Patent Description:
It should be noted that hereinafter, the term "household appliance" will generally refer to an apparatus or machinery of the type prevalently driven by electric current or gas, such as, for example, a refrigerator, dishwasher, oven, washing machine, etc..

In the known art, hinges used to connect a door to a household appliance compartment are known, such as, for example, the compartment of an oven, dishwasher and similar. These hinges typically comprise a fastening bracket suitable for being fastened to the household compartment and a movable support to rotatably constrain the door to such bracket. In particular, the movable support of the hinge, fastened to the door, is pivoted to the fastening bracket so that the door is rotatable around a rotation axis (e.g. horizontal or vertical) between an open position and a closed position.

Known hinges can also be provided with elastic means for bringing the door towards the closed position. For example, in case of ovens, the elastic means can be coupled to an activating arm comprising a first end portion constrained to the door or better to the relative movable support, and a second end portion coupled to the fastening bracket. The elastic means can, for example, act on the first end portion, so as to move the door towards the closed position.

In order to facilitate the opening of the door, known hinges are provided with a motor drive, typically electrical, and are suitable for performing the opening/closing functions of the door. These hinges, for example, can be provided with a manual user control that, once actuated, turns on an electric motor to open or close the door. The electric motor, acting directly on the hinge of the door, is normally sized to fully move the door autonomously between the open position and the closed position.

In particular, in order to allow the door to move from the closed position to the open position, by counteracting the force exerted by the elastic means, the motor used on known hinges can be large and expensive, in addition to consuming a high amount of electric energy.

Known motorized hinges may also have difficulties in opening and closing the door (not fluid or tiring for the user) in case of motor malfunctions or in the absence of electric current. In certain cases, known motorized hinges could remain locked in the absence of electric current. This problem is particularly annoying when motorized hinges are installed on an oven. In this case, any absence of electric energy while cooking food, or even the malfunctioning of the motor of the hinge, could prevent the oven door from opening, therefore resulting in a consequent excessive cooking time (also due to, for example, the oven's thermal inertia), which could ruin or burn the food inside of the oven itself.

<CIT> relates to a movement system for a door or openable part of an electrical household appliance and to an electrical household appliance equipped with the system.

The object of the present invention is to solve the aforesaid problems and to provide a hinge for connecting a door to a household compartment able to be motorized, while simultaneously allowing a user to freely move the door when the door is stationary.

Another further object of the present invention is to provide a hinge able to be motorized by using an electric motor of reduced size and with reduced electric consumptions.

These and further objects are achieved by the present invention, thanks to a hinge according to claim <NUM> and to a household appliance according to claim <NUM>. Preferred aspects are set forth in the dependent claims.

In particular, the hinge for connecting a door to a household appliance compartment comprises a fastening bracket suitable for being fastened to the compartment of the household appliance, and a movable support to rotatably constrain the door to the fastening bracket.

The hinge further comprises an activating arm coupled to the fastening bracket and movement means suitable for moving the activating arm.

The activating arm comprises a first end portion suitable for being constrained to the movable support of the door and a second end portion suitable for being coupled to the movement means to move the activating arm between an open position of the door and a closed position of the door.

Furthermore, the movement means comprise an electric motor and reversible connecting means to couple and decouple selectively the electric motor to/from the activating arm, and, in particular, these means allow the direct or indirect coupling or decoupling between the drive shaft of such electric motor and the aforesaid second end portion of the activating arm.

The hinge is configured so that, when the electric motor is coupled to the second end portion of the activating arm, the electric motor causes the movement of the activating arm, in particular it pushes or pulls the movable support of the door to make it rotate, while, when the electric motor is decoupled from the second end portion, the manual movement of the first end portion of the activating arm occurs independently of the electric motor (i.e. without operating on the motor) to allow a user to freely move the door.

In this way, the second end portion of the activating arm can only be coupled to the electric motor when a door movement is required, a movement that is physically carried out by suitable movement means.

Moreover, the movement means comprise a slider linearly moved, by means of a screw for example, by means of the electric motor. The slider is constrained to the second end portion of the activating arm.

