EP1834027B1 - Door lock for the door of a household appliance - Google Patents

Abstract

The invention relates to a door lock (1) for the door of a household appliance. Said door lock comprises a first device (10) for detecting the closed state of the door, and a second device (24) for locking the door, said first and said second device being connected in series.

Description

The present invention relates generally to door locks for home appliances, particularly washing machines, dishwashers, clothes dryers, and cookers, and more particularly to a door lock of home appliances having three terminals.

In the field of household appliances door locks are known, comprising means for detecting a closed state of a household appliance door, means for locking and, if necessary, unlocking the household appliance door and means for detecting a locking state of the household appliance door.

The device for detecting the closed state determines whether the household appliance door (hereinafter also referred to as the door) is closed. In this case, a closed state of the door is to be understood as meaning that the door closes the associated opening of the household appliance, if necessary sealingly, that is, it is not just ajar. In the following it is assumed that the closed state of the door is a prerequisite for being able to lock the door. However, the door can also be unlocked in the closed state.

If the door is in the closed state, for example when the domestic appliance is started up, the means for locking can be actuated in order to lock the closed door, ie to bring it into a state in which the door can not be opened.

If the door is locked, this is detected by the device for detecting the locking state.

The means for detecting the closed state of the door provides a signal indicating that the door is closed. This signal indicates to a door lock controller that the door is closed and can now be locked. Thereafter, the means for locking is activated by the controller to close the door lock. The means for detecting the locked state of the door provides a signal indicating that the door is locked. This signal indicates to the controller that the door can no longer be opened and, accordingly, an operation of the household appliance is possible.

Referring to Fig. 1 to 3 a known door lock for washing machines is explained in more detail:

The total of 100 designated door lock has a housing shell 102, are arranged in the components described below. To close the assembled housing shell 102 is a housing cover, not shown, which forms the housing of the door lock 100 together with the housing shell 102.

In the housing shell 102 a horizontally displaceable in the figures main slide 104 is arranged. The main slide 104 is acted upon by a main slide spring 106. The main spool 104 has a stop 108, the function of which is described in more detail below.

In the door latch 100, a device for detecting the closed state of a household appliance door comprises a door contact switch 110. The door contact switch 110 has a first door contact 112 and a second door contact 114. Are the first and second door contacts 112 and 114, as in Fig. 1 Shown separately, this indicates that the door is open. The first and second door contacts 112 and 114, as in FIG Fig. 2 and 3 shown, this indicates that the door is closed.

The first door contact 110 is arranged adjacent to a free end 116 of a first door contact conductor 118 designed as a leaf spring. The first door contact conductor 118 is biased to the right in the figures, ie, the free end 116 exerts a rightward force. The end 120 of the first door contact conductor 118 facing the free end 116 is fixed to an inner end (not labeled) of a first terminal contact 122. This can be done for example by gluing, soldering or riveting. The first connection contact 122 is designed as a rigid, rigid conductor. The connection of the first door contact conductor 118 opposite end 120 of the first terminal 122 used for connection to a non-illustrated plug connection of the household appliance.

The second door contact 114 is disposed at an end 124 of a second door contact conductor 126. The second door contact conductor 126 is formed as a rigid, rigid conductor. Movements of the first and second door contacts 112 and 114 relative to each other are thus possible due to the flexible configuration of the first door contact conductor 118. The end 124 of the opposite end 128 of the second door contact conductor 126 forms a second terminal contact 128 and serves for connection to said connector.

In the door latch 100, a device for detecting a lock state of a home appliance door includes a lock contact switch 130. The lock contact switch 130 has a first lock contact 132 and a second lock contact 134. The first locking contact 132 is disposed adjacent a free end 136 of a first latching contact conductor 138 formed as a leaf spring. The first latch contact conductor 138 is biased to the left in the figures, i. So exerts a force to the left. The free end 136 opposite end 140 of the first locking contact conductor 138 is fixed to a third terminal contact 150, for example by soldering, gluing or riveting. The end of the third connection contact 150 opposite the connection point with the first locking contact conductor 138 serves for connection to the said connector.

