This invention relates to a resettable door locking device for an electric household appliance in particular a dishwasher, and electric household appliance provided therewith. In particular, the invention relates to a door locking device that can be used even when one of its latching devices, for any reason, is incorrectly placed in the locking position already with the electric household appliance door still open.
EP1344486 is known for a door locking device of high simplicity and reduced size based on a rotating latching device combined with a bistable elastic mechanism which makes the latching device selectively assume two different stable positions, consisting respectively of a locking position, wherein the latching device engages, with the door closed, a hooking element, usually constituted by a U-shaped bracket, and in an unlocking position, wherein the latching device does not engage the hooking element.
It is also known, from DE 102007033451, a door locking device for a dishwasher wherein the hooking element, carried by the electric household appliance casing, is to be coupled with a revolving latching device carried by a support body, in turn in use, which can be positioned on the door of the electric household appliance.
However, many known devices, even when they are completely satisfactory, are generally bulky and those of a less modern conception are designed to be mounted with their bulkier part in the thickness of the electric household appliance door, this prevents the construction of electric household appliances with increased load capacity, which would be extremely useful, particularly in the dishwasher field, and the creation of thin doors.
In addition, in known door-locking devices, if the rotating latching device is accidentally positioned in the locking position when the electric household appliance door is still open, on the one hand it is impossible to lock the door correctly and, on the other hand, the microswitch signal of locked door, which cooperates directly with the rotating latching device or with an element associated with it, mistakenly provides a locked door signal to the electric household appliance, which can therefore be started with the consequent risk of fluid leakage to the outside.
Even if the user then detects the incorrect positioning of the rotating latching device, he/she should fit/reset it manually, making it rotate to the unlocked position. In order to do this, dedicated tools are indispensable, without which there is a risk for the user to get hands or fingers injured, albeit slightly.
It is an object of this invention to provide a door locking device for an electrical household appliance, in particular a dishwasher, which is constructively simple, of reduced cost and dimensions and of high reliability and which allows to overcome the drawbacks of the prior art, in particular that allows to report any abnormal positioning of the latching device and to fit/reset the device automatically, without a manual intervention by the user.
Therefore, this invention relates to a resettable door locking device for an electrical household appliance, in particular a dishwasher, and to an electrical household appliance equipped with such a device, as defined in the annexed claims.
Further characteristics and advantages of this invention will become clear from the description which is given below of a preferred embodiment, illustrated purely by way of non-limiting example and with reference to the attached drawings, wherein:
With reference to
Although the following non-limiting description refers to the case of a dishwasher with front door, it remains clear that the door locking device 1 according to the invention can be applied both to doors with horizontal rotation axis and to doors with vertical rotation axis. Therefore, the invention can also be used on drawer dishwasher machines.
The door locking device 1 comprises a support body 6 configured to be fixed in a known way to the door 5 of the electric household appliance 2, a bracket 7, for example U-shaped or frame-shaped, and configured to be fixed in a known way to the structural element 3 and a latching device 8 carried by the support body 6 and configured to cooperate in use with the bracket 7, in the manner that will be illustrated later.
The latching device 8 in turn comprises a locking tooth 10 carried by the support body 6 and constrained to the support body 6 so as to be able to rotate relatively thereto around a first A axis (
The locking tooth 10 comprises a first hook-shaped end 12, configured to couple with a transversal element 11 of the bracket 7 to lock in use, in a known way, the door 5 against the structural element 3 of the electric household appliance 1.
The latching device 8 further comprises a stem 13 carried by the support body 6 sliding along a symmetry B axis (
Furthermore, the end 14 is delimited by a first cam profile 15 which cooperates in contact with a second cam profile 16 obtained on a head 17 of the stem 13 facing the locking tooth 10.
In combination with the foregoing, the latching device 8 also includes, in addition to the stem 13 and the respective cam profiles 15, 16, a compression spring 18, in the non-limiting example illustrated a helical spring, operatively associated with the stem 13 and configured to thrust cam profiles 15 and 16 into contact with each other.