In particular, according to an aspect of the present invention, the second end portion can be constrained to the slider by means of a connecting lever comprising a first end rotatably constrained to the fastening bracket and a second end rotatably constrained to the slider. The second end portion of the activating arm is advantageously rotatably constrained to an intermediate portion of the connecting lever between the first end and the second end of the connecting lever.

Preferably, the second end portion of the activating arm is rotatably constrained to the intermediate portion of the connecting lever by means of a pin slidingly constrained along a guide (e.g. a slot) arranged in the intermediate portion of the connecting lever.

The guide is advantageously shaped to impose a given law of motion on the activating arm along its own path between the open position and the closed position of the door. Some embodiments can provide that the electric motor is a magnetic linear motor, alternatively, as already mentioned, the movement means comprise a reversible screw suitable for being rotated by means of the electric motor (e.g. a direct current electric motor). The slider is therefore coupled to the screw, preferably by means of a screw-nut screw coupling so as to transform the rotation of the screw into a translation of the slider. In this embodiment, the reversible connecting means are configured to couple and decouple selectively the electric motor to/from the screw.

Preferably, the activating arm is subjected to an elastic countering force suitable for bringing this activating arm towards the closed position of the door. More preferably, the aforesaid elastic countering force is provided by elastic countering means housed inside of the door and acting on the first end portion, or better on one of its branches, of the activating arm.

According to an aspect of the present invention, the reversible connecting means comprise a joint of the coupling type, by means of complementary toothing for example, provided with a first member constrained to a driven member kinematically coupled to the activating arm, such as a screw for example, and a second member constrained to the drive shaft of the electric motor. The second member is movable with respect to the first member and/or vice-versa between a configuration of mutual engagement, wherein the rotation of the drive shaft of the electric motor is transferred to the activating arm, such as by means of the screw for example, and a configuration of mutual disengagement, wherein the activating arm and member to which it can be constrained, such as a screw, are free to move independently of the rotation of the drive shaft of the electric motor.

Advantageously, the reversible connecting means comprise elastic means configured to bring the second member and/or first member of the coupling joint to the configuration of mutual disengagement.

Preferably, the reversible connecting means comprise an electromagnet (or any electromechanical actuator known in the art) to bring the second member and/or first member of the coupling joint to the configuration of mutual engagement.

According to a further aspect of the present invention, the reversible connecting means are configured to couple the electric motor to the activating arm and, in particular, to the second end portion of the activating arm, in response to a user actuation command. Preferably, the activating arm comprises a sliding surface slidingly resting on an idle roller fastened to the fastening bracket, during at least part of its own path between the open position of the door and the aforesaid closed position of the door. The sliding surface advantageously has at least one cam profile. The hinge can preferably comprise means for detecting the electric current absorption of the electric motor. The presence of at least one cam resting on the idle roller during the movement of the activating arm and/or the position assumed by the door during the path between the open position and the closed position causes a variation in the electric current absorption of the electric motor and, since it is easily detectable, it can be advantageously used to obtain the position of the activating arm.

According to an aspect of the present invention, the movement means comprise a connecting bracket configured to rotatably constrain the electric motor to the household appliance compartment.

A further object of the present invention is a household appliance comprising at least one hinge according to the present invention.

Further aspects and advantages of the present invention will be more evident from the following description, made for illustration purposes only and without limitation, referring to the accompanying schematic drawings, in which:.

<FIG> show a particular embodiment of the hinge <NUM> according to the present invention for connecting a door to a household appliance compartment. In particular, <FIG> shows the hinge <NUM> when the door is in a closed position P1, and <FIG> shows the hinge <NUM> when the door is in an open position P2.

The hinge <NUM> comprises a fastening bracket <NUM> suitable for being fastened to the compartment of the household appliance, such as by means of screws or other known fastening means. The door is configured to be rotatably constrained to the fastening bracket <NUM> by means of a movable support <NUM>. This movable support <NUM>, which can consist of an additional bracket or a box-like body for housing the various optional components of the lock, is stably fastened to the door, inside of a housing arranged inside the door itself for example, and is rotatably constrained to the fastening bracket <NUM>, such as by means of a pin <NUM>, so that the door can rotate around a rotation axis (e.g. a horizontal axis) with respect to the fastening bracket <NUM>.