The second latch contact 134 is disposed at one end 144 of a second, second rigid contact conductor 146 formed as a rigid, rigid conductor. The opposite end of the second latch contact conductor 146 forms a fourth terminal contact 142 and serves to connect to said connector.

In the door latch 100, a means for locking and unlocking the home appliance door comprises a total of 152 designated electromagnetic actuator. The actuator 152 has a magnet 154 with an armature, not shown. The control and power supply of the actuator 152 via a fifth terminal contact 156 and a sixth terminal contact 158, which are designed as rigid, rigid conductors and are used for connection to said connector. The actuator 152 further includes an actuating tappet 160, which is in operative connection with the armature of the magnet 154 and can be actuated by this.

The locking and unlocking device further comprises a rotary valve 162 which serves to lock and unlock the main slide 104. The rotary valve 162 is rotatably mounted in the housing shell 102. A return spring 164, whose function is described in more detail below, can act on the rotary valve 162 in dependence on its position. The rotary valve 162 has an extension 165 which, as explained in more detail below, can cooperate with the first locking contact conductor 138 and with the return spring 164. A locking bracket 166 may cooperate with the rotary valve 162 so that the rotary valve 162, as described in more detail below, is held in a position suitable for locking.

An electrical equivalent circuit diagram of the door lock 100 is shown in FIG Fig. 4 shown.

The operation for the door lock 100 is described below.

Fig. 1 shows the door latch 100 in a state in which the household appliance door is at least partially open, so is not in the closed or locked state. In this state, the main slider spring 106 urges the main slider 104 to be pushed to the left. In this case, the main slide spring 106 is dimensioned such that the first door contact conductor 118 due to an operative connection of its end 116 with the structure 108 against its bias in the in Fig. 1 shown position is held. Thereby, the first and second door contacts 112 and 114 are separated from each other. The door contact switch 110 is thus opened and indicates that the household appliance door is not closed.

The rotary valve 162 is in the in Fig. 1 shown position, for example, held by a torsion spring, not shown. In one embodiment, not shown, the return spring 164 is configured so that it is in accordance with the state Fig. 1 engages the extension 165 and thereby the rotary valve 162 in the in Fig. 1 holds position shown; on the aforementioned torsion spring, not shown, can then be dispensed with. In this case, the rotary slide 162 counteracts by means of an extension or stop 170 of the biasing force of the first locking contact conductor 138 such that the first locking contact conductor 138 in the in Fig. 1 shown position is held. The first and second latch contacts 132 and 134 are separated, the lock contact switch 138 is thus opened, thereby indicating that the household appliance door is not locked.

Fig. 2 shows the door lock 100 in a state in which the household appliance door is closed, but not yet locked (yet). The closing of the appliance door causes the main slide 104 to be moved counter to the force of the main slide spring 106 to the right. In this case, movement of the first door contact conductor 112 due to its bias is made possible such that the first and second door contacts 112 and 114 are brought into contact with each other. According to Fig. 2 This is achieved by completing the movement of the main slider 104 to the right, the operative connection between the free end 116 of the first door contact conductor 118 and the structure 108. Now, the door contact switch 110 is closed, thereby indicating that the home appliance door is closed. At the states of the rotary valve 162 and the latch contact switch 130 has faced here Fig. 1 nothing changed.

Fig. 3 shows the door lock 100 in a state in which the home appliance door is closed and locked. This condition is achieved by activating the actuator 152 to achieve movement of the actuating plunger 160 to the left. In this case, the actuating plunger 160 engages the extension 165 and rotates the rotary valve 162 in a clockwise direction, until a structure, not shown (eg, a gate circuit) of the rotary valve 162 with the locking bracket 166 cooperates so that the rotary valve 162 in the in Fig. 3 shown position is held. In this case, the operative connection between the extension 170 and the first locking contact conductor 138 is terminated. Due to its bias, the first latch contact 138 takes the in Fig. 3 shown position. The first and second latch contacts 132 and 134 are brought into contact with each other. The lock contact switch 130 is thus closed, thereby indicating that the home appliance door is locked.

