Patent Description:
It is to be noted that in the present application the expression "washing machine" may indicate a "simple" washing machine (i.e. a washing machine which can only wash and rinse the laundry) as well as a washing-drying machine (i.e. a washing machine which can also dry the laundry). It may also indicate a washer-extractor or a washer without extractor. The washing machine may have a horizontal, inclined, or vertical axis of rotation.

Washing machines for household or professional use generally comprise an inner drum with an opening for loading and unloading laundry. This opening may be in a flat side of the drum (e.g. front-loaded washers and vertical-axis top-loaded washers) or in the curved surface of the drum (e.g. top-loaded and side-loaded horizontal-axis washers). An opening in the curved surface of the drum may be closed by a hatch using different types of locking mechanisms, generally some sort of hooking system. In case of failure in the locking mechanism the hatch may open during operation of the washing machine. This may cause the hatch or the locking mechanism to come into contact with and/or get stuck on a stationary outer drum, or an edge of an opening of the stationary outer drum. Depending on the revolution speed of the inner drum such an accidental opening of the hatch may cause damage to the washing machine. Solutions presented in prior art have proven insufficient in solving these kinds of problems.

An example of prior art may be found in patent applications <CIT> and <CIT>, which disclose a washing machine with a tub and a drum, both equipped with a tub door and a drum door, respectively. The tub door and the drum door may be in an engaged state, such that the drum door opens or closes with the opening or closing of the tub door.

There is therefore a need in the field for solutions for the above-mentioned problem.

The inventors have reached the insight that there is a need for a washing machine that at least partially improves the safety of the washing machine and prevents mechanical damages due to the hatch opening as result of a locking mechanism failing. Further, there is a need for a washing machine which, if such a hatch opening occurs during use, shuts down in a safe manner.

Generally, locking mechanisms securing the hatches of washing machines work properly. However, as with many mechanical product certain features may degrade slightly over time or get damaged when treated improperly. A locking mechanism in a washing machine may fail due to different reasons and it is therefore important to, at least partially, solve the issues such a failure may bring.

The present disclosure seeks to provide at least some embodiments of a washing machine which reduces at least some of the above-mentioned drawbacks. More specifically, the present disclosure aims at providing at least some embodiments offering a safety element which prevents damages to the washing machine in case of a hatch opening mid-use of the washing machine. Further, the present disclosure aims at providing at least some embodiments that, in case of a hatch opening, turns the washing machine off in a secure manner.

The invention is defined by the appended independent claim, wherein claim <NUM> relates to a washing machine.

In a first aspect of the present invention, there is provided a washing machine comprising a stationary drum. The stationary drum comprises at least one first opening. The washing machine further comprises an inner drum rotatably arranged around an axis of rotation A inside the stationary drum. The inner drum comprises a second opening for accessing an interior of the inner drum, a hatch configured to cover the second opening, and a locking mechanism configured to secure the hatch in a closed position. The washing machine further comprises at least one first safety element extending across the at least one first opening, wherein the at least one first safety element is arranged to provide a sliding surface.

Thus, there is provided a washing machine with at least a first function of providing a sliding surface for the hatch in case the hatch accidentally opens during rotation of the inner drum. The hatch may open during use in case of the locking mechanism failing, or if the locking mechanism has not been secured properly. The safety element extends across the first opening during use of the washing machine and together with the stationary drum provides a complete cylinder surface. This is advantageous at least in that the washing machine will not get damaged if the hatch accidentally opens during use. In prior art washing machines, the risk of the hatch getting stuck on the edges of the first opening is present which may cause damage to the machine. Further, it is advantageous in that the sliding surface may help preventing some disturbing noises that may occur if the hatch accidentally opens while the inner drum is rotating. Further, it is advantageous in that the sliding surface may prevent abrupt stops of the washing machine that could occur if the hatch gets stuck if it opens during rotation. The safety element and the sliding surface it provides improve the general safety of the washing machine.

