EP2483502B1 - Door opener for domestic appliance and domestic appliance with such a door opener - Google Patents

Description

The invention relates to a door opening device for a domestic appliance, which is designed for automatically opening a door of the domestic appliance, and having a drive motor which is mechanically coupled via an actuating device with a door hook. Furthermore, the invention relates to a domestic appliance, in particular an oven, with such a door opening device.

Domestic appliance door opening devices such as ovens, microwave ovens, freezers, refrigerators or the like are known in a variety of ways. The doors are provided in this context for closing a cooking chamber or other storage space. In this context, doors are known which have on a front panel at the front at least one handle element which can be gripped by a user and manually operated, so that the door can be opened. Such grip elements are usually over to the front, so that they need a place and on the other hand, a user can push it. In addition, in such exclusively manually operable handle elements, if necessary, a relatively high application of force be expended in order to ensure the opening can.

Furthermore, automatic door opening devices are provided on door devices for opening the door. For example, it is provided here that the door is unlocked by pressing an actuating element or an opening button and is automatically opened or pops up. In case of failure of the said actuating mechanism or the necessary electronics, the opening is only possible by a service staff or customer service. Furthermore, in the case of such electronically controlled door opening devices which can be actuated by a user via a control button arranged at the front, no further explicit grip element is provided any longer. The handling is therefore user-unfriendly. For complete opening, therefore, the user must explicitly the front panel or the usual Do not touch areas of the door that are not primarily gripped and open the door completely. As a result, the door is contaminated by finger marks and the like and must therefore also often wiped and cleaned due to hygienic conditions.

Furthermore, the previously known electronically controlled door opening devices have a very complex structure and are relatively slow in their reaction time.

From the DE 202 12 615 U1 is an electric motor adjustment with a safety limit known.

Furthermore, from the US 2006/0213239 A1 a device for opening and closing a door for a household appliance known. The said mechanical coupling is via a motor which drives an adjusting device with a toothed wheel. At the adjustment of the door hook is arranged. The adjusting device comprises two curved and rising webs revolving around a longitudinal axis of the adjusting device, on each of which a corresponding element can roll, in order then to actuate the door hook as a function of the rotation of the adjusting device.

It is an object of the present invention to provide a door opening device for a domestic appliance and such a domestic appliance with a door opening device with which or with which the door is opened comfortably and without jerky movements and in particular the door hook can be moved evenly by the drive motor.

This object is achieved by a door device having the features of claim 1, a domestic appliance, which has the features of claim 13.

With regard to the specific embodiment of a door opening device according to the invention, this is designed to automatically open the door of the household appliance. In particular, the door opening device has a drive motor, which is mechanically coupled via an actuating device of the door opening device with a door hook. The drive motor is coupled to a cam element of the actuating device, which has a helical cam track which abuts a transmission element of the actuator, which is coupled to the door hook and with which the movement of the cam member is transferable to the door hook. By such a specific embodiment of the door opening device with the specific embodiments of the elements and the interaction, a rotational movement of the drive motor, in particular its shaft, can be converted into a linear movement of the door hook to open the door. Due to the very specific design of the cam member with the helical cam track, this motion conversion can be particularly smooth and smooth, so that even here unwanted movements can be prevented. Thus, the occurrence of high torques or force effects on the components when opening can be avoided, so that the wear of the door opening device can be significantly reduced. Not least can be made possible by this helical or tortuous path of the cam a particularly precise, metered and accurate motion control.

It is the rotational position of the cam member detected by an electronic switch. As a result, the motion control can be made even more precise with regard to the precise control.

It is envisaged that a turning back of the motor and the cam element from the end position to the zero position or basic position takes place in such a way that a rotation continues in the direction in which the cam element has been moved from the zero position to the end position. This means that the motor shaft is always rotated in one direction of rotation. In a transfer of the cam member from the zero position to the end position is thus rotated in the same direction as in the subsequent transfer from the end position to the zero position. By this only one direction of rotation of the engine and the cam element, the driving of the motor by the control unit can be achieved much easier and thereby with less effort and less error rate.

Preferably, the cam member is rotatable by the drive motor about its longitudinal axis and the rotational movement is converted by the helical cam track in a linear movement, through which the door hook for opening the door is linearly movable.