To allow the household appliance door to open, the household appliance door must be unlocked. For this purpose, the actuator 152 is reactivated. The thus caused movement of the actuating plunger 160 to the left rotates the rotary valve 162 a little clockwise against the force of the return spring 164, wherein the operative connection of the structure of the rotary valve 162 is not shown terminated with the locking bar 166 and a rotation of the rotary valve 162 against the Clockwise is possible. The rotation of the rotary valve 162 back into its in Fig. 2 respectively. Fig. 1 Position shown by the reference to Fig. 1 said torsion spring, not shown, and initially due to the operative connection between the return spring 164 and the extension 165. This rotation can also be effected the return spring 164 alone, if it is designed so that it also for the state according to Fig. 1 can attack on the extension 165.

The door latch 100, which is a representative example of known door locks of the type mentioned, has disadvantages. To connect the door latch 100, a plug-in connection with a total of 6 plug contact receptacles is required to accommodate the six terminal boxes 122, 128, 142, 150, 156 and 158. The resulting space for a connector is disadvantageous because the same space must be provided on the part of the household appliance. Also, the number of plug contact receptacles on the part of the connector is disadvantageous because it draws due to the design and material cost corresponding manufacturing costs. This also applies to the door lock 100 itself, where the total of six connection contacts corresponding installation space and expense.

Another disadvantage is the reliability of such known door locks. If the actuator 152 is activated so that the rotary valve 162 in the in Fig. 3 Although the door contact switch 110 is not shown closed, it may cause damage to the door lock 100 when the household appliance door is closed in such a state of the door lock 100. Furthermore, it can lead to a faulty operation of the household appliance as a whole. When the actuator 152 is actuated in the stated manner, this results in a closing of the lock contact switch 130. Usually, the closed state of the lock contact switch 130 indicates to the home appliance controller that startup is permitted. However, if the appliance door is not closed in such a situation, injuries may result from a drum rotating in the domestic appliance, leakage of water in the case of household water appliances, and heat leakage from dryers and stoves.

The U.S. Patent 4,718,705 discloses a door closure for a washing machine or other household appliance, wherein the closure comprises a closing when the door closing door contact switch and a bimetal actuator, by means of which a locking element for locking the closed door is actuated. The bimetallic actuator is energized when the door contact switch is closed. Electrically parallel to the bimetal actuator, a shorting switch is arranged, which serves to intermittently interrupt the power supply of the bimetallic actuator to keep the current flowing through the bimetallic actuator at an optimum value. The result of repeated opening and closing of the short-circuit switch is an oscillating movement of the locking element.

The postpublished patent document WO 2005/106099 A1 shows in his FIG. 9 the electrical diagram for the electrical components of a door lock for a household electrical appliance. According to this diagram, the door lock has a total of three electrical connections. In an extending between two of the terminals electrical path are in series a door switch and an electromagnet for actuating a locking element of the door lock. The door switch closes when the door is closed, energizing the solenoid. According to the statements in this document, the device control in the household appliance can actuate the electromagnet via the remaining third connection by means of an auxiliary contact in order to bring the interlock into the desired state.

The object of the invention is to provide a reliable door lock for a door of a household appliance, which can be easily and inexpensively manufactured.

To achieve this object, a door lock according to claim 1 is provided according to the invention. Preferred developments of the door lock according to the invention are specified in the dependent subclaims.

• Fig. 1 eine bekannte Türverriegelung bei nicht geschlossener und nicht verriegelter Tür,
• Fig. 2 die bekannte Türverriegelung von Fig. 1 bei geschlossener Tür,
• Fig. 3 die bekannte Türverriegelung von Fig. 1 bei geschlossener und verriegelter Tür,
• Fig. 4 eine schematische Darstellung einer Schaltungsanordnung zur Verwendung bei der bekannten Türverriegelung gemäß Fig. 1 bis 3,
• Fig. 5 eine Ausführungsform der erfindungsgemäßen Türverriegelung bei nicht geschlossener und nicht verriegelter Tür,
• Fig. 6 die Ausführungsform von Fig. 5 bei geschlossener und nicht verriegelter Tür,
• Fig. 7 die Ausführungsform von Fig. 4 bei geschlossener und verriegelter Tür,
• Fig. 8 eine schematische Darstellung einer Schaltungsanordnung zur Verendung bei der erfindungsgemäßen Türverriegelung, und
• Fig. 9 eine schematische Darstellung einer Schaltkreisanordnung zur Verwendung bei einer bekannten Türverriegelung mit thermoelektrischem Aktuator.