According to the invention, the at least one first safety element provides a sliding surface for guiding the hatch on a smooth trajectory in case the hatch accidentally opens during use of the washing machine. If the hatch opens during use it may first come in to contact with the inside of the stationary drum. During rotation it will eventually come into to contact with the safety elements which extend across the first opening. In some prior art the edges of the first opening are exposed, and the hatch may get stuck or simply bump into these during continuous rotation. This may cause disturbing noises or damage the washing machine. By guiding the accidentally opened hatch on a smooth trajectory the acceleration is kept constant and therefore mechanical impacts and vibrations are reduced to a minimum. By providing a sliding surface the present embodiment ensures that such unwanted features are removed, which is advantageous. The smooth trajectory may be a circular trajectory and the sliding surface may be coaxial with the stationary drum, which could be advantageous if the stationary drum is a circular cylinder.

According to an embodiment, the inner drum and the stationary drum are circular cylinders, and the sliding surface has a circular shape with the same radius as the stationary drum and is arranged concentric about axis A. The present embodiment is advantageous in that the safety element provides a sliding surface that easily guides the hatch in case it accidentally opens during use. It is however understood that other geometries of the inner drum, stationary drum, safety element and sliding surface are plausible. For example, the stationary drum and the inner drum do not need to be coaxial. Further, the stationary drum and/or the inner drum may be shaped as an elliptical cylinder.

According to an embodiment, the at least one first safety element comprises at least two safety element segments, wherein the at least two safety element segments each comprises a first sliding surface segment bridging the first opening in a tangential direction of rotation of the inner drum. The present embodiment is advantageous in that the two safety element segments may provide a sliding surface providing a more stable support to the hatch moving at potentially high speed with high acceleration forces. This is advantageous in that the pressure from the hatch on the sliding surface, in case the hatch opens during use, is exerted evenly over the safety element which reduces damages from friction. Further it is advantageous that the risk of deformation of the hatch is reduced and thus the risk of impacts in the transition from sliding on the first safety element to sliding on the inner surface of the outer drum.

According to an embodiment, the sliding surface is arranged at a radial distance of <NUM> - <NUM> millimeters from the inner drum. The present embodiment ensures that if the hatch accidentally opens during rotation it will only be able to open <NUM> - <NUM> millimeters before it comes into contact with the safety element. This is advantageous in that the opening angle for the hatch will not be great enough for the hatch to break and in that the risk of the hatch getting stuck is diminished. It is understood that depending on the dimensions of the hatch, inner drum, stationary drum, and other parts of the washing machine other radial distances might be preferable.

According to the invention, the hatch comprises at least one protruding rib arranged to engage the at least one first safety element if the hatch accidentally opens during use of the washing machine. The present embodiment is advantageous in that the at least one protruding rib will engage with the safety element if the hatch accidentally opens which may ensure a smoother sliding along the sliding surface provided by the safety element. Further a rib being the element in contact with the first safety element ensures a good distribution of the contact force within the hatch. The at least one protruding rib may have many shapes and sizes, but it is preferably that the at least one protruding rib engages the safety element before any other part of the hatch, this to ensure a smoother sliding and avoid the locking mechanism to get stuck or damaged.

According to an embodiment, the at least one protruding rib has a width of at least <NUM> millimeters. An increased width of the protruding ribs is preferable since the pressure is smaller upon the protruding ribs if the area in contact with the safety element and/or the inside of the stationary drum is larger. It is understood that other solutions are possible, for example the skilled man understands that providing more protruding ribs may have the same effect as providing a wider area. However, there are also drawbacks arising from increasing the number of ribs and/or their width. The number of ribs and their width may vary depending on other features and dimensions of the washing machine.

