring, particularly by means of cable harnesses, which have to be connected manually on assembly lines. With Figs. 10 to 19 more efficient, in particular more cost-efficient, connection processes can be performed, which connection processes also enable a fully automated assembling of interconnection means, e. g. by means of assembly robots. The presented examples also take into account the different arrangement levels of power board 22 and user interface 20. It is to be further considered that the user interface 20 must have a close contact to the glass plate 14, more specifically to the user interface zone 21 arranged thereon, in order to secure that the touch elements of the user interface 20 can be operated by the user from the upper glass surface. Furthermore, also the display, e. g. LEDs or a TFT screen can be readily seen through the glass plate 14.
A first example of connecting a power board 22 with a user interface 20 is illustrated schematically in Figs. 10 and 11 and is based on the embodiment according to Fig. 3 showing two pairs of a power board 22 and a user interface 20 interconnected by means of a UI connector block 36. Such a UI connector block is generally separated into three sections 36a, 36b, 36c, including a first section 36a arrangeable directly above and establishing electrical contact with the power board 22, a third section 36c arrangeable directly below and establishing electrical contact with the user interface 20 and a second section 36b connecting mechanically and electrically the first section 36a with the third section 36c.
The three sections 36a, 36b, 36c are characterized by three separate plastic housings or boxes, which enclose information communication and power supply wires 54 or strip conductors isolated from each other or by way of plastic moulding. The information communication and power supply wires 54 or strip conductors are connected to a power board contact plate 56 arranged on a bottom side of the first section 36a as well as to a UI contact plate 58 arranged on a top side of the third section 36c. Said power board contact plate 56 includes contacting means for establishing electrical contact with compatible contacting means on the power board 22 and said UI contact plate 58 includes contacting means for establishing electrical contact with compatible contacting means on the user interface 20. Said contacting means may be designed in the same or in a similar way as described above with the contacting means related to interconnections between two power boards 22. As illustrated, the power board contact plate 56 is configured to be connected to the power board 22 from above in a top down movement. On the contrary, the UI contact plate 58 is configured to be connected to a bottom side of the user interface 20, which is performed in an assembly line in that the user interface 20 is placed on the third section 36c of the already assembled UI connector block 36, thereby establishing the electrical contacts.
In order to compensate tolerances, particularly in a vertical direction as indicated by arrow 60, the third section is mechanically connected to the second section 36b, and preferably also the second section 36b is connected to the first section 36a, in a spring-loaded way, so that a spring force acting at least on the third section 36c presses the UI contact plate 58 against the bottom side of the user interface 20. The mechanical coupling of the first section 36a with the power board 22 is not shown, but may be arranged similarly to the latching mechanism indicated in Fig. 5 by hold-down clips 48.
A second example of connecting a power board 22 with a user interface 20 is illustrated schematically in Figs. 12 and 13. Said connection is supported by using a wiring carrier 62, which is a separate part and may be produced from a plastic material. Similar to the first example, the wiring carrier 62 includes information communication and power supply wires 54, in Fig. 12 indicated by a freehand line, which are connected to a power board contact plate 56 arranged on a bottom surface of the wiring carrier as well as to a UI contact plate 58 arranged in a top portion of the wiring carrier 62. Said power board contact plate 56 includes contacting means for establishing electrical contact with compatible contacting means on the power board 22 and said UI contact plate 58 includes contacting means for establishing electrical contact with compatible contacting means on the user interface 20. Said contacting means may be designed in the same or in a similar way as described above with the contacting means related to interconnections between two power boards 22. As illustrated, the power board contact plate 56 is configured to be connected to the power board 22 from above in a top down movement. On the contrary, the UI contact plate 58 is configured to be connected to a bottom side of the user interface 20, which is performed in an assembly line in that the user interface 20 is electrically connected to the UI contact plate 58 of the already assembled wiring carrier 62. The wiring carrier is also balancing the height difference, which is necessary for the mounting, specifically for the automated mounting.
During the assembly of the induction cooking hob 10 as schematically illustrated by Figs. 12 and 13, at first the power board 22 is placed on the bottom wall 12a of the casing 12. This may be performed in an automated way by an assembly robot. Thereafter, the wiring carrier 62 is arranged inside of the casing 12, preferably during a simple vertical movement fro above, partly on top of the power board 22, thereby establishing the electrical connections as described above, partly on the bottom wall 12a by means of an integrated leg support 64. After that, the user interface 20 together with its UI carrier 66 is placed on the top portion of the wiring carrier 62 in a vertical movement, thereby establishing the electrical connection with the UI contact plate 58 by pressing the user interface 20 on the UI contact plate 58. The connection between user interface 20 and UI contact plate 58 may be established by means of plugs and related sockets, which are complementary connection elements and are arranged on the involved components 20, 58.