This is precisely what makes possible an actuation concept in which as few components as possible are used and, moreover, reliable conversion of the directions of movement via the coupled elements is achieved. The linear motion guide of the door hook allows a more robust and much freer opening possibility compared to a direct action on a catch of the door opening device. Jamming, spreading or undesired twisting can be prevented and locking of the door opening can be avoided.

Preferably, the cam member has a first rotational position interval. When the cam member is located relative to a position detection switch in this first rotational position interval, a position of the cam member is detected which allows the door to be completely closed. Since the cam member is coupled to the motor, thereby a position of the motor is detected, in which he has virtually reached its zero position. The engine is so, in particular after opening the door, as long rotated until he has reached its zero position again, and then sometime subsequently to close the open door completely manually again. As a result, high safety requirements are taken into account, since the engine and thus also the cam element do not remain in an undesired position in which a complete closing of the door would no longer be possible. Just then, if this position would be just that can not be easily recognized by a user, whether the door is completely closed or not, then safety-critical conditions, for example, in a pyrolysis a baking oven could occur. This is avoided by this design.

Preferably, an elevation is formed on an outer side of the cam element, which can be detected by an electronic switch for detecting the rotational position of the cam element. By this survey on the lateral surface of the cam member and the spaced apart electronic switch, this change in the lateral surface can be detected and reliably detected at any time, in which rotational position, the cam member is.

Not least can be achieved by this specific embodiment for position detection, a very robust and reduced component design, which is also constructed very compact beyond. Because the formation of the survey takes place in Essentially by one-piece design of the cam member, so that the survey is also formed and arranged particularly stable position and low wear.

Last but not least, a very component-reduced design is possible as a result.

Preferably, the cam member has a second rotational position interval. In particular, this second rotational position interval extends from the first rotational intermediate position to an end position. In particular, thus over the entire rotational movement possibility of the element two rotational positions intervals or two zones formed, depending on which zone is currently in the range of the electronic switch and is detected by him, it is recognized whether the complete closing of the open door is possible or not.

Preferably, the length of the cam path encompassed by the second rotational position interval is substantially longer, in particular by a multiple, such as the length of the cam track encompassed by the first rotational position interval. By such a specific length dimensioning of the precisely guided movement of the transmission element on the cam track is taken into account and allows the very accurate detection of positions to fully close the door.

Preferably, the joined lengths of the rotational position intervals of the helical cam track make a full revolution about the longitudinal axis of the cam member. The possibility of rotation of the cam member about its axis of rotation therefore preferably corresponds to a single full revolution. By such a configuration can be achieved in a particularly advantageous manner that must not be too fast rotational movements in view of the full linear movement of the door hook, so that slippage of the transmission element can be prevented by the cam track. In addition, by this design, the wear can be kept very low and a particularly guided and smooth movement of the door hook can be ensured.

Last but not least occur by the lowest possible torques, so that here too the interaction of the components can be carried out particularly wear.

Preferably, the transmission element comprises a ball bearing. In addition, it is provided that a longitudinal ball bearing is arranged between a motor carrier and the cam member. By this arrangement and the specific design with a longitudinal ball bearing, the occurrence of axial forces can be avoided on the drive shaft of the motor. The radial force on the drive shaft of the motor is thus also very low.

In particular, only the door hook is arranged on the door and the other components of the door opening device are on the household appliance itself and not on the door arranged. Preferably, the components not arranged on the door are arranged on a lower closure of the household appliance for opening and closing the door. In particular, by the linear movement of the door hook when opening the door, a locked state between the door hook and a catch can be solved.

In particular, the door opening device operates to drive the drive motor through the control unit, and the cam or cam element coupled to the drive shaft of the motor rotates accordingly. As a result of this rotational movement, the helical cam track and a transmission element contacted with it, in particular a ball bearing, also rotate along this helical cam track. This ball bearing is attached to a plunger that presses directly on the door hook, wherein the plunger moves in the housing of the door opening device. As a result, the door hook is moved in only a linear direction and the locked state with a rotary latch is opened. Furthermore, it is provided that the drive motor can be stopped quickly by being closed for a short time. This allows a good cam position adjustment, as the system responds very fast and has virtually no caster. In addition, a very fast deactivation can be achieved, for example, if the door is blocked by, for example, being locked or a person is leaning against it. In this case, the electrical supply of the motor may be limited or the current in the motor may be limited, for example, by a series resistor. Damage to the engine can be prevented and a quick shutdown can be made possible at any time.