The invention will be further explained below with reference to the accompanying drawings. They show:

• Fig. 1 a known door lock with not closed and not locked door,
• Fig. 2 the well-known door lock of Fig. 1 with the door closed,
• Fig. 3 the well-known door lock of Fig. 1 with closed and locked door,
• Fig. 4 a schematic representation of a circuit arrangement for use in the known door lock according to Fig. 1 to 3 .
• Fig. 5 an embodiment of the door lock according to the invention with not closed and unlocked door,
• Fig. 6 the embodiment of Fig. 5 with closed and unlocked door,
• Fig. 7 the embodiment of Fig. 4 with closed and locked door,
• Fig. 8 a schematic representation of a circuit arrangement for use in the door lock according to the invention, and
• Fig. 9 a schematic representation of a circuit arrangement for use in a known door lock with thermoelectric actuator.

With reference to Fig. 5 to 7 is a preferred embodiment of the door lock according to the invention and variants thereof described.

The door lock 1 comprises a housing shell 2, in which the following components of the door lock 1 are arranged. The housing shell 2 can be closed with a housing cover, not shown, which forms a housing of the door lock 1 together with the housing shell 2.

In the housing shell 2, a main slide 4 is arranged horizontally movable in the figures. The main slide 4 is acted upon by a main slide spring 6, which urges the main slide 4 according to the figures to the right. At the end of the main spool 4, which is opposite to its side cooperating with the main spool spring 6, a stopper area 8 is provided. The stop region 8 can, as shown in the figures, be provided by this end of the main slide 4 itself. The stop region 8 can also be provided on the main slide 4 in the form of a structure extending substantially perpendicular to the directions of movement of the main slide 4.

The door lock 1 has a door contact switch 10. The door contact switch 10 comprises a first door contact 12 and a second door contact 14. The first door contact 12 is arranged on a first door contact conductor 16. The first door contact conductor 16 is designed as a resilient element, for example in the form of a leaf spring. The first door contact conductor 16 is biased to the right according to the figures. The first door contact 12 is arranged on the first door contact conductor 16 so that movements of the first door contact conductor 16 described below can bring the first and second door contacts 12 and 14 into contact with each other and separate from each other.

A free end 18 of the first door contact conductor 16 can, as explained below, interact with the stop region 8. The free end 18 opposite end 22 of the first door contact conductor 16 is connected, for example, by soldering, gluing or riveting with an inner end of a first terminal 20 contact. The arrangement of the second door contact switch 14 is described below. By "inside" this means area and components that are not accessible from the outside when the housing is closed (i.e., the housing shell is closed with the housing cover); The same applies to "lying outside".

The door lock 1 has a device for locking and unlocking a household appliance door with an actuator 24 designed as an electromagnetic actuator. The actuator 24 includes a magnet 26, whose armature, not shown, cooperates with an actuator 28. Activation of the actuator 24 by energizing the magnet 26 causes movements of the actuator 28 according to the figures to the left.

The actuator 24 has a first actuator port 30 and a second actuator port 32 for power supply. The first actuator terminal 30 is electrically conductively connected to the second door contact 14. This can, as shown in the figures, be achieved, for example, in that the first actuator connection 30 is formed as a conductor extending away from the actuator 24, the free, outer end of which permits an arrangement of the second door contact 14.