The UI contact plate 58 is movable in vertical direction, preferably, as schematically indicated, by a free movement within a guiding means 68. Said guiding means 68 may be designed as a cu-boid guide cage comprising a base area complying with the horizontal extensions of the UI contact plate 58 as well as a vertical extension that provides a stopper limiting the vertical movement in the upwards direction. This guarantees that the UI contact plate 58 will not be pulled out of the wiring carrier 62 unintendedly, e.g. during repair works.
The UI carrier 66 is configured to accommodate the user interface 20. This is performed by pressing the user interface 20 to the bottom surface of the glass plate 14. The UI carrier 66 is spring mounted by means of coil springs 70, preferably arranged in the four corner areas of the rectangular UI carrier 66. A top side of the UI carrier 66 comprises a through hole 72 enabling the connection of the user interface 20 with the UI contact plate 58. During assembly of the User interface 20 from above, it is favourable that the UI contact plate has less play than the user interface 20 from above. Accordingly, in an automated assembly process, the user interface 20 can be connected to the UI contact plate 58 by performing a connection force from above. In a mounted state, the UI carrier 66 is still spring-loaded, which performs a pressure of the user interface 20 into an upwards direction, i. e. against the bottom surface of the glass plate 14. Said glass plate 14 is mounted in a final step, again from above in a top down movement, what is also executable during an automated mounting process. As is known in the prior art, on the bottom surface of the glass plate 14 snapping elements (not shown) are arranged for mechanically connecting the glass plate 14 to the casing 12.
Optionally, the wiring carrier 62 comprises additional spring elements 74 (see Fig. 13) at its upper face for upwardly pressing the UI contact plate 58 against the stopper, i. e. against the top side of the guiding means 68.
A third example illustrated in Figs. 14 and 15 differs from the second example in an omission of the UI carrier 66. The wiring carrier 62 has similar functionalities related to the connection with the power board 22, i. e. using a power board contact plate 56. In order to take on the spring-loaded pressing of the user interface 20 against the bottom surface of the glass plate 14, as it is performed by the UI carrier 66 in the second example described above, a top side of the wiring carrier 62 supports a plurality of UI spring elements 76, which may be attached either to the bottom side of the user interface 20 or to said top side of the wiring carrier 62. Said UI spring elements 76 are configured to push the user interface 20 towards the glass plate 14.
According to a further optional embodiment, as an alternative to the embodiment according to Figs. 14 and 15, only the UI contact plate 58 is spring-loaded and pushes the user interface 20 towards the glass plate 14, thereby omitting the UI spring elements 76. In that case, the user interface 20 may additionally be supported and guided by lateral guiding elements (not shown), which may be formed as integral parts of the wiring carrier 62.
Fig. 16 schematically illustrates a fourth example of connecting a power board 22 with a user interface 20. This example differs from the embodiments according to Figs. 12 to 15 in an omission of the wiring carrier 62. Instead, a UI carrier 66 takes on the tasks of said wiring carrier 62. Again, the user interface 20 is pressed against the bottom side of the glass plate 14 by spring force. The respective spring element, or a plurality of spring elements, operates as a conductor spring 78, i. e. on the one hand it functions as a means of pressure for effecting the user interface 20 being pressed against the glass plate 14, and on the other hand it forms the electrical connection between user interface 20 and power board 22, particularly to a contact pad 50 on or connected to conducting path of the power board circuit. In this way, the connection between the conductor element and the terminal point of the power board 22 and/or of the user interface 20 may be realized without plugs and sockets. The conductor spring 78 may be continuously formed as a coil spring, or, as illustrated in Fig. 16, only the end sections thereof are formed in this way, while a middle section is elongated and passes a channel provided in the wiring carrier 62 or is supported by the wiring carrier 62 by overmoulding. The wiring carrier 62 may also be pushed upwardly by coil springs 70 and guide pins 80 guided within guide sleeves 82, which interact with the casing 12 or the support frame 42, may be arranged for a guided movement and positioning of the wiring carrier 62.
A fifth example will be now described with reference to Figs. 17 and 18. While all above-described embodiments are characterized in that the user interface 20 has to be pressed against the bottom side of the glass plate 14 in order to guarantee that the touch elements on the user interface 20 will be properly operated by the user touching the respective area on the upper side of the glass plate 14, the embodiment according to the fifth example is designed with spring-loaded touch control elements 84, which are individually pressed against the bottom side of the glass plate 14. Due to this arrangement of spring-loaded touch control elements 84, there may be no need for a provision of a spring-loaded user interface 20 and/or for a spring-loaded UI carrier 66 in order to guarantee proper functionality of the touch control operation, however, the display image will be improved by a user interface 20 also touching the bottom side of the glass plate 14.

