VACUUM CLEANER COMPRISING AN INTEGRATED CIRCUIT PRESSURE SWITCH

The present invention relates to a vacuum cleaner and a pressure switch device for a vacuum cleaner.

Vacuum cleaners are widely used appliances, particularly house ^¬ hold appliances, which use an air pump to create a partial vacu- urn to suck up dust and dirt, usually from floors, and optionally from other surfaces as well.

The dirt is collected by a dust bag, filter or a cyclone for later disposal. Vacuum cleaners, which are used in homes as well as in industry, exist in a variety of sizes and models — small battery-operated hand-held devices, domestic central vacuum cleaners, canister vacuum cleaners, upright/stick vacuum cleaners and robotic vacuum cleaners.. Usually the filter, dust compartments or dust bag is filled, polluted or clogged during operation of the vacuum cleaner. As such filters, cyclones or dust bags are usually arranged inside the vacuum cleaner the degree of pollution or filling level may be hardly achieved by user's eye inspection.

The performance of the vacuum cleaner, particularly the suction level and/or the capacity for further intake of dust and dirt, is, however, dependent on the filling level or degree of pollu ^¬ tion of the dust bag and/or the filter, respectively.

It is known to provide a sensor to indicate the degree of fill ^¬ ing of such dust bag and/or the degree of pollution of such filter. Such sensors, however, are often complicate, expensive and/or difficult to install or to exchange; usually the motor power can be controlled to provide a predefined vacuum and/or air-flow on the vacuum nozzle and/or the intake duct and/or connected parts. Document US 4,514,874 describes a device for automatically con ^¬ trolling the suction power of vacuum cleaner. Thereby a diaphragm-actuated switch is so arranged in the vacuum region of the vacuum cleaner that, depending on the variation in the air pressure as a result of external operation conditions, a con- tacting is produced which leads to a switching of the speed con ^¬ trol range of the vacuum cleaner motor. However, this document discloses a relatively complicated and relatively fragile switch, which consists of a multitude of parts, particularly a relatively fragile tensioning spring, and which is relatively complicate and neither cheap to manufacture nor easy to assemble in the vacuum cleaner.

It is an object of the present invention to provide a vacuum cleaner having a pressure switch, which in particular may be easy and cheap to manufacture and assemble in the vacuum clean ^¬ er .

These and other problems are solved by the subject-matter of the attached independent claims.

Particularly, the above objects of the invention are achieved by a vacuum cleaner according to claim 1 and a pressure switch device for such vacuum cleaner according to claim 15. Preferred embodiments may be taken from the dependent claims. A vacuum cleaner according to claim 1 comprises a vacuum system for guiding through and removing dust and debris from suctioned air, and a pressure switch device which comprises at least one electronic pressure switch capable of switching from a first switch position to at least one second switch position.

The pressure switch device is arranged such that at least one pressure sensitive surface of the pressure switch is in fluid communication with a section of the vacuum system of the vacuum cleaner .

The section of the vacuum system may for example be a dust col ^¬ lection chamber, implemented for example as a dust-bag based chamber or as a dust-bag less collection chamber, a section of a ducting of the vacuum system, e.g. an inlet or outlet duct, a section or chamber containing a filter element, in particular fine filter element.

In embodiments, several, e.g. two, integrated circuit pressure switches may be provided in different sections of the vacuum system, in particular to be able to identify, by corresponding switching signals of the switches, different operational situa ^¬ tions and conditions of the vacuum system of the vacuum cleaner.

The electronic pressure switch is implemented as an integrated circuit pressure switch, or pressure sensor, which in particular shall mean that the electronic pressure switch may be implement ^¬ ed on a printed circuit board, in particular in form of a digi ^¬ tal integrated circuit pressure switch.

Switching from the first to the second switch position may result in an electric, in particular digital, switching signal, in particular related or assigned to a, e.g. predefined, operation ^¬ al condition of the vacuum cleaner. The at least one electronic pressure switch may comprise as the switching element an integrated on-board capacitive pressure switch element and/or an integrated on-board pressure sensitive conductive spring switch membrane. This in particular shall mean, that the capacitive switch element and/or spring switch membrane may be implemented as pressure sensitive, electronic switching components on a printed circuit board, in particular as part of the switch device.

The printed circuit board may comprise additional electronic components designed for signal handling and signal processing of electronic signals generated by the electronic pressure switch. The on-board pressure sensitive switching element may be elec ^¬ trically connected directly to the printed circuit board, for example by soldering. Soldering may be used both for mechanical ^¬ ly and electrically connecting the pressure sensitive switching element as such to the printed circuit board. In particular em- bodiments, the conductive spring switch membrane or element may be directly soldered to the printed circuit board.

The conductive spring switch membrane may be made from metal or at least partially from metal, comprising but not restricted to a copper alloy, in particular a bronze, such as for example a phosphor bronze.

The conductive spring contact membrane may be implemented as a (closed) cup spring membrane or similar.

Apart from being made from metal as a whole, the membrane may be implemented for example as a composite structure, comprising for example a non-metallic carrier and an electrically conductive metallic conductive, in particular sheet structure, in particu- lar layer or track. The conductive structure may be implemented such that a defined deformation of the switch membrane is suita ^¬ ble for establishing or interrupt an electrical contact between switching contacts, wherein the conductive structure may repre- sent one of the switching elements. A corresponding further switching contact may be implemented, for example, on a printed circuit board, associated with the switch membrane.

The spring contact membrane may be designed to be able to occupy two different, in particular exactly two different, predefined contact or switching states or conditions.

The spring contact membrane may be designed, for example by providing an adequate shape and/or spring stiffness and/or mem- brane wall thickness and/or membrane wall structure, such that transition between the contact states is associated, e.g. fixed ^¬ ly tied, to a predefined pressure or predefined pressure differ ^¬ ential, for example acting on or prevailing between corresponding pressure sensitive surfaces of the switch, in particular membrane .

Similarly, the capacitive pressure switch element may, but need not, be designed such that two different, in particular exactly two different, predefined switching states may be occupied.

The capacitive pressure switch element may be implemented such that transition between two or even more switching states corresponds to one or more predefined pressures or pressure differen ^¬ tials, for example acting on or prevailing between corresponding pressure sensitive surfaces of the switch or sensor.

The predefined pressure or pressure differential may be as ^¬ signed, for example by the manufacturer, to a specific opera- tional condition or state of the vacuum cleaner, in particular of the vacuum system of the vacuum cleaner.

The specific operational condition or state may for example be assigned to an operational error condition, for example selected from the group comprising maximum dust bag or dust chamber filling level reached, maximum dust bag clogging reached, maximum dust filter clogging reached, and others. The spring contact membrane may be attached to the printed cir ^¬ cuit board by soldering. One or more contact elements, in par ^¬ ticular switching contacts, may be provided and implemented on the printed circuit board such that the switching element may be electronically implemented on an associated printed circuit board being part of the pressure switch device. In particular, the pressure switch may be implemented as a circuit board mount ^¬ ed pressure switch

The pressure switch device is arranged such that at least one pressure sensitive surface thereof is in fluid communication with a section of the vacuum system. A pressure sensitive surface in particular shall mean a surface capable of bringing about or inducing a switching operation by the action of a certain relative or absolute pressure onto the surface. Thus, the term pressure sensitive in particular shall be related to the sensitivity as regards switching or bringing about a switching action or signal.

In specific embodiments, the pressure switch device may be im- plemented and arranged in the vacuum cleaner such that a first side of the pressure switch device, i.e. a first pressure sensi ^¬ tive side or surface, is in fluid communication with a first compartment of the vacuum cleaner, and a second side, i.e. a second pressure sensitive side or surface, of the pressure switch device is in fluid communication with a second compart ^¬ ment of the vacuum cleaner. Here, a pressure differential be ^¬ tween the first and second compartment may act on the switch and may trigger a switching action, for example in case that the pressure differential exceeds or is below a certain, for example predefined, threshold.