In the embodiment herein shown, the movable support <NUM> is pivoted to the fastening bracket <NUM> so that when the movable support <NUM> is fastened to a respective door, the door is rotatably constrained to the fastening bracket <NUM> around a horizontal axis.

Further embodiments can however provide that the movable support <NUM> is shaped variously and made integral with the door in ways per se known to the art, in addition to being pivoted to the fastening bracket <NUM> in various modes, still remaining within the scope of protection of the present invention.

The hinge <NUM> further comprises an activating arm <NUM> that can be coupled to the fastening bracket <NUM> and that is constrained to the movable support <NUM>, or directly to the door, and movement means <NUM> suitable for moving the activating arm <NUM> between an open position of the door P2 (shown by way of example in <FIG>) and a closed position of the door P1 (shown by way of example in <FIG>). In particular, the activating arm <NUM> comprises a first portion 5a rotatably constrained to the movable support <NUM> (e.g. by means of pins <NUM>) and a second portion 5b suitable for being coupled to the movement means <NUM>. The movement means <NUM> act on the second portion 5b of the activating arm <NUM> so as to move the activating arm <NUM> between the open position P2 and the closed position P1 of the door. It should be noted that in the embodiment shown herein, such first portion 5a and second portion 5b of the activating arm <NUM> are end portions, i.e. substantially the end parts of this arm <NUM>. However, further configurations of the arm <NUM>, that provide a first portion 5a thereof constrained to the movable support <NUM> and a different second portion 5b thereof that can be coupled, reversibly, to the aforesaid movement means <NUM>, still fall within the scope of protection requested herein.

The movement means <NUM> comprise an electric motor <NUM> and reversible connecting means <NUM> to couple and decouple selectively, i.e. reversibly, the electric motor <NUM> and the activating arm <NUM> and, in particular, this electric motor <NUM> and the second portion 5b of the activating arm <NUM>.

The hinge <NUM> is therefore configured so as to ensure that when the electric motor <NUM> is coupled to the second portion 5b of the activating arm <NUM>, the actuation of the electric motor <NUM> causes the movement of the activating arm <NUM>, whereas when the electric motor <NUM> is decoupled from this second portion 5b, the manual movement of the activating arm <NUM>, and therefore of its first portion 5a, occurs independently of the electric motor <NUM> (i.e. without acting on the electric motor <NUM>) so as to allow a user to freely move the door of the household appliance.

In other words, when the second portion 5b of the activating arm <NUM> is decoupled from the electric motor <NUM>, the user can freely move the door, substantially as if there were no movement means <NUM>, that is to say as if the hinge <NUM> was a non-motorized hinge. The second portion 5b can therefore only be coupled to the electric motor <NUM> when the movement means <NUM> are asked to move the activating arm <NUM>.

As can be better seen below, these reversible connecting means <NUM>, which can consist of a joint, such as of the coupling type, and which is functionally interposed between the electric motor <NUM> and the activating arm <NUM>, can be controlled by a special electromagnetic member, such as by a manual switch or door movement sensor or even an electric current absorption detector of the electric motor <NUM> itself for example, so as to determine the mechanical coupling or decoupling of the motor <NUM> to/from the arm <NUM>, depending on the operative requirements of the household appliance to which the hinge <NUM> is applied.

These movement means <NUM> comprise a slider <NUM> linearly moved by means of the electric motor <NUM>. This slider <NUM> is constrained to the second portion 5b of the activating arm <NUM> to move, by pushing or pulling for example, this activating arm <NUM> between the open position P2 and the closed position P1 of the door.