List of reference numerals

10: cooking hob
12: casing
12a: bottom wall
12b: side walls
14: glass panel
15: cooking zones
16: heating coil units
18: coil carrier
20: user interface
20a: pedestal
21: user interface zone
22: power board
24: electric / electronic elements
28: cooling channel
30: fan
32: connection block for power transfer
32': section
34: connection block for information transmission
36: UI connector block
36a, 36b, 36c: first, second and third sections
38: channel
40, 40': conductor rails
42: support frame
44, 44': first and second end sections
46, 46', 46'': rail housings
48: hold-down clamps
50: contact pad
52: strain relief clamp
54: information communication and power supply wires
56: power board contact plate
58: UI contact plate
60: arrow
62: wiring carrier
64: leg support
66: UI carrier
68: guiding means
70: coil spring
72: through hole
74: additional spring elements
76: UI spring elements
78: conductor spring
80: guide pin
82: guide sleeve
84: touch control element

Claims

A household appliance (10), particularly a cooking appliance, more particularly a cooking hob, even more particularly an induction cooking hob, comprising
- a first circuit board (22) and a second circuit board (20) or

- a first circuit board and a mains connection unit, particularly a mains terminal block,
which are electrically connectable by a connection means comprising at least one connection line (40, 40', 54, 78), wherein each one of
- the first circuit board (22) and the second circuit board (20)
or

- the first circuit board and the mains connection unit comprises at least one first connector (50) for an electrical connection for power and/or information transmission, the first connector (50) of the first circuit board (22) being of the same or of a different type as the first connector (50) of the second circuit board (20) or of the mains connection unit,
wherein the connection line (40, 40', 54, 78) comprises a second connector (44, 44') at a first line end and a second connector (44, 44') at a second line end,
wherein the first connector (50) of the first circuit board (22) is connectable to the second connector (44, 44') at the first line end and the first connector (50) of the second circuit board (20) or of the mains connection unit is connectable to the second connector (44, 44') at the second line end,
wherein each pair of first (50) and second (44, 44') connectors is compatible to one another and comprises a terminal or connection point or a connecting pin or a plug or a socket, and wherein the second connector (44, 44') at the first line end and the second connector (44, 44') at the second line end are arranged in a pre-defined first distance from each other at least before performing the electrical connection between
- the first circuit board (22) and the second circuit board (20) or