The second actuator terminal 32 is electrically connected to a second terminal contact 34. This can take place in that the second actuator connection 32 is designed as a conductor extending away from the actuator 24, whose free end serves as a third connection contact 34. It is also possible to provide the second actuator terminal 32 as a connection point formed on the actuator 24, which is connected to an inner end of an electrical conductor, the second terminal contact 34 provides at its opposite, outer end.

Furthermore, a rotary member 36 is provided. The rotary member 36 is operable by the actuator 24, thereby causing rotations of the rotary member 36 are used for locking and unlocking of the main slide 4. The rotary member 36 is rotatable clockwise and counterclockwise, with a spring, not shown, biases the rotary member 36 in the counterclockwise direction.

The rotary member 36 has a lever 38, the free end for actuating the rotary member 36 by the actuator 28 is used. Furthermore, the rotary member 36 has a projection 40 designed as a stop. A formed on the rotary member 36 or arranged thereon locking structure 42 cooperates with a locking bracket 44.

The door lock 1 also has a lock contact switch 46. The locking contact switch 46 comprises a first locking contact 48 and a second locking contact 50. The first locking contact 48 is arranged on a resilient, for example designed as a leaf spring first locking contact conductor 52. At its lower end in the figures 54, the first locking contact conductor 52 is fixed and electrically conductively connected to an inner end of a third terminal contact 56. The third terminal contact 56 may also be provided by a corresponding, longer configuration of the first locking contact conductor 52 itself. The opposite end 58 of the first latch contact conductor 52 is a free and movable end as described below. Movements of the end 58 allow the first and second latch contacts 48 and 50 to contact and disconnect from each other.

The second locking contact 50 is arranged on a second locking contact conductor 60 opposite the first locking contact 48. The second locking contact conductor 60 is electrically conductively connected to the first connection contact 20 and, as shown in the figures, preferably formed integrally therewith. Referring to the figures, the end 22 of the first door contact conductor 16 is connected to the terminal contact 20 by connecting the end 22 to the second locking contact conductor 60.

For a basic understanding of the operation of the door lock 1 is on Fig. 8 With respect to the door contact switch 10, the lock contact switch 46 and the actuator 24 can be considered as an equivalent electrical circuit diagram. The door contact switch 10 and the actuator 24 are electrically connected in series between the first terminal contact 20 and the second terminal contact 34. Parallel to this series connection, the interlocking contact switch 46 is connected between the first connection contact 20 and the third connection contact 56.

The door contact switch 10 is open as long as the household appliance door is not closed. Activation of the actuator 24 by supplying energy via the first and second connection contacts 20 and 34 is then not possible.

When the domestic appliance door is closed, the door contact switch 10 shoots in response thereto. Then, the first and second actuator terminals 30 and 32 are electrically connected to the first and second terminal contacts 20 and 34. In this state, the actuator 24 can be controlled by supplying power through the first and second terminal contacts 20 and 34, for example, in the form of a pulse-like operation. As described in more detail below, activation of the actuator 24 to lock the appliance door causes the latch contact switch 46 to close Fig. 8 indicated by the dashed line.

The latch contact switch 46 closed in response to latching establishes an electrical connection between the first and third terminals 20 and 56. An electrical connection of the first and third terminal contacts 20 and 56 thus produced indicates to a home appliance controller that the household appliance door is locked and commissioning can take place.

The first connection contact 20 is preferably connected to ground. The second connection contact 34 is preferably connected to an electrical connection of a household appliance control via which control signals (eg pulse signals) can be supplied to the actuator 34. The third terminal contact 56 is preferably connected to a terminal of a household appliance control, which has a predetermined, different from ground potential. When the lock contact switch 46 is closed, flows between the first and third Terminal contacts 20 and 56 Power. This current flow indicates the locked state of the household appliance door.

The operation of the door lock 1, as in Fig. 5 to 7 is illustrated in more detail below.

The in Fig. 5 shown state of the door lock 1 is present when the household appliance door is neither completely closed nor locked. In this state, the skin slider spring 6 holds the main slider 4 in the position shown. In this case, the stop region 8 and the free end 18 of the first door contact conductor 16 cooperate so that the first door contact conductor 16 is held against its bias in the portion shown. The first and second door contacts 12 and 14 are separated from each other. This indicates that the appliance door is not closed. Any activation of the actuator 24 is not possible here.