In particular, in the embodiment of the present invention shown in <FIG>, the second portion 5b of the activating arm <NUM> is constrained to the slider <NUM>, preferably by means of a connecting lever <NUM> comprising a first end 13a rotatably constrained to the fastening bracket <NUM> and a second end 13b rotatably constrained to the slider <NUM>. The second portion 5b of the activating arm <NUM> is, for example and preferably, rotatably and slidingly constrained to an intermediate portion 13c of the connecting lever <NUM> comprised between the first and the second ends 13a, 13b of the connecting lever <NUM>. The first end 13a of the connecting lever acts as a fulcrum, the second end 13b acts as driving force and the intermediate portion 13c acts as resisting force, therefore obtaining a second class lever.

The second portion 5b of the activating arm <NUM> is preferably rotatably and slidingly constrained to the intermediate portion 13c of the connecting lever <NUM> by means of a pin <NUM> slidingly constrained along a guide <NUM>.

The guide <NUM> is obtained in the intermediate portion 13c of the connecting lever <NUM> and can, for example, be shaped like a slot within which the pin <NUM> is slidingly housed. In <FIG>, the pin <NUM> is shown outside of the guide <NUM>, to show the connection between the second portion 5b of the activating arm <NUM> and the connecting lever <NUM> more clearly.

The slot or, in general, the guide <NUM>, is advantageously shaped to impose a given law of motion to the activating arm <NUM> along its path between the open position P2 and the closed position P1 of the door and to transmit motion from the slider <NUM> to the second portion 5b of the activating arm <NUM> according to certain predefined distance ratios. The shape of the slot is chosen during the design phase to obtain a fluid door movement during the opening and closing of the same.

For example, the shape of the slot <NUM> can be obtained by simulating a given law of motion of the door based on the movement of the connecting lever <NUM>. In particular, the simulation can be carried out by maintaining the second portion 5b disconnected from the connecting lever <NUM> and by carrying out a given movement of the door between the closed position P1 and the open position P2 depending on a given movement of the connecting lever <NUM>. By tracing the path taken from the constraint point (the through hole through which the pin <NUM> passes) of the second portion 5b, it is possible to obtain the shape of the slot <NUM> on the portion 13c of the connecting lever <NUM> needed to obtain the given law of motion that connects a predefined movement of the connecting lever <NUM> to a given movement of the door.

In addition to making it possible to reduce the force needed for the movement means <NUM> to move the activating arm <NUM>, this configuration makes it possible to obtain a door movement with a given pattern, such as, for example, with given accelerations or decelerations or substantially uniform (i.e. without accelerations or decelerations) during its path between the closed position P1 and the open position P2.

It should be noted that, according to the Applicant, the connecting lever <NUM> is per se inventive and can be used in other embodiments of motorized hinges, independently of the presence of the reversible connecting means <NUM> described in the present disclosure.

In other words, the present invention further provides an embodiment wherein the hinge <NUM> comprises the aforesaid fastening bracket <NUM> suitable for being fastened to the compartment of a household appliance, the aforesaid activating arm <NUM> and the movement means <NUM> comprising an electric motor <NUM> and a slider <NUM>, preferably, but not exclusively, linearly moved by means of the electric motor <NUM> in order to move the activating arm <NUM> between an open position P2 and a closed position P1 of the door. This embodiment provides the presence of the aforesaid connecting lever <NUM> that connects the activating arm <NUM> to the slider <NUM>, so as to transform the motion of the slider <NUM> into a predefined motion of the activating arm <NUM> according to a motion law - and of motion transformation - predetermined by the designer, and only optionally provides for the presence of the aforesaid reversible connecting means <NUM> suitable for coupling and decouple the motor <NUM> from the activating arm <NUM>.

Further embodiments can however provide that the second portion 5b of the activating arm <NUM> is, for example, directly constrained to the slider <NUM> of the movement means <NUM>, and therefore directly actuated by that slider <NUM>, still remaining within the scope of protection of the present invention.