Preferably, a door device for a household appliance comprises a door with a first vertical longitudinal side, to which preferably at least one stop element for pivoting the door can be attached parallel to the longitudinal side. In addition, the door comprises a second longitudinal longitudinal side opposite the first longitudinal side and an upper side extending between the longitudinal sides. The door device further includes a door opening device for automatically opening the door. It is provided that on the second longitudinal side of a handle member and / or on the upper side a handle member is formed, wherein the door has at least one recognition sensor, which is designed to detect a finger in a detection area around or on the or a handle member, and a control unit through the Door device is formed, which is formed depending on the information of the detection sensor for controlling the door opening device. Thus, a door device is provided in which the door is designed in particular for lateral abutment, so that the door can be moved about a vertical longitudinal axis for opening and closing. In addition, the handle element is not mounted on the front side of the door in a very special positioning, but in quasi space-minimized and space-saving design on the second vertical longitudinal side and / or on the top. Since the door has a certain thickness, this second longitudinal side and the thickness associated therewith are suitable for receiving the gripping element, so that in this respect the thickness of the door does not change due to the gripping element. The long side therefore represents the area that results from the thickness of the door and extends from the front surface to the rear. In addition, this special positioning of the handle element on the longitudinal side can also prevent persons from hitting it, as is the case with handle elements which rise from the front side or the like. In addition, this specific position of the handle element is also a very user-friendly attachment, which leads the user virtually intuitively to the right place, especially in view of the already intended and intuitive opening and gripping the door on the right side. By explicitly forming a gripping member for gripping with the fingers, a configuration can also be provided in which unwanted attacking or slipping on other parts of the door with the fingers or the hand can be avoided, so that their contamination by the human hand can be prevented. Last but not least, a very ergonomic, adapted gripping possibility can be created by this explicit gripping element, which prevents slippage or the like, so that in this respect a user-friendly design for safe further opening and moving the door is ensured by a user after the automatic opening. In a particularly advantageous embodiment, at least one detection sensor is provided by which very quickly and promptly touching, grasping or at least in a nearby environment contact finger is detected to the handle element detected, so that an opening request is detected very quickly and early by the user and thus Also, the door opening device can be controlled much faster. The reaction time of the automatic door opening device can thereby be significantly reduced and reduced to an opening duration of less than 0.5 seconds.

Preferably, the grip element is formed as a stable part, which is designed in one piece. In particular, it is provided that the grip element is stationary and thus not relatively movable to the door on the second longitudinal side and / or the top is arranged. It is therefore not intended that the handle element sets by a relative mobility to the door a certain opening mechanism in motion. The grip element thus serves only for gripping. Preferably, a slot is formed on the second longitudinal side and / or the top of the door, in which the grip element is arranged. By such an arrangement, at least partially recessed, an even more space-saving and space-minimized design can be achieved. On the other hand, it can be mounted mechanically stable.

Preferably, the gripping element is a particularly rectilinear strip which has an engagement region, in particular a corner-free groove corresponding to a recessed grip. Such a configuration is a particularly ergonomic design that allows particularly easy to intervene with the fingers and manually open the door by little effort by the automatic opening. Here, too, thus slipping and due to the corner-free design a hurting or snagging can be avoided. Not least can be formed by such a configuration already by a relatively shallow well sufficient grip area.

Preferably, a gutter leg facing a door front is designed longer than a gutter leg facing away from the door front. As a result of this embodiment of the legs or walls, which is asymmetrical with regard to the trough, it is also possible here to take into account the most precise and stable holding possible. This allows for a larger area, with which one can get into the engagement area with the fingers, so that here too the accessibility to the engagement area is improved. On the other hand, the space depth on the side facing away from the door front can also be reduced, so that undesired stops on other components of the domestic appliance can be avoided.

Preferably, the handle element is arranged on the front side of the door behind a front panel of the door and covered by this. This is a special one protected arrangement, so that it can be avoided bumping and beyond unwanted wear or damage to the handle member can be avoided. Last but not least, this also allows high quality and design requirements to be taken into account, since the handle element can not be viewed when viewed from the front.

Preferably, the at least one detection sensor is a capacitive sensor. This allows a very fast detection of a finger in a detection area or on the handle element itself and is also functionally relatively robust.

Preferably, at least one electrode of the capacitive sensor is arranged in the door behind the grip element, in particular on the grip element behind an engagement region. As a result, a particularly accurate and particularly sensitive detection can be made possible. In addition, given by this specific local positioning of the electrode also a very protected and low-wear position. Not least can be made possible by this position even with a nondestructive detachable attachment of the handle member on the longitudinal side easy accessibility to the electrode for replacement or maintenance purposes.