In the state of the door lock 1 according to Fig. 5 is the free end of the lever 38 to the actuator 28 due to the force of the above-mentioned, not shown, torsion spring of the rotary member 36 at. In this case, the extension 40 and the free end 58 of the first locking contact conductor 52 cooperate so that the first locking contact conductor 52 is held against its bias in the position shown. The first and second locking contacts 48 and 50 are separated from each other. This indicates that the appliance door is unlocked. A current flow between the first and third terminal contacts 20 and 56 is not possible.

The in Fig. 6 illustrated state of the door latch 1 corresponds to a situation in which the household appliance door is closed, but not locked. The closing of the household appliance door causes a movement of the main slide 4 against the pressing force of the main slide spring 6 to the right. In this case, the operative connection between the stop region 8 and the free end 18 of the first door contact conductor 16 is terminated. The bias of the first door contact conductor 16 causes movement in the in Fig. 6 shown position. As a result, the first and second door contacts 12 and 14 are brought into contact with each other in an electrically conductive manner. Due to the resulting electrical connection between the first and second terminal contacts 20 and 34, the actuator 24 can be controlled. With regard to the rotary member 36 and the lock contact switch 46, there are no changes in this state of the door lock 1.

The in Fig. 7 illustrated state of the door lock 1 corresponds to a situation in which the household appliance door is closed and locked. In order to bring the door lock 1 into a state in which the household appliance door is locked, the actuator 24 is activated, which is possible due to the electrical connection of the first and second connection contacts 20 and 34 via the closed door contact switch 10. The activation of the actuator 24 causes a movement of the actuator 28, preferably pulse-like, to the left. In this case, the rotary member 36 is rotated due to the operative connection with the actuator 28 and the free end of the lever 38 in a clockwise direction. The rotation of the rotary member 36, which also results in a displacement of the extension 40, causes the first locking contact conductor 52 due to its bias in the in Fig. 7 shown position moves. It is possible that the operative connection between the extension 40 and the free end 58 of the first locking contact conductor 52 is terminated or, as in Fig. 7 shown, the extension 40 and the end 58 are still in contact. In this position of the first locking contact conductor 52, the first and second locking contacts 48 and 50 make electrical contact, so that there is an electrically conductive connection between the first and third connection contacts 20 and 56.

The rotation of the rotary member 36 further causes the latching structure 42 and the locking bracket 44 cooperate with each other so that the rotary member 36 in the in Fig. 7 shown position is held.

To unlock the home appliance door, the actuator 24 is reactivated. The resulting, preferably pulse-like, movement of the actuator 28 exerts a force on the rotary member 36 in a clockwise direction via the lever 38. This force, which can cause a further rotation of the rotary member 36 in a clockwise direction, has the result that the latching structure 42 and the locking bracket 44 cooperate with each other so that the operative connection, the rotary member 36 in the in Fig. 7 shown position stops. Thereafter, the rotary member 36 of the above-mentioned spring, not shown in the counterclockwise direction in the in Fig. 5 shown position. In this case, the extension 40 urges the end 58 of the first locking contact conductor 52 in the position according to Fig. 6 , The electrically conductive connection between the first and second latch contacts 48 and 50 is terminated. The missing electrical connection between the first and third connection contacts 20 and 56 indicate that the appliance door is not (anymore) locked.

After unlocking the appliance door, where the door lock 1 in the in Fig. 6 is shown, the household appliance door can be opened. Opening the household appliance door causes the main slide spring 6, the main slide 4 from the in Fig. 6 shown position in the in Fig. 5 position shown urges. In this case, the stop region 8 moves the free end 18 of the first door contact conductor 16 in the in Fig. 5 shown position. In this case, the first and second door contacts 12 and 14 are separated from each other. There is no electrically conductive connection between the first and third connection contacts 20 and 34. Activation of the actuator 34 is not possible.

