Door lock mechanism for household appliances

Abstract

The invention relates to a door lock mechanism 100 for household appliances, in particular for dishwashers, with a cam element 200 which can be engaged by at least one pivotable, spring-loaded lever arm 110, 110' to close a door of the household appliance. This door lock mechanism is characterized by a slidably mounted locking element 300, which, depending on its position of movement, can block or release the at least one lever arm 110, 100' in a pivot position, such that in a first position of movement of the cam element 200, the at least one lever arm 110, 110' contacts a cam 210, 210' of the cam element 200, which rises in the opposite direction of a closing movement D of the cam element 200, closer to its upper end 220, 220' than to its lower end 230, 230', and in a second position of movement of the cam element 200, the at least one lever arm 110,110' the cam element 200 contacts even closer to the upper end of its rising cam 210, 210', a gap is formed between the at least one lever arm 110, 110' and the locking element 300, and in a third movement position of the cam element 200 the at least one lever arm 110, 110' contacts a cam 240, 240' of the cam element 200 which slopes down in the opposite direction to the closing movement D of the cam element 200, wherein the locking element 300 is displaceable from the cam element 200 in the second and / or in the third movement position.

Description

[0001] The invention relates to a door lock mechanism for household appliances according to the preamble of claim 1, in particular for dishwashers, comprising a guide element that can be engaged behind by at least one pivotable, spring-loaded lever arm for closing a door of the household appliance. The invention further relates to a method for locking and unlocking the door of a household appliance with such a door lock mechanism according to claim 13, and a preferred use of the door lock mechanism for a dishwasher according to claim 15.

[0002] A door lock mechanism for household appliances is typically located on the cabinet of a dishwasher, for example. With such door lock mechanisms, a closing force must first be applied up to a turning point. From this turning point, the door lock mechanism pulls the door into the closed position.

[0003] The US patent specification US 9,101,259 B2 discloses a door lock mechanism which, for the secure locking of the door of a dishwasher, comprises lever arms which are pushed apart by a deflection surface and close again behind this.

[0004] The German patent application DE 10 2021 104 747 A1 discloses a mechanism for the door of an electrical household appliance, which can be opened automatically by a handle that is separate from the lock opening mechanism and decoupled from its movement.

[0005] However, the door lock mechanisms known from the state of the art do not allow the door of a household appliance to be closed with little force while still locking the door securely and reliably.

[0006] An object of the present invention is to simplify the operation of the door of a household appliance and, in particular, to reduce the closing force required without, from a turning point of the force applied, impairing the pulling force for closing the door.

[0007] The object is achieved by a door lock mechanism according to the invention according to the characterizing part of claim 1, with a displaceably mounted locking element which, depending on its movement position, can block or release the at least one lever arm in a pivot position, so that in a first movement position of the link element, the at least one lever arm contacts a link of the link element which rises counter to a closing movement direction of the link element closer to its upper end than to its lower end, and in a second movement position of the link element, the at least one lever arm contacts the link element even closer to the upper end of its rising link, a gap is formed between the at least one lever arm and the locking element,and in a third movement position of the link element, the at least one lever arm contacts a link of the link element which slopes downwards counter to the closing movement direction of the link element, wherein the locking element is displaceable by the link element in the second and / or in the third movement position.

[0008] A key feature of the door lock mechanism according to the invention is that the at least one lever arm only comes into contact with the guide element shortly before a turning point for the closing forces to be applied. This means that the guide element no longer needs to apply any force to counteract the springback of a lever arm along the entire ascending guide element. This lever arm is reset and blocked by the locking element against its spring, so that it only comes into contact with the guide element near the upper end of the ascending guide element, i.e. shortly before the turning point for the closing forces to be applied. At this point, however, only a small amount of force is sufficient to overcome the turning point and trigger automatic engagement of the guide element. A lever arm, driven by its spring, slides down the descending guide element, pulling it towards itself and engaging it, thus locking the door lock mechanism.During this final movement of a lever arm, the locking element is displaced with the aid of the guide element in such a way that the blockage of a lever arm is released. Such unlocking can also be initiated in the second movement position of the guide element, if a blocking surface must first be completely overcome before reaching the third movement position. Due to the low actuation force required by the user, such a door lock mechanism is also referred to as a 'soft close'. The subclaims comprise preferred embodiments of the door lock mechanism according to the invention.

