Patent Application
20210123181
The present invention relates generally to a door latch for a domestic electrical appliance and relates further to the mounting of such a door latch on a mounting wall of the domestic appliance.
Conventional domestic electrical appliances such as, for example, washing machines, dishwashers, tumble dryers, baking ovens, microwave ovens and the like are conventionally equipped with a door latch for keeping closed a door of the domestic appliance, which permits access to a working chamber thereof (for example in the case of a washing machine to a washing chamber in a washing drum), after the door has been closed. Conventional door latches have a latch assembly group which is composed of a plurality of individual components and pre-assembled to form a structural unit and which, on closing of the door, cooperates with a closing member, for example in the form of a pivotable closing hook or in the form of a fixed closing shackle, which enters an insertion mouth of the latch assembly group and holds it in place. The closing member is, for example, attached to the door of the domestic appliance, whereby the latch assembly group is then attached to a main body (carcass) of the domestic appliance containing the working chamber, or vice versa.
Regardless of whether the latch assembly group is attached to the main body or to the door of the domestic appliance, the latch assembly group is fitted in the case of conventional door latches by engaging the latch assembly group in a mounting opening of a mounting wall of the main body or of the door, usually without the use of additional screw connections. In conventional solutions, the latch assembly group, which owing to its configuration as a single coherent module is also referred to hereinbelow as a latch module, has a collar which extends around the insertion mouth and with which the latch module must be pushed through the mounting opening. In the finished fitted state, the collar projects beyond the mounting opening in the region of two opposing opening edges of the mounting opening, that is to say the extent of the collar is greater in that direction than the width of the mounting opening. In order nevertheless to be able to push the collar through the mounting opening, the latch assembly group must be tilted relative to the mounting wall. In this manner, a first portion of the collar can first be pushed through the mounting opening. An opposite second portion of the collar can then also be pushed through the mounting opening and the tilting of the latch assembly group can be reversed again. However, this method of pushing the collar through the mounting opening in a tilted manner requires the adjoining neck region beneath the collar to be narrower than the mounting opening. EP 1 418 266 A2 shows such a solution. In order that the latch module cannot slide along the mounting wall in the inserted state, that EP document provides positioning nubs on the latch module which engage into additional positioning holes of the mounting wall.
On the other hand, it is desirable that the neck region beneath the collar fills the mounting opening substantially completely in the finished mounted state. Additional positioning aids such as, for example, in the form of the positioning nubs of the mentioned EP document are then not required. In WO 2019/010020 A1, a solution is proposed in which, after the collar has been pushed through the mounting opening, a movable auxiliary member of the latch assembly group is pushed up into the remaining free space between the neck region and the opening edge of the mounting opening in order thus to fill the mounting opening completely.
However, the mentioned solutions according to EP 1 418 266 A2 and WO 2019/010020 A1 are comparatively complicated in terms of construction and correspondingly expensive to produce. The mounting operation itself is also comparatively laborious.
Accordingly, an object of the invention is to provide a door latch for a domestic electrical appliance which can be produced inexpensively and installed in a simple manner in the domestic appliance.
In order to achieve that object there is provided according to a first aspect of the invention a door latch for a domestic electrical appliance, comprising a latch module having an insertion mouth for receiving a closing member on closing of a door of the domestic appliance, two collar portions which are arranged opposite one another in a first direction on both sides of the insertion mouth and project away from one another, wherein collar undersides of the collar portions define a first positioning plane parallel to the first direction, support surfaces, separate from the collar portions, which define a second positioning plane parallel to the first positioning plane and at a distance beneath the first positioning plane, a first lateral wall beneath a first of the collar portions, wherein the first lateral wall is arranged laterally inwards from an outer collar edge of the first collar portion and extends as far as the collar underside of the first collar portion, and a second lateral wall beneath the second of the collar portions, wherein the second lateral wall is arranged laterally inwards from an outer collar edge of the second collar portion and extends as far as the collar underside of the second collar portion.
