The present invention relates generally to door latch for a domestic dishwashing machine.
A door latch for installation in a domestic electrical appliance is known from DE 10 2006 037 494 B4, wherein in the known door latch, on closing of the door, an elongate closing member having a closing lug enters a depression formed on the door. As the door closes, it pushes against a control lever, which is separate from the closing member, and sets the control lever in rotation. The control lever in turn strikes against the closing member and frees it from blocking engagement with an abutment surface against which the closing member is urged by a closing spring when the door is open. As soon as the closing member is freed from blocking engagement with the abutment surface, the closing spring is able to relax. The closing member is thereby pulled back into a closed position. Since the closing lug of the closing member has in the meantime entered the door depression, the closing member takes the door with it as it is pulled back. The door is thereby pulled shut with the compression of a door seal, for which reason the door latch disclosed in the mentioned DE specification is a representative of the category of pull-shut latches.
In dishwashing machines for domestic use, the door is increasingly used to accommodate control electronics and display and operating elements. This limits the space available for accommodating components of a door latch in the door of the dishwashing machine. Therefore, in many dishwashing machines, a main assembly of the door latch is accommodated in the body of the machine, namely in a body roof above the dishwashing chamber of the dishwashing machine. Although the body roof offers a comparatively large installation space in terms of depth, that is to say in the direction horizontally backwards from the point of view of a user standing in front of the dishwashing machine, the space available in the body roof is usually limited in terms of height. Door latches as are disclosed in DE 102006037494 B4 are particularly suitable for installation in dishwashing machines because the elongate closing member, owing to its comparatively small overall height and owing to its comparatively small movement stroke which is necessary for releasing the blocking engagement with the abutment surface, can readily be accommodated inside the body roof.
As well as the requirement to address the question of the available installation space in the domestic appliance in question, there is the problem when designing a door latch for a domestic appliance that the installation of the door latch should not unduly weaken bearing or other structurally important wall parts of the domestic appliance. If, for example, the installation of the door latch requires a large cutout to be introduced into a body wall, this can weaken the stability of the body as a whole.
It is an object of the present invention to provide a domestic dishwashing machine in which the installation of a door latch is to impair the structural stability of the machine as little as possible.
In achieving this object the invention starts from a domestic dishwashing machine which comprises: a machine body having a dishwashing chamber formed therein; a door for closing the dishwashing chamber, which door is mounted on the machine body so as to be pivotable about a horizontal pivot axis close to the floor; and a door latch for holding the door closed, having a latch assembly installed in a body roof above the dishwashing chamber, wherein the latch assembly comprises a one-piece closing member arranged so as to be movable between an open position and a closed position, and a closing spring arrangement which is supported on the closing member and which, in the open position of the closing member, urges the closing member into blocking engagement with a blocking surface, which blocking engagement prevents relaxation of the closing spring arrangement, wherein the closing member has a contact surface for a blocking-release element which, on closing of the door, pushes against the contact surface and thereby frees the closing member from blocking engagement with the blocking surface, wherein the closing member, on closing of the door, comes into gripping engagement with an engagement structure arranged on the door and pulls the door shut under the action of the relaxing closing spring arrangement.
According to the invention it is provided in such a dishwashing machine that the engagement structure is formed by a closing shackle which at the same time forms the blocking-release element, which closing shackle protrudes from a first wall portion, extending substantially parallel to the plane of the door, of an inner lining of the door, and that the closing shackle forms a shackle crosspiece which extends substantially horizontally and is in advance on closing of the door and behind which the closing member engages on closing of the door. The use of a closing shackle having a shackle crosspiece behind which a gripping component engages on closing of the door of a domestic appliance is in itself a conventional measure from the field of door latches for domestic electrical appliances. The important factor within the scope of the invention is that such a closing shackle is arranged on the door, specifically on a wall portion (first wall portion) of an inner lining of the door that is substantially parallel to the plane of the door. In conjunction with a one-piece closing member accommodated in the body roof, the closing shackle on the door side allows the latch assembly to be installed in the body roof in such a manner that a cutout of only a comparatively small size has to be introduced into the outside walls of the body roof and thus the structure of the body roof is weakened only minimally. In the solution according to the invention, the closing shackle is both the engagement structure and the blocking-release element. On closing of the door, the closing shackle pushes against the closing member directly and thereby initiates a movement stroke of the closing member that is required for releasing the blocking. As part of this blocking-releasing movement stroke, the closing member engages behind the shackle crosspiece of the closing shackle and thus establishes the condition that the closing member pulls the door with it during its subsequent return movement effected by relaxation of the closing spring arrangement. It is sufficient to provide on the body roof, in a front wall, that is to say a wall that faces a user standing in front of the dishwashing machine, a cutout which the closing shackle can enter on closing of the door. The solution according to the invention does not require the cutout to extend into the region of a roof bottom wall. The cutout can remain limited to the region of the front wall of the body roof. This benefits the structural stability of the body roof.