Preferably, the grip element is formed at least in the region of the detection sensor of an electrically non-conductive material.

The detection sensor may also be an inductive sensor or a microswitch.

In particular, the automatic door opening device is designed with a child safety device. This is a particular advantage since it can prevent unwanted automatic opening of the door when grasping the handle element by a child. Especially in household appliances, such as ovens or the like, which have relatively high temperatures during operation in the oven, which is closed with the door, thus a high security potential for children can be created.

Preferably, the door has an operating device, which is formed on a front panel of the door. By this door integrated arrangement of the operating device is in turn created an advantageous compact design and user-friendly arrangement, which is clear and accessible at all times.

It is particularly preferably provided that the child-safety device can be activated and deactivated electronically controlled by the control unit via the operating device. Thus, this child safety device can be operated quickly and reliably. In addition, the operating device may have a display device, through which a wide variety of information can be presented to the user. By the display unit of the operating device is also integrated in the door and in particular formed on the front panel, the visibility is particularly large for a user. In this context, the display of an activated or deactivated child safety device can thus be detected quickly and reliably by an adult.

Preferably, the door opening device can also be actuated via the operating device. By such a redundant configuration of the door opening possibility can then, if the possibility of opening via the handle element fails or is not fully accessible, also follow the control device.

This is particularly advantageous when two household appliances are positioned directly adjacent to one another with such a door opening device and the two vertical longitudinal sides facing one another essentially abut one another substantially directly.

Preferably, the activation of the door opening device, in particular a motor, by the control unit depends on detecting an operating state of the domestic appliance, in particular in a non-activated pyrolysis of the oven, and / or an electronically detected detection of a locking position of a cam member of a drive device of the door opening device and / or a closed door. Also, the safety precautions can be increased with regard to an undesirable opening of the door.

The door can also be opened manually at any time. As a result, a safe opening can be made possible even in the event of a power failure, and safety-critical conditions can be avoided.

By the two possibilities of a door opening, on the one hand on the handle member and the other on the operating device, it can be provided in this regard that this is configurable via the control device and this associated controls. User-specific can thus also be set, by which of the two options an operation of the automatic door opening device is to take place. Also, the customer benefit can be significantly increased.

In this regard, the control unit of the door device is designed accordingly and the individually set by a user configuration can be stored in it until it is possibly changed again.

Preferably, the door opening device of the door device has a door hook, which is arranged on the door, and which can be unlocked by means of a separately arranged for door drive device of the door opening device linearly actuated and with a drive device arranged rotary latch to open the door. The linear operation of the door hook opening can be done very reliable and without jamming or spreading. Since the catch is more complex in terms of its movement, namely performs a linear and a rotary movement, the action on the catch in the door opening would be more complex. By acting on the door hook and its linear movement, the error rate of the automatic door opening device can be significantly reduced.

Furthermore, the invention relates to a domestic appliance, in particular an oven with a door opening device according to the invention or an advantageous embodiment thereof.

Advantageous embodiments of the door opening device according to the invention are to be regarded as advantageous embodiments of the domestic appliance.

Fig. 1

eine perspektivische Darstellung eines Hausgeräts mit geöffneter Tür;

Fig. 2

eine perspektivische Darstellung eines Griffelements einer Türvorrichtung;

Fig. 3

eine schematische Schnittdarstellung der Tür gemäß Fig. 1 im Bereich des Griffelements;

Fig. 4

eine perspektivische Darstellung eines Ausführungsbeispiels einer Türöffnungsvorrichtung;

Fig. 5

eine perspektivische Ansicht von unten der Türöffnungsvorrichtung gemäß Fig. 4;

Fig. 6

eine Darstellung der Türöffnungsvorrichtung von unten in der Nullstellung des Nockenelements; und

Fig. 7

eine vergrößerte Darstellung eines Teilausschnitts der Türöffnungsvorrichtung gemäß Fig. 4.

An embodiment of the invention will be explained in more detail with reference to schematic drawings. Show it:

Fig. 1

a perspective view of a household appliance with the door open;

Fig. 2

a perspective view of a handle member of a door device;

Fig. 3

a schematic sectional view of the door according to Fig. 1 in the region of the handle element;

Fig. 4

a perspective view of an embodiment of a door opening device;

Fig. 5

a bottom perspective view of the door opening device according to Fig. 4 ;

Fig. 6

an illustration of the door opening device from below in the zero position of the cam member; and

Fig. 7

an enlarged view of a partial section of the door opening device according to Fig. 4 ,

In the figures, identical or functionally identical elements are provided with the same reference numerals.