It shall be noted, that separate pressure switches may be as ^¬ signed to different sections or chambers of the vacuum system may. In this case, a pressure differential between respective sections or chambers may be determined from switching states of the pressure switches.

As an example, if a first switching device is associated with a chamber located downstream a dust bag chamber, and a second switching device is associated with a chamber located upstream the dust bag chamber, a comparatively low or even missing pres ^¬ sure differential may be indicative of a missing dust bag, whereas a comparatively high pressure differential may be indic- ative of a high filling level of the dust bag requiring ex ^¬ change .

In particular, the pressure switch may be arranged and associat ^¬ ed with a certain section of the vacuum system such that a first pressure sensitive surface is in fluid communication with the vacuum system, and that a second pressure sensitive surface is exposed to ambient pressure.

In embodiments, the pressure switch may be designed to be capa- ble of switching from the first switch position to the second switch position dependent on a predetermined pressure or pres ^¬ sure differential ΔΡ. The pressure switch in particular may be designed in such a way, that switching or a switching action oc- curs at or essentially at the predetermined pressure or pressure differential .

The pressure differential may relate for example to a pressure prevailing within the vacuum system relative to ambient pressure, or it may relate to a pressure differential prevailing be ^¬ tween different sections, e.g. chambers or compartments, of the vacuum system, for example located at different locations along or within the vacuum system. The pressure differential may for example be the difference between the pressure Pu of a first compartment in fluid communication with a first pressure sensi ^¬ tive surface, and the pressure Po of a second compartment in fluid communication with a second pressure sensitive surface, the surfaces associated either with a single pressure switch or with two or more separate pressure switches.

As regards embodiments having several pressure switches, it may be provided, that one or more pressure switches are implemented on the same printed circuit board.

The predetermined pressure or pressure differential may for ex ^¬ ample be based on empirical or experimental data related to op ^¬ erational conditions of the vacuum cleaner. In particular, one or more predetermined pressure or pressure differential values may be determined by the manufacturer for the vacuum system and pressure switches having switching conditions corresponding to the predetermined values may be mounted or provided in the vacu ^¬ um system of the vacuum cleaner. In this way, by monitoring respective switching elements of the pressure switches, presence or absence of the predetermined pressure or pressure differen ^¬ tial value or values can be determined. Based on respective de ^¬ termination, operation of the vacuum cleaner may be altered, e.g. in that operation is blocked and/or information related to an irregular operational condition of the vacuum cleaner is made available, for example on a display or user interface.

The vacuum cleaner as proposed, in particular comprising the pro- posed pressure switch device provides a comparative reliable and/or cost efficient way of equipping a vacuum cleaner with a unit or system for monitoring, based on operating pressures or pressure differentials, proper function and operation of the vacuum cleaner. The pressure switch device as proposed in par- ticular may easily be attached and assembled to or at or in re ^¬ spective sections of the vacuum system. Beyond that, compara ^¬ tively reliable results may be obtained by implementing the switches as integrated circuit pressure switches. Further, re ^¬ spective switches may easily be connected to or integrated in to the electronic control of the vacuum cleaner.

Switching states of the pressure switch, in particular corresponding to specific states defined by the predefined pressure/s and/or pressure differential/s, may be represented by electronic signals that may be processed by a decentralized data processing unit on the respective printed circuit board, or may be pro ^¬ cessed by a central processing unit of the vacuum cleaner. Sig ^¬ nals of the pressure switches and/or of the decentralized data processing units may be transferred to a data processing unit, e.g. implemented for example in connection with a user interface, via a wire-bound or wire-less connection.

Particularly, said vacuum cleaner and such pressure switch device allows for a direct sensing of a predetermined pressure and/or differential ΔΡ between the pressures prevailing in two different sections, in particular in two different compartments or in two different sections of a single compartment, of the vacuum cleaner, for example between the pressure Pu prevailing, e.g. during operation, within a first compartment and the pres- sure Po prevailing, e.g. during operation, within a second compartment .

As already indicated, a pressure differential ΔΡ may occur, for example, in case that a filter is clogged or polluted and/or in case that a dust bag or dust compartment reaches a certain de ^¬ gree of filling level.

Via the pressure switch, respective irregular operational condi- tions may be detected, e.g. by correspondingly observing the oc ^¬ currence of switch events or signals of the pressure switches.

Based on observed switch events, predefined actions may be per ^¬ formed by a control unit of the vacuum cleaner, such as for ex- ample providing for display to the user the irregular status of the vacuum cleaner and/or disabling operation of the vacuum cleaner and others .

The present inventor has found that the on-board pressure switches as proposed herein, in particular enabling the detection of pressure differentials ΔΡ may be useful to detect filter clogging and/or pollution and/or dust bag clogging and/or upper filling states of a dust bag or dust chamber. If a predetermined pressure differential ΔΡ is reached, the pressure switch may switch from the first switch position to the second switch position. Thereby, a switching signal may be generated indicative of a respective operational condition for which the pressure differential has been defined.

In embodiments, the at least one pressure switch or sensor, or the several pressure switches or sensors may be designed and specifically adapted to be operated such that a status, in par- ticular operational status of a section or compartment or cham ^¬ ber of the vacuum system may be observed or determined.

The operational status in particular may relate to a filling and/or clogging level and/or the presence or absence of a dust filter inlay or dust collecting bag or similar.

The pressure switch/es or sensor/s in particular may be adapted to observe, monitor and/or control cleaning efficiency and/or dust removal efficiency of the vacuum cleaner.

In particular, one or several pressure switches or sensors may be provided, in particular arranged in such a way, that a pres ^¬ sure distribution over at least a certain section of the vacuum system, in particular vacuum ducting, may be observed or monitored, for example in order to obtain information on proper functioning and cleaning efficiency of the vacuum cleaner.

The integrated circuit pressure switches may for example be in- terconnected via a wire-bound or wire-less network, in particu ^¬ lar to evaluate and monitor the pressure distribution over at least a section of the vacuum system and/or to determine adverse operational conditions related to clogging and/or overfill lev ^¬ els of filters, dust containers and/or dust bags.

As already indicated, it may be provided that at least two, i.e. two or more, pressure switches or sensors, are provided, dis ^¬ tributed over the vacuum system, in particular vacuum ducting system, in such a manner that the operational status as regards cleaning efficiency and dust removal may be determined.

The integrated circuit pressure switch or sensor may be config ^¬ ured such that it comprises a mounting surface suitable to mount the switch or sensor to a surface of the vacuum system. In embodiments, the mounting surface may be configured such that it can be attached, for example by gluing, to a surface of the vacuum system, in particular vacuum ducting. The switch or sensor may be further adapted to be mounted to an outer or external surface of the vacuum system while a pressure sensitive surface of the sensor or switch may be in fluid con ^¬ nection, via a bore in a wall of the vacuum system, with the fluid of the flow volume of the vacuum system.

In particular in embodiments it may be provided that only a pressure sensitive surface or at least a part of a pressure sen ^¬ sitive surface is in fluid connection with the vacuum system, whilst the other part of the sensor not being in fluid connec- tion with the vacuum system, but e.g. with ambient atmosphere.

In embodiments, it may be provided that at a predetermined pres ^¬ sure differential ΔΡ between a pressure Pu in a first compart ^¬ ment and a pressure Po of a second compartment of the vacuum system, in particular between air on a first and on a second side of the pressure switching device, a switching action from a first switch position to a second switch position, occurs.

In either the first or second switch position switch contacts of the pressure switch or sensor may be brought in contact with each other, allowing a current to flow and the generation of an active switch signal.