According to an embodiment, the at least one protruding rib extends further outward in a radial direction from the axis of rotation A than said locking mechanism and any other part of the hatch when the hatch is in an open position and the at least one protruding rib engages the at least one first safety element and/or the stationary drum. In certain embodiments the protruding rib extends further from the hatch, i.e. has a higher height, then the locking mechanism to ensure that the rib engages the first safety element and/or the stationary drum in case the hatch accidentally opens during use. However, it is possible to achieve this while having a protruding rib with a lower height than for example the locking mechanism. Therefore the present embodiment is preferable where the protruding rib extends further away from the axis of rotation A than any other part of the hatch when the hatch is in the opened position and when the protruding rib touches the stationary drum and/or the at least one first safety element. The locking mechanism may be the part of the hatch that gets stuck when the hatch accidentally opens during use, therefore it is advantageous to ensure that the protruding rib is the first part of the hatch to come into contact with the safety element and/or the stationary drum, and not the locking mechanism. Different types of locking mechanism are used in different designs and washing machines, the protruding ribs may therefore have different heights and shapes ensuring that the invention works properly depending on the model of the washing machine.

According to an embodiment, the washing machine further comprises at least one door arranged to cover the at least one first opening, wherein the at least one first safety element is attached to the at least one door. The present embodiment is advantageous in that the safety element may be put into its correct position before operation by closing the door to cover the first opening. Such a solution is more practical since it simplifies for the user and removes possible errors such as misplacing the safety element across the first opening.

According to an embodiment, the at least one first safety element comprises an interlocking element connected to the stationary drum and arranged to interlock with the at least one first safety element. The present embodiment is advantageous in that the interlocking element may complete the sliding surface of the at least one first safety element and provide a sliding surface extending fully over the at least one first opening. For example, the interlocking element may be arranged to interlock with the safety element segments of the safety element.

According to an embodiment, the interlocking element is configured to slidably interlock with the at least one first safety element. The present embodiment is advantageous in that the washing machine is more easily opened. The interlocking element may easily slide in the safety element so that the safety element is placed in the correct operational position extending across the at least one first opening. In a preferred embodiment, the safety element may comprise safety element segments comprising slots extending along the safety element segments. The interlocking element may be slidably interlocked with these slots.

According to an embodiment, the washing machine further comprises a sensor configured to detect if the at least one first safety element is in contact with the hatch, and a control unit configured to turn off the washing machine when the sensor detects a contact between the at least one first safety element and the hatch. The present embodiment is advantageous in that the washing machine can detect if the hatch opens during use and safely stop the rotation of the inner drum. Even if the safety element may prevent mechanical damages and disturbing noises the washing machine is preferably stopped as quickly as possible after a hatch malfunction to avoid friction wear. Different sensors may be used to detect that the hatch has opened during use. The control unit may be the same control unit controlling other features of a washing machine. It may also be a different and/or extra control unit.

According to an embodiment, the sensor is an inductive sensor configured to detect a displacement of the at least one first safety element. The present embodiment is advantageous in that the at least one first safety element will be slightly displaced by the hatch in case it opens during use. An inductive sensor may be placed so that it can measure such a movement, or measure if the at least one first safety element is moved closer to the sensor. The at least one first safety element may also be connected to a frame of the washing machine and the sensor configured to detect a movement of the frame. It is understood that different types of displacements may be measured by an inductive sensor.

According to an embodiment, the at least one first safety element comprises a spring element configured to be released by the hatch in case the hatch accidentally opens during use of the washing machine. And the sensor is an inductive sensor configured to detect the spring element being released. In the present embodiment the spring may for example be held in place by plastic screws. In case the hatch opens during rotation of the inner drum, the hatch will break the plastic screws which releases the spring element, and the spring element will come near the inductive sensor which will therefore detect that the hatch has been opened. The present embodiment is advantageous in that it requires an intervention by a technician before the machine can be used again. This will diminish the risk of the user using the washing machine more times despite the hatch and/or its locking mechanism being damaged or broken. Such a condition may require professional maintenance before further use. Other manners of releasing the spring element are possible and may be implemented as well.

According to an embodiment, the stationary drum further comprises a third opening. And the washing machine further comprises a heating box configured to contain a heating element for heating a content of the stationary drum via the third opening, and a second safety element extending across the third opening, wherein the second safety element is arranged to provide a second sliding surface. Today, most washing machines provide heat to the water in the stationary drum by heating elements placed in a heating box extending from the stationary drum. The water can circulate between the heating box and the inside of the stationary drum through an opening in the stationary drum. The present embodiment is advantageous in that the stationary drum has a third opening for allowing water to circulate between the heating box and the stationary drum and provides a sliding surface for both the first opening and the third opening. This diminishes the risk of the hatch getting stuck after a malfunction during use which decreases the risk of mechanical damages to the machine.

