TECHNICAL FIELD OF THE INVENTION

The present invention belongs to the field of electrical household appliances, such as dryers, washing machines, dishwashers and/or similar appliances. In particular, the present invention relates to an opening and closing device, in particular for doors, hatches or the like, e.g. of electrical household appliances of the aforesaid type. In detail, the present invention relates to a device of the aforesaid type suited to allow improving the user's perception when manually opening and closing the door. In particular, the present invention relates to an opening and closing device of the aforesaid type suited to uniform the user's effort when opening and closing the door, whereby avoiding discontinuities and/or resistance peaks generated by the kinematics of the device. The present invention further relates to a closing and opening system comprising a closing and opening device of the aforesaid type and to an electrical household appliance (e.g. a washing machine or similar appliance) equipped with a device and/or system of the aforementioned type.

BACKGROUND ART

The most widespread and commonly used closing and opening devices and/or systems for electrical household appliances, in particular for dryers, washing machines and/or similar appliances, essentially comprise a closing (and opening) assembly itself, usually applied to the casing of the electrical household appliance and a catch element (or latch) usually fastened to the door of the appliance itself. According to the most common solutions, the closing and opening assembly further comprises a fork-shaped closing element which can be switched by rotation between a first opening position and a second closing position and vice versa, wherein the closing element in the closing position engages the corresponding catch element of the door, thus ensuring the closing of the door itself, while on the contrary, in the opening position, it allows the disengagement of the catch element and thus the opening of the door. Automatic switching devices and/or systems are known, for example, in which the switching of the closing and opening element and opening occurs automatically under the bias of the latch or catch and then following the thrust on the door by the user.

Figures 1 to 4 relate to a device and/or system according to the most common prior art and the operating methods of the closing device shown in them will be described with reference to figures 1 to 4.

In figures from 1 to 4, reference numerals 1 1 , 10 and 12 relate respectively to: a latch or catch (suited to be fixed to a door), a closing and opening element which can be switched by rotation (see description below), and elastic means.

During the closing of the door, e.g. of a dryer (not shown for the sake of clarity), the progressive approach of the door to the main body of the electrical household appliance (equipped with the device 100), results firstly in the engagement of the element or cam 10 by the latch or catch 1 1 (the curved end of the catch 1 1 engages the forked portion of the element 10, see figure 2) and thus in a progressive switching by clockwise rotation (with respect to the figures), of the cam 10 from the opening position in figure 2 to the intermediate position in figure 3 (against the elastic bias of the spring 12) and finally from the intermediate position in figure 3 to the (final) closing position in figure 4, the latter switching being at least partly promoted or facilitated by the elastic response or reaction of the spring. In practice, passing from the position in figure 3 to that in figure 4 the reversal point (also referred to as dead point) of the spring 12 is reached and exceeded, wherein the closing element is held by a spring 12 in the position in figure 4, the spring 12 whereby avoiding undesired openings of the door. In practice, during the switching from the position in figure 2 to that in figure 3, the spring is compressed, while on the contrary, during the switching from the position in figure 3 to that in figure 4, the spring expands.

The opening of the door occurs according to substantially reversed procedures, which can thus be summarized as follows, wherein the reverse switching of the locking lever 12 occurs by traction on the door, and thus on the latch 1 1 , exerted by the user. In practice, the element 10, firstly switches from the closing position in figure 4 to the intermediate one in figure 3 (against the resistance applied by the spring 12, which is thus compressed), and thus from the intermediate position in figure 3 to the opening position in figure 2, the latter switching being either encouraged or facilitated by the thrust of the spring 12, which expands), wherein the latch 1 1 is practically expelled from the cam 10, the expulsion of the latch or catch 1 1 resulting in the opening of the door without requiring a further traction on the door by the user.

The closing devices and/or systems of the type described above, although appreciable from many points of view (simplicity of construction and operation, good reliability, overall low manufacturing and/or installation costs), have some drawbacks which the present invention intends to overcome.