[0009] According to an advantageous embodiment of the door lock mechanism according to the invention, the at least one lever arm is released when the guide element moves from the second to the third movement position, and the at least one lever arm is blocked when the guide element moves from the second to the first movement position. This ensures, on the one hand, that the guide element engages behind the guide element without blockage when the door lock mechanism is closed. Conversely, a force-reduced opening of the door lock mechanism corresponding to the closing is possible, since the lever arm is blocked again and positioned friction-free along the rising guide. This supports both force-reduced closing and opening of the door lock mechanism.

[0010] The at least one lever arm preferably has a stop located approximately centrally in the longitudinal direction of the lever arm and projecting in the direction of the locking element for abutment against the locking element. When the locking element is moved, the at least one lever arm is returned to the locking element by the projecting height of the stop, counter to its spring action, and is locked in the returned position, thus enabling particularly simple adjustment of a lever arm to the rising guide. Preferably, the stop is provided with a run-on bevel for the locking element, along which the locking element can slide and block the at least one lever arm in a pivoted position. Alternatively or additionally, the locking element can also be provided with such a run-on bevel to fulfill this function. In any case, this allows a simple movement coupling between the locking element and the lever arm to be realized.

[0011] A particular advantage arises when the locking element is mounted so that it can spring back against the guide element. This allows the locking element to be coupled in a simple and reliable manner to the guide element and, at the same time, to a lever arm. Preferably, the springback force of at least one lever arm is selected to be stronger than the springback force of the locking element. This supports a force-reduced closing and opening of the door mechanism without reducing its closing force. The closing force of a lever arm can be implemented by a compression and / or tension spring.

[0012] A movement coupling of the locking element can preferably be realized via a magnetic connection to the guide element, wherein the locking element can be equipped with or without springback. Such a coupling is easy to implement and allows the locking element to be coupled and moved to block and release a lever arm depending on the movement of the guide element.

[0013] In a further embodiment of the door lock mechanism according to the invention, it is provided that an inclination angle of the rising gate is smaller than an inclination angle of the falling gate. The inclination angle of the rising gate is to be understood as the included angle between the rising gate and a longitudinal axis of the gate element. The inclination angle of the falling gate is to be understood as the included angle between the falling gate and the longitudinal axis of the gate element. If the inclination angle of the rising gate is smaller than the inclination angle of the falling gate, the force required to close the door lock mechanism is reduced, while the tensile force required to lock the door lock mechanism is increased.This is because the user only needs to exert minimal force to push the gate element against the lever arm resting on the gently rising gate until the force application point is reached. From this point onward, the steeply falling gate, in contrast, allows for a particularly high locking and pulling force of the lever arm. Ideally, the included angle between the rising and falling gates is between 90° and 130°.

[0014] In a particularly preferred embodiment of the door lock mechanism according to the invention, two lever arms are provided, which can be pivoted about respective pivot axes running parallel to each other, thus enabling a particularly powerful and thus more secure and reliable locking of the door lock mechanism. In this case, the gate element is engaged from behind, for example, from two opposite sides, although only a single locking element arranged between the two lever arms can be provided.

[0015] To couple the movement of the gate element to the locking element, it is preferred if the gate element has a projection, in particular a plunger. The movement coupling can be adjusted, for example, along the length of the plunger so that when the inflection point of the force application is exceeded, i.e., when a lever arm contacts the descending gate of the gate element and the locking process occurs, the plunger contacts the locking element and moves together with the gate element to release a blockage of a lever arm. This allows a lever arm to slide down along the descending gate and engage behind the gate element, locking it.However, a length of the plunger can also be selected such that a movement coupling of the link element with the locking element is created already in the second movement position of the link element, for example if the unlocking of a lever arm up to the third movement position of the link element requires a pre-travel distance of the locking element in order to completely overcome a locking surface.

[0016] In a preferred embodiment of the door lock mechanism according to the invention, the guide element can have a polygonal, in particular triangular or quadrangular, in the latter case preferably diamond-shaped, cross-section, or a round or semicircular cross-section. A diamond-shaped cross-section, in particular, allows for a different choice of inclination angles in order to design a lever arm to engage according to the invention on a gently rising guide element and a desired setting of a locking force behind the inflection point of the force application on a steeply falling guide element.

[0017] The present object is also achieved by a method according to claim 13. A key aspect of the method according to the invention is that, compared to the prior art, no additional process steps or operating elements, such as an additional push button, are required for a 'soft close' operation of the door of a household appliance, and the user benefits from a conventional, but less force-requiring, operation of the appliance with the same locking properties. The subclaims comprise preferred embodiments of the door lock mechanism according to the invention.