In a embodiments, the pressure switch or sensor may configured such that if no or no significant or essential pressure differ ^¬ ence between the pressure Pu of the first compartment and the pressure Po of the second compartment is detectable via the switch or sensor, the switch is in a first switch position. Further, if a significant, predetermined pressure differential ΔΡ between the pressure Pu of the first compartment and the pressure Po of the second compartment is present, e.g. an abso ^¬ lute pressure differential having a predetermined value signif- icantly above zero, switching from a first switch position to a second switch position may occur or be initiated, whereby pref ^¬ erably in such second switch position the contacts of such switch may are brought in contact, allowing an electric current to flow, and thus an electric signal to be generated.

In an embodiment, the pressure switch or sensor may be imple ^¬ mented to be capable of switching from a first switch position to a second switch position in dependency on a predetermined pressure differential ΔΡ, which may for example be associated with an over-pressure or an under-pressure as regards the pres ^¬ sure Pu of the first compartment on the first side relative to the pressure Po of the second compartment on the second side of the pressure switch device. In embodiments, the pressure switch may be implemented as a make contact switch or a break contact switch, preferably a single- throw make contact switch or a single-throw break contact switch . In embodiments in which the pressure switch is implemented as a make contact switch, i.e. enables switching from a first switch position to a second switch position, a corresponding switching action may involve bringing electrical contacts of the switch together or disconnecting respective contacts.

In particular, the switch may be implemented as an OFF/ON- switch, representing for example a digital 1/0 switch. In particular, in a second switch position the contacts of the switch may be in contact, allowing a current to flow and/or a switching signal to be generated.

In embodiments, it may be provided that as long as the predeter- mined pressure and/or pressure differential ΔΡ is present, ex ^¬ ceeded and/or has fallen below the predetermined pressure dif ^¬ ferential, the pressure switch may be in the second switching position (ON) or in a first switch position (OFF) , or vice versa. The current will flow through the thus contacted contacts.

In embodiments in which the pressure switch is implemented as a break contact switch, switching from the first switch position to the second switch position may comprise a switching operation from an ON-state to an OFF-state. In other words, in the first switch position, electric contacts of the switch may be brought or may be in electrical contact, allowing for example an elec ^¬ trical current to flow.

As long as the predetermined pressure differential ΔΡ is present or exceeded urging the pressure switch to the first switching position (ON-state) electrical current can flow through the con ^¬ tacts electrically contacting each other. A corresponding switch signal or current may be used to identify or detect presence of the pressure differential.

In embodiments, an electronic control unit may be provided, as ^¬ sociated with the at least one pressure switch device and con ^¬ figured to handle and process switching signals, in particular digital switching signals and/or switching currents.

The control unit may be adapted to provide for display an opera ^¬ tional condition associated with the switching status of the at least one pressure switch. If, for example, a certain pressure or pressure differential de ^¬ fined for the dust bag compartment and indicative of a high filling level of the dust bag impairing adequate vacuuming, an indication may be provided for display on a user interface, the indication indicating a high filling level or prompting the user to exchange the dust bag.

Similarly, a respective operation of the control unit may be provided in connection with a pressure switch device associated with a dust filter and indicating upon switching filter clogging .

In embodiments, the pressure switch device may be implemented such that the predetermined pressure differential ΔΡ upon which the pressure switch executes a switching action from the first switch position to the second switch position, is an underpressure in which a pressure acting on the second side of the pressure switch device is lower than a pressure acting on the first side of the pressure switch device.

In embodiments, the pressure switch device may be implemented such that if no or no significant pressure differential is pre ^¬ sent or in case that the pressure differential is below a de ^¬ fined threshold, the switch may be in a first switch position, and in case that a predetermined pressure differential ΔΡ is reached fulfilling the predetermined switching condition of the pressure switch device, a switching action from the first switch position to a second switch position may be triggered and a cor ^¬ responding switching signal may be generated indicative of the presence of the predetermined pressure or pressure differential.

The pressure differential may for example prevail between a first compartment and a said second compartment of the vacuum cleaner or between a compartment or section of the vacuum system of the vacuum cleaner and the environment.

In an embodiment, the predetermined pressure differential ΔΡ may be characterized or defined such that a pressure Pu in a first compartment of the vacuum system of the vacuum cleaner is higher than a pressure Po of a second compartment of the vacuum system or external thereto. In particular, the pressure differential may be associated with a pressure differential between two different compartments of the vacuum system, or between a first compartment of the vacuum system and a second compartment external to the vacuum system. In particular, the second compartment may be related to ambient pressure, e.g. the second compartment may be in fluid communica ^¬ tion with the atmosphere surrounding the vacuum cleaner. The first compartment may be a dust bag compartment or a dust cham ^¬ ber or a dust filter section, an air channel before or after the dust bag compartment or the dust chamber or filter section of the vacuum cleaner, or vice versa.

The predetermined pressure differential ΔΡ under this provision may reflect an under-pressure in the first compartment, i.e., for example, in the dust bag compartment or the dust chamber or filter section, or an air channel before or after the dust bag compartment or the dust chamber or filter section of the vacuum cleaner, as compared to ambient pressure. As already indicated, in embodiments, the second or first com ^¬ partment may be a compartment being in fluid communication with the ambient atmosphere surrounding the vacuum cleaner and the first or second compartment may be a dust bag compartment of the vacuum cleaner or a dust chamber of the vacuum cleaner or a dust filter section of the vacuum cleaner, or an air channel before or after the dust chamber or before or after the dust bag compartment or before or after a dust filter section of the vacuum cleaner .

In embodiments the pressure switch device, particularly the pressure switch, may comprise a printed circuit board having a through hole. The through hole may, in embodiments, be adapted in structure and/or size such that it may provide, in terms of fluid technology, a passageway reaching through the printed cir ^¬ cuit board. Additional layers or structures arranged in parallel with the printed circuit board may comprise corresponding through holes, holes or openings adapted to enable a passageway or conduct reaching through from one side of the pressure sensor to the other.

The pressure switch may in embodiments be connected to the printed circuit board such that at least a section of the pres ^¬ sure switch device, in particular the pressure switch, in par- ticular a pressure sensitive surface of the pressure switch, co ^¬ vers or overlays or communicates with the through hole.

In embodiments, the pressure switch device may be configured such that the pressure switch device, in particular pressure switch, is connected to a first side of the printed circuit board. In particular, a through hole or associated passage may be provided such that a pressure sensitive section or surface of the pressure sensor fluidly accessible, i.e. accessible in terms of fluid technology, from a second side averted from the first side, while, preferably, a further pressure sensitive section or surface being fluidly accessible from the first side.

The pressure switch may be connected in such a way to the print ^¬ ed circuit board, that a pressure sensitive surface faces and directly communicates with the through hole and, as regards flu ^¬ id communication, is accessible through the through hole from a second side averted from the first side. In embodiments, a or the second side, in particular of the printed circuit board, averted from the first side, or in more general terms a side averted from the mounting side of the pres ^¬ sure switch on the printed circuit board, may comprise or pro ^¬ vide means for attaching the pressure switch device to, for ex- ample, a surface. The means for attachment may comprise any type of attachment including gluing, bonding, heat sealing, snap- fitting, locking in place and similar.

In embodiments, the through hole may be designed and implemented on the printed circuit board in such a way that it can be over- layed and aligned with a corresponding hole in a wall of the vacuum system, for example such that the pressure switch, in particular the pressure sensitive surface of the pressure switch is, as regards fluid communication, accessible via the hole in the wall and through hole in the printed circuit board.

In particular, it may be provided to attach the pressure switch device to an outer side of a wall adjacent to or partitioning off a compartment, chamber or section intended for pressure or pressure differential monitoring, while being able to fluidly connect the pressure sensitive surface of the pressure switch with the inner volume of the compartment, chamber or section.

The wall may be an outer wall of the vacuum system. In particu- lar in the latter case, it may be of advantage that the pressure sensor or switch device, in particular pressure sensor or switch, including for example the printed circuit board, can be mounted external to the vacuum system, to thereby shield the switch or switch device at least to a major extend from dust swirling through the vacuum system during use of the vacuum cleaner .