According to the invention, the second lateral wall has a first lateral wall sub-portion which extends as far as the collar underside of the second collar portion and points substantially sideways and, beneath the first lateral wall sub-portion, a second lateral wall sub-portion which is offset laterally inwards relative to the first lateral wall sub-portion and points substantially sideways, wherein the second lateral wall sub-portion is arranged at least partially and in particular wholly beneath the second positioning plane.
In this solution, the second lateral wall is constructed with different sub-portions which are offset inwards by different distances relative to the outer edge of the second collar portion. A first of these sub-portions of the second lateral wall advantageously lies directly beneath the second collar portion and is offset inwards to a lesser extent than is a second sub-portion of the second lateral wall, which lies beneath the first sub-portion. The second sub-portion of the second lateral wall allows the first collar portion to be pushed through a mounting opening in a mounting wall of the domestic appliance in a tilted position of the latch module in which the second collar portion has already previously been pushed through the mounting opening and the latch module is supported with the second sub-portion of the second lateral wall on an opening edge of the mounting opening. After the first collar portion has been pushed through the mounting opening, the latch module can be shifted along the mounting wall relative thereto until the first sub-portion of the second lateral wall is able to fall into the mounting opening. Because the first sub-portion is offset inwards relative to the outer edge of the second collar portion to a lesser extent than is the second sub-portion, play between the latch module and the mounting wall is reduced and in particular even largely eliminated along the mounting wall when the first sub-portion falls into the mounting opening. The solution according to the invention does not require additional positioning holes in the mounting wall for receiving separate positioning nubs of the latch module, as in EP 1 418 266 A2, for example, nor is a movable auxiliary member on the latch module required in order to fill a free space that remains between the latch module and the opening edge of the mounting opening, as in WO 2019/010020 A1.
The support surfaces of the latch module ensure that the latch module is held securely on the mounting wall in a direction perpendicular to the positioning planes after the first sub-portion of the second lateral wall has slid into the mounting opening. The presence of the support surfaces can have the result that, when the latch module is pivoted inwards with the aim of also moving the first collar portion through the mounting opening after the second collar portion has previously been pushed through the mounting opening, temporary elastic bending of the mounting wall occurs, caused by part of the support surfaces pressing against the mounting wall from beneath. The mounting wall relaxes, however, and returns to its unbent state when the first sub-portion of the second lateral wall then slides into the mounting opening.
In some embodiments, the transition between the first lateral wall sub-portion and the second lateral wall sub-portion of the second lateral wall is formed by a wall step in the second lateral wall. It is of course conceivable to make the transition between the first lateral wall sub-portion and the second lateral wall sub-portion smooth, that is to say without an angular transition.
In some embodiments, the second lateral wall sub-portion forms the pocket base of an insertion pocket which allows an opening edge of a mounting opening formed in a mounting wall of the domestic appliance to be inserted into the insertion pocket. An upper pocket wall of the insertion pocket can thereby be formed by a wall step of the second lateral wall which forms the transition between the first and the second lateral wall sub-portion, and a lower pocket wall of the insertion pocket can be formed by a third lateral wall sub-portion of the second lateral wall which adjoins the second lateral wall sub-portion therebeneath and extends obliquely outwards and downwards.
In some embodiments, the pocket base has a height, measured perpendicularly to the positioning planes, which corresponds at least approximately to the height of the first lateral wall sub-portion and is preferably substantially equal to the height of the first lateral wall sub-portion.
In some embodiments, the lateral offset of the second lateral wall sub-portion relative to the first lateral wall sub-portion corresponds at least approximately to the projecting length of the first collar portion over the first lateral wall and is preferably substantially equal to that projecting length.
In some embodiments, the first lateral wall sub-portion has a height, measured perpendicularly to the positioning planes, which is substantially equal to the distance between the two positioning planes.