In particular, the most important drawback relates to the fact that the user perceives an undesired resistance peak during both the closing and opening of the door. Said resistance peak is generated by the spring and occurs near the reversal point of the spring itself. Indeed, the compression of the spring 12 is maximum and therefore the resistance applied by the spring 12 is also maximum near the reversal point (both in the switching of the closing element 10 from the position in figure 3 to that in figure 4 and in the reversed switching).

Therefore, it is the main object of the present invention to overcome, or at least minimize, the drawbacks summarized above and found in the closing devices and/or systems of the prior art.

In particular, it is a first object of the present invention to provide an opening and closing device which, in use, requires a more uniform effort by the user, in particular both during closing and during opening of the door, wherein the user does not need to overcome the resistance peaks generated by the devices according to the prior art but needs to overcome a more uniform and constant resistance and wherein the maximum resistance is lower than the maximum resistance generated by the devices according to the prior art.

It has in fact to be considered that an excessive effort required to the user may cause the user to suspect that the device is faulty or that the operation of the device is compromised or even fear that persisting in the opening and/or closing operations may cause faults or damage to the device.

Finally, according to the present invention, the aforesaid results should be ensured by a device and/or system characterized by small size and dimensions, as well as in that of being applicable to electrical household appliances of the known type according to equally simple and low-cost solutions, and finally without requiring substantial modifications to said electrical household appliances.

DESCRIPTION OF THE PRESENT INVENTION

The present invention is based on the general consideration according to which the aforesaid objects can be achieved by means of a device in which the reversal (inversion) of the elastic means (in particular of the spring) from the step of compression to that of expansion occurs at a degree of compression of the spring (and thus of resistance applied by the spring) which is lower than that at which the spring reversal (inversion) occurs in the devices according to the prior art. In particular, according to a further consideration on which the present invention is based, the advanced reversal of the spring can be obtained by allowing the spring to reposition itself (and thus not only to compress and expand) during the switching of the closing element. Furthermore, according to a further consideration underlying the present invention, the repositioning of the spring can be effectively achieved by providing, for the closing element, a constraint which allows, during the switching, not only the rotation but also the translation on a plane substantially perpendicular to the axis of rotation.

On the basis of the considerations above, as well as with reference to the problems and/or drawbacks affecting the closing and opening devices and/or systems according to the prior art, according to a first embodiment the present invention relates to a device for closing and opening doors and/or hatches and/or similar components, in particular of electrical household appliances such as washing machines, dishwashers, and the like, said device comprising a main unit or body, which houses a closing and opening element 10 designed to be engaged and disengaged alternatively by a latch or catch designed to be rigidly fixed to said door, wherein said closing and opening element can be switched by rotation between a first opening position and a second closing position, wherein the mutual engagement by thrust of said catch against said closing and opening element results first in said closing and opening element being switched from said first, opening, position to said second, closing, position, said closing assembly comprising elastic means set between said closing and opening element 10 and said main unit or body, wherein said closing and opening element can be switched by rotation between said first opening position and said second opening position about a rotation pin of said closing and opening element, which is housed at least partially engaging in a housing and engagement seat of said main unit or body, wherein said housing and engagement seat is shaped so as to enable not only the rotation of said rotation pin but also the translation of said rotation pin.

According to an embodiment, said housing and engagement seat of said rotation pin has an oblong conformation and defines two end portions, wherein with said closing and opening element in said first opening position, said rotation pin engages a first end portion of said housing seat, whereas with said closing and opening element in said second closing position, said rotation pin engages the second end portion of said housing and engagement seat opposite to said first end portion.

According to an embodiment, said housing and engagement seat is shaped so as to enable the translation of said rotation pin on a plane perpendicular to the direction or axis of longitudinal extension of said rotation pin.

According to an embodiment, said housing seat is delimited by an inner surface substantially parallel to the direction or axis of longitudinal extension of said rotation pin, wherein at said first end portion the intersections of the generatrices of said inner surface with a plane perpendicular thereto lie on a first arc of circle with substantially constant radius of curvature.