According to an embodiment, the second safety element comprises at least two metal strips extending across the third opening, wherein each of the at least two metal strips comprises a second sliding surface segment bridging the third opening in a tangential direction of rotation of the inner drum. The second sliding surface segments may complete the shape of the stationary drum. In case the stationary drum is a circular cylinder, they may have the shape of circular arcs. The segments may for example be made when cutting the third opening, instead of cutting one opening the stationary drum may be cut so that at least two metal strips extending across the opening are left intact. This will ensure that the metal strips have the correct radius as well as allowing the heating element to heat the inner drum via the opening. Other ways of providing these segments are possible.

According to an embodiment, each first sliding surface segment and/or each second sliding surface segment is extending in a plane defined by a circular trajectory of one of the at least one protruding ribs when the inner drum is rotating. The present embodiment is advantageous in that it ensures that the first sliding surface segments and the second sliding surface segments are in the same plane as the protruding ribs. This ensures that the protruding ribs engages the first and second sliding surface segments during rotation in case the hatch accidentally opens during use of the washing machine.

Exemplifying embodiments will now be described in more detail, with reference to the following appended drawings:.

As illustrated in the figures, the sizes of the elements and regions may be exaggerated for illustrative purposes and, thus, are provided to illustrate the general structures of the embodiments.

Exemplifying embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.

With reference to <FIG> a washing machine <NUM> in accordance with an embodiment of the present invention is disclosed.

The washing machine <NUM> may be a "simple" washing machine (i.e. a washing machine which can only wash and rinse the laundry) as well as a washing-drying machine (i.e. a washing machine which can also dry the laundry). It may also be a washer-extractor or a washer without extractor.

The washing machine <NUM> comprises a door <NUM> arranged to cover a first opening. Attached to the door <NUM> is a first safety element <NUM>. Visible through the opening is a hatch <NUM> of an inner drum of the washing machine <NUM>.

The washing machine <NUM> may comprise a similar door (not shown) on an opposite side to the door <NUM> shown in <FIG>.

The washing machine <NUM> may be configured for home use or for professional use. The washing machine <NUM> may for example be placed within a wall dividing two rooms and allow for access from each of the two rooms. This may be advantageous in certain environments where unwashed laundry and washed laundry may not be kept in the same room, for example in certain hospital environments.

Further details regarding the washing machine <NUM> and plausible embodiments will follow with reference to the remaining Figures.

The washing machine <NUM> in <FIG> comprises a stationary drum <NUM> and an inner drum <NUM> arranged within the stationary drum. The inner drum <NUM> is rotatably arranged around an axis of rotation A. Both the inner drum <NUM> and the stationary drum <NUM> are concentric around the axis A.

The stationary drum <NUM> comprises two doors <NUM> covering two first openings (not shown). The doors may have a safety element each attached in accordance with the invention and described with reference to the remaining Figures.

The washing machine <NUM> disclosed in <FIG> has two doors <NUM> and is a side-loaded washing machine <NUM>. However, it is understood that possible embodiment of the invention includes top-loaded, side-loaded with one door, front-loaded or any other type of conventional washing machine.

In the following Figures, details regarding features of the washing machine <NUM> will be discussed.

With reference to <FIG> an exemplary first safety element <NUM> in accordance with an embodiment of the present invention is disclosed.

<FIG> discloses a section of a washing machine <NUM>, for example the washing machine <NUM> as described with reference to <FIG>.

The washing machine <NUM> comprises a stationary drum <NUM> comprising a first opening <NUM>. The first opening <NUM> is placed in the curved surface of the stationary drum. The washing machine further comprises a door <NUM>, shown in an opened position, to cover the first opening <NUM>. The washing machine <NUM> further comprises an inner drum <NUM> rotatably arranged around an axis of rotation A inside the stationary drum <NUM>. The inner drum <NUM> comprises a second opening (not shown) for accessing an interior of the inner drum. The inner drum <NUM> further comprises a hatch <NUM> configured to cover the second opening, and a locking mechanism <NUM> configured to secure the hatch <NUM> in a closed position. The washing machine <NUM> further comprises a first safety element <NUM> extending across the first opening <NUM> when the door <NUM> is closed. The first safety element <NUM> is arranged to provide a sliding surface 152a, 152b.