In some embodiments, the latch module comprises at least one resilient biasing member which, in a state of minimal tension, projects upwards beyond the second positioning plane into the region between the two positioning planes and is resiliently deflectable downwards. The state of minimal tension is, for example, a relaxed state. The biasing member serves to reduce or even completely eliminate any loose movement play of the latch module perpendicularly to the mounting wall in the installed state.
In some embodiments, the biasing member, as seen in the first direction, projects beyond the second positioning plane at a point which lies between the two collar portions but closer to the second collar portion than to the first collar portion.
In some embodiments, the latch module comprises a module housing which has the insertion mouth and forms the collar portions, wherein the biasing member is formed by a flexible tongue which is formed integrally with the module housing and is clamped at one end or at both ends.
In some embodiments, the support surfaces form at least one support edge for the latch module. The support edge can form a pressure point at which the latch module presses against the mounting wall on pivoting of the first collar portion into and through the mounting opening and thereby causes temporary bending of the mounting wall. In some embodiments, the support edge, as seen in the first direction, is arranged at a point which is offset relative to a mid-point between the two collar portions towards the second collar portion. In this manner, a tilting moment acting on the latch module can be reduced or avoided if, with the door of the domestic appliance closed, the door is pulled and a force pressing the support surfaces against the underside of the mounting wall is thereby generated.
In some embodiments, a support edge is formed in front of and behind the collar portions as seen in a second direction parallel to the positioning planes and perpendicular to the first direction.
According to a further aspect, the invention provides a door latch for a domestic electrical appliance, comprising a latch module having a mouthpiece which delimits an insertion opening for a closing member which enters the insertion opening on closing of a door of the domestic appliance, a first recess beneath a first edge region of the mouthpiece, a second recess beneath a second edge region of the mouthpiece located diametrically opposite the first edge region beyond the insertion opening, where the first and the second edge region of the mouthpiece define a first positioning plane and the first and the second recess are configured for engagement by opposing opening edges of a mounting opening formed in a mounting wall of the domestic appliance, where the latch module has stationary support points for supporting the latch module on a wall underside of the mounting wall, where the stationary support points lie in a second positioning plane located at a distance beneath the first positioning plane and parallel thereto and—as seen in a direction from the second edge region to the first edge region of the mouthpiece—are arranged on the other side of the second recess and at least partially also on the other side of the first recess, where the second recess has a region of smaller depth between the two positioning planes and a region of greater depth beneath the second positioning plane, and where the latch module has at least one resiliently movable support point, projecting into the space between the two positioning planes, for supporting the latch module on the wall underside of the mounting wall, wherein the resiliently movable support point—as seen in the direction from the second edge region to the first edge region of the mouthpiece—lies in front of a mid-point between the two recesses.
In some embodiments, the resiliently movable support point can at the same time form a pressure point at which the latch module presses against the mounting wall on pivoting of the first edge region of the mouthpiece through the mounting opening and causes temporary bending of the mounting wall. In such embodiments, the stationary support points can have solely a positioning function for the latch module relative to the mounting wall, without exerting a bending action on the mounting wall on pushing of the mouthpiece through the mounting opening. In other embodiments, on the other hand, the resiliently movable support point can be so spring-soft that it is unable to exert a relevant bending action on the mounting wall. In such a case, the stationary support points can include at least one support point (for example in the form of a support edge) which has a bending action on the mounting wall.
There is additionally provided according to the invention a method for mounting a door latch of the first aspect outlined above on a mounting wall of a domestic electrical appliance, wherein a mounting opening for the latch module of the door latch is formed in the mounting wall, wherein the mounting opening has two opposing opening edges which are at a distance from one another which corresponds substantially to the distance between the first lateral wall and the first lateral wall sub-portion of the second lateral wall. In the method, the second collar portion is first guided through the mounting opening and moved over one of the two opening edges of the mounting opening so that the one of the opening edges is in contact with the second lateral wall sub-portion of the second lateral wall. The latch module is then tilted relative to the mounting wall, with temporary elastic bending of the mounting wall and with continued contact of the one of the opening edges on the second lateral wall sub-portion, until the first collar portion passes through the mounting opening past the other of the opening edges. The latch module is then shifted in the direction towards the other of the opening edges in order to move the first collar portion over the other of the opening edges until the one of the opening edges snaps in front of the first lateral wall sub-portion of the second lateral wall owing the action of a spring return force.