According to an embodiment, at said second end portion the intersections of the generatrices of said inner surface with a plane perpendicular thereto lie on a second arc of circle with substantially constant radius of curvature smaller than that of said first arc of circle. According to an embodiment, the portions of said inner surface at said first end and said second end, respectively, of said housing and engagement seat are connected by a third portion, by a fourth portion and by a fifth portion of said inner surface, wherein the intersections of the generatrices of said third portion, fourth portion and fifth portion of said inner surface lie on a first half-line, on a second half-line and on a third half-line, respectively.

According to an embodiment, said rotation pin is delimited by an outer surface substantially parallel to the direction of longitudinal extension of said rotation pin, which comprises a first portion and a second portion connected to each other, wherein the intersections of the generatrices of said first portion with a plane perpendicular thereto lie on a third arc of circle while the intersections of the generatrices of said second portion with a plane perpendicular thereto lie on a fourth half-line.

According to an embodiment, the radius of curvature of said third arc of circle coincides with that of said first arc of circle.

According to an embodiment, the extension or the length of said fourth half-line is equal to or smaller than that of said second half-line.

According to an embodiment, with said closing and opening element (10) in said first, opening, position, said first portion of said outer surface of said rotation pin engages by contact the inner surface of said housing and engagement seat at said first end portion, whereas, with said closing and opening element in said second closing position, said second portion of said outer surface of said rotation pin engages by contact said fourth portion of said inner surface of said housing and engagement seat.

According to an embodiment, said elastic means are shaped and set between said element and said main body or unit so that switching by rotation and translation of said closing and opening element both from said first opening position, into said second closing position, and from said second closing position, into said first opening position takes place in a first step against the elastic action of said elastic means, whereas in a second step it is favored by the elastic reaction of said elastic means. According to an embodiment, said elastic means comprise a torsion spring with a spiral portion, wherein, during the switching of said closing and opening element both from said first opening position into said second closing position, and from said second closing position into said first opening position, the intersection of the axis of symmetry of said spiral portion with a plane perpendicular to the longitudinal axis of said spiral portion thereto describes an arc of circle.

The present invention further relates to a system for closing and opening doors and/or hatches and/or similar components, in particular of electrical household appliances, such as washing machines, dishwashers, and the like, said system comprising a catch designed to be rigidly fixed to a said door, said system comprising a closing and opening device according to any one of the embodiments summarized above.

Finally, the present invention relates to an electrical household appliance, such as for example a dryer, comprising at least one door, said electrical household appliance comprises a device according to one of the embodiments summarized above and a catch element rigidly fixed to the said door.

Further possible embodiments of the present invention are defined in the claims. BRIEF DESCRIPTION OF THE FIGURES

Hereafter, the present invention will be further explained by means of the following detailed description of the possible embodiments shown on the drawings, in which corresponding or equivalent features and/or component parts of the present invention are identified by the same reference numbers. It should be noted that the present invention is not limited to the embodiments described below and shown on the accompanying drawings; on the contrary, all the variants and/or modifications to the embodiments described below and shown on the accompanying drawings fall within the scope of the present invention and will appear obvious and immediate to those skilled in the art.

In the drawings:

- Figure 1 shows a perspective view of an opening and closing system according to the prior art; - Figures from 2 to 4 each show a side and partial section view of a device according to the prior art during a step of the closing sequence or procedure, respectively;

- Figure 5 shows a perspective view of the device and of the system according to an embodiment of the present invention;

- Figure 6 and 7 each show a perspective view of the device and of the system according to an embodiment of the present invention;

- Figures from 8 to 10 each show a side and partial section view of the device and of the system according to an embodiment of the present invention during a step of the closing sequence or procedure, respectively;

- Figures from 1 1 to 13 each show a side and partial section view of the device and of the system according to an embodiment of the present invention during a step of the opening sequence or procedure, respectively;

- Figure 14 shows superimposed diagrams of the forces required for switching of a device according to the prior art and a device according to an embodiment of the present invention, respectively.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

The present invention is particularly suitable for applications in the field of electrical household appliances, such as dryers, washing machines, dishwashers and similar appliances, this being the reason why the present invention is described below with particular reference to its applications in the field of electrical household appliances, in particular of a washing machine.