For example, a first side of the pressure switch device may be in fluid communication with the second compartment associated with ambient pressure, whereas the through hole may be aligned with a hole in a wall surrounding the first compartment to thereby fluidly connect a second, pressure sensitive side of the pressure switch device with the interior of the first compart- ment .

Accordingly, the pressure switch device is capable of monitoring or sensing the pressure differential ΔΡ between the first and second compartment of the vacuum cleaner. If a predetermined pressure differential ΔΡ is reached, the pressure switch is ca ^¬ pable of switching from the first switch position to the second switch position.

Practically speaking, the through hole in the printed circuit board may be regarded as a type of through-connection in terms of flow technology.

In embodiments, the pressure switch device may be designed and may comprise attachment means, in particular as described fur- ther above, and/or sealing elements and/or a sealing structure such that the pressure switch device can be fluid-tightly, in particular pressure-tightly as regards suction pressures pre ^¬ vailing within the vacuum system of the vacuum cleaner, attached to a surface of the vacuum system. In particular in such embodi- ments, a hole in a wall of the vacuum system may be used to mon ^¬ itor the pressure or pressure differential inside the vacuum system with the pressure switch device being mounted external and fluid-tightly and pressure tightly sealing the hole in the vacuum system. As already mentioned, the pressure switch device may comprise, or at least be connected in terms of signaling technology, to a control unit.

The control unit may for example be located on the printed cir ^¬ cuit board, wherein the control unit may be adapted to handle and process output signals of the pressure switch device and, in particular may be adapted for execution of certain tasks in de- pendence of the output signals or processed output signals of the pressure switch device. For example, the control unit may control an output function of the vacuum cleaner and/or provide for presentation on a user interface an operational status of the vacuum cleaner.

In embodiments, the control unit may be adapted such that upon receiving a signal, e.g. a current or voltage signal, resulting from a switching action of the pressure switch device from a first switch position to a second switch position, where the first switch position may be an OFF switch position and the second switch position may be an On switch position, the control unit controls an output function of the vacuum cleaner and/or provides for display an operational status or executes other predefined tasks associated with the switching event, i.e. a pressure or pressure differential assigned to the switching event .

As already mentioned, the vacuum cleaner in embodiments may com ^¬ prise an output unit, e.g. a user interface, for example com- prising a display for displaying a vacuum cleaner functional parameter to a user. The output unit may be operatively connected to the control unit, and/or the control unit may be designed to operate the output unit in dependency of available switching signals or switching events. For example, a switching action of the pressure switch device, resulting for example in a current flow and/or voltage or current signal for example in a make contact switch, may be indica- tive for a pressure or pressure differential, e.g. an under ^¬ pressure as compared to ambient pressure, resulting from a full dust chamber and/or full dust bag and/or a clogged filter.

The control unit may receive a respective current or a signal and may, based on the signal or current, control the output unit accordingly, e.g. generate an output signal to the output unit.

For example, the output unit may be designed to be able to dis ^¬ play to the user of the vacuum cleaner functional parameters or an information item associated with the vacuum cleaner functional parameter representative for the observed switching action.

For example, the user interface may indicate that the dust bag is full and/or needs to be emptied or exchanged.

In other words, depending on the particular switch position or switching state of the pressure switch device and/or depending on the sensed signal, the control unit may provide for display a corresponding message on the display to the user, particularly, whether the dust bag and/or the filter are full and needs to be replaced .

Additionally, or alternatively, such control unit may control the active control of the vacuum or vacuum system. In particu- lar, the suction power of the vacuum cleaner may be controlled by the control unit dependent on switching signals or switching events of the pressure switch device. For example, the control of an output function of the vacuum cleaner may be an adaption of the suction power or air-flow, for example at the nozzle and/or the intake duct. The control unit may be implemented to be able to respond auto ^¬ matically to an increasing amount of dust in the dust bag or in ^¬ creased filter clogging in the vacuum cleaner vacuum system.

Additionally or alternatively, the control unit may allow to regulate or control given power of the vacuum cleaner motor depending on the existing vacuum and/or the predetermined pressure and/or predetermined pressure differential ΔΡ.

In particular, the control unit may inactivate or modify opera- tion of the vacuum cleaner in case that one or more switching states of the pressure sensor device is/are indicative of irreg ^¬ ular operational conditions, such as upmost dust bag or dust compartment filling level and/or upmost filter clogging. Further, the control unit may regulate a speed of the blower motor of the vacuum cleaner to avoid motor overloads.

In embodiments, the pressure switch may be implemented as digi ^¬ tal switch, in particular a switch outputting or generating a digital signal.

In embodiments, the pressure switch may be implemented as a two position digital switch, i.e. a switch configured for outputting two digital values, such as ON and OFF, or "1" and "0". In embodiments the spring switch membrane may be configured for switching between the first switch position and the second switch position through a predefined elastic deformation, in particular associated with the predefined pressure or pressure differential. The predefined elastic deformation may be defined or set by the shape of the spring switch membrane. In particu ^¬ lar, it is considered possible, to adapt the shape of the spring switch membrane to obtain a switching action at a predefined pressure or pressure differential.

In embodiments, the spring element may be configured such that the predefined deformation of the spring switch membrane, repre ^¬ senting a spring switch element, comprises a buckling, a snapping change of shape, or similar, at the predetermined pressure or predetermined pressure differential ΔΡ.

A respective predefined deformation may be associated with es ^¬ tablishing (making-contact) or breaking (breaking contact) bridging electrical connection between first and second switch- ing contacts, and/or a first track, for example a first track on a printed circuit board, and a second track, for example a sec ^¬ ond track on the printed circuit board, preferably annular tracks on the printed circuit board. It may be, that the deformation of the spring element, particu ^¬ larly a buckling of the spring element, is caused by the prede ^¬ termined pressure differential ΔΡ, preferably passively by an under-pressure . More preferably, such spring element in an ON switching position is capable of bridging electrical connection between annular tracks on a printed circuit board.

In embodiments, bridging electrical contacts may be established by a predefined deformation of a spring switch membrane made, at least in part, from electrically conductive material to thereby electrically contact a switching contact of the pressure switch. In particular, the membrane may represent a switch contact of the pressure switch device. The spring switch membrane therefore may be considered or be im ^¬ plemented as a first switching contact suitable for establishing electric contact with a second switching contact. The second switching contact may be implemented as an electric contact ele ^¬ ment, e.g. a track, on the printed circuit board.

However, the pressure switch device may also be implemented such that deformation or restoration of the ordinary form of the spring switch membrane causes two switch contacts different from the spring switch membrane to be contacted or released.

In embodiments, the spring switch membrane may be positioned such that a pressure differential ΔΡ between a pressure sensi- tive first side and a pressure sensitive second side of the pressure switch device causes the predefined deformation when reaching or exceeding the predetermined pressure differential ΔΡ. Shape changes at the membrane such as for example buckling, snapping and/or flipping may be involved.

The shape change may cause that contacts of the switch are broad in direct contact, preferably resulting or enabling in a flow of current through the contacts and/or the generation of a current and/or voltage signal. In particular, the spring element may be configured such that a predefined deformation, e.g. flip, snap and/or buckling, action of the spring element occurs if a prede ^¬ termined pressure differential ΔΡ is reached or exceeded.

It is to be understood that contacts of the pressure switch are preferably brought in contact by the predefined deformation, e.g. flipping, snapping and/or buckling, of the spring. Thereby it is preferred that at least one of the pair of contacts, which are to be brought in contact, is arranged at or on the spring element, wherein a second contact may be a stationary contact, which may for example be located on or at the printed circuit board, the plastic laminate of the printed circuit board, a part of the mechanical vacuum cleaner assembly, or the like, or in more general terms on or at a carrier element of the pressure switch or pressure switch device.

In embodiments having a make-contact configuration, it is to be understood that as long as the predefined pressure differential ΔΡ acts on the pressure switch, the pressure switch keeps its corresponding switching configuration enabling or disabling current flow and/or the generation of current and/or voltage sig ^¬ nals .