In some embodiments, the spring return force results at least in part from the elastic bending of the mounting wall or/and at least in part from elastic deformation of a resilient biasing member of the latch module.
The invention will be explained further hereinbelow with reference to the accompanying drawings.
Reference will first be made to
A door latch designated generally 24 serves to hold the lid 18 closed, that is to say when it has been folded down onto the machine main body 12, which door latch comprises as two fundamental components a closing element 26 and a latch assembly group 28, which is also referred to hereinbelow as a latch module. The closing element 26 and the latch module 28 cooperate, on closing of the lid 18, in that the closing element 26 enters an insertion mouth 30 of the latch module 28 and is secured against lifting out of the insertion mouth 30 by a movably arranged securing element which is contained in the latch module 28 and not shown in detail in
The mentioned securing element in the latch module 28, which is to cooperate with the closing element 26, can be formed, for example, by a rotatably mounted gripping member which is constructed with a gripping mouth formed by two opposing gripping jaws and which the closing member 26 (which in such a case can be in the form of a closing shackle) enters on closing of the lid 18 and thereby sets the gripping member in rotation, whereby the closing member 26 is caught in the gripping mouth of the gripping member. In the field of door latches for domestic washing machines, such rotatable gripping members for catching and holding a closing shackle are known per se among experts, so that a more detailed explanation can be dispensed with. Reference may be made by way of example to DE 198 37 248 A1.
The lid 18 forms a door within the meaning of the present disclosure. Any form of lid, flap or other movable, in particular pivotable, element which is able to selectively block and free an access to a working chamber of a domestic electrical appliance is to be understood as being a door within the meaning of the present disclosure.
Before
The mouthpiece 36a forms a first collar portion 38a and a second collar portion 40a. The two collar portions 38a, 40a, which can also be referred to as the first and second edge region of the mouthpiece 36a, respectively, lie opposite one another in a first direction R1 indicated in
Beneath the first collar portion 38a there is formed on the latch module 28a a first recess 46a, and beneath the second collar portion 40a there is formed on the latch module 28a a second recess 48a. The base (bottom) of the recess 46a is formed by a first lateral wall 50a, which is offset inwards relative to the outer collar edge of the first collar portion 38a and extends as far as the underside of the first collar portion 38a. Unlike the first recess 46a, which can be referred to as a single-step recess, the second recess 48a is in multi-step form and is delimited by a second lateral wall 52a which has two sub-portions 56a, 58a separated by a stepped shoulder 54a. The sub-portion 56a of the second lateral wall 52a can be referred to as a first lateral wall sub-portion and the sub-portion 58b can be referred to as a second lateral wall sub-portion. Based on the outer collar edge of the second collar portion 40a, the second lateral wall sub-portion 58a is offset laterally inwards to a greater extent than is the first lateral wall sub-portion 56a. The first lateral wall sub-portion 56a extends as far as the underside of the second collar portion 40a and in the example shown has substantially the same height as the first lateral wall 50a. By means of the two lateral wall sub-portions 56a, 58a, regions of different depth (measured inwards) are formed in the second recess 48a, namely a region of comparatively smaller depth delimited by the first lateral wall sub-portion 56a and a region of comparatively greater depth delimited by the second lateral wall sub-portion 58a.
At a distance beneath the first positioning plane P1, the latch module 28a defines a second positioning plane P2 (
A portion of the support surfaces 60a, 62a, in the case of
The support surface(s) 62a forms or form a support edge 64a which lies in the positioning plane P2 and which, on installation of the latch module 28a in the mounting opening 34a of the mounting wall 32a, presses from beneath against the mounting wall 32a and effects temporary reversible bending of the mounting wall 32a.
