MOBILE VACUUM CLEANER WITH AIR FLOW CONTROL

Description

Technical field of the invention

[0001] The present invention relates to mobile vacuum cleaners.Background of the invention

[0002] Typically, most mobile vacuum cleaners will work with an air flow that is up to twice as strong as needed when the filters are clean, after which the air flow will gradually decrease as the filter is clogged. Vacuum cleaners are therefore almost always running with an unnecessarily strong air flow corresponding to an estimated additional power consumption of up to 30%.

[0003] Working tools are today often combined with mobile vacuum cleaners to remove particulate matter from the work pieces or surfaces that are machined. The required air flow level depends on the type of particulate matter to be removed from the work site, i.e., the density and surface area of the particles. A greater air flow in the suction hose is needed to disengage and transport particles, such as e.g., sand and pebbles, than needed to detach and transport e.g., sawdust. However, when using a vacuum cleaner in combination with a grinding machine, the suction can be so powerful that the grinder is sucked so hard against the surface to be grinded that it adversely affects the grinding result and at the same time causes unnecessary wear on the grinder's mechanical parts. Another problem is that a relatively higher air flow velocity results in a higher noise emission, and in a relatively higher turbulence in the collection chamber, and therefore a faster clogging of the air filter. An exemplary vacuum cleaner is disclosed in EP 2 460 453 A1.

[0004] For reasons of power consumption, noise emission, air filter clogging, tool function, and tool wear, it is desirable to be able to adapt the vacuum cleaner air flow to the task in question.Description of the invention

[0005] A vacuum cleaner according to the present invention is defined by claim 1. Further preferred embodiments are defined by the dependent claims.

[0006] In the present context, the term "mobile vacuum cleaner" should be understood as a vacuum cleaner being movable, such as moved between worksites, moved together with a tool, moved for cleaning operations at different positions at a worksite, such as liftable, wheeled, slidable, integrated in a trailer, or the like.

[0007] In the context of the present invention, the term "vacuum cleaner" should be understood narrowly, and only to include devices for professional or domestic use that perform the cleaning of particulate matter from machines, work pieces, or surfaces by means of suction. Therefore, the term "vacuum cleaner" will comprise a vacuum cleaner, a so-called multipurpose drum vacuum cleaner, a robot vacuum cleaner, or the like, but not a centralized suction or ventilation system that is integrated or fixed to a building or production site for domestic or industrial use.

[0008] The inventor of the present invention seeks to solve the problem by using three or more electrical motors to allow for an automatic control of activation or deactivation of said electric motors to meet a user defined threshold value in response to air flow data received from said sensor unit. This configuration allows the user to predefine an optimal air flow for the specific job at hand, while the controller will keep the air flow according to this threshold air flow value, by activating or deactivating said electrical motors. The more electrical motors, the more accurate the regulation. In one or more embodiments, the suction unit comprises at least three electric motors each configured for driving at least one air pump, such as 3-10 electric motors, e.g., at least four electric motors, such as 4-9 electric motors, e.g., 5-7 electric motors each configured for driving at least one air pump.

[0009] There are vacuum cleaners on the market that are equipped with multiple electrical motors, which individually and manually can be switched on and off, thereby allowing the air flow to be set. This is positive in terms of power consumption, noise emission, filter clogging speed, tool function, and connected equipment wear, but this solution does not take into account that the filter clogging gradually reduces the air flow, and that the operator has to continuously switch on more pumps as the filters are clogged. In practice, this will not happen. To avoid the disruptive element of continually having to observe that the air flow is adequate and to interrupt the working process to adjust the suction power, the typical operator will always have the vacuum cleaner set to maximum suction power from the start, knowing that if it is then not adequate, it is because the vacuum cleaner is clogged and needs to be stopped and emptied. This can adversely affect safety and the working environment. Partly, because the focus has to be divided between the working process on hand, that may involve tools that can be hazardous if they are not handled with complete focus and respect, and partly, because the operator will first realize that the suction power is inadequate when visible particulate matter is starting to build up around the working site. The particulate matter may potentially be hazardous, and some of the particles will even be invisible to the worker.

