Door latch for a domestic electrical appliance and method for mounting such a door latch

Abstract

A latch module has an insertion mouth for receiving a closing member on closing of a door of a domestic appliance. Two collar portions which project away from one another are formed on both sides of the insertion mouth. Beneath a first of the collar portions there is formed a first recess, and beneath the second of the collar portions there is formed a second recess, which in some exemplary embodiments has two steps, where a first, less deep step is formed by a first lateral wall sub-portion and a second, deeper step is formed by a second lateral wall sub-portion.

Claims

1. A door latch for a domestic electrical appliance, comprising a latch module comprising: an insertion mouth for receiving a closing member on closing of a door of the domestic electrical 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 collar portion of the two 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 a second collar portion of the two 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, wherein the second lateral wall further comprising: a first lateral wall sub-portion which extends as far as the collar underside of the second collar portion and points substantially sideways; and a second lateral wall sub-portion beneath the first lateral wall sub-portion, the second lateral wall sub-portion being offset laterally inwards relative to the first lateral wall sub-portion and pointing substantially sideways, wherein the second lateral wall sub-portion is arranged at least partially beneath the second positioning plane.

2. The door latch according to claim 1, wherein 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 side wall.

3. The door latch according to claim 1, wherein 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.

4. The door latch according to claim 3, wherein an upper pocket wall of the insertion pocket is 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 is 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.

5. The door latch according to claim 3, wherein 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.

6. The door latch according to claim 1, wherein 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.

7. The door latch according to claim 1, wherein 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.

8. The door latch according to claim 1, wherein 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.

9. The door latch according to claim 8, wherein 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.

10. The Door latch according to claim 8, wherein 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 by the module housing and is clamped at one end or at both ends.

11. The door latch according to claim 1, wherein the support surfaces form at least one support edge for the latch module.

12. The door latch according to claim 11, wherein the support edge, as seen in the first direction, is located at a point which is offset relative to a mid-point between the two collar portions towards the second collar portion.

13. The door latch according to claim 11, wherein 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.

14. A door latch for a domestic electrical appliance, comprising a latch module comprising: 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; and a second recess beneath a second edge region of the mouthpiece located diametrically opposite the first edge region beyond the insertion opening, wherein 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, wherein the latch module has stationary support points for supporting the latch module on a wall underside of the mounting wall, wherein 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, wherein 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, wherein 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.

15. A method for mounting the door latch according to claim 1 on a mounting wall of a domestic electrical appliance, comprising: forming a mounting opening for the latch module of the door 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, guiding the second collar portion through the mounting opening and moved over one of the two opposing opening edges of the mounting opening so that the one of the two opposing opening edges is in contact with the second lateral wall sub-portion of the second lateral wall; tilting the latch module relative to the mounting wall, with temporary elastic bending of the mounting wall and with continued contact of the one of the two opposing opening edges with the second lateral wall sub-portion, until the first collar portion passes through the mounting opening past the other of the two opposing opening edges; shifting the latch module in the direction towards the other of the two opposing opening edges in order to move the first collar portion over the other of the two opposing opening edges until the one of the two opposing opening edges snaps in front of the first lateral wall sub-portion of the second lateral wall caused by the action of a spring return force.

16. The method according to claim 15, wherein the spring return force results at least in part from the elastic bending of the mounting wall.

17. The method according to claim 15, wherein the spring return force results at least in part from elastic deformation of a resilient biasing member of the latch module.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 is a perspective view, in schematic form, of a domestic washing machine according to an exemplary embodiment.

[0027] FIGS. 2a, 2b show, schematically, phases during the installation of a latch module of a door latch of a domestic electrical appliance in a mounting wall of the domestic appliance.

[0028] FIG. 3a is a perspective view of a detail of a latch module of a door latch according to an exemplary embodiment which is more true to reality.

[0029] FIG. 3b is a lateral plan view of a detail of the latch module of FIG. 3a having a mouthpiece.

[0030] FIG. 4a shows an error-prone attempt to install the latch module of FIGS. 3a, 3b in a mounting wall.

[0031] FIGS. 4b to 4e show successive phases of a correct procedure for installing the latch module of FIGS. 3a, 3b in a mounting wall.

DETAILED DESCRIPTION OF THE INVENTION

[0032] Reference will first be made to FIG. 1. The domestic washing machine shown therein, which is designated generally 10, is of the top-loader type in the example shown, but that is not important within the scope of the present disclosure since the invention can equally be used in door latches for domestic washing machines of the front-loader type and also in other types of domestic electrical appliance, for example in dishwashers, tumble dryers or baking ovens, to mention only a few examples. The washing machine 10 comprises a machine main body (appliance main body) 12 in which there is accommodated a liquor container 14 indicated schematically by a broken line. A washing drum (not shown) is rotatably mounted in the liquor container 14 in a manner known per se, which drum forms a working chamber (washing chamber) of the washing machine 10. This washing chamber is accessible through an access opening 16 which, in the case of the top-loader washing machine 10 shown in FIG. 1, is formed on the upper side of the machine main body 12. A lid 18 which is pivotably mounted on the machine main body 12 can be pivoted upwards in order to free the access opening 16, and can also be folded down so that the lid 18 lies horizontally on the machine main body 12 and blocks the access opening 16. On a control panel 22 there are provided various operating elements and display elements which serve as a control interface of the washing machine for the user and allow the user to set different wash programs, for example.