In some embodiments, the closing shackle is inserted from behind through a wall aperture in the first wall portion. For example, the closing shackle can be formed by a shackle body which is designed with one or more screw receivers. On mounting of the door latch, a mounting screw is screwed into each of the screw receivers from the outside (i.e. from the side that is visible from outside) of the first wall portion through a corresponding mounting hole in the first wall portion. Only the closing shackle protrudes from the wall aperture. The screw receivers remain concealed behind the first wall portion. The shackle body can be, for example, an injection-moulded member manufactured from plastics material.
In some embodiments, the inner lining has a wall step which is formed by the first wall portion and a second wall portion extending transversely (perpendicularly or obliquely) relative to the door plane beneath the closing shackle. A gap is thereby formed between the closing shackle and the second wall portion, which gap can be, for example, at least 3 mm or at least 4 mm or at least 5 mm or at least 6 mm.
In some embodiments, the body roof has in a front wall a wall opening which the closing shackle enters on closing of the door. On the underside of the roof, a roof bottom wall adjoins the front wall, wherein the wall opening ends before the transition of the front wall into the roof bottom wall, for example at a distance of at least 1 mm or at least 2 mm or at least 3 mm or at least 4 mm. For example, the wall opening can end at a distance of approximately from 3 to 5 mm before the transition of the front wall into the roof bottom wall.
In some embodiments, the striking of the closing shackle against the contact surface of the closing member on closing of the door initiates a tilting of the closing member that leads to the release of the blocking engagement. The subsequent relaxation of the closing spring arrangement effects a substantially translational displacement of the closing member in a direction deeper into the body roof into the closed position of the closing member. Both the tilting and the translational displacement are thereby carried out by the closing member as a whole.
In some embodiments, the latch assembly comprises a frame having mounting structures for fastening the frame to a structural component of the body roof. In such embodiments, the latch assembly further comprises a housing member which is supported on the frame and in which the closing member is arranged so as to be movable between its open position and its closed position, wherein the blocking surface is arranged stationarily relative to the housing member. The housing member is supported on the frame so as to be movable, in particular pivotable, relative thereto, such that, when the door is open, a change of position, in particular a vertical change of position, of the contact surface of the closing member relative to the frame can be brought about by movement of the housing member relative to the frame.
In the above embodiment, the housing member is supported on the frame with movement play relative thereto. This movement play can be used to compensate for any mounting tolerances of the closing shackle (or generally: of the blocking-release element). Such mounting tolerances can originate from tolerances of the closing shackle (blocking-release element) on mounting on the door or/and from tolerances on mounting of the door on the machine body. By mounting the housing member on the frame with play, self-alignment of the housing member, and thus of the closing member, relative to the closing shackle can be achieved on closing of the door. A centring bevel can thereby be formed on the housing member, which centring bevel serves to cooperate with the closing shackle in order to centre the housing member relative to the closing shackle. If required, a plurality of such centring bevels can be formed on the housing member in order to be able to exert a centring action on the closing shackle in different directions.
According to a further aspect, the invention provides a door latch for a domestic electrical appliance, for example a dishwashing machine, wherein the door latch comprises: a housing member; a one-piece closing member arranged in the housing member so as to be movable between an open position and a closed position; and a closing spring arrangement which is supported on the closing member and which, in the open position of the closing member, urges the closing member into blocking engagement with a blocking surface arranged stationarily relative to the housing member, which blocking engagement prevents relaxation of the closing spring arrangement. The closing member forms a gripping mouth, delimited by an upper and a lower jaw structure, for a closing shackle which, on closing of the door, pushes against one of the upper and lower jaw structures and thereby initiates a tilting of the closing member that leads to the release of the blocking engagement. The subsequent relaxation of the closing spring arrangement effects a substantially translational displacement of the closing member relative to the housing member into the closed position. On closing of the door, the other of the upper and lower jaw structures engages behind the shackle crosspiece of the closing shackle. Both the tilting and the translational displacement are carried out by the closing member as a whole.