- the first circuit board and the mains connection unit.
The household appliance (10) according to claim 1,
characterized in that
the connection means comprises a plurality of connection lines (40, 40', 54, 78) for electrical connection for power and/or information transmission, preferably including all electrical connections for power and/or information transmission between
- the first circuit board (22) and the second circuit board (20)
or

- the first circuit board and the mains connection unit, each one of the plurality of connection lines (40, 40', 54, 78) comprising second connectors (44, 44') at their first and second line ends, wherein the second connectors (44, 44') in a pairwise relationship are arranged in a pre-defined first distance from each other at least before performing an electrical connection between

- the first circuit board (22) and the second circuit board (20)
or

- the first circuit board and the mains connection unit.
The household appliance (10) according to claim 1 or 2,
characterized by
a defined course of the connection line (40, 40', 54, 78) between the second connectors (44, 44') at the first and second line ends at least before performing the electrical connection between
- the first circuit board (22) and the second circuit board (20)
or

- the first circuit board and the mains connection unit, the defined course in particular being formed

- by a stiff connection line (40, 40', 78), particularly a conductor rail (40, 40'), or

- by a cable (54) that is guided in a defined manner, in particular fixed by means of plastic injection moulding.
The household appliance (10) according to anyone of the preceding claims,
characterized in that
the connection means comprises a housing (46, 46', 46", 62), preferably a plastic housing, enclosing the connection line (40, 40', 54, 78), the housing (46, 46', 46'', 62) particularly comprising fixation means for the connection line (40, 40', 54, 78) and/or completely enclosing the connection line (40, 40', 54, 78).
The household appliance (10) according to anyone of the preceding claims,
characterized in that
the second connector (44, 44') of the first line end and the second connector (44, 44') of the second line end are arranged in a second distance from each other after performing the electrical connection between
- the first circuit board (22) and the second circuit board (20)
or

- the first circuit board and the mains connection unit, wherein the connection means comprises transfer means for transferring the distance between the second connectors (44, 44') at the first and second line ends from the first distance to the second distance during performance of the electrical connection.
A household appliance (10) according to anyone of the preceding claims,
characterized in that
at least one first connector (50) is or comprises a terminal or connection point and the electrical connection is performed by means of at least one stiff connection line (40, 40', 78), in particular a conductor rail (40, 40'), which connection line (40, 40', 78) is resiliently mounted in the connection means and/or is elastically flexible or formable at least in the area of connection to the related terminal or connection point (50), particularly in the area of the first line end and/or of the second line end, wherein preferably at least a section (44, 44') of the connection line (40, 40', 78) next to or around the electrical connection includes a bulge-formed shaping, in particular with an Omega-shaped course and/or cross-section.
The household appliance (10) according to claim 6,
characterized in that
the connection line (40, 40', 78) comprises a first line end or end section (44, 44') contacting the terminal or connection point (50) of the first circuit board (22) and a second line end or end section (44, 44') contacting a terminal or connection point (50) of the second circuit board (20) or of the mains connection unit, wherein a contact pressure is provided between at least one of the first and second line ends or end sections (44, 44') and the related terminal or connection point (50), the contact pressure preferably being performed by elastic force having a magnitude that is selected to perform a bending of the connection line (40, 40', 78), in particular of the conductor rail (40, 40'), below the elastic limit of the material of the connection line (40, 40', 78).
The household appliance (10) according to claim 6 or 7,
characterized in that
the terminal or connection point (50) is a contact pad or area, in particular comprising a particularly conductive material or surface, the electrical connection preferably being designed to provide an installation condition with a two-dimensional, more preferably a three-dimensional, tolerance compensation.
The household appliance according to anyone of the claims 6 to 8,
characterized by
- a first circuit board (22), and