In embodiments the proposed switching device may allow for a relatively simple and cheap implementation and design of a pres ^¬ sure switch device. Further, in embodiments, comparatively easy mounting and attachment of the pressure switch device may be ob- tained.

In embodiments the spring switch element or membrane, or at least a part thereof, may be manufactured from a conductive ma ^¬ terial, particularly a metal, more particularly a metal selected from the group comprising metal alloys, copper alloys, bronze, phosphor bronze.

In particular such materials allow using the spring switch membrane as such as a switching contact of the pressure switch.

In embodiments, a predefined deformation, e.g. buckling, snap ^¬ ping and/or flipping, switching the pressure switch from a first switch position (e.g. OFF) to a second switch position (e.g. ON) allows contacting or disconnecting the spring, more precisely the part of the spring serving as switch contact, to a second contact of the pressure switch.

In an embodiment, the spring switch membrane may have a dome shape, cup or disc-spring type shape.

In embodiments, the shape of the spring switch membrane may re ^¬ semble a hollow upper half of a sphere, and may have a continu ^¬ ous, in particular round, preferably circular, base or base ar- ea, preferably lying in a single plane.

The base area, e.g. an outer circumferential rim of the spring switch membrane, may be in contact with and/or fixed to the printed circuit board, whilst the remainder of the spring switch membrane may extend away from the printed circuit board.

In embodiments corresponding to a make contact configuration, where a switching action is a consequence of the presence of a predetermined pressure or pressure differential, it is possible, for example, to sense the predefined pressure or pressure dif ^¬ ferential ΔΡ between a first side and a second side of the pres ^¬ sure switch device, in particular the printed circuit board, by a switching action of the pressure switch from the first switch position to the second switch position.

In embodiments, a switching action may comprise moving a central part of the, for example dome shaped, pressure switch by a de ^¬ fined amount or distance towards a plane defined by the base of the spring switch membrane, for example having a dome shape.

The defined movement may be such that it allows establishing contact between the switching contact of the spring switch membrane and a counterpart switching contact, implemented for exam ^¬ ple on or at the printed circuit board. In embodiments, the capacitive pressure switch element may com ^¬ prise or be implemented as a capacitive sensor. The capacitive sensor in embodiments may be designed such that exposing the sensor to a predefined pressure or pressure differ ^¬ ential causes a detectable change in the electrical capacity of the sensor. The change in capacity may be detected and used as an indication for the presence and/or absence of the predefined pressure or pressure differential.

In embodiments related to capacitive sensors, the pressure switch, particularly the printed circuit board or other elements or layers, may represent or implement one or more capacitor plates of a capacitor. An under-pressure generated by the vacuum system or suction motor corresponding to a certain pressure or pressure differential may modify the distance between the capac ^¬ itor plates, thereby changing or altering capacitance. The capacitance may be considered to represent an analogue value of the pressure or pressure difference. A microprocessor or mi ^¬ crocontroller may be arranged and configured to monitor, observe and/or measure the capacitance and convert a change in the ca ^¬ pacitance to any ON/OFF signal or transduce the analog value in analogue, e.g. 0-lOV, or 4-20mA; or digital, e.g. PWM or serial, way .

In embodiments, the pressure switch device may comprise a seal ^¬ ing, in particular wherein a gap between a rim of the through hole, in particular the through hole of the printed circuit board, and the pressure switch is sealed, preferably essentially airtight sealed. The sealing in particular may be implemented such that a fluid-tight and pressure-tight connection as regards flow and vacuum technology related to the vacuum system of the vacuum cleaner is obtained.

A respective sealing may prevent, at least partially, that a pressure compensation between a first side and a second side of the printed circuit board associated with a different pressure and measurement environments occurs.

In embodiments the sealing may be soldering joint, preferably a soldering joint fixing the pressure switch on the printed circuit board. The soldering joint may establish a mechanical and/or electrical connection between the pressure switch and the printed circuit board, in particular conductor track or pad of the printed circuit board. In embodiments, the sealing may be implemented as a soldering, in particular soldering bulge. The soldering or soldering bulge may for example be implemented as a direct connection between the printed circuit board and the con ^¬ ductive spring switch membrane. The soldering may provide a me ^¬ chanical, electrical as well as fluid tight connection.

In embodiments in which the pressure switch device and/or the pressure switch has a shape involving a continuous base region, as may for example be the case with dome-shapes, the base sec ^¬ tion, in particular a circumferential rim of the base section or at least a section thereof, may be soldered to the printed cir ^¬ cuit board such that the soldering joint is implemented as a fluid-tight, in particular pressure tight, sealing for the gap between a rim of the through hole and the rim of the base sec ^¬ tion. This advantageously may prevent, at least partially, that a pressure compensation between a first side and a second side of the printed circuit board associated with different measure ^¬ ment environments or chambers or compartments occurs. Using sol ^¬ dering for establishing fluid tight seal may be effective in re ^¬ ducing overall manufacturing effort and cost. In embodiments, the vacuum cleaner may be selected from the group comprising canister vacuum cleaners, upright vacuum cleaners, stick type vacuum cleaners, handheld vacuum cleaners, and robotic vacuum cleaners.

A person skilled in the art will immediately acknowledge that the present invention may be advantageously applied to various different types of vacuum cleaners with only slight modifica- tion. Dependent on the particularly chosen vacuum cleaner type there are particular advantages in any equipment where vacuum or over pressure is used like air cleaner or any air conditioning system, vacuum cleaning machines like canisters, handhelds, up ^¬ rights/sticks, robotic vacuum cleaners or central vacs.

In embodiments, the pressure switch device may be arranged and implemented in or within the vacuum cleaner, in particular in the vacuum system of the vacuum cleaner, such that the predetermined pressure or pressure differential ΔΡ between the pressure Pu of said first compartment and the pressure Po of said second compartment is indicative of and/or in relation to a degree of pollution, a degree of clogging and/or a filling level of at least one of a dust bag, dust collecting compartment and/or a filter placed in the vacuum cleaner.

A filter as referred to herein, may refer to a filter, e.g. an exhaust filter, eg. a "HEPA filter", which is positioned after the motor to clean the output airflow from remaining fine dust and/or carbon brush emission.

In embodiments, the pressure switch device may be arranged in or at a wall or wall element arranged adjacent to a flow volume or section, in particular an inner flow volume or section of the vacuum system. In embodiments, the or a wall or wall element may be implemented to separate a first compartment of the vacuum system from a sec ^¬ ond compartment of the vacuum system or the vacuum cleaner, in particular of a casing of the vacuum cleaner. The second com- partment, for example, may be arranged outside or external to the flow volume of the vacuum system and may be fluidly connect ^¬ ed with ambient environment of the vacuum cleaner.

In embodiments, the wall or wall element comprises a through hole and a pressure switch aligned with the through hole such that at a pressure sensitive section or surface of the pressure switch is fluidly accessible through the through hole.

The pressure switch device, in particular the pressure switch, may be connected to a wall or wall element such that the through hole is aligned with a corresponding hole in the wall or wall element. The alignment and structure and design may be such that that a pressure sensitive section of the pressure sensor is, as regards fluid technology, fluidly accessible through a passage- way defined by the through hole and the hole in the wall or wall element .

The pressure switch device may be arranged to fully cover the through hole such that the pressure switch is in fluid communi- cation with a first compartment and in contact with the fluid on a first side of the pressure switch, whereas the through hole advantageously allows that the pressure switch is also in direct contact with the air or fluid on a second side of the pressure switch device, i.e. is in fluid communication with a second com- partment of the vacuum cleaner. Accordingly, the pressure switch device may be implemented to be capable of sensing the pressure differential ΔΡ between the first side of the pressure switch device being in fluid communication with the first compartment and the second side of the pressure switch being in fluid commu- nication with the second compartment, different from the first compartment of the vacuum cleaner.