Here and below, by “compression spring” is intended an elastically deformable spring configured/mounted so as to be subjected, both at rest and during its operation, to only compression stresses.
According to an aspect of the invention, the latching device 8 finally comprises a frame-shaped tilting element 19, in the illustrated example configured as a substantially quadrangular frame, and hinged to the support body 6 so as to be able to rotate relatively thereto around a second C axis parallel to the first A axis; in addition, the tilting element 19 is configured to cooperate with the transversal element 11 of the bracket 7 regardless of the locking tooth 10.
In fact, the tilting element 19 is mounted externally on the support body 6 to which it is hinged around the C axis in a distal and independent position of the A axis and has opposite ends 20, 21 (
According to an aspect of the invention, the cam profiles 15, 16 are configured to form, together with the locking tooth 10, the support body 6, to the stem 13 and to the compression spring 18, a bistable mechanism 24 (
In the receiving position, a recess 25 obtained in the first end 12 of the locking tooth 10 is directed in parallel to respective longitudinal side members 26 of the bracket 7, perpendicular to the transversal element 11 of the bracket 7, to receive the transversal element 7 inside it.
Furthermore, the support body 6 has a reception slit 27 (
In the receiving position, the tooth 10 has the recess 25 facing towards, and faces, the slit 27; the end 20 or crosspiece of the frame-shaped tilting element 19 also faces, and faces the, slit 27. The end 20 also has a central portion 29 shaped like a C (
In the locking position, instead, the recess 25 is directed transversely to the side members 26 of the bracket 7 and is arranged substantially perpendicular, or at least transversely, to the slit 27 (
Preferably, the head 17 of the stem 13 is hinged to an arm 30, for example shaped like a fork (
In the non-limiting but illustrated preferred example, the support body 6 comprises a hollow boxed portion 31 (
The first A axis is defined by a pair of profiled elements 33 (
The laterally protruded overhanging profiled elements 33 cooperate in contact with a radially internal perimeter edge 34 (
In particular, the radially internal perimeter edge 34 of the boxed portion 31 of the support body 6 forms a loop 35 (
The lateral protruding overhanging profiled elements 33 of the locking tooth 10, instead of being simple pins, are also preferably shaped as rounded wedges or, anyhow, configured to cooperate selectively with respective portions of the radially internal perimeter edge 34 of the boxed portion 31 immediately adjacent, from opposite sides, to the loop 35, to act as end stops to determine the angular position of the receiving and locking positions of the locking tooth 10 with respect to the support body 6.
The stem 13 is engaged axially passing through a shoulder ring 36 (
The recess 25 is configured to retain within it the transversal element 11 of the bracket 7 when the locking tooth 10 is in the locking position and when the recess 25 thereof has previously been engaged by the transversal element 11 of the bracket 7 with the locking tooth 10 in the receiving position (i.e. when the tooth 10 was previously in the receiving position).
According to a further aspect of the invention, the locking tooth 10 is delimited, between the recess 25 and the second end 14 thereof, by a plane surface 37, obtained in a position immediately adjacent to the cam profile 15 and on the part of the recess 25. The plane surface 37 faces towards, or on the side of, the slit 27 of the support body 6 and, in the locking position, defines an inclined plane facing the slit 27 and configured to cooperate with the transversal element 11 of the bracket 7 if the recess 25, with the locking tooth in the locking position, had not already been engaged by the bracket 7 (
This inclined plane defined by the surface 37 is configured to determine, as a consequence of a thrust exerted thereon by the transversal element 11 of the bracket 7, an axial thrust on the compression spring 18, through the stem 13, which thrusts the first A axis to move away from the slit 27 to allow the transversal element 11 of the bracket 7 to “jump” the locking tooth 10 and snap-fit with the recess 25 thereof (
The operation of the described door locking device 1 is as follows.