[0010] In the present context, the term "vacuum hose" should be interpreted relatively broadly, and the hose may or may not be flexible, and may be of any suitable length, e.g., suitable for connection to a working tool.

[0011] The term "particle collection chamber" as used herein refers to a volume suitable for receiving particulate matter removed from the air flow by the air filter unit.

[0012] In one or more embodiments, the control unit further comprises a rotary potentiometer, a multistep switch, or the like, configured for variably adjusting said threshold value of said air flow passing between said suction unit and said outlet. This configuration allows the operator to adjust the threshold air flow to fit the adequate air flow fitting the working process on hand.

[0013] The sensor unit may be of any suitable type adapted for determining the air flow passing between said suction unit and said outlet. Suitable examples may be a hot wire anemometer, a vane anemometer, an ultrasonic anemometer, an acoustic resonance anemometer, an air flow meter based on the pressure drop over an orifice, an air flow meter based on an orifice or a venturi, and the like.

[0014] In one or more embodiments, the control unit further comprises a rotary potentiometer, a multistep switch, or the like for variably adjusting said threshold value of said air flow passing between said suction unit and said outlet.

[0015] In one or more embodiments, the sensor unit comprises a sensor suitable for measuring the actual airflow, such as a hot wire anemometer, a vane anemometer, an ultrasonic anemometer, an acoustic resonance anemometer, an air flow meter based on the pressure drop over an orifice, an air flow meter based on an orifice or a venturi, and the like.

[0016] In one or more embodiments, the control unit is configured to prioritize which of said electric motors that should be activated at any given time based on information about each of said motors accumulated operating time. As the filter material starts to clog, more force is needed to maintain a given air flow. Hence, one of the deactivated electric motors will need to be activated. Any inactivated electric motor may be selected from the ones available. However, in order to secure that the vacuum cleaner has a relatively long service life, the motors should preferably be evenly used to avoid that one of the motors will wear out before the others. Therefore, this configuration allows for a controlled use of each motor. The control unit may e.g., be equipped with a timer for each electric motor.

[0017] In one or more embodiments, the prioritization is performed by continuously keeping track of said electric motors' accumulated operating time and / or listing said electric motors according to their accumulated operating time, and at any given time selecting the electric motor with the shortest accumulated operating time to be activated.

[0018] As with the case of activating electric motors, it may also be necessary to deactivate electric motors if the vacuum cleaner is overperforming relative to a predetermined threshold of air flow passing between said suction unit and said outlet. Again, to avoid that one of the motors will wear out before the others it is an advantage to deactivate the motor with the longest operating time.

[0019] In one or more embodiments, the control unit is configured to prioritize which of said electric motors that should be deactivated at a given time based on information about each of said motors accumulated operating time.

[0020] In one or more embodiments, the prioritization is performed by continuously keeping track of said electric motors' accumulated operating time and / or listing said electric motors according to their accumulated operating time, and at any given time selecting the electric motor with the longest total operating time to be deactivated.

[0021] In one or more embodiments, the prioritization includes disregarding an electric motor that is determined to be out of order. The determination of an electric motor that is out of order may e.g., be identifying that the power consumption is not within the limits that are to be expected for the given electrical motor.

[0022] The control unit may be configured to continuously observe the power consumption of each electrical motor. This can be performed e.g., by a Hall-element for each motor, measuring the actual current and communicating with the control unit. If a motor is determined as out of order it will be disregarded, and the control unit will continue working on obtaining the optimal result by using the remaining pumps until the motor being out of order can be serviced.

[0023] If a motor is out of order, the control unit may be configured to warn the operator, by sending an audible and / or visible alarm, e.g., by using a piezo electric beeper and / or lamp.