In embodiments, if during operation of the vacuum cleaner, a predetermined pressure differential ΔΡ is reached or exceeded, the pressure switch is capable of switching from a first switch position to a second switch position. A hole present in the printed circuit board of the pressure switch device may be ar ^¬ ranged to overlap the hole in the wall or wall element, allowing for a fluid communication of the pressure switch device with the compartment through both the through hole in the printed circuit board and hole in the wall or wall element.

In embodiments, the pressure switch device may be attached to the wall or wall element with the through hole and hole in the wall or wall element arranged in overlapping arrangement such that a gap or space between the pressure switch device, e.g. the printed circuit board, and the wall is sealed air-tightly, pref ^¬ erably pressure-tightly as regards flow and vacuum technology of the vacuum system. In particular, the pressure switch may be glued to the wall or wall element, wherein the glue as such, for example implemented as a glue layer, functions as a tight seal ^¬ ing . In embodiments the pressure switch device may be arranged such the second compartment is a dust bag compartment or a dust cham ^¬ ber or a filter unit or an air channel before or after the dust bag compartment or the dust chamber or filter unit of the vacuum cleaner .

In embodiments, the pressure switch device may be arranged such that the second compartment is or is in fluid communication with the compartment comprising a dust bag, dust compartment and/or a filter unit arranged in the vacuum cleaner, wherein preferably the pressure switch device is arranged in or at a wall or wall element separating the compartment comprising a dust bag, dust compartment and/or a filter unit from a first compartment, and/or wherein the first compartment is or is in fluid communi- cation with an intake duct and/or nozzle channel and/or outlet duct .

Particularly, the or a wall or wall element to which the pres ^¬ sure sensor is attached to may be a wall or wall element of an inner compartment of the vacuum system of the vacuum cleaner, the inner compartment being in fluid communication with the compartment comprising a dust bag arranged in the vacuum cleaner.

A person skilled in the art knows, that in a usual vacuum clean- er the nozzle sucks air into the nozzle compartment, nozzle channel and/or the intake duct, where an underpressure occurs. The air further is blown/sucked into the dust bag. The air sucked into the dust bag is further sucked through the motor/fan unit and through the housing and out through the exhaust filter.

If the dust bag is clogged the airflow through the dust bag is limited. The limited air flow after the dust bag and a motor/fan unit running in the same way will increase the under-pressure prevailing in the flow volume after the dust bag. Such an under- pressure may lead to situations in which the pressure differen ^¬ tial exceeds a predefined switching pressure differential of the pressure switch. Exceeding the predefined pressure differential may lead to a switching action detectable by, for example a con ^¬ trol unit, and which may be indicative of the presence of the predefined pressure differential.

With a vacuum cleaner and, particularly with a pressure switch device, as proposed herein under-pressures , in particular ad ^¬ verse pressure states or conditions associated with certain op- erational states of the vacuum system of the vacuum cleaner, may advantageously be detected.

In particular, a pressure switch as proposed herein may be con- sidered suitable for switching from a first switch position to a second switch position dependent on specific pressure states or conditions prevailing within the vacuum system.

The pressure switch device and pressure switch may be designed in such a manner that switching is associated and tied to a pre ^¬ determine pressure or predetermined pressure differential ΔΡ, for example related to a pressure Pu of a first compartment and a pressure Po of a second compartment. In embodiments in which the conductive spring switch membrane is implemented as a dome-shaped spring, the membrane may be ar ^¬ ranged such that the side facing the printed circuit board is directed to and/or in fluid communication with a compartment or section of the vacuum system to be observed or monitored as re- gards the predetermined pressure or predetermined pressure dif ^¬ ferential .

In embodiments, the pressure switch device may be located in an area connected to a nozzle of the vacuum system. Switching sig- nals of the pressure switch devices may in embodiments be used to control the motor power, in particular suction power. In such case the vacuum cleaner may provide a predefined air flow on the nozzle. This is particularly advantageous to adjust and/or con ^¬ trol a desired cleaning performance, particularly if the dustbag is getting full, but reduce the vacuum with empty dustbag to get less motion resistance (friction) for the user.

The problems underlying the present invention are also solved by a pressure switch device according to claim 15 for a vacuum cleaner according to the present invention. Such pressure switch device may comprise at least a printed circuit board having a through hole, and a pressure switch, as set out and described in any embodiment herein, wherein the pressure switch is aligned with the through hole such that at a pressure sensitive section of the pressure switch is fluidly accessible through the through hole, i.e. a passage way involving the through hole.

In connection therewith, it is to be understood that various features and effects described in connection with the vacuum cleaner according to the present invention, particularly with a pressure switch device in such vacuum cleaner, may also be fea ^¬ tures of the pressure switch device according to the present in ^¬ vention .

In particular, all described embodiments of the invention have the advantage, that a vacuum cleaner having a pressure switch device as proposed herein allows for easy and cheap manufactur ^¬ ing thereof and an easy assembly or exchange of the vacuum pres- sure switch device in the vacuum cleaner.

Further the number of parts needed for implementing the pressure sensor device may be reduced as compared to known solutions. Further, the assembly of the pressure switch device as proposed herein can be carried out in a fully automated manner, which may lead to time and cost savings.

Selective soldering of the spring member may be used to adapt the switching behavior of the pressure switch, in particular to adapt the switching behavior of the pressure switch in accord ^¬ ance with the predefined pressure or pressure differential. This in particular means that a switching action can be obtained upon occurrence of the predetermined pressure or pressure difference. The present invention will be described in further detail with reference to the drawings from which further features, embodi ^¬ ments and advantages may be taken, and in which:

FIGs 1A to ID illustrate a series of perspective views of a

pressure switch device and parts thereof according to an exemplary embodiment of the invention;

FIG 2A illustrates a top view of the pressure switch de ^¬ vice according to FIG. 1A;

FIGs 2B and 2C illustrate a side cross-sectional views of the

pressure switch device in two switching positions;

FIG 2D illustrates a schematic side-view of a spring ele ^¬ ment of the pressure switch device; and

FIGs 3A to 3D illustrate side cross-sectional views of a vacuum cleaner comprising the pressure switch device.

Figures 1A to ID illustrate a series of perspective views of a pressure switch device 2 and parts thereof according to an exem ^¬ plary embodiment of the invention.

Particularly, Fig. 1A and Fig. 1C illustrate perspective views of a first side 3a of the fully assembled pressure switch device 2. Fig. ID shows a side view thereof.

The pressure switch device comprises a printed circuit board 3 having a through hole 4 (cf. FIG. IB), and a pressure switch 5 capable of switching from a first switch position to at least one second switch position. The pressure switch 5 is connected to a first side 3a of the printed circuit board 3 covering in the assembled state the through hole 4.

The through hole 4 can for example be seen in Fig. IB, here showing a tape 14, intended for fastening the pressure switch device 2 to a surface, for example. However, also the printed circuit board 3 comprises such through hole 4 and allows fluid communication of the pressure switch 5 through the through hole, and thereby despite of the pressure switch being attached to the printed circuit board 3, pressure sensitive surfaces can be in fluid communication with either the first side 3a or a second side 3b averted therefrom.

The pressure switch device 2 can advantageously applied to and arranged in a vacuum cleaner 1 according to the present invention such that the first side 3a of the pressure switch 5 is in fluid communication with a first compartment 9a (cf. FIG. 3A to 3D) and a second side 3b of the pressure switch 5 is in fluid communication with a second compartment 9b (cf. FIG. 3A to 3D) of the vacuum cleaner 1.

The pressure switch 5 is capable of switching from said first switch position to said second switch position dependent on a predetermined pressure differential ΔΡ between a pressure Pu prevailing in the first compartment 9a and a pressure Po pre ^¬ vailing in the second compartment 9b.