[0033] 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 FIG. 1. The engagement of the closing element 26 with the securing element holds the lid 18 closed. In the example shown, the closing element 26 is mounted on the lid 18, while the latch module 28 is attached to the machine main body 12, specifically to an upper housing wall 32 of the machine main body 12 which serves as a mounting wall for the latch module 28. It will be appreciated that the pattern of arrangement of the closing element 26 and the latch module 28 can be reversed, that is to say the closing element 26 can be mounted on the machine main body 12 while the latch module 28 can be attached to a suitable wall portion of the lid 18 serving as the mounting wall.

[0034] 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.

[0035] 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.

[0036] Before FIGS. 2a, 2b are next discussed, it is pointed out generally that, in all the figures, components which are the same or have the same action are provided with the same reference numerals, with the addition of a lowercase letter from FIGS. 2a, 2b onwards. For the explanation of such components which are the same or have the same action, the first comments made apply, unless specified otherwise thereafter.

[0037] FIGS. 2a, 2b show, in highly schematic form, phases in the mounting of a latch module 28a on a mounting wall 32a, which can be, for example, the upper housing wall 21 of the washing machine 10 of FIG. 1. The mounting wall 32a has a mounting hole 34a, framed on all sides, which has a quadrilateral outline, for example, when the mounting wall 32a is seen from above. The latch module 28a has an insertion mouth 30a, indicated only by a broken line in FIGS. 2a, 2b, which is formed in a mouthpiece 36a of the latch module 28a. A closing member 26a (FIG. 2b) in the form of a closing shackle, for example, enters the insertion mouth 30a (which can also be referred to as an insertion opening) on closing of the door of a domestic appliance which has the mounting wall 32a and is equipped with the latch module 28a. FIG. 2a shows an intermediate phase in the mounting of the latch module 28a on the mounting wall 32a, FIG. 2b shows the finished mounted state.

[0038] 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 FIG. 2a on both sides of the insertion mouth 30a and project away from one another. With their collar undersides, the two collar portions 38a, 40a define a first positioning plane P1 (FIG. 2a), which is oriented parallel to the first direction R1. The undersides of the collar portions 38a, 40a have a positioning function in that, in the finished mounted state according to FIG. 2b, they project over a respective opening edge 42a or 44a of the mounting opening 34a and provide contact surfaces located on both sides of the insertion mouth 30a for the upper side of the mounting wall 32a.

[0039] 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.

[0040] At a distance beneath the first positioning plane P1, the latch module 28a defines a second positioning plane P2 (FIG. 2a) which is parallel to the first positioning plane P1. The second positioning plane P2 is formed by support surfaces 60a, 62a which serve to support the latch module 28a on the underside of the mounting wall 32a. Where mention is made here of above and beneath or of an upper side and an underside, these expressions refer to the representation in FIGS. 2a, 2b, in which the latch module 28a is inserted from beneath into the mounting opening 34a of the mounting wall 32a. It will be appreciated that with an inverted orientation of the latch module 28a and the mounting wall 32a, the expressions top, bottom, upper side, underside used are to be transposed accordingly.

[0041] A portion of the support surfaces 60a, 62a, in the case of FIG. 2a the support surface(s) 60a, is—as seen in the first direction R1—formed remote from the mouthpiece 36a on the upper side of the latch module 28a, and another part, in FIG. 2a the support surface(s) 62a is, in contrast, arranged within the region of the mouthpiece 36a and is located—as seen in a second direction R2 perpendicular to the first direction R1 and parallel to the positioning planes P1, P2 (perpendicular to the plane of the drawing of FIG. 2a)—in front of and/or behind the mouthpiece 36a. For example, the latch module 28a forms two support surfaces 62a, of which one is arranged in front of the mouthpiece 36a and the other behind the mouthpiece 36a as seen in the second direction R2.

[0042] 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.

[0043] 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 FIG. 2b in the direction perpendicular to the positioning planes P1, P2 could be reduced or eliminated. In order to avoid such play movements, additional spring elements are provided on the latch module in the exemplary embodiment of FIGS. 3a, 3b yet to be described hereinbelow, which additional spring elements are also conceivable in the exemplary embodiment of FIGS. 2a, 2b shown in schematic form but are not shown in the drawing. If such a spring element is also to be provided in the exemplary embodiment of FIGS. 2a, 2b, it projects beyond the positioning plane P2 in the direction towards the positioning plane P1, that is to say it projects into the space between the two positioning planes P1, P2.