Notwithstanding the in Fig. 5 to 7 1, it is possible to use, instead of separate first door contact conductor 16 and second locking contact conductor 60, a conductor comparable to the first door contact conductor 16, on which both the first door contact and the second locking contact are arranged.

It is also possible, instead of using separate conductors for the connection contacts, to have integral conductors which, integrated into the unitary structure, provide the connection contacts and door contact and locking contact conductors or actuator connections.

Further, it is provided to firmly connect the first lock contact 48 to the rotary member 36 and to arrange so that rotation of the rotary member 36 for locking the home appliance door brings the first and second door contacts into contact with each other.

In addition, embodiments are provided in which individual, several or all principles of action, compared with the embodiment of Fig. 5 to 7 , as far as possible, are reversed. For example, one embodiment may include a latch contact switch whose open state (ie latch contacts 48 and 50 are in contact) indicates that the appliance door is latched while its closed state (ie latch contacts 48 and 50 do not touch) indicates an unlocked home appliance door.

The door lock according to the invention has several advantages.

The electrical series connection of door contact switch and actuator ensures that the actuator can really only be activated when the household appliance door is closed.

Furthermore, the number of used connection contacts is significantly reduced. This leads to a smaller number of components, reduced material requirements, simpler construction and thereby reduced manufacturing costs. In addition, the space in the area of the connection contacts is reduced. The reduced number of connection contacts but also has the consequence that the total required space is reduced. The advantages resulting from the reduced number of connection contacts also apply to the intended household appliance-side connection.

Nevertheless, it is still possible to detect the positions of the door contact switch 10 and / or the lock contact switch 46 to determine whether the door contact switch 10 and the lock contact switch 46 are closed or opened.

Another advantage will be apparent in light of the following explanations. Many home appliance manufacturers equip their home appliances price-dependently with simple door locks whose doors are locked by means of a thermoelectric actuator (e.g., PTC element) or with door locks in which door locks are effected by means of an electromagnetic actuator.

The simpler door locks with thermoelectric actuators point, as in Fig. 9 illustrates three terminal contacts I, II and III. These door locks, unlike the door locks discussed herein, do not include means to determine if a home appliance door is closed. Fig. 9 schematically represents an electrical equivalent circuit diagram for a known door lock with thermoelectric actuator TA in the form of a PTC element and a device DV for detecting a locking state.

So far, it has been necessary, depending on whether door locks with thermoelectric actuator or with electromagnetic actuator to be used to provide household appliance side different connection devices, namely on the one hand connections with three contacts and on the other hand connections with six contacts. This is no longer necessary with the present invention. Rather, household appliance side identical connections can be provided regardless of which type of door lock is to be used. Thus, it is possible with the present invention, for example, to equip one and the same household appliance optionally with a door lock according to the invention or a known door lock with thermoelectric actuator, without being required by the home appliance structural changes.

Claims (5)

1. A door lock device for a door of a domestic appliance, comprising:

   - a door contact switch (10) responsive to the closing of the door,

   - an actuator (24) electrically coupled in series with the door contact switch (10) for actuating a door locking member (36), and

   - a locking contact switch (46) which is responsive to the door locking member (36) and of which the switching state indicates whether the door is locked or unlocked,

   characterized in that the door lock device includes three terminal contacts (20, 34, 56) for connecting to an appliance control unit, wherein the series connection of the door contact switch (10) and the actuator (24) is coupled between a first (20) and a second (34) of the terminal contacts and wherein the locking contact switch (46) is coupled in parallel to the series connection of the door contact switch (10) and the actuator (24) between the first and a third of the terminal contacts (56).
2. The door lock device of claim 1, characterized in that the actuator (24) is an electromagnetic actuator.
3. The door lock device of claim 1 or 2, characterized in that the first terminal contact (20) is electrically connected to ground.
4. The dock lock device of any one of claims 1 to 3, characterized in that the locking contact switch (46) is closed in the locked condition of the door.
5. The door lock device of any one of claims 1 to 3, characterized in that the locking contact switch (46) is open in the locked condition of the door.

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