This way, by way of example, some embodiments can provide that the electric motor <NUM> is a magnetic linear motor typically comprising a slider <NUM> arranged on a sliding guide (stator) integrated within the magnetic linear motor. The cursor <NUM> is moved along the sliding guide by means of a magnetic field provided by coils arranged on the sliding guide. In this case, the slider and the sliding guide are magnetically coupled to one another when the coils are driven. When the magnetic linear motor is deactivated, the slider <NUM> freely slides on the sliding guide, in particular when this slider and the relative guide are shaped to be mutually separated by a layer of air. In this embodiment, the movement means <NUM> have the aforesaid reversible connecting means (constituted, for example, by a switch for selectively activating and deactivating the power supply of the magnetic linear motor) configured for the selective magnetic coupling and magnetic decoupling of the sliding guide and the slider <NUM>.

With reference to <FIG> and <FIG>, in the embodiment of the invention herein shown, the movement of the slider <NUM> preferably occurs by means of a screw <NUM> of the reversible type, which is rotated by the electric motor <NUM>. The slider <NUM> is coupled, such as by means of a complementary nut screw <NUM>1a, to the screw <NUM>, so as to transform the rotation of the screw <NUM> into a translation of the slider <NUM>.

Surprisingly, a multi-threaded screw <NUM>, preferably with more than two threads (e.g. with five threads) and with a pitch between <NUM> and <NUM>, preferably with a pitch between <NUM> and <NUM> (e.g. with a pitch of about <NUM>), provides optimal performance in terms of the reversibility and reduction of friction between the slider <NUM> and the screw <NUM> (with a screw-nut screw coupling). In particular, when the reversible connecting means <NUM> decouple the second portion 5b of the activating arm <NUM> from the electric motor <NUM>, the translation of the slider <NUM>, due to a manual movement of the door, causes the rotation of the screw <NUM> with reduced friction. In other words, the transformation of the translatory motion of the slider <NUM> into a rotary motion of the screw <NUM> produces a substantially negligible frictional force.

With reference to the embodiment in <FIG>, <FIG>, the activating arm <NUM> can also preferably rest slidingly on an idle roller <NUM> fastened to the fastening bracket <NUM> during at least part of its path between the open position P2 and the closed position P1 of the door. Preferably, the activating arm <NUM> comprises a sliding surface <NUM> adapted to rest slidingly on the roller <NUM>. This sliding surface <NUM> is preferably shaped according to one or more cam profiles, so as to engage itself and rest on the idle roller <NUM> in various ways, when the activating arm <NUM> reaches given positions of reference. For example, with reference to <FIG>, the activating arm <NUM> can comprise a first cam profile 17a suitable for resting on the idle roller <NUM> when the activating arm <NUM> reaches the open position P2 and a second cam profile 17b suitable for resting on the idle roller <NUM> when the activating arm <NUM> reaches the closed position P1. Further embodiments can provide, in addition or alternatively, that the sliding surface of the activating arm <NUM> has a cam profile (not shown) arranged so as to rest on the roller <NUM> in a certain path when the activating arm <NUM> reaches a given intermediate position of reference between the open position P2 and the closed position P1 of the door.

According to a preferred aspect of this invention, the hinge <NUM> may comprise a logic control unit <NUM> intended to control, in response to one or more control signals of the manual type and/or of the type generated automatically by special sensors or system status detectors, the movement means <NUM> of the activating arm <NUM> and, in particular, at least the aforesaid reversible connecting means <NUM> to couple and decouple the electric motor <NUM> and the activating arm <NUM>.

This logic control unit <NUM>, according to an aspect of the present invention, can preferably be configured to actuate the movement means <NUM>, and/or in particular the aforesaid reversible connecting means <NUM> in response to a user actuation command. This actuation command can, for example, be imparted by means of a button and/or by means of a vocal command or other.

The logic unit <NUM> can preferably be configured to control at least the reversible connecting means <NUM> so as to couple the electric motor <NUM> to the second portion 5b of the activating arm <NUM> in response to the aforesaid actuation command.

Alternatively, or in conjunction with a manual control, the actuation command of the logic unit <NUM> can be, as mentioned, imparted by sensors or by other status detection means of the system and able to detect the need to actuate the movement means <NUM> and/or operate the coupling or decoupling of the reversible connecting means <NUM>.