Particularly, such pressure switch device 2 may comprise a printed circuit board 3 as shown in Figs. 1A, 1C and ID, having a through hole 4, and a pressure switch 5 capable of switching from a first switch position, corresponding for example to an OFF switching condition, to a second switch position corresponding for example to an ON switching condition. Exemplarily, schematically side sectional view of such configu ^¬ rations are also shown in Fig. 2A, Fig. 2B, respectively showing an OFF switching position, and Fig. 2C showing an ON switching position .

The pressure switch 5 may be connected to a first side 3a of said printed circuit board 3 such that at least a pressure sen ^¬ sitive element or surface covers and is aligned with the through hole 4.

The pressure switch 5 is capable of switching dependent on a predetermined pressure differential ΔΡ prevailing between the first side 3a and the second side 3b of the printed circuit board 3.

The printed circuit board 3 may be fixed, for example, to a plastic base plate 13, which is exemplarily shown in Fig. IB. Such plastic base plate 13 may comprise a through hole 4, which may be dimensioned similar or identical to the dimension of the through hole 4 on the printed circuit board 3 and/or tape 14 or other elements arranged in a layered manner with the sensor.

The printed circuit board 3 and the plastic base plate 13 may be fixed to each other, e.g. by glue, such that the through holes are lined up with each other, allowing, as regards fluid technology, access to a pressure sensitive element or surface of the pressure switch 5 through the through openings, defining a type of passageway from the second side 3b. The second side 3b may in embodiments be assigned with an inner compartment of the vacuum system of the vacuum cleaner (1) .

Advantageously, the printed circuit board 3 may be fixed on the plastic base plate 13 using the tape 14, as shown for example in Fig. IB. Such a tape 14 can advantageously be used for fixing the printed circuit board 3 on the plastic base plate 13.

Also, said plastic plate 13 comprises a through hole 4, which may be dimensioned similar or identical to the dimension of the through hole 4 on the printed circuit board 3, and may be par ^¬ ticularly aligned with the through hole of the printed circuit board 3. Accordingly, all through holes may be advantageously arranged such that, as regards fluid technology, access to a pressure sensitive element or surface of the pressure switch 5 is possi ^¬ ble through the through openings forming a passageway from the second side 3b to the pressure sensitive element or surface. This for example allows obtaining facilitated assembly and manu ^¬ facturing options, because, for example wire routing, if used at all, can be simplified.

In the embodiment as shown in connection with the figures, the pressure switch 5 may be implemented as a digital switch single- throw make contact switch which comprises a dome-shaped metal spring 7, manufactured from a conductive metal preferably se ^¬ lected from the group comprising phosphor bronze. The metal spring 7 implemented as previously described can be used as one switch contact of the switch 5. Accordingly, a flipping of the spring 7 switching the pressure switch from a first switch position - here OFF as shown in Fig. 2A - to a second switch position - here ON as shown in Fig. 2C - allows to con- tact the spring 7, more precisely the part of the spring serving as contact 75, 76, to the second contact 16 of the pressure switch 5. As the pressure switch 5 has a dome shape resembling the hollow upper half of a sphere, and having a round, for example circular base area, the base area, particularly the outer circumferential rim of such a dome shape pressure switch 5 may be in contact with and fixed to the printed circuit board 3, whereby the hol ^¬ low part of the dome shaped pressure switch 5 extends away from the printed circuit board, particularly from the first side 3a, and a concave inner volume of the dome shape faces the printed circuit board 3, more specifically faces the through hole 4.

The pressure switch device 2 may further comprise a sealing 8 arranged such that a gap between a rim of the through hole 4 and the pressure switch 5 is sealed, preferably essentially airtight sealed, which prevents, at least partially, that a pressure com- pensation between the air and pressure on the first side 3a and the second side 3b of the printed circuit board 3 occurs.

In embodiments, the sealing may be in the form of a soldering joint 8 fixing the pressure switch 5, more specifically the met- al spring element 7 on or to the printed circuit board 3.

As may for example be taken from Fig. 2A the pressure switch 5 is preferably fixed to a PCB track 3, in form of the soldering 8, which is sealing the pressure switch, and which may also serve as a first switching contact or pole of the pressure switch 5.

It is to be understood that in the embodiment according to the figures, the sealing 8 is connected to the spring element 7, particularly the contact area 76, 75 of the spring element 7 and a stationary contact 16 may be provided as a second switching contact of the pressure switch 5. The PCB plastic laminate base plate 13 may serve as a mechanical carrier of the pressure switch device 2.

At the second side 3b of the printed circuit board 3 where ac- cording to the figures no soldering for attaching the spring element 7 is present, a second pole 19 of the electronic switch is arranged, which is electronically contacted to the stationary contact 16. Such configuration may be advantageously achieved using a tape 14 as a part of the electronic design. Other gluing methods are also possible to apply like hot glue or contact glue. The electronic component values are preferably not influ ^¬ encing the function.

The printed circuit board 3 with its second side 3b may be glued with glue 20 to a carrier structure, e.g. a part of the mechani ^¬ cal assembly of the vacuum cleaner 1, e.g. a plastic part dust bin, preferably such that adequate sealing between the pressure switch device 2 can be obtained. As may be taken from Fig. 2B, the through hole 4, and the respective holes in the tape and the mechanical assembly, e.g. a wall of the vacuum system of the vacuum cleaner 1, a passageway is formed, which allows the direct access of the pressure switch 5 with a space or chamber or compartment associated with the second side 3b of the printed circuit board 3.

A passageway compartment may be in fluid communication with a dust bag compartment 11 such that it is capable of switching de ^¬ pendent on a predetermined pressure differential ΔΡ between the first side 3a and the second side 3b of the printed circuit board 3 associated with the compartment, wherein the predeter ^¬ mined pressure differential ΔΡ is indicative for and/or in rela ^¬ tion to a degree of pollution or degree of filling of a dust bag 10 placed in the dust bag compartment 11 of the vacuum cleaner 1.

A switching action of the spring 7, e.g. a predefined defor- mation, e.g. flipping movement of the spring 7 can be inferred for example from a comparison of Fig. 2B and Fig. 2C.

As can be seen, a depression force F impinges, e.g. pulls on the dome-shaped spring 7 towards the second side 3b. Said depression force results from an under-pressure Po on the second side 3b as compared to the pressure Pu prevailing at the first side 3a of the pressure switch device 5.

If a predetermined pressure differential ΔΡ is reached, the de- pression force exceeds a flipping force of the spring 7, and consequently, the spring deforms and flips such that the contact area 75, 76 of the spring 7 are brought in electrical contact with the stationary contacts 16 on the printed circuit board 3. It is to be understood that contacts 75, 76, 16 of the pressure switch 5 are brought in electrically conductive contact by the flipping of the spring 7.

At least one of the pair of contacts 75, 76 and 16, which are to be brought in contact, may be arranged at or on the spring ele ^¬ ment 7.

In the case shown in FIG. 2D, the contact area 75, 76 represents a fist switching contact, and the second contact 16 implemented as a stationary contact represents a second switching contact, which most preferably is located at a carrier element of the pressure switch device, here on the printed circuit board 3, particularly on the first side 3a of the printed circuit board 3 connected to a pole located for example on the second side 3b of the printed circuit board 3.

As long as the pressure differential ΔΡ is present and holds the pressure switch in the second switching position (ON) as shown in Fig 2C, current may flow through the contacted contacts and/or switching signals, e.g. current or voltage signals may be generated and detected. The spring element 7 in the present embodiment has, as already mentioned, a dome shape, which may be best seen from Fig. 2D. Particularly, the spring element 7 has a flat rim base 71, which advantageously allows placement of the spring element 7 on the first side 3a of the printed circuit board 3, e.g. by soldering.

An intermediate rim portion 72 may be connected to said rim base 71 by a substantially upright or inclined flanking portion 73, which e.g. may increase stability of the spring 7, and/or which may be configured and/or designed such that at the spring 7 de- forms in accordance with a predefined shape change and/or in ac ^¬ cordance with a predetermined pressure differential ΔΡ.