- a second circuit board (20), and

- a mains connection means,
wherein at least one point or section of the connection line (40, 40') is fixedly connected to a support or carrier of at least one of
- the first circuit board (22),

- the second circuit board (20),

- the mains connection means,
or to a frame or housing part of the household appliance (10),
the fixed connection preferably being located at or close to the line end or end section (32') contacting a terminal or connection point of the mains connection unit.
The household appliance (10) according to anyone of the claims 6 to 9,
characterized in that
at least one terminal or connection point of the mains connection unit or of a third circuit board is connected with at least one terminal or connection point of the first circuit board (20) and with at least one terminal or connection point of the second circuit board (20), the connection line (40, 40') contacting the terminal or connection points of the first (22) and second (20) circuit boards and of the mains connection unit or the third circuit board particularly being T- or Omega-shaped.
The household appliance (10) according to anyone of the claims 6 to 10,
characterized by
- a first circuit board (22), and

- a second circuit board (20), and

- a mains connection means,
wherein the first circuit board (22) and the second circuit board (20) are connected to the mains connection unit by connection lines (40) for power transmission,
particularly including a first phase conductor (L1), a second phase conductor (L2), a neutral conductor (N) and a protective conductor (PE), at least the connection (40) lines for the neutral conductor (N) and for the protective conductor (PE) being T- or Omega-shaped.
The household appliance (10) according to anyone of the claims 6 to 11,
characterized in that
the at least one connection line (40, 40', 78), in particular the conductor rail (40, 40'), is included, preferably embedded, in a housing (46"), in particular a plastic housing, the housing (46") preferably
- being T- or Omega-shaped and/or

- comprising pre-centering means and/or

- comprising fixing means, particularly screw holes, for connecting the housing (46") to a frame or housing part of the household appliance (10) or to a support or carrier of at least one of
> the first circuit board (22),

> the second circuit board (20),

> the mains connection means.
A household appliance (10) according to anyone of the preceding claims,
characterized in that
the connection line (54, 78) is enclosed or covered or supported at least partially or in several sections (36a, 36b, 36c) by a rigid block or support element (36, 62),
- the block or support element (36, 62) being non-conductive and preferably being a plastic block or support element (36, 62)
or

- isolation means between the block or support element (36, 62) and the at least one connection line (54, 78) being included,
wherein the block or support element (36, 62) includes or supports the second connectors at the first and second line ends.
The household appliance (10) according to claim 13,
characterized in that
the block or support element (36, 62) is adapted to be connected to at least one of the first circuit board (22) and the second circuit board (20) or the mains connection unit in an assembly movement mainly in a direction at least approximately orthogonally to a main surface of the first circuit board (22) and/or of the second circuit board (20) and/or of the mains connection unit.
The household appliance (10) according to claim 13 or 14,
characterized in that
the block or support element (36, 62) comprises guiding means (68) and/or positioning means and/or engagement means for a precise coupling with the first circuit board (22) and/or with the second circuit board (20) and/or with the mains connection unit.
The household appliance (10) according to anyone of the claims 13 to 15,
characterized in that
the block or support element (36, 62) is adapted to be connected simultaneously to
- the first circuit board (22) and the second circuit board (20)
or

- the first circuit board and the mains connection unit, wherein

- the first circuit board (22) and the second circuit board (20)
or

- the first circuit board and the mains connection unit, are arranged side by side or in an only partially overlapping arrangement, so that their first connectors (50) are arranged side by side or stepped.
The household appliance (10) according to anyone of the claims 13 to 15,
characterized in that
- the first circuit board (22) and the second circuit board (20)
or

- the first circuit board and the mains connection unit, the first circuit board (22) and the second circuit board (20) or the mains connection unit are arranged one above the other and the block or support element (36, 62) is arranged or arrangeable at least partially between