For example, as already mentioned, some embodiments of this invention can provide that the hinge <NUM> is equipped with means <NUM> to detect the current absorption of the electric motor <NUM> (symbolically shown with a rectangle), such as an ammeter or similar means for example. This embodiment can also provide that the aforesaid means <NUM> to detect the current absorption of the electric motor <NUM> provide an absorption value indicative of the position assumed by the activating arm <NUM> during its path between the open position P2 and the closed position P1 of the door.

In particular, the weight force of the door generates a moment that varies according to the position assumed by the door and causes a different current absorption of the electric motor. In other words, as the door rotates from the closed position P1 towards the open position P2, the weight force acting on the door generates an increasing moment that can be detected by the means <NUM> to detect the current absorption of the electric motor. Moreover, by means of one or more cam profiles 17a, 17b provided on the sliding surface of the activating arm <NUM>, it is possible to cause easily detectable current absorption variations of the electric motor <NUM> during the path of the activating arm <NUM> between the position P1 and the position P2. A logic control unit <NUM> (also symbolically shown with a rectangle) can recognize these variations and can thus associate them to one or more of the aforesaid positions of reference of the activating arm <NUM>. In this way, it is possible to obtain an indication of the real position of the activating arm <NUM> with respect to the fastening bracket <NUM>.

It should be noted that further embodiments of the hinge <NUM> according to the present invention can provide that the hinge <NUM> is not directly equipped with a logic control unit <NUM> and/or means <NUM> to detect the electric current absorption of the electric motor. However these components can be, for example, provided in a household appliance (such as an oven, for example) comprising the hinge according to the present invention. In this case, the logic control unit <NUM> and/or means <NUM> to detect the current absorption of the electric motor can be connected to the electric motor <NUM> of the hinge <NUM> and/or to the reversible connecting means <NUM>, such as by means of electric wires, or in other known ways of the art.

In this embodiment of the invention with reference to <FIG>, the reversible connecting means <NUM>, which, as mentioned, are configured to couple and decouple selectively the electric motor <NUM> to/from the activating arm <NUM>, are functionally interposed between this motor <NUM> and a screw <NUM> that, as mentioned, enables the actuation of a slider <NUM> intended to transmit a pushing or pulling motion, or any other motion that allows the rotation of the door, to the activating arm <NUM>. In this embodiment, the reversible connecting means <NUM> comprise a coupling joint <NUM> provided with a first member 19a constrained to said screw <NUM> and a second member 19b constrained to the motor shaft 10a of said electric motor <NUM>.

For example this coupling joint <NUM> can be of the type comprising, on the relative rotating members 19a, 19b, complementary coupling profiles, such as for example with teeth or of the type with protrusions and recesses, able to transmit a torque from one member to the other 19a, 19b when they are mutually engaged.

It should be noted that a coupling joint <NUM> of this type, and in particular of the type described below, can be interposed for the selective coupling and decoupling of any two rotating members arranged downstream of the electric motor <NUM>, independently of the use of a screw <NUM> to transform the rotary motion of the motor shaft of the motor <NUM> into the translatory, or rotary-translatory or even rotary motion, of the activating arm <NUM>. In other words, independently of the arrangement used for the possible transformation of the rotary motion of the electric motor <NUM> into the motion required by the activating arm <NUM>, this coupling joint <NUM>, which belongs to a preferred embodiment of the aforesaid reversible connecting means <NUM>, can be interposed between any two rotating members, such as, for example, two shafts that transmit the rotary motion generated by the electric motor <NUM> to the motion transformation arrangement possibly positioned upstream of the aforesaid activating arm <NUM>.

With reference to the <FIG>, in the embodiment herein shown, the second member 19b is movable, for example axially, with respect to the first member 19a between a configuration C1 of mutual engagement, wherein the rotation of the motor shaft 10a of the electric motor <NUM> is transferred to the screw <NUM>, and a disengagement configuration C2, wherein the screw <NUM> is free to rotate independently of the rotation of the motor shaft 10a.