In some embodiments, the support surfaces 60a, 62a are formed by a one-piece housing part of the latch module 28a which at the same time forms the mouthpiece 36a. The support surfaces 60a, 62a form stationary support points for supporting the latch module 28a on the underside of the mounting wall 32a, that is to say they do not have appreciable resilience with which any movement play between the latch module 28a and the mounting wall 32a in the finished installed state corresponding to
The distance of the support surfaces 60a, 62a from the undersides of the collar portions 38a, 40a determines the distance between the two positioning planes P1, P2. This distance of the two positioning planes P1, P2 from one another is such that it corresponds at least to the thickness of the mounting wall 32a and is optionally slightly larger, wherein in the latter case one or more suitable spring elements can be provided on the latch module 28a—as explained—in order to avoid any movement play between the mounting wall 32a and the latch module 28a. If, as a numerical example, a wall thickness of the mounting wall 32a of approximately 0.7 mm is assumed, the distance between the two positioning planes P1, P2 could be, for example, approximately 0.75 or 0.80 mm.
In the example shown, the second lateral wall sub-portion 58a of the second recess 48a lies wholly beneath the second positioning plane P2, that is to say outside the space delimited between the two positioning planes P1, P2. In the example shown, the stepped shoulder 54a lies substantially in the positioning plane P2. The height of the second lateral wall sub-portion 58a (measured in a direction perpendicular to the positioning planes P1, P2) corresponds in the example shown at least to the wall thickness of the mounting wall 32a and in some circumstances may even be slightly larger. Because the second lateral wall sub-portion 58a is offset backwards relative to the first lateral wall sub-portion 56a, an insertion pocket 66a (
The extent to which the second lateral wall sub-portion 58a is offset relative to the first lateral wall sub-portion 56a of the second lateral wall 52a, in other words the length, measured in the first direction R1, of the stepped shoulder 54a, is at least as great as the backward offset of the lateral wall 50a relative to the outer collar edge of the first collar portion 58a. In the example shown, the backward offset of the second lateral wall sub-portion 58a relative to the first lateral wall sub-portion 56a is shown even slightly larger than the backward offset of the first lateral wall 50a relative to the outer collar edge of the first collar portion 34a. The size of the backward offset of the second lateral wall sub-portion 58a relative to the first lateral wall sub-portion 56a can be equated with the depth, measured starting from the first lateral wall sub-portion 56a, of the insertion pocket 66a. Correspondingly, the backward offset of the first lateral wall 50a relative to the outer collar edge of the first collar portion 34a can be equated with the depth, measured starting from the outer collar wall of the first collar portion 34a, of the first recess 46a. By making the insertion pocket 66a at least as deep as the first recess 46a and in particular even slightly deeper, it can be ensured that in the situation shown in
In order to install the latch module 28a on the mounting wall 32a, the latch module 28a is brought up to the mounting wall 32a from beneath and brought into an oblique position relative to the mounting wall 32a in the manner shown in
After the first collar portion 38a has been pivoted past the first opening edge 42a through the mounting opening 34a, the latch module 28a can be shifted along the mounting wall 32a, that is to say in the first direction R1, to the first opening edge 42a so that the first opening edge 42a penetrates increasingly more deeply into the first recess 46a. The second opening edge 44a thereby gradually moves out of the insertion pocket 66a. As soon as the second opening edge 44a has passed the stepped shoulder 54a completely, the first lateral wall sub-portion 56a is able to snap downwards into the mounting opening 32 in front of the second opening edge 44a. This snap movement can be driven at least in part by the flexural stress which the mounting wall 32 develops as a result of the mentioned temporary bending. The finished mounted state according to
Looking at
Reference will now be made to the exemplary embodiment of
It will further be seen in
In contrast,
Although the preferred embodiments of the present invention have been described herein, the above description is merely illustrative. Further modification of the invention herein disclosed will occur to those skilled in the respective arts and all such modifications are deemed to be within the scope of the invention as defined by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102019007428.6 | Oct 2019 | DE | national |