With the door 5 open, the device 1 is in the configuration of
When the door 5 closes, the bracket 7 receives the slit 27, the transversal element 11 is supported against the end 12 of the tooth 10, up to inside the recess 25 (
In this position the recess 25 is rotated by about 90°, and therefore engages the transversal element 11 so that it can no longer be extracted through the slit 27. The elastic pre-load of the spring 18 also keeps the door 5 compressed in the closed position.
During the described movement, the tilting element 19 is also rotated by the thrust of the transversal element 11 on the C axis, bringing the end 21 against the microswitch 23, which is activated, signaling the status of closed and locked door.
In the opening phase, an opposite movement takes place; starting from the configuration in
During these opening movements, the microswitch 23 is disconnected since the tilting element 19 is rotated in the inverted direction either by the thrust of the microswitch 23 thereof (which is internally equipped with a spring) or by a specially provided spring (not shown) for example on the C axis, following the backward movement of the transversal element 11 with the end 20 thereof.
With specific reference to
Firstly, the user is informed of the anomaly in the event that the door 5 is half-closed, but not locked, since even if the tooth 10 is in the locking position, the absence of the bracket 7 within the slit 27 does not cause the rotation of the tilting element 19 and therefore does not activate the microswitch 23.
Secondly, by thrusting the door 5 towards the closed position, the user thrusts the bracket 7 into the slit 27. The tooth 10 is in the locking position. This implies that the inclined plane defined by the plane surface 37 faces the slit 27 and therefore intercepts the transversal element 11 of the bracket 7, which begins to slide along the inclined plane 37 while the door 5 progressively approaches the closed position.
This movement involves an axial thrust against the stem 13 which compresses the spring 18, but the B axis remains to the left of the rotation A axis of the tooth 10.
Therefore, the tooth 10 is pushed to move away from the slit 27 descending into the boxed portion 31 through the slit 32, following a straight section 38 (
Consequently, the tooth 10 assumes sequentially the positions of
To mount the latching device 8 within the boxed portion 31 it is possible to obtain the support body 6 by means of a single block. Thanks to the elasticity of the thermoplastic material and the entrance 39, it is possible to snap-fit the shoulder ring 36 and the different components of the latching device 8 described within the boxed portion 31, in containment holes 28(6).
Through the containment holes 28, the shoulder ring 36 rotates relatively to the support body around a fourth E axis, passing through the center of the containment holes 28.
Finally, from what has been described it is clear that the invention also relates to an electric household appliance 2, in particular a dishwasher, comprising a structural element 3 delimiting an access compartment a washing chamber or tub 4 and a door 5 operatively associated with the access compartment and configured to assume an open position, wherein it allows access to the washing chamber or tub 4, and a closed position wherein it is locked against the structural element 3.
The electric household appliance 2 comprises a door locking device 1 as described having the support body 6 fixed jointly and severally to the door 5 in a known way, for example by means of screws not illustrated for simplicity, and the bracket 7 fixed jointly and severally to the structural element 3, also in a known way and not illustrated for simplicity.
The support body 6 has a lateral seat 22 housing a microswitch 23 and the frame-shaped tilting element 19 is configured to cooperate with the microswitch 23 only when the transversal element 11 of the bracket 7 engages the recess 25 of the locking tooth 10, thus warning the user in case of anomalies or in any case preventing the electric household appliance 2 from starting if the door 5 is not locked.
All the purposes of the invention are therefore achieved.
Number | Date | Country | Kind |
---|---|---|---|
10 2019 000003155 | Mar 2019 | IT | national |
PCT/US2020/019926 | Feb 2020 | US | national |
Italian Patent Application IT 102019000003155, filed 5 Mar. 2019 and PCT International Patent Application No. PCT/US2020/019926, filed 26 Feb. 2020, the priority documents corresponding to this invention, to which a foreign priority benefit is claimed under Title 35, United States Code, Section 119, and their entire teachings are incorporated, by reference, into this specification.