Preferably, an epicyclic reduction gear <NUM> suitable for reducing the number of revolutions of the motor shaft of the electric motor <NUM> can be interposed between the second member 19b of the coupling joint <NUM> and the electric motor <NUM>. In general, the reference 10a therefore denotes the motor shaft moved by means of the electric motor <NUM>, this motor shaft 10a can therefore be the motor shaft exiting the epicyclic reduction gear <NUM> or exiting further other stages arranged between the electric motor <NUM> and the second member 19b of the coupling joint <NUM>.

Although the embodiment shown in <FIG> provides that the second member 19b is movable with respect to the first member 19a of the coupling joint <NUM>, further embodiments can provide that the first member is movable with respect to the second member or that both the first member and the second member are movable with respect to one another, while remaining within the scope of protection of the present invention.

The first member and the second member 19a, 19b have complementary edges, preferably provided with slightly tapered teeth (visible, for example, in <FIG>) suitable for engaging with one another in the configuration of mutual engagement C <NUM> shown in <FIG>.

Preferably, the reversible connecting means <NUM> comprise elastic means <NUM> configured to bring the first member and the second member of the coupling joint <NUM> to the disengagement configuration C2. For example, the elastic means <NUM> can comprise a spring arranged between the first and the second members 19a, 19b of the coupling joint <NUM>, the spring being shaped to push a member 19a away from, and thus disengaging it from, the other member 19b.

In this embodiment with reference to <FIG>, the reversible connecting means <NUM> further comprise an electromagnet <NUM> to bring, when they are actuated, the first and the second members 19a, 19b of the coupling joint <NUM> to the configuration of mutual engagement C1. This actuator <NUM> is preferably controlled by the logic control unit <NUM> (as symbolically shown in <FIG> and <FIG>).

In particular, in response to a user actuation command and/or in response to an actuation command generated automatically by sensors or detectors of the hinge <NUM> or by the household appliance, the logic control unit <NUM> actuates (i.e. energizes) the electromagnet <NUM>, which moves the second member 19b of the coupling joint <NUM> towards the configuration of mutual engagement C1 shown in <FIG>. Once the configuration of mutual engagement C1 has been reached, the logic control unit <NUM> controls the actuation of the electric motor <NUM>. In particular, in the embodiment of the invention herein shown, the electric motor <NUM> is actuated to rotate the screw <NUM> in one direction or in the opposite direction depending on the position of the door. This position can, for example, be detected by an encoder configured to detect the number of revolutions accomplished by the electric motor <NUM> or with known means detecting the position of the door, or with microswitches automatically operated depending on the position of the door itself, or even preferably with means <NUM> to detect the electric current absorption of the motor <NUM> previously described.

When the electric motor <NUM> is actuated, the rotation of the motor shaft 10a, i.e. the relative torque, is transferred from the second member 19b to the first member 19a of the joint <NUM> and therefore to the screw <NUM> that translates the slider <NUM> to move the activating arm <NUM> between the closed position P1 and the open position P2 of the door. When one of the aforesaid positions P1, P2 has been reached, variously detected as mentioned above, the logic control unit <NUM> controls the switching off of the electric motor <NUM> and of the electromagnet <NUM>. By means of the spring <NUM> arranged between the first and the second members 19a, 19b of the coupling joint <NUM> (and possibly by means of a spring <NUM> provided on the electromagnet <NUM>), the coupling joint <NUM> is brought into the disengagement configuration C2 wherein the electric motor <NUM> and the screw <NUM> are decoupled.

In this configuration, the manual movement of the door by a user can be carried out effortlessly, substantially as if there were no movement means <NUM>.

This solution is advantageous also in case of absence of electric current while the door is being moved by means of the movement means <NUM>. In particular, if the electric current is interrupted during the movement of the door by means of the electric motor <NUM>, the electromagnet <NUM> is no longer energized, the electric motor is inactive and the screw <NUM> stops. In this case, the elastic force of the spring <NUM> brings the first member 19a away from the second member 19b of the coupling joint <NUM>, bringing them in the disengagement configuration C2 and therefore decoupling the electric motor <NUM> from the screw <NUM>.

In this configuration, the door can, for example, be brought back towards the closed position P1 by means of the elastic countering force acting on the activating arm <NUM>. For example, the elastic countering force can be provided by the elastic countering means (not shown in the figures) housed, for example, inside the door (or inside the movable support <NUM>) and acting on the first portion 5a of the activating arm <NUM>.