The placement of the second opening is such that it can be accessed through the first opening <NUM> when the inner drum <NUM> is rotated to a specific position.

The first safety element <NUM> provides a sliding surface 152a, <NUM> for guiding the hatch <NUM> on a smooth trajectory in case the hatch <NUM> accidentally opens during use of the washing machine <NUM>. The inner drum <NUM> and the stationary drum <NUM> may be circular cylinders and the smooth trajectory may be a circular trajectory. The sliding surface 152a, 152b may have a circular shape with the same radius as the stationary drum <NUM> and be arranged concentric about the axis A.

The hatch <NUM> may accidentally open during use of the washing machine <NUM> in case the locking mechanism <NUM> fails or breaks. This may happen after heavy or repeated misuse of the washing machine <NUM>. The hatch <NUM> may also open during use in case the locking mechanism <NUM> has not been secured properly. Such a failure may cause various problems which the safety element <NUM> at least partially solves.

The first safety element <NUM> of the washing machine <NUM> disclosed in <FIG> comprises two safety element segments 155a, 155b. The two safety element segments 155a, 155b each comprise a first sliding surface segment 152a, 152b bridging the first opening in a tangential direction of rotation of the inner drum <NUM>. The safety element segments 155a, 155b are arranged to engage with the hatch <NUM> in case it opens during rotation of the inner drum <NUM> so that the hatch <NUM> does not get stuck on the edges of the first opening <NUM>. It is understood that there could be less or more than two safety element segments 155a, 155b.

The sliding surface 152a, 152b of <FIG> has a circular shape with the same radius as the stationary drum <NUM> and is arranged concentric about axis A, when the door <NUM> is closed. It is however understood that the sliding surface 152a, 152b may have other shapes depending on the shape of the stationary drum <NUM>. In case the stationary drum <NUM> is elliptically cylindric, the shape of the sliding surface 152a, 152b, may be configured to match this. The stationary drum <NUM> may also be arranged about a second axis than the axis A which the inner drum <NUM> is arranged about, then the sliding surface 152a, 152b may be concentric about this second axis. This ensures that the first opening <NUM> is bridged by the sliding surface 152a, 152b and the tangential path along the surface of the stationary drum <NUM> is completed across the first opening <NUM> which decreases the risk for the hatch <NUM>, in case it accidentally opens during use, to get stuck during rotation.

The hatch <NUM> further comprises at least one protruding rib <NUM>. The at least one protruding rib is arranged to engage the first safety element <NUM> if the hatch <NUM> accidentally opens during use of the washing machine <NUM>. The protruding ribs <NUM> may have a width of at least <NUM> millimeters depending on the material they are made from. An increasing width may be advantageous in that the wear will decrease on the ribs <NUM>.

Each of the first sliding surface segments 152a, 152b are preferably extending in a plane defined by a circular trajectory of one of the at least one protruding ribs <NUM> when the inner drum <NUM> is rotating. This ensures that the protruding ribs <NUM> are engaging the at least one first safety element <NUM> in case the hath <NUM> opens during use.

The at least one protruding rib <NUM> may extend further outward in a radial direction from the axis A than the locking mechanism <NUM>. In particular the at least one protruding rib <NUM> may extend further outward radially than the locking mechanism <NUM> in the situation when the hatch <NUM> is opened to the degree that any of its elements touches either the stationary drum <NUM> and/or the first safety element <NUM>. This so that the at least one protruding rib <NUM> engages the stationary drum <NUM> and/or the first safety element <NUM> in case the hatch <NUM> accidentally opens during use of the washing machine <NUM>.