However, it has be pointed out that the possible applications of the present invention are not limited to those described below. On the contrary, the present invention is advantageously applied in all cases in which the possibility of priority manual opening with respect to the electrical and/or electromechanical opening is either necessary or desirable.

Looking at Figures 6 and 7 allows to appreciate the most important particularities of the device according to the present invention, in particular of the closing and opening element 10 and of the housing seat 18 of the respective rotation pin 13. Indeed, it has to be noted that, in the case of the device according to the prior art 100 shown in figures 1 to 4, the opening and closing element 10 is constrained in rotation only to the main body or unit 101 by the rotation pin 13 engaged in the housing and engagement seat 18; in practice, it is a substantially cylindrical pin or pole 13 (with substantially circular cross section and predetermined diameter), at least partially housed in a circular seat 18 of the lever 12, the shape and size (diameter) of the seat 18 thus corresponding to those of the pole or pin 13, wherein then the engagement of the pole 13 in the seat 18 allows only the rotation of the element 10 in the two opposite directions of rotation (clockwise and counterclockwise with respect to the figures), and thus the switching of the element 10 from the closing position (figure 4) to the opening position (figure 2) and vice versa, but only where the mutual engagement of the pin 13 and the seat 18 does not allow different movements of the element 10, in particular does not allow any translation of the element 10.

On the contrary, in the case of the device 100 according to the embodiment of the present invention as depicted in figures from 5 to 13, the seat 18 in which the pin 13 is engaged and housed has an oblong and elongated shape, and thus defines two opposite end portions, each suited to be engaged by the pin or pole 13, and wherein therefore the pin 13 and the element 10 can betranslated with respect to the seat 18 (and thus with respect to the main unit or body 101 ), and in particular on a plane substantially perpendicular to the extension direction of the pole 13 (and thus to the rotation axis of the element 10), according to methods described in detail below.

In particular, by comparing figures 8 and 10 (and respective figures 10 and 13) it can be seen that with said closing and opening element 10 in said first opening position (figure 8), the rotation pin 13 engages a first end portion 181 (on the top in the figures) of said housing seat 18, whereas, with said closing and opening element 10 in said second closing position (figure 10), said rotation pin 13 engages the second end portion 182 (opposite to said first end portion 181 and thus on the bottom in the figures) of said housing and engagement seat 18. Obviously and again as shown, in all the intermediate positions of the element 10 between the opening and the closing positions, and therefore in all the positions shown in figures 9 and 1 1 to 13, the pole or pin 13 is positioned in the seat 18, respectively in the intermediate position between the end portions 181 and 182. It is apparent that the switching of the element 10 between the opening and closing positions occurs both by rotation and by translation.

The shape of the seat 18 can be summarized as follows.

As depicted, said housing and engagement seat 18 is defined by an inner surface 183 substantially parallel to the longitudinal extension axis of the coupling pin (rotation and translation) 13 and thus perpendicular to the plane of the figures, wherein then the generating lines of the inner surfaces 183 are parallel to the direction of longitudinal extension of the pin 13 and of the respective axis of rotation, and wherein the intersections of the generatrices of said inner surface 183 with a plane perpendicular to them (parallel to that of the figures) define a closed path. In particular, at the first end portion 181 , the intersections of the generatrices with a plane perpendicular to them lie on a first arc of a circle with a substantially constant radius of curvature.

Similarly, at said second end portion 182, the intersections of the generatrices of said inner surface 183 still lie on an arc of a circle with a substantially constant radius of curvature but in this case smaller than that of the arc of a circle defined by the intersections of the generatrices of the surface 183 at the first end portion 181 of the seat 18.