According to yet a further aspect, the invention provides a domestic electrical appliance which is in the form of, for example, a dishwashing machine. The domestic appliance comprises: an appliance body having a process chamber formed therein; a door for closing the process chamber, which door is movably mounted on the appliance body; and a door latch for holding the door closed. The process chamber is a chamber in which a working process performed by the domestic appliance takes place. The working process is, for example, a cleaning process, as is the case in dishwashing machines or laundry washing machines. However, the domestic appliance is not limited to such cleaning appliances; the domestic appliance can likewise be, for example, a tumble dryer or an electric oven. In such cases, the process chamber is formed by a drying chamber or a cooking chamber, respectively. The door latch comprises a latch assembly installed in the appliance body, wherein the latch assembly comprises a frame having mounting structures for fastening the frame to a structural component of the appliance body. The structural component is, for example, formed by a wall portion of sheet metal. The latch assembly further comprises a housing member supported on the frame, a closing member, in particular in one-piece form, arranged in the housing member so as to be movable between an open position and a closed position, and a closing spring arrangement supported on the closing member. In the open position of the closing member, the closing spring arrangement urges the closing member into blocking engagement with a blocking surface arranged stationarily relative to the housing member, which blocking engagement prevents relaxation of the closing spring arrangement. The closing member has a contact surface for a blocking-release element which is arranged on the door and which, on closing of the door, pushes against the contact surface and thereby frees the closing member from blocking engagement with the blocking surface. On closing of the door, the closing member comes into gripping engagement with an engagement structure arranged on the door and pulls the door shut under the action of the relaxing closing spring arrangement. According to the invention, the housing member is supported on the frame so as to be movable relative thereto, namely such that, when the door is open, a change of position of the contact surface of the closing member relative to the frame can be brought about by movement of the housing member relative to the frame.
In some embodiments, the housing member is supported on the frame so as to be pivotable relative thereto and, by pivoting, makes possible a vertical change of position of the contact surface.
The invention will be explained in greater detail hereinbelow with reference to the accompanying drawings.
Reference will first be made to
On the door 18 there is mounted a closing shackle 24 which, on closing of the door 18, cooperates with a latch assembly (not shown in greater detail in
Reference will now additionally be made to
In
The closing shackle 24 is formed by a shackle body 40 which is inserted on the rear side through a wall aperture 42 formed in the wall portion 34, so that the closing shackle 24 protrudes from the wall portion 34 and, on closing of the door, is in advance of the wall portion 34. The shackle body 40 can be screwed or otherwise fastened to the inner lining 42. It will be seen that the closing shackle 24 is at a distance from the wall portion 36, wherein the gap, designated in
For an exemplary form of the closing shackle 24 and of the latch assembly 30, reference will now be made to
The closing lever 48 is pivotable as a unit together with the housing member 47 relative to the frame 44. A pivot axis is depicted in
The closing lever 48 forms a gripping mouth 54 which is delimited by two jaws 50, 52 and arranged in the region of the front lever end, and which, on closing of the door 18, the closing shackle 24 enters with an advance shackle crosspiece 56 (advance as seen in the closing direction of the door 18). The shackle crosspiece 56 is oriented with its crosspiece longitudinal direction horizontal. Behind the shackle crosspiece 56, the closing shackle 24 forms a gripping recess 58 which, on closing of the door 18, one of the two jaws 50, 52 of the gripping mouth 54 enters and thereby comes into gripping engagement with the closing shackle 24. In the exemplary embodiment shown, it is the jaw 52 which enters the gripping recess 58 of the closing shackle 24 on closing of the door 18. The jaw 52 is the upper of the two jaws 50, 52 in the illustrations of
While the upper jaw 52 of the gripping mouth 54 serves to a certain extent as a gripping jaw which establishes the gripping engagement between the closing lever 48 and the closing shackle 24, the lower jaw 50 acts as a striking or contact jaw, against which the closing shackle 24 pushes with its shackle crosspiece 56 on closing of the door 18 and thereby initiates tilting of the closing lever 48 as a whole relative to the housing member 17 about a horizontal tilt axis, which in the example shown is located approximately in the region of the longitudinal centre of the closing lever 48. This tilt axis is not necessarily fixed stationarily relative to the housing member 47; the tilting movement of the closing lever 48 can to a certain extent be a floating tilting movement, in which the closing lever 48 performs a vertical tilting movement (downwards in the illustrations of
As soon as the closing lever 48 is freed from engagement with the blocking surface 60, the closing spring 62, which is formed, for example, by a helical compression spring, is able to relax and, as a result of its relaxation, urge the closing lever 48 as a whole backwards in the housing member 47 relative thereto. Owing to the engagement of the upper jaw 52 into the gripping recess 58, the closing lever 48 takes the closing shackle 24 with it as it moves back. This has an effect of pulling the door 18 shut.
Mounting tolerances of the closing shackle 24 relative to the door 18 or/and mounting tolerances of the door 18 relative to the machine body 12 can have the result that, in different machines of a series of dishwashing machines 10 of the type shown in
The housing member 47 is additionally the carrier of components of an electric switch which, on closing of the door 18, changes its switching state and thereby signals the door state (open or closed) to a controller. These switch components are accommodated in a lateral housing prolongation 70 of the housing member 47 (
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 |
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10 2020 122 689.6 | Aug 2020 | DE | national |