The washing machine <NUM> further comprises a door <NUM>. In <FIG> the door <NUM> is shown in an opened position. The door <NUM> is arranged to cover the at least one first opening <NUM> when the door <NUM> is in its closed position. The first safety element <NUM> is attached to the at least one door <NUM>. It is understood that the washing machine <NUM> may comprise two first openings <NUM> and two doors <NUM> covering the openings <NUM>. It is further understood that one first safety element <NUM> may be attached to each door <NUM>.

The locking mechanism <NUM> may be of different kinds depending on the embodiment and type of washing machine <NUM>. It may for example by a hook and loop solution, or any other locking mechanism <NUM>.

In <FIG>, the hatch <NUM> comprises two hatch doors 132a, 132b but it is understood that other hatch designs are plausible.

The washing machine <NUM> according to the invention may be used in the following manner. Firstly, the inner drum <NUM> may be loaded with laundry while the hatch <NUM> is in an open position. When the inner drum <NUM> has been loaded the hatch <NUM> may be closed and the locking mechanism <NUM> may be used to secure the hatch <NUM> in its closed position. The door <NUM> may then be closed. When closing the door <NUM> the first safety element <NUM> will be placed so that it is extending across the first opening <NUM> providing a sliding surface <NUM>. The washing machine <NUM> may then be started. During rotation of the inner drum <NUM> the hatch <NUM> may accidentally open due to different reasons. In case this happens the hatch <NUM> will engage the stationary drum <NUM> and the at least one first safety element <NUM> during rotation. The sliding surface 152a, 152b will ensure that the washing machine <NUM> does not get damaged. Preferably the washing machine further comprises a sensor as described throughout the application. The sensor may detect that the hatch <NUM> has opened and a control unit may shut down the washing machine <NUM>.

With reference to <FIG> an exemplary first safety element in accordance with an embodiment of the present invention is disclosed.

<FIG> discloses a section of a washing machine <NUM> with at least one first opening in a stationary drum <NUM> and at least one first safety element <NUM> extending across the first opening.

In both <FIG> the at least one first safety element <NUM> comprises an interlocking element 157a, 157b connected to the stationary drum <NUM> and arranged to interlock with the at least one first safety element <NUM>. The interlocking element 157a, 157b may be configured to slidably interlock with the at least one first safety element <NUM>.

In certain embodiments the interlocking element 157a, 157b may be connected to the stationary drum <NUM> and arranged to interlock with the safety element segments 155a, 155b of the at least one first safety element <NUM>. In certain embodiments the safety element segments 155a, 155b may comprise slots extending along the safety element segments 155a, 155b. The interlocking element 157a, 157b may be arranged to interlock with the safety element segments 155a, 155b via these slots allowing it to be slidably interlocked with the safety element segments 155a, 155b.

As can be seen in <FIG> the interlocking element 157a, 157b comprises two interlocking parts 157a, 157b configured to slidably interlock with the first safety element <NUM>. In <FIG> one of the interlocking parts 157b is visible. The interlocking part 157b is rotary connected on one end to the stationary drum <NUM>. On the other end the interlocking part 157b is connected to the first safety element <NUM> by interlocking with one of the safety element segments 155b. The interlocking parts 157a, 157b are slidably connected to the safety element <NUM> which is advantageous when opening the washing machine <NUM>. The safety element <NUM> is connected to the door <NUM>, and when a user opens the door <NUM> the interlocking parts 157a, 157b easily slide in slots formed in the safety element segment 155a, 155b. Thanks to the rotary connection to the stationary drum <NUM> and the slidable connection to the safety element segment 155a, 155b, the interlocking part 157a, 157b is passively placed in the first opening <NUM> when the door <NUM> is closed and moved to the edge and out of the opening <NUM>, when the door <NUM> is opened.

The safety element <NUM> may be arranged so that the sliding surface <NUM> is arranged at a radial distance of <NUM> - <NUM> millimeters from the inner drum <NUM>. The safety element <NUM> may be constructed so that the sliding surface <NUM> completes the surface provided by the inside of the stationary drum <NUM>. A relatively small distance between the inner drum <NUM> and the hatch <NUM> is advantageous in case the hatch <NUM> accidentally opens during rotation of the inner drum <NUM>. Depending on the type and model of the washing machine <NUM> other radial distances may be advantageous.