[0018] In order to achieve a less forceful and at the same time safe opening and closing of the door of a household appliance, it is advantageous if, by moving the locking element, at least one lever arm is released when the door lock mechanism is closed and blocked when the door lock mechanism is opened.

[0019] Due to the space-saving and simple implementation of the door lock mechanism according to the invention, it is intended to be used in particular in household appliances with high usage frequency, in particular on dishwasher doors.

[0020] Further advantages, objects, and features of the present invention will be explained in the following description of the accompanying figures. Similar components may have the same reference numerals in the various embodiments. In the figures: Fig. 1a a functional diagram of a door lock mechanism according to the invention with a link element shortly before insertion between two lever arms; Fig. 1b the functional diagram of the Fig. 1a, in which the link element is in a first movement position; Fig. 1c the functional diagram of the Fig. 1a, in which the link element is in a second movement position; Fig. 1d the functional diagram of the Fig. 1a, where the link element is at a turning point of the force application; Fig. 1e the functional diagram of the Fig. 1a, in which the link element is in a third movement position, and Fig. 2 a diagram explaining the force required when closing a door lock mechanism according to the invention.

[0021] The Fig. Figure 1 shows a functional diagram of a door lock mechanism 100 according to the invention with a guide element 200 shortly before being inserted between two lever arms 11, 110'. The guide element 200 shown is, for example, that of a dishwasher door, which is about to close against the dishwasher's housing. The door lock mechanism 100 is mounted on the dishwasher's container, not inside it.

[0022] The gate element 200 here has a diamond-like cross-sectional shape, with its respective gates 210, 210', which rise counter to a closing movement direction D (Direction), extending from a lower end 230, 230' to an upper end 220, 220', which simultaneously represents the transition to gates 240, 240', which fall counter to the closing movement direction D. The rising gates 210, 210' terminate in an elongated plunger 250 in the closing movement direction, which can establish a movement coupling between the gate element 200 and a locking element 300.

[0023] The two lever arms 110, 110' are resiliently mounted on respective pivot axes X1, X1', which run parallel and offset from one another, and have an approximately central stop 120, 120', which bears against the 300. The locking element 300 is slidably mounted along its longitudinal direction and resiliently mounted against bevels 130, 130'. Via the respective bevel 130, 130', the locking element can reset the lever arms 110, 110' during its movement from right to left and lock them against a closing pincer movement. Before the guide element 200 is inserted when closing the door, the lever arms 110, 110' both bear against the locking element 300, but are under spring pressure and / or tension towards each other.

[0024] In principle, the door lock mechanism 100 shown is constructed in a mirror image along a horizontal longitudinal axis, although this need not necessarily be the case. In particular, a door lock mechanism according to the invention can also be designed solely from a single lever arm 110 and, for example, a triangular link element. It is of course also conceivable to use a spherical or hemispherical link element instead of a square link element. The basic procedure described below is important: to close the door lock mechanism, first reset and lock the lever arm, then unlock it again to lock the door lock mechanism, and proceed in the reverse order to open the door lock mechanism.

[0025] The Fig. 1b shows the functional diagram of the Fig. 1a, in which the link element 200 is in a first movement position P1 (position 1), in which the lever arms 110, 110' contact the rising links 210, 210' near their upper ends 220, 220'. The locking element 300 thus ensures that the lever arms 110, 110' are retracted to such an extent that no force is required to move them along a large section of the rising links 210, 210'. In this position, the locking element 300 is still unaffected by the plunger 250.

[0026] To reduce the force required by a user to move the guide element 200 during the further course of the closing process, an inclination angle A1 (Angle 1) of the rising guide elements 210, 210' can be selected to be significantly smaller than the inclination angle A2 (Angle 2) of the falling guide elements 240, 240'. However, a limit is reached where the overall length of the door lock mechanism 100 ultimately reaches the size restrictions for a dishwasher. The angle A3 (Angle 3) enclosed between the rising and falling guide elements 210, 210' and 240, 240' results from subtracting the angles A1 and A2 from the sum of all angles in a triangle (180°), and ideally lies between 90° and 120° to ensure reliable sliding down and retraction of the guide element 200 by the lever arms 110, 110'.