- the first circuit board (22) and the second circuit board (20)
or

- the first circuit board and the mains connection unit.
The household appliance (10) according to claim 17,
characterized in that
the block or support element (36, 62) comprises
- an upper connector at its upper side for a connection to the upper one of
> the first circuit board (22) and the second circuit board (20)
or

> the first circuit board and the mains connection unit, and

- a lower connector at its lower side for a connection to the lower one of
> the first circuit board (22) and the second circuit board (20)
or

> the first circuit board and the mains connection unit.
The household appliance (10) according to claim 17 or 18,
characterized in that
the block or support element (62) comprises a connector carrier (58) carrying the upper connector, which connector carrier (58) is movably arranged at the block or support element (62), preferably movable within a moving compartment (68), particularly a cage or retainer compartment, by a limited movement in a direction towards the upper one of
- the first circuit board (22) and the second circuit board (20)
or

- the first circuit board and the mains connection unit.
The household appliance (10) according to claim 19,
characterized in that
the movement of the connector carrier (58) is spring-loaded or executable against the force of a spring.
The household appliance (10) according to claim 20,
characterized in that
the upper one of the first (22) and second (20) circuit boards is a user interface, which is pressed against an upper plate (14) of the household appliance (10), particularly against a worktop of the cooking hob, by means of at least one spring element arranged between the user interface (20), particularly a support or carrier (66) of the user interface (20), and the lower one of the first (22) and second (20) circuit boards, particularly a power board of the household appliance (10), or a support (42) or carrier of the lower one of the first and second circuit boards or a bottom wall (12a) of the housing (12) of the household appliance (10), particularly a protection box of the cooking hob.
A connection device for electrical connection of
- a first circuit board (22) and a second circuit board (20) or

- a first circuit board and a mains connection unit, particularly a mains terminal block,
in particular for the household appliance (10) according to anyone of the preceding claims, the connection device comprising

- at least one connection line (40, 40', 54, 78) for transmission of electrical power and/or information signals,

- second connectors (44, 44'), in particular contacting or connecting elements or surfaces, connected to a first line end and a second line end of the connection line (40, 40', 54, 78) and allocated or allocatable to first connectors (50), in particular terminal points or connecting pins or plugs, arranged
> at the first circuit board (22) and the second circuit board (20)
or

> at the first circuit board and the mains connection unit,
and

- support means for the connection line (40, 40', 54, 78) and/or for the second connectors (44, 44'), which are configured to provide a coupling of at least one of the second connectors (44, 44') with at least one of the first connectors (50) of at least one
> of the first circuit board (22) and the second circuit board (20)
or

> of the first circuit board and the mains connection unit
in an assembly movement mainly in a direction at least approximately orthogonally to the at least one

- of the first circuit board (22) and the second circuit board (20)
or

- of the first circuit board and the mains connection unit.
A method for assembling a household appliance (10), particularly a cooking appliance, more particularly a cooking hob, even more particularly an induction cooking hob, the method comprising the steps
a. providing a housing (12) or an installation case, particularly a protection box;

b. mounting a first circuit board (22) into or on the housing (12) or the installation case;

c. mounting a second circuit board (20) or a mains connection unit, in particular a mains terminal block, into or on the housing (12) or the installation case; and

d. mounting of a connection means (32, 34, 36, 62) comprising or supporting at least one connection line (40, 40', 54, 78) for providing an electrical connection between
- the first circuit board (22) and the second circuit board (20)
or

- the first circuit board and the mains connection unit
into or on the housing (12) or the installation case, each of the mounting steps b., c. and d. being performed in an assembly movement in a direction at least approximately orthogonally to a base area (12a) of the housing (12) or the installation case, the method in particular being applied on a household appliance (10) according to anyone of the claims 1 to 21.
The method according to claim 23,
characterized in that
the mounting step a. is the first one, the mounting step b. or c. is the second one and the mounting steps d. is the third or fourth one of the mounting steps a. to d..