With reference to <FIG> an exemplary washing machine <NUM> in accordance with an embodiment of the present invention is disclosed. The washing machine <NUM> disclosed in <FIG> may for example be the washing machine <NUM> disclosed in <FIG> but with open doors <NUM>.

The washing machine <NUM> comprises two doors <NUM> covering one first opening <NUM> each when closed. Attached to the two doors <NUM> are a first safety elements <NUM> each extending across the first openings <NUM> when the doors <NUM> are closed. It is advantageous but not essential that the safety elements <NUM> are attached to the doors <NUM> since it simplifies usage of the washing machine <NUM>, as the first safety elements <NUM> are passively moved out of the first openings <NUM> when the doors <NUM> are opened and placed in the openings <NUM> when the doors <NUM> are closed.

The washing machine <NUM> disclosed in <FIG> also comprises a heating box <NUM> configured to contain a heating element for heating water contained in the stationary drum <NUM>. The stationary drum <NUM> and the heating box <NUM> may be configured to be connected by a third opening (not shown) in the stationary drum <NUM>, through which the water can circulate freely between the inside of the stationary drum <NUM> and the heating box <NUM>.

The inner drum <NUM> of the washing machine <NUM> comprises two hatches <NUM> configured to cover the second openings (not shown) in the inner drum <NUM>. It is understood that an embodiment with two doors <NUM> and two first safety elements <NUM> may comprise an inner drum <NUM> with only one hatch <NUM>. The placement of the second openings is such that it can be accessed through the first opening <NUM> when the inner drum <NUM> is rotated to a specific position.

The washing machine <NUM> comprises a sensor <NUM> configured to detect if at least one first safety element <NUM> is in contact with one of the hatches <NUM>. The sensor <NUM> is arranged on the stationary drum <NUM> or on the frame around the at least one first opening <NUM>, facing one of the two first safety elements <NUM>. It is understood that there might be more than one sensor <NUM> and two similar, or two different sensors may be used two detect if any one of the first safety elements <NUM> is in contact with one of the hatches <NUM>.

With reference to <FIG> a sensor arrangement in accordance with an embodiment of the present invention is disclosed.

The washing machine may comprise a sensor <NUM> configured to detect if at least one safety element is in contact with the hatch <NUM>. The washing machine may further comprise a control unit <NUM> configured to turn off the washing machine when the sensor detects a contact between the at least one first safety element and the hatch <NUM>. The control unit <NUM> may further prevent any new start of the washing machine <NUM> before the at least one first safety element is restored to its original configuration.

Different types of sensors <NUM> are possible to achieve the objective of the invention. <FIG> discloses an embodiment that is preferred. The at least one safety element, more details are found throughout the application, may comprise a spring element <NUM>. The spring element <NUM> may be configured to be released by the hatch <NUM> in case the hatch <NUM> accidentally opens during use of the washing machine. The sensor <NUM> may be an inductive sensor configured to detect the spring element <NUM> being released.

The spring element <NUM> may be kept in place by screws <NUM>. In case the hatch <NUM> opens while the inner drum of the washing machine is rotating, the screws <NUM> may be beheaded, i.e. part of the screws <NUM> may be mechanically removed by the hatch <NUM> so that the spring element <NUM> is released. It is preferable if the screws <NUM> are made of a material that can be easily broken by the hatch <NUM>, for example a plastic material. There may be more than two screws <NUM>. There may also be less than two screws <NUM>. It is also understood that other solutions may be available.

There are other solutions present for detecting in case the hatch <NUM> is in contact with one of the at least one safety element. The sensor <NUM> may for example be an inductive sensor configured to detect a displacement of the at least one first safety element. The displacement may be a result of the hatch <NUM> accidentally opening during use of the washing machine and pressing on the at least one first safety element.

The sensor <NUM> may also be configured to detect a displacement of certain parts of the at least one first safety element. For example, the sensor <NUM> may be configured to detect a displacement of the interlocking element 157a, 157b.