[0027] The Fig. 1c shows the functional diagram of the Fig. 1a, in which the link element 200 is in a second movement position P2 (position 2), in which the link elements 200 have already been pushed a little further in the closing movement direction D by the application of force by a user, so that the lever arms 110, 110' on the rising links 210, 210' have been pushed even further towards their upper ends 220, 220'. In this movement position P2, a respective gap G, G' (gap) is created between the stops 120, 120' and the locking element 300, so that its longitudinal displaceability is released. In this movement position P2, the plunger 250 of the link element 200, the locking element 300 establishes a movement coupling between the link element 200 and the locking element 300.

[0028] The Fig. 1d shows the functional diagram of the Fig. 1a, in which the gate element 200 is at a turning point of force application, which is located at the upper ends 220, 220' of the rising gates 210, 210'. To close the door, the user therefore only has to work against the force of the lever arms 110, 110' between the movement position P1 and the turning point of force application 220, 220' (soft close). At the turning point of force application 220, 220', the locking element 300 has already been retracted to the left by a portion of the width of the stops 120, 120' until just before the ramps 130, 130'.

[0029] The Fig. 1e shows the functional diagram of the Fig. 1a, in which the link element 200 is in a third movement position P3 (position 3), in which it is finally completely engaged behind the lever arms 110, 110' and the door lock mechanism is locked. For this purpose, the locking element 300 was displaced by the plunger 250 so far to the left that the stops 120, 120' are released and a pincer movement of the lever arms 110, 110' is no longer blocked, so that they have slid down along the sloping links 24, 240' and pulled the link element 200 towards themselves (closed position). The user no longer needs to exert any force for this process, since it is carried out by the spring action of the lever arms 110, 110'.

[0030] The Fig.Figure 2 shows a diagram illustrating the force required to close a door lock mechanism 100 according to the invention. The ordinate indicates a positive or negative force F (Force) required to operate the door lock mechanism 100, while the abscissa indicates the corresponding movement position of the gate 200 (closing movement direction D to the left). Accordingly, if the gate 200 is moved from the movement position P1 to the upper end 240, 240' of the rising gate 210, 210', the user must apply a closing / opening work (force x distance) corresponding to the area CW (Close Work). However, the movement of the gate 200 from this point to the locking position P3 no longer requires any force from the user, but is applied by the springs of the lever arms 110, 100' themselves, which allow the lever arms 110, 110' to engage behind the gate 200 and pull it between them.The locking and unlocking work required is given by the area PW (Pull Work).

[0031] A comparison of the surfaces CW and PW shows that the user has to exert significantly less effort to close the dishwasher door (soft close). At the same time, a secure and reliable locking of the door is ensured by the use of the spring-loaded lever arms 110, 110'. The springback of the locking element 300 can be selected such that it only ensures its return to block the lever arms 110, 110' and has no further influence on their closing force, which could jeopardize a secure closing position behind the gate 200.

[0032] By blocking the lever arm movement in the open position and releasing the entire lever travel for the locking process, a relatively low closing force can be achieved that has to be applied by the user without this having any effect on the pulling force and the pulling travel.

[0033] In principle, the locking element 300 does not necessarily have to be mounted in a spring-loaded manner. The locking element 300 can also be retracted against the stops 120, 120' by means of a motion coupling with the gate, in which the gate separably grips the locking element 300 in the opening direction, for example, via a hook or magnet, and retracts it to the left into the locking position.

[0034] Overall, this provides a door lock mechanism 100 that is structurally simple, safe to operate, and reliably closing, offering the user a 'soft close' function without any other restrictions. List of reference symbols 100 door lock mechanism 110, 110' lever arm 120, 120' Projecting stop 130, 130' approach slope 200 backdrop elements 210, 210' Rising scenery 220, 220' Top of the rising backdrop (turning point of effort) 230, 230' Lower end of the rising scenery 240, 240' Sloping backdrop 250 pestles 300 locking element A1 Angle of the rising backdrop against its direction of movement A2 Angle of the sloping backdrop with its direction of movement A3 Included angle between rising and falling backdrop B Closing movement direction CW closing-opening work F Actuating force G, G' gap between locking element and lever arm P1 First movement position P2 Second movement position P3 Third movement position PW locking / unlocking work X1, X1' pivot axis of the lever arm QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 9,101,259 B2

[0003] DE 10 2021 104 747 A1

[0004]