In Fig. 1 is shown in a simplified perspective view of a baking oven 1, which has a housing 2. In the housing 2, a cooking chamber 3 is formed, which is bounded by a muffle 4. A front loading opening 5 is closed by a door 6. The door 6 is shown in the open state. The door 6 is pivotable about a vertical longitudinal axis A according to the arrow. The door 6 has a first vertical longitudinal side 7, are arranged on the stop elements, with which the door 6 is fixed to the housing 2 and relative to the housing 2 is movable. In addition, the door 6 has one of the first vertical longitudinal side 7 opposite the second vertical longitudinal side 8, in the embodiment, a handle member 9 is formed. In addition, the door has an upper side 41. It can be provided that a further additional gripping element is arranged on this upper side 41 or that optionally the gripping element 9 is arranged on this upper side 41 and not on the longitudinal side 8. The door 6 also has a front panel 10, wherein on a front surface 11 of the front panel 10, an operating device 12 is formed. The operating device 12 comprises a display unit 13 as well as control elements 14 and 15 shown only in the form, position and number as an example. The operating device 12 and the grip element 9 are thus integrated in the door 6.

In Fig. 2 is shown in perspective view, the handle element 9. It is an integrally formed straight-line rail, which has an engagement region 16. This is designed as a corner-free recessed grip or groove, wherein parallel to each other groove legs 17 and 18 limit the recessed grip or the engagement portion 16. In this regard, the handle member 9 is formed asymmetrically, since the front plate 10 facing gutter leg 18 is longer or further extends forward than the front plate 10 facing away gutter legs 17th

In Fig. 3 is a schematic representation of a section along the section line III / III in Fig. 1 shown. It can be seen that the grip element 9 is integrated in a slot 19 of the door 6. The grip element 9 is thus virtually integrated into the door 6 and formed recessed. At least one electrode 20 of a capacitive sensor, which is a recognition sensor, is formed on the rear side of the grip element 9. By means of the recognition sensor it is detected whether a finger 21 extends into a detection area 22, which is exemplarily delimited by the dashed line, and / or whether the finger 21, as in Fig. 3 shown, the handle member 9 touches. The electrodes 20 may additionally or instead of the shown rearward position also be arranged on the grip element 9 or be integrated in the door 6.

The information of the detection sensor is sent to a control unit 23 (FIG. Fig. 1 ), which may be arranged in the door 6 or at another position in the housing 2, transmitted, wherein the control unit 23, depending on the information of the detection sensor controls a door opening device by means of which the door 6 is opened automatically.

If it is detected that one or more fingers 21 are located within the detection area 22 or a finger 21 is contacted with the gripping element 9, then in this regard, at the latest when contacting the gripping element 9, it is recognized that an opening request of a user is present and via the control unit be responded to very quickly and the door opening device to be controlled.

In the illustration according to Fig. 3 In addition, it can be seen that the front panel 10 extends in the x-direction so far that it is at least as long as the leg 18 of the handle member 9. Thus, in a front view of the oven 1 and thus also in a front view of the closed Door 6, the handle member 9 covered by the front panel 10.

The grip element 9 is stationary and thus not relatively movable relative to the door 6 positioned at this. The grip element 9 is formed in particular in the areas in which one or more electrodes 20 are arranged, made of an electrically non-conductive material.

The oven 1 can be actuated via the handle element 9 for automatic door opening or moreover also via the operating device 12, wherein, for example, a button 14 or 15 is actuated to effect the activation of the automatic door opening device. As a result of this configuration, the user can also make an individual configuration, depending on the needs, as to whether an activation and activation of the automatic opening device should take place via the grip element 9 or via the operating device 12.

It is preferably provided that the drive motor is then actuated to automatically open the door 6 when the grip element 9 is touched when the door 6 is closed and when the pyrolysis operation of the oven 1 is no longer activated. Preferably, if the door 6 is open anyway, it is provided that the drive motor is not activated. In this regard, he is then disabled even with a gripping of the handle member 9 to further open the door or to close the door 6.