Furthermore, the portions of said inner surface 183 at said first end 181 and said second end 182, respectively, of the housing and engagement seat 18 are connected by a third portion 184, by a fourth portion 185 and by a fifth portion 186 of said inner surface 183, wherein the intersections of the generatrices of said third, fourth and fifth portion 184, 185 and 186 lie on a first half-line, a second half- line and a third half-line, respectively. In particular, the portions 184 and 185 are successive to one another and join the two portions shaped as an arc of a circle, said two portions shaped arc of a circle of the surface 183 being finally joined on the opposite side of the seat 18 by the fifth portion 186. Furthermore, the half-line on which the intersections of the generatrices of the fourth portion 185 lie is oblique with respect to the half-lines defined by the intersections with a plane perpendicular to them of the generatrices of the third portion 184 and the fifth portion 186 of the inner surface 183, respectively.

The pin or pole 13, as depicted, is radially delimited (in a direction perpendicular to its longitudinal direction) by an outer surface 131 , substantially parallel to the direction of longitudinal extension, wherein the outer surface 131 comprises a first portion 132 and a second portion 133 connected to one another, wherein the intersections of the generatrices of said first portion 132 with a plane perpendicular to them lie on a third arc of a circle, while the intersections of the generatrices of said second portion 133 lie on a third half-line having a length not greater than that defined by the intersections of the generatrices of the portion 185 with a plane perpendicular to them.

Again with reference to figure 7, in relation to the closing and opening element 10, it can be seen that the engagement portion (intended to be engaged by the latch or catch element 1 1 ) is fork-shaped and comprises a first prong 101 and a second prong 102 connected by means of a connecting portion 103.

The two prongs 101 and 102 thus define an inner space 104 surrounded by a surface substantially parallel to the outer surface 131 of the pin 13, wherein the surface surrounding the space 104 comprises two opposed portions 105 and 106 which are not parallel. On the contrary, the intersections of the generatrices of the portion 105 with a plane perpendicular to them define a half-line, while the intersections of the generatrices of the portion 106 with a plane perpendicular to them define a curved path; in particular, the prong 102 defines a concavity facing the inner space 104 and the prong 101 .

The switching methods of the element 10 between the closing and opening positions can be further explained as follows.

In the open door condition (figures 5 and 8) and thus with the element 10 in the first opening position, the action of the spring 12 results in a thrust being exerted on the element 10, wherein the pole or pin 13 engages the first end portion 181 of the seat 18. However, the thrust of the spring 12 against the element 10 does not prevent the switching of the element 10 from the opening position to the closing position. Indeed, during the closing of the door (figure 9), e.g. of a dryer (not shown for the sake of clarity), the progressive approach of the door to the main body of the electrical household appliance (equipped with the device 100) firstly results in the engagement of the element 10 by the latch or catch 1 1 (the curved end of the catch 1 1 engages the forked portion of the element 10) and then in a switching by clockwise rotation (with respect to figure 9) and by translation against the elastic bias of the spring 12 (of which one end engages the portion of the element 10 opposite to the forked portion with respect to the pin or pole 13) of the element 10 from the opening position in figure 8 to the intermediate position of figure 9, wherein the spring 12 is compressed (the end portions which extend from opposite sides of the spiral-shaped portion of the spring 12 are brought closer to each other) during this step of switching. Furthermore, during this step of switching, the spring 12 is not only compressed, but also repositioned precisely by virtue of the translation of the pin 13; indeed, in the intermediate position of figure 9, the axis of symmetry of the spiral-shaped portion of the spring 12 is translated rightwards and partially upwards with respect to the starting position of figure 8. This repositioning of the spring 12 (and of the pin 13) means that during the successive step of switching from the position in figure 9 to that in figure 10, the reversal of the spring occurs at a compression (and therefore a reaction force) of the spring lower than those at which the reversal of the spring 12 would occur in the case of pin 13 which is rotatable but not translatable. So the resistance peak perceived by the user is lower than that perceived in the case of a pin which is rotatable and not translatable, e.g. a cylindrical pin 13 engaged in a circular seat, as in the case of the solution according to the prior art shown in figures from 1 to 4. Furthermore, the reversal of the spring 12 means that the final step of switching from the position in figure 9 to that in figure 10 is promoted by the elastic reaction of the spring 12; indeed, after the reversal of the spring 12, the end portions of the spring 12 which extend from the spiral-shaped portion, return to move away from one another, wherein the element 10 is further rotated and translated to engage the second end portion 182 of the seat 18. Furthermore, during the aforesaid final step of switching, by virtue of both the thrust of the spring 12 and the shape of the prong 102 of the fork, the catch or latch 1 1 is recalled into the body or the main unit 101 , wherein the force which is required by the user to complete the closing of the door then decreases.