A top part of the dome shaped spring element 7 may, as shown in FIG. 2D, be formed as a plate shaped top 75 connected to the in- termediated rim portion 72 by an inclining flank 74, which may serve as a spring area of the spring element 7, and which may for example be designed and/or configured to be more flexible as compared to adjacent sections of the spring element. The plate shaped top 75 may comprise a lowered central region 76, prefera- bly of round, more preferably of circular, geometry.

In Figs. 3A, 3B, 3C and 3D different configurations of vacuum cleaners 1 according to the present invention are shown, com- prising a pressure switch device 2 in particular as previously described .

Such vacuum cleaner 1 comprises, as can be inferred from the figures, a housing in which a dust bag 10 can be placed in a dust bag compartment 11. A blower or suction fan 15 is usually driven by a motor unit 21. The vacuum cleaner 1 usually further comprises electric or electronic speed control. However, also other types of vacuum cleaners may be envisaged, e.g. cyclonic vacuum cleaners, handheld vacuum cleaners, robotic vacuum clean ^¬ ers, upright/stick vacuum cleaners.

As shown in Fig. 3A, the pressure switch device 2 is positioned in the vacuum cleaner 1 such that it is capable of switching de- pendent on a predetermined pressure differential ΔΡ between the first side 3a and the second side 3b of the printed circuit board 3, wherein the predetermined pressure differential ΔΡ is indicative for and/or in relation to a degree of pollution of a dust bag 10 placed in the vacuum cleaner 1.

Specifically, the second side 3b is associated with the inner volume of the dust bag compartment 11, and the first side 3a is associated with a compartment fluidly connected to ambient at ^¬ mosphere. In particular, the pressure switch device 2 is ar- ranged such that it is capable of measuring an under-pressure prevailing in the dust bag compartment 11 representing a second compartment 9b, as compared to ambient pressure prevailing in a first compartment 9a fluidly connected with ambient atmosphere. For this purpose, the pressure switch device 2 is positioned at wall 17 separating the dust bag compartment 11, 9b from the com ^¬ partment 9a having ambient pressure. As apparent from Fig. 3A the pressure switch device 2 is arranged in the vacuum cleaner 1 such that the first side 3a of the pressure switch device 2 is in fluid communication with the first compartment 9a of the vac ^¬ uum cleaner 1, and the second side 3b of the pressure switch de ^¬ vice 2 is in fluid communication with said second compartment 9b. Specifically, a hole provided in the wall 17, aligned with the through-hole 4 of the pressure switch device 2 fluidly con ^¬ nects the concave inner volume of the dome-shaped spring 7 with the inner volume of the second compartment 9b.

In case that the dust bag 10 is clogged or has reached a prede- fined filling level, the under-pressure in the second compart ^¬ ment 9b will rise.

As soon as the predetermined pressure differential ΔΡ between the pressure Pu of the first compartment 9a (ambient) and the pressure Po of the second compartment 9b is obtained or reached, the spring 7 deforms, and the pressure switch 5 is capable of switching from the first switch position (Fig. 2B) to the second switch position (Fig. 2C) . The predetermined pressure differential ΔΡ thereby is character ^¬ ized in that the pressure Pu of the first compartment 9a is higher than the pressure Po of the second compartment 9b, i.e. reflecting an under-pressure in the dust bag compartment 11. Thus the predetermined pressure differential ΔΡ between the pressure Pu of said first compartment 9a and the pressure Po of said dust bag compartment 11, 9b is indicative for and/or in re ^¬ lation to a degree of pollution of the dust bag 10 placed in the vacuum cleaner 1. The predetermined pressure differential may be set or predeter ^¬ mined by the manufacturer of the vacuum cleaner. The predetermined pressure differential may be determined or fixed in de ^¬ pendence of the type or material of dust bag, 10 and/or filter 12 used for a respective type of vacuum cleaner 1. In Fig. 3B an alternative placement for the pressure switch de ^¬ vice 2 is shown. Here the pressure switch device 2 is positioned in a wall 17 of an air intake duct 18, i.e. inner volume of the dust bag compartment 9b and the air intake duct 18 reflecting a first compartment 9a. This advantageously allows the pressure switch device 2 to detect and switch according to a predetermined pressure differential between the compartment located be ^¬ fore 9a and a compartment located after 9b the dust bag 10, with regard to the direction of flow in usual sucking mode of the vacuum cleaner 1.

In the embodiment as shown in Fig. 3C, the pressure switch de ^¬ vice 2 is positioned in the vacuum cleaner 1 such that it is ca- pable of switching dependent on a predetermined pressure differ ^¬ ential ΔΡ between the first side 3a associated with an exhaust compartment upstream a fine filter 12, and the second side 3b of the pressure switch device 2 associated with ambient atmosphere. In this case, the predetermined pressure differential ΔΡ is in- dicative for and/or in relation to a degree of pollution of a filter 12 placed in the vacuum cleaner 1.

Increasing clogging of the filter 12 will lead to increased pressure values in the exhaust compartment associated with the filter 21 as compared to ambient air, for example. Positioning the pressure switch device 2 at the wall 17 separating the ex ^¬ haust compartment of the filter 12 from compartment 9b associat ^¬ ed to ambient atmosphere is therefore suitable for detecting clogging of filter 12.

Accordingly, the pressure switch device 2 as positioned in the embodiment shown in Fig. 3C is capable of switching from a first switch position to a second switch position dependent on a predetermined pressure differential ΔΡ being indicative for and/or in relation to a degree of pollution of the exhaust filter 12 placed in the vacuum cleaner 1.

According to the embodiment shown in Fig. 3D the pressure switch device 2 may be positioned in a wall 17 separating the air in ^¬ take duct 18, reflecting a second compartment 9b from a cabinet, reflecting a first compartment 9a, fluidly connected to ambient atmosphere through an opening 22 in the vacuum cleaner housing. In such arrangement the pressure switch device 2 is capable of sensing and switching dependent on an under-pressure in the in ^¬ take duct 18 or inlet nozzle or inlet tube of the vacuum cleaner 1 as compared to the ambient. The pressure switch device 2 may be arranged and mounted in such a way to a wall of the intake duct 18, such that a hole in the wall is aligned with the through hole 4 of the pressure switch device 2, and that the concave inner volume of the spring 7 is fluidly connected with the intake duct 18.

The vacuum cleaner may comprise a control unit 6 connected, as regards signaling technology, with the pressure switch device 2 of the vacuum cleaner 1. In dependence of the occurrence of a switching event of the pressure switch device 2, the control unit 6 may execute a pre ^¬ defined action, such as for example providing for display on a user interface an information item representative for the ob ^¬ served switching condition.

The control unit may indicate that the filter 12 or dust bag 10 is clogged or filled and/or that the filter 12 or dust bag 10 needs to be replaced. Further, the control unit 6 may be designed to change operation of the vacuum system in case of a switch event. In one embodi ^¬ ment, the control unit may, for example, deactivate operation of the vacuum cleaner 1 in order to avoid undue motor loads.

The features of the present invention disclosed in the specifi ^¬ cation, the claims, and/or the figures and related description may both separately and in any combination thereof be material for realizing the invention in various forms thereof.

List of reference numerals

1 vacuum cleaner

2 pressure switch device

3 printed circuit board

3a first side of pressure switch device

3b second side of pressure switch device

4 through hole

5 pressure switch

6 control unit

7 spring element

8 sealing

9 inner compartment

9a first compartment

9b second compartment

10 dust bag

11 dust bag compartment

12 filter

13 plastic base plate

14 tape

15 blower

16 stationary contact

17 wall

18 intake duct

19 second pole

20 glue

21 motor unit

22 opening

71 rim base

72 intermediate rim portion

73 flanking portion

74 spring area

75 plate shaped top

76 central region F depression force

Pu pressure prevailing in first compartment Po pressure prevailing in second compartment