[0044] 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.

[0045] 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 (FIG. 2b) is formed in the second recess 48a, the pocket base of which insertion pocket is formed by the second lateral wall sub-portion 58a. The stepped shoulder 54a forms an upper pocket wall of the insertion pocket 66a, and a lower pocket wall is formed by a third lateral wall sub-portion 68a (FIG. 2b) of the second lateral wall 52a which adjoins the second lateral wall sub-portion 58a therebeneath and extends obliquely outwards and downwards. This oblique configuration of the third lateral wall sub-portion 58a ensures the necessary free space in the insertion pocket 66a for the insertion of the second opening edge 44a of the mounting wall 32a into the insertion pocket 66a in a tilted orientation of the latch module 28a (see FIG. 2a).

[0046] 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 FIG. 2a, in which the second opening edge 44a of the mounting opening 34a extends into the insertion pocket 66a and is in contact with the second lateral wall sub-portion 58a, the first collar portion 34a can be pivoted upwards through the mounting opening 32a at the first opening edge 42a of the mounting opening 34a.

[0047] 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 FIG. 2a. In this oblique position, the second collar portion 40a can be guided through the mounting opening 34a and moved on the upper side of the mounting wall 32a over the second opening edge 44a of the mounting opening 34a. The second opening edge 44a of the mounting wall 32a thereby enters the second recess 48a. The mounting person must ensure that the second opening edge 44a enters the insertion pocket 66a, as shown in FIG. 2a, and does not hook directly beneath the second collar portion 40a in front of the first lateral wall sub-portion 56a. Starting from the state so achieved corresponding to FIG. 2a, the mounting person must pivot the latch module 28a so that the first collar portion 38a moves through the mounting opening 34a until the first collar portion 38a has moved past the first opening edge 42a of the mounting opening 34a completely. The second opening edge 44a remains caught to a certain extent in the insertion pocket 66a during this pivoting movement. During the pivoting movement, temporary bending of the mounting wall 32a can occur, as already explained, because the support edge(s) 64a presses or press against the underside of the mounting wall 32a.

[0048] 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 FIG. 2b is then reached.

[0049] Looking at FIG. 2b, it will be seen that the support edge 64a, based on a notional mid-point between the two collar portions 38a, 40a, is offset in the direction towards the second collar portion 40a. In other words, the support edge 64a is offset in the direction towards the second collar portion 40a relative to a mid-point, seen in the first direction R1, of the insertion mouth 30a. The support surfaces 60a, on the other hand, are arranged offset in the direction towards the first collar portion 38a in relation to that notional mid-point. The latch module 28a accordingly has support points on both sides of the mentioned notional mid-point. Therefore, if a tensile force is exerted via the closing member 26 on the latch module 28a while the domestic appliance is in use, there is no or only a comparatively small tilting moment on the latch module 28a. The latch module 28a is therefore not at risk of unintentionally being tilted out of the mounting opening 34a to a certain extent.

[0050] Reference will now be made to the exemplary embodiment of FIGS. 3a, 3b. In this exemplary embodiment, the latch module 28b has a housing part 70b which forms the mouthpiece 36b and, in the second direction R2, on both sides of the mouthpiece 36b, a spring tongue 72b. The spring tongues 72b project, as can be seen in FIG. 3b, beyond the second positioning plane P2 and serve to compensate for play between the latch module 28b and a mounting wall in a direction perpendicular to the positioning planes P1, P2. In the example shown, the spring tongues 72b are connected in one piece to adjacent regions of the housing part 70b at both tongue ends and have maximum elastic deflectability in the region of their tongue middle. It will be appreciated that, instead of such spring tongues which are clamped at both ends, it is also possible as an alternative for one or more spring tongues that are clamped only in the region of one tongue end to be formed by the housing part 70b.

[0051] It will further be seen in FIG. 3a that the third lateral wall sub-portion 68a is formed by a comparatively thin rib portion 74b which is formed beneath the second collar portion 40b by the housing part 70b.

[0052] FIG. 4a illustrates the situation when, during mounting on a mounting wall 32b, the latch module 28b of FIGS. 3a, 3b is first threaded through the mounting opening 34b in such a manner that the second opening edge 44b of the mounting opening 34b does not enter the insertion pocket 66b but is hooked in front of the first lateral wall sub-portion 56b. The first collar portion 38b then cannot be moved through the insertion opening 34b but strikes the first opening edge 42b.

[0053] In contrast, FIGS. 4b to 4e illustrate a correct mounting procedure, in which the second opening edge 44b first enters the insertion pocket 66b (FIG. 4b), then the latch module 28b is pivoted in order to move the first collar portion through the mounting opening 34b (FIGS. 4c, 4d), and then the latch module 28b is shifted sideways in order that the first lateral wall sub-portion 56b is able to spring into the mounting opening 34b (FIG. 4e).

[0054] 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.