With reference to <FIG> and <FIG>, the elastic countering means can be housed inside the housing <NUM> of the movable support <NUM>. In particular, the elastic countering means can comprise a spring fastened to a retainer <NUM> of the housing <NUM> and a retainer <NUM> of the first portion 5a of the activating arm <NUM>. The expansion action of the spring tends to bring the activating arm towards the closed position of the door, preferably when the door reaches a given opening angle (e.g. less than <NUM>°).

In order to simplify the design of the hinge <NUM>, the movement means <NUM> can advantageously comprise a connecting bracket <NUM> configured to rotatably constrain the electric motor <NUM> to the household appliance compartment. In particular, between the closed position P1 and the open position P2 of the door, the movement of the activating arm <NUM> causes a rotation of the connecting bracket <NUM> to which the electric motor <NUM> is fastened.

If the movement means <NUM> comprise, by way of example, the screw <NUM> of the embodiment herein shown, this rotation occurs both when the electric motor <NUM> is coupled to the screw <NUM> and when the electric motor <NUM> is decoupled from it.

In particular, during the disengagement configuration C2 between the first and the second members 19a, 19b of the coupling joint <NUM>, the screw <NUM> can freely rotate following the translation of the slider <NUM> caused by the manual movement of the door. In order to further reduce the friction, the screw <NUM> can preferably be supported by means of a ball bearing <NUM> (visible in <FIG>) arranged inside a casing <NUM> inside which the screw <NUM> itself is housed. The slider <NUM> further comprises a tubular element <NUM> arranged coaxially with the screw <NUM> inside the casing <NUM>. The rotation of the connecting bracket <NUM> makes it possible to substantially maintain the tubular element <NUM> of the slider <NUM> coaxial with the screw <NUM> by further reducing the friction and therefore increasing the fluidity of the manual movement of the door when the electric motor is decoupled from the activating arm <NUM>.

Claim 1:
Hinge (<NUM>) for connecting a door to a household appliance compartment, comprising a fastening bracket (<NUM>) suitable for being fastened to the compartment of said household appliance, a movable support (<NUM>) to rotatably constrain said door to said fastening bracket (<NUM>), an activating arm (<NUM>) coupled to said fastening bracket (<NUM>), movement means (<NUM>) suitable for moving said activating arm (<NUM>), said activating arm (<NUM>) comprising a first portion (5a) suitable for being constrained to said movable support (<NUM>) and/or to said door, and a second portion (5b) suitable for being coupled to said movement means (<NUM>) to move said activating arm (<NUM>) between an open position (P2) of the door and a closed position (P1) of the door, and wherein said movement means (<NUM>) comprise an electric motor (<NUM>) and a slider (<NUM>) linearly moved by means of said electric motor (<NUM>), said slider (<NUM>) being constrained to said second portion (5b) of the activating arm (<NUM>), said movement means (<NUM>) further comprising reversible connecting means (<NUM>) to couple and decouple selectively said electric motor (<NUM>) to/from said second portion (5b) of the activating arm (<NUM>), said electric motor (<NUM>) causing the activating arm (<NUM>) to move when said reversible connecting means (<NUM>) determine the coupling between said electric motor (<NUM>) and said second portion (5b) of the activating arm (<NUM>), the movement of said activating arm (<NUM>) occurring freely when said reversible connecting means (<NUM>) determine the decoupling of said electric motor (<NUM>) from said activating arm (<NUM>), characterized in that said second portion (5b) of the activating arm (<NUM>) is constrained to said slider (<NUM>) by means of a connecting lever (<NUM>) comprising at least one first end (13a) rotatably constrained to said fastening bracket (<NUM>) and at least one second end (13b) rotatably constrained to said slider (<NUM>), said second portion (5b) of said activating arm (<NUM>) being rotatably constrained to an intermediate portion (13c) of said connecting lever (<NUM>) between said first end (13a) and said second end (13b) of said connecting lever (<NUM>).