In particular, it is also provided that the oven 1 has a child safety device which can be activated and deactivated via the operating device 12. If the child-safety device is activated, then the door-opening device can not be actuated automatically by gripping the grip element 9 in the closed state of the door 6 and the simple activation of the activation of the automatic door-opening device can not be achieved simply by operating a control element 14 or 15. Only then, when the child safety device is deactivated again or if specific further multiple combinable actions, for example actuation of one or more control elements 14 and 15 in a specific manner, are carried out, then the control of the automatic door opening device can be achieved even when the child safety device is set.

In Fig. 4 an embodiment of a door opening device 24 is shown in a perspective view. This comprises a drive motor 25 with a drive shaft 26. The motor 25 is attached to a motor carrier 27. In addition, the door opening device 24 comprises a cam element 28, which is hollow-cylindrical and has a helically shaped cam track 29 at its end remote from the motor 25. The cam member 29 and the motor 25 are supported by a longitudinal ball bearing or thrust ball bearing 30, with which axial forces are avoided on the drive shaft 26.

In addition, the door opening device comprises an electronic switch 31, which is arranged on the motor mount 27. This switch 31 is disposed adjacent to the cam member 28, being used to detect rotational positions of the cam member 28 about the axis of rotation, which is equal to the axis of the drive shaft 26, is trained. On the cam track 29, a transmission element 32 is attacking or rolling, which is designed as a ball bearing. This transmission element 32 is connected to a plunger 33 or attached to it. The plunger 33 is in mechanical operative connection with a door hook 34. The door hook 34 in turn is connected to a catch 35 for generating the locked state of the door 6. The plunger 33, the motor mount 27, the rotary latch 35 and possibly also other components are arranged in a housing 36 of the door opening device 24. This conceptual design of the door opening device 24, a rotational movement of the motor 25, in particular the drive shaft 26 are transmitted to the cam member 28, wherein due to the specific shape of the cam member 28 with the helical cam 29, this rotational movement in a linear movement of the plunger 33 and thus also the door hook 34 can be converted. The door hook 34 is thus moved only linearly in the direction of the axis B.

In Fig. 5 is shown in a perspective view from below the door opening device 24. In this case, a first operating position is shown, namely the end position of the cam member 28, wherein the transmission element 32 analogous to the representation in Fig. 4 has arrived at the top end of the cam track 29.

In Fig. 6 is in analogous representation to Fig. 5 a bottom perspective view of the door opening device 24, wherein in this regard, another operating state is shown. In Fig. 6 the zero position of the cam member 28 is shown, wherein the transmission element 32 has arrived at the lowermost point of the cam track 29.

The motor 25 is electrically connected to the control unit 23 and is controlled via this.

The control unit 23 and the door opening device 24 are connected to the door 6 of a door device 37 (FIG. Fig. 1 ).

In Fig. 7 is an enlarged section I of the illustration in Fig. 4 shown. The representation is opposite to the view in Fig. 4 something turned. It is both the switch 31 to the motor carrier 27 and the specific position to the cam member 28 to detect. The cam member 28 is rotatable about its longitudinal axis C by the coupling with the drive shaft 26, wherein between the initial position or zero position and the end position only a full revolution about the axis C is performed. On a lateral surface 38 of the cam member 28, a survey 39 is formed. In the direction of circulation starting from the in Fig. 7 The projection 39 extends to an end 40. This end 40 also defines the end of a first rotational position interval, which extends from the initial position to this defined by the end 40 rotational intermediate position. This zone or rotational position interval is shown between the lines shown by way of example only, which are not shown in the actual embodiment and merely show the limits of the first rotational position interval and thus the angular range α. Within this angular range a, which marks the first rotational position interval, the switch 31 can detect this position accurately by detecting the elevation 39. As long as the cam member 28 is within this first rotational position interval relative to the detection range of the switch 31, the zero position of the motor 25 is detected and the further movement of the motor 25 is stopped. In this position of the motor 25 and thus also of the cam member 28 is ensured that the door 6 can be completely closed manually again. If the cam element 28 is outside this first rotational position interval and is thus in a rotational position between the rotational intermediate position, which begins at the end of the angular range α, and an end position of the cam element 28 (second rotational position interval), complete door closing can not take place. The motor 25 is then brought to its zero position, which in turn is detected via the cam member 28 and the switch 31. A too wide turning or too little wide turning of the cam member 28 and the motor 25 can be avoided. This movement of the cam member 28 and the motor 25 within the first rotational position interval prevents the transmission element 32 from contacting the cam track 29 too soon when the door 6 is closed and thus when the door hook 34 is moved in the direction of the cam element 28 and is not moved any further can. The length of the cam track 29 in the first rotational position interval, which is characterized by the angular range α, is substantially smaller than the partial section of the cam track 29, over which the second rotational position interval extends.