With reference to <FIG> an exemplary second safety element <NUM> is disclosed. <FIG> discloses a washing machine according to the invention where the inner drum has been removed in order to explain certain features. <FIG> shows a detailed view of certain features present in <FIG>.

The stationary drum <NUM> may comprise a third opening <NUM>. The washing machine may comprise a heating box <NUM> configured to contain a heating element for heating a content of the stationary drum <NUM> via the third opening <NUM>. The washing machine may further comprise a second safety element <NUM> extending across the third opening <NUM>. The second safe element <NUM> is arranged to provide a second sliding surface 197a, 197b.

The second safety element <NUM> may comprise at least two metal strips 195a, 195b extending across the third opening <NUM>. Each of the at least two metal strips 195a, 195b may comprise a second sliding surface segment 197a, 197b bridging the third opening in a tangential direction of the inner drum. Depending on the shape of the stationary drum <NUM> the shape of the second sliding surface segments 197a, 197b may vary. In the present embodiment they may each comprise a circular arc shaped surface with the same radius as the stationary drum <NUM> and be arranged to face the inner drum.

Each of the second sliding surface segments 197a, 197b may be extending in a plane defined by a circular trajectory of one of the at least one protruding ribs when the inner drum is rotating. In case the hatch of the inner drum opens during rotation the protruding ribs will engage the second sliding surface segments 197a, 197b during rotation which is preferable and advantageous.

In <FIG> the protruding ribs <NUM> are extending further outward in a radial direction from the axis of rotation of the inner drum <NUM> than the locking mechanism <NUM>. This is to ensure that the at least one protruding rib <NUM> engages the stationary drum <NUM> or the at least one first safety element in case the hatch <NUM> accidentally opens during use of the washing machine. It is also understood that in other embodiments the locking mechanism <NUM> or other parts of the hatch <NUM> may extend further outwards in a radial direction from the axis of rotation of the inner drum <NUM>. However, the at least one protruding rib <NUM> preferably extends further outward in a radial direction from the axis of rotation A than said locking mechanism <NUM> and any other part of the hatch <NUM> when the hatch <NUM> is in an open position and the at least one protruding rib <NUM> engages the at least one first safety element <NUM> and/or the stationary drum <NUM>. Depending on the embodiment, the locking mechanism <NUM> may extend further outward in a radial direction from the hatch <NUM> when the hatch <NUM> is closed, but the at least one protruding rib <NUM> may still be the part of the hatch <NUM> engaging the at least one safety element <NUM> or the stationary drum <NUM> in case the hatch <NUM> opens during use.

The locking mechanism <NUM> disclosed in <FIG> is a hook and loop type solution, however other locking mechanisms <NUM> are possible.

In <FIG> the hatch <NUM> has accidentally opened during rotation of the inner drum <NUM>. As can be seen in the Figure one of the at least one protruding ribs <NUM> is engaging the at least one first safety element <NUM>.

The at least one protruding rib <NUM> extends further outward in a radial direction from the axis of rotation A than said locking mechanism <NUM> and any other part of the hatch <NUM> when the hatch <NUM> is in an open position and the at least one protruding rib <NUM> engages the at least one first safety element <NUM> and/or the stationary drum <NUM>.

Claim 1:
A washing machine (<NUM>) comprising;
a stationary drum (<NUM>) comprising at least one first opening (<NUM>);
an inner drum (<NUM>) rotatably arranged around an axis of rotation (A) inside said stationary drum, comprising;
a second opening (<NUM>) for accessing an interior of said inner drum;
a hatch (<NUM>) configured to cover said second opening; and
a locking mechanism (<NUM>) configured to secure said hatch in a closed position;
characterized in that the washing machine further comprises at least one first safety element (<NUM>) extending across said at least one first opening, and said hatch comprises at least one protruding rib (<NUM>) arranged to engage said at least one first safety element, wherein said at least one first safety element is arranged to provide a sliding surface (152a, 152b) for guiding said hatch on a smooth trajectory in case said hatch accidentally opens during use of said washing machine.