The manual opening of the door occurs according to substantially reversed methods and can be summarized as follows, accordingly.

In practice, in the closed door condition (figure 10), the traction applied on the door by a user, results firstly in the engagement of the prong 101 by the latch or catch 1 1 and thus in a switching by counterclockwise rotation (with respect to figure 10) and by translation against the elastic bias of the spring 12 of the element 10 firstly from the closed position in figure 10 to the intermediate position in figure 1 1 , and subsequently from the position in figure 1 1 to that (also intermediate) in figure 12, wherein during the switching from the position in figure 10 to that in figure 1 1 , the spring 12 is compressed (the end portions which extend on opposite sides of the spiral-shaped portion of the spring 12 are approached to each other), while the reversal of the spring 12 occurs during the switching from the position in figure 1 1 to that in figure 12. So, during switching from the position in figure 1 1 to that in figure 12, the spring 12 is first compressed further, while successively it is free to expand. Additionally, during the switching from the position in figure 12 to that in figure 13, the spring 12 expands further and is repositioned precisely by virtue of the translation of the pin 13 which is then repositioned in the position in which it engages the end portion 181 of the slot or seat 18 again. Also in this case, the repositioning of the spring 12 (and of the pin 13) means that during the step of switching from the position in figure 1 1 to that in figure 12, the reversal of the spring occurs at a compression (and therefore a reaction force) of the spring lower than those at which the reversal of the spring 12 would occur in the case of pin 13 which is rotatable but not translatable. So, also during the opening of the door, the resistance peak perceived by the user is lower than that perceived in the case of a pin which is rotatable and not translatable, e.g. a cylindrical pin 13 engaged in a circular seat, as in the case of the solution according to the prior art shown in figures from 1 to 4. Furthermore, also the final step of switching from the position in figure 12 to that in figure 13 is promoted by the elastic reaction of the spring 12; indeed, after the reversal of the spring 12, the end portions of the spring 12 which extend from the spiral-shaped portion, return to move away from one another, where, by virtue of both to the thrust of the spring 12, the catch or latch 1 1 is expelled from the body or the main unit 101 , where the force which is required for the user to complete the opening of the door then decreases.

Figure 14 shows the lowering of the reaction peaks obtained by the solution described previously.

Thus, by means of the foregoing detailed description of the embodiments of the present invention shown in the drawings, we have demonstrated that the present invention allows to obtain the desired objects and to overcome or at least limit the drawbacks found in the prior art.

In particular, the present invention provides an opening and closing device which ensures the possibility of manually opening the door avoiding resistance peaks both in closing and in opening generated by kinematics of the devices according to the prior art and thus the negative perception by the users.

Furthermore, according to the present invention, the above results are ensured by a device and/or system characterized by small size and dimensions, as well as in that it is applicable to electrical household appliances of the known type according to equally simple and low-cost solutions, and finally without requiring substantial modifications to said electrical household appliances.

The above objects are also achieved and ensured for a prolonged period of time, in particular even after a minimum number opening and closing cycles compatible with market requirements.

Although the present invention has been explained above by means of the detailed description of the embodiments thereof shown in the drawings, the present invention is not obviously limited to the embodiments described above and shown on the drawings; on the contrary, all the variants and/or changes to the embodiments described and shown on the accompanying drawings fall within the scope of the present invention and appear obvious and immediate to those skilled in the art.

The scope of protection of the present invention is thus defined by the claims.