Only the door hook 34 can be fastened to the door 6, whereas the other components in the housing 2 are arranged separately from the door 6. The door opening device 24 is formed on a lower shutter of the door 6.

By the survey 39 practically the switch 31 is turned on and thus recognized this first rotational position interval. The motor 25 is stopped when it receives information about, for example, a pulse edge from the switch 31. The switch 31 detects the angular position of the cam member 28. In order to stop the motor 25 quickly, for example, when the automatic door opening by holding or leaning against a user unintentionally, the motor 25 is shorted.

LIST OF REFERENCE NUMBERS

1

oven

2

casing

3

oven

4

muffle

5

loading port

6

door

7, 8

long sides

9

handle element

10

front panel

11

front surface

12

operating device

13

display unit

14, 15

controls

16

engagement area

17, 18

channel arm

20

electrode

21

finger

22

detection range

23

control unit

24

Door opening device

25

drive motor

26

drive shaft

27

engine support

28

cam elements

29

cam track

30

Axialkugellager

31

switch

32

transmission element

33

tappet

34

door hook

35

catch

36

casing

37

door means

38

lateral surface

39

survey

40

The End

41

top

A, B, C

axes

α

angle range

Claims (13)

1. Door-opening device for a domestic appliance (1) which is configured for automatic opening of a door (6) of the domestic appliance (1), and comprises a drive motor (25) which is mechanically coupled via an actuating device to a door hook (34), wherein the drive motor (25) is connected to a cam element (28) of the actuating device, said cam element having a helical camway (29) against which abuts a transmission element (32) of the actuating device, said transmission element (32) being coupled to the door hook (35) and being able to transmit the movement of the cam element (28) to the door hook (34), characterised in that the rotary position of the cam element (28) is detectable by a switch (31) and, in order to transfer the cam element (28) and in order to move from the home position to the end position and from the end position to the home position, the drive motor (25) is rotatable in only one rotary direction.
2. Door-opening device according to claim 1, characterised in that the cam element (28) is preferably rotatable about the longitudinal axis (C) thereof by the drive motor (25) and the rotary motion is converted by the helical camway (29) into a linear movement by means of which the door hook (34) can be moved linearly to open the door (6).
3. Door-opening device according to claim 1 or 2, characterised in that the cam element (28) has a first rotary position interval by means of which a home position interval of the motor (25) can be detected.
4. Door-opening device according to claim 3, characterised in that the first rotary position interval extends between the home position of the cam element (28) and a first rotary intermediate position.
5. Door-opening device according to claim 3 or 4, characterised in that an elevation (39) is provided at an external side (38) of the cam element (28), said elevation being detectable by the switch (31) for detecting the rotary position of the cam element (28).
6. Door-opening device according to one of the preceding claims, characterised in that, arranged immediately adjacent to the first rotary position interval, the cam element (28) has a second rotary position interval in which complete closing of the door (6) is prevented and which extends as far as an end position of the cam element (28) for opening the door (6).
7. Door-opening device according to claim 6, characterised in that the joint lengths of the rotary position intervals along the helical camway (29) amount to a complete rotation about the longitudinal axis (C) of the cam element (28).
8. Door-opening device according to one of the preceding claims, characterised in that the transmission element (32) comprises a ball bearing.
9. Door-opening device according to one of the preceding claims, characterised in that the door (6) is laterally mounted and is pivotable about a vertical axis (A) for opening and closing.
10. Door-opening device according to one of the preceding claims, characterised in that only the door hook (34) is arranged at the door (6) and the further components of the door-opening device (24) are arranged at the domestic appliance (1).
11. Door-opening device according to claim 12, characterised in that the components not arranged at the door (6) are arranged at a lower closure of the domestic appliance (1) for opening and closing the door (6).
12. Door-opening device according to one of the preceding claims, characterised in that through the linear movement of the door hook (34) during opening of the door (6), a locked state between the door hook (34) and a rotary catch (35) can be released.
13. Domestic appliance, in particular for preparing food, in particular an oven (1) comprising a door (6) and a door-opening device (24) according to one of the preceding claims.

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