Claims

[1] Door lock mechanism (100) for household appliances, in particular for dishwashers, with a link element (200) which can be engaged behind by at least one pivotable, spring-loaded lever arm (110, 110') for closing a door of the household appliance, characterized by a displaceably mounted locking element (300) which, depending on its position of movement, can block or release the at least one lever arm (110, 100') in a pivoting position, so that - in a first movement position (P1) of the link element (200), the at least one lever arm (110, 110') contacts a link (210, 210') of the link element (200) rising counter to a closing movement direction (D) of the link element (200) closer to its upper end (220, 220') than to its lower end (230, 230'), and - in a second movement position (P2) of the link element (200), the at least one lever arm (110, 110') contacts the link element (200) even closer to the upper end of its rising link (210, 210'), a gap (G, G') is formed between the at least one lever arm (110, 110') and the locking element (300), and - in a third movement position (P3) of the link element (200), the at least one lever arm (110, 110') contacts a link (240, 240') of the link element (200) which slopes downwards counter to the closing movement direction (D) of the link element (200), wherein the blocking element (300) is displaceable by the link element (200) in the second and / or in the third movement position. [2] Door lock mechanism (100) according to claim 1, characterized byreleasing the at least one lever arm (110, 110') when the link element (200) moves from the second into the third movement position (P2, P3), and blocking the at least one lever arm (110, 110') when the link element (200) moves from the second into the first movement position (P2, P1). [3] Door lock mechanism (100) according to claim 1 or 2, characterized by that the at least one lever arm (110, 110') has a stop (120, 120') which is located approximately centrally in the longitudinal direction of the lever arm (110, 110') and projects in the direction of the locking element (300) for bearing against the locking element (300). [4] Door lock mechanism (100) according to claim 3, characterized by that the stop (120, 120') is provided with a run-on slope (130, 130') for the locking element (300), along which the locking element (300) can slide and block the at least one lever arm (110, 110') in a pivoting position. [5] Door lock mechanism (100) according to one of the preceding claims, characterized by that the locking element (300) is resiliently mounted against the link element (200). [6] Door lock mechanism (100) according to claim 5, characterized by that the springback force of the at least one lever arm (110, 110') is selected to be stronger than a springback force of the locking element (300). [7] Door lock mechanism (100) according to one of the preceding claims, characterized by that the locking element (300) can be coupled to the link element (200) via a magnetic connection. [8] Door lock mechanism (100) according to one of the preceding claims, characterized by that an angle of inclination (A1) of the rising backdrop is smaller than an angle of inclination (A2) of the falling backdrop (240, 240'). [9] Door lock mechanism (100) according to claim 8, characterized bythat an included angle (A3) between the rising backdrop (210, 210') and the falling backdrop (24, 24') is between 90° and 130°. [10] Door lock mechanism (100) according to one of the preceding claims, characterized by that two lever arms (110, 110') are provided which can be pivoted about respective pivot axes (X1, X1') running parallel to one another. [11] Door lock mechanism (100) according to one of the preceding claims, characterized by that the link element (200) has a projection, in particular a plunger (250) for coupling the movement with the blocking element (300). [12] Door lock mechanism (100) according to one of the preceding claims, characterized by that the link element (200) has a polygonal, in particular triangular or square, in the latter case preferably diamond-shaped cross-section, or a round or semicircular cross-section. [13] Method for locking and unlocking the door of a household appliance with a door lock mechanism (100) according to one of the preceding claims, in which at least one pivotably resiliently mounted lever arm (110, 110') is blocked against a displaceably mounted blocking element (300), so that the at least one lever arm (110, 110') contacts a guide element (210, 210') rising counter to the closing movement direction (D) of the guide element (200) closer to its upper end (220, 220') than to its lower end (230, 230'), and upon further movement of the guide element (200) towards the at least one lever arm (110, 110'), at least one lever arm (110, 110') and the locking element (300) is opened, and upon further movement of the link element (200), in which the at least one lever arm (110, 110') has a rising link (210,210') adjacent to the gate element (200) and sloping in the opposite direction to the closing movement (D) of the gate element (200), the locking element (300) is displaced by the gate element (200). [14] Method according to claim 13, characterized by that by moving the locking element (300) the at least one lever arm (110, 110') is released when the door lock mechanism (100) is closed and blocked when the door lock mechanism (100) is opened. [15] Use of a door lock mechanism (100) according to any one of claims 1 to 12 for the door of dishwashers.

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