[0024] As an example, and in order for the control unit to operate, it may comprise a computing system including a processor, a memory, a communication unit, an output device, an input device, and a data store, which may be communicatively coupled by a communication bus. The mentioned computing system should be understood as an example and that it may take other forms and include additional or fewer components without departing from the scope of the present disclosure. For instance, various components of the computing device may be coupled for communication using a variety of communication protocols and / or technologies including, for instance, communication buses, software communication mechanisms, computer networks, etc. The computing system may include various operating systems, sensors, additional processors, and other physical configurations. The processor, memory, communication unit, etc., are representative of one or more of these components. The processor may execute software instructions by performing various input, logical, and / or mathematical operations. The processor may have various computing architectures to method data signals (e.g., CISC, RISC, etc.). The processor may be physical and / or virtual and may include a single core or plurality of processing units and / or cores. The processor may be coupled to the memory via the bus to access data and instructions therefrom and store data therein. The bus may couple the processor to the other components of the computing system including, for example, the memory, the communication unit, the input device, the output device, and the data store. The memory may store and provide data access to the other components of the computing system. The memory may be included in a single computing device or a plurality of computing devices. The memory may store instructions and / or data that may be executed by the processor. For example, the memory may store instructions and data, including, for example, an operating system, hardware drivers, other software applications, databases, etc., which may implement the techniques described herein. The memory may be coupled to the bus for communication with the processor and the other components of computing system. The memory may include a non-transitory computer-usable (e.g., readable, writeable, etc.) medium, which can be any non-transitory apparatus or device that can contain, store, communicate, propagate, or transport instructions, data, computer programs, software, code, routines, etc., for processing by or in connection with the processor. In some implementations, the memory may include one or more of volatile memory and non-volatile memory (e.g., RAM, ROM, hard disk, optical disk, etc.). It should be understood that the memory may be a single device or may include multiple types of devices and configurations. The input device may include any device for inputting information into the computing system. In some implementations, the input device may include one or more peripheral devices. The output device may be any device capable of outputting information from the computing system. The data store may include information sources for storing and providing access to data. In some implementations, the data store may store data associated with a database management system (DBMS) operable on the computing system. For example, the DBMS could include a structured query language (SQL) DBMS, a NoSQL DMBS, various combinations thereof, etc. In some instances, the DBMS may store data in multi-dimensional tables comprised of rows and columns, and manipulate, e.g., insert, query, update and / or delete, rows of data using programmatic operations. The data stored by the data store may be organized and queried using various criteria including any type of data stored by them. The data store may include data tables, databases, or other organized collections of data. The data store may be included in the computing system or in another computing system and / or storage system distinct from but coupled to or accessible by the computing system. The data stores can include one or more non-transitory computer-readable mediums for storing the data. In some implementations, the data stores may be incorporated with the memory or may be distinct therefrom. The components may be communicatively coupled by the bus and / or the processor to one another and / or the other components of the computing system. In some implementations, the components may include computer logic (e.g., software logic, hardware logic, etc.) executable by the processor to provide their acts and / or functionality. These components may be adapted for cooperation and communication with the processor and the other components of the computing system.

[0025] As used in the specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" or "approximately" one particular value and / or to "about" or "approximately" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about", it will be understood that the particular value forms another embodiment.

[0026] It should be noted that embodiments and features described in the context of one of the aspects of the present invention also apply to the other aspects of the invention.Detailed description of a preferred embodiment of the invention

[0027] Figure 1 shows a sketch of the principle of a vacuum cleaner 100 in accordance with the present invention. The air flow passes through a suction hose 110 into a particle collection chamber 120. From here, the air flow passes through an air filter 130, passes one or more air pumps 140 (here up to four air pumps may be activated or deactivated) driven by electric motors 150 (which are supplied with energy from the power grid 190), through a sensor unit 160, and finally out of the vacuum cleaner 100 through an air outlet 170. Hence, the air flow through the vacuum cleaner 100, is measured between the suction unit and the outlet 170. A control unit 180 is in communication with the sensor unit 160 and configured to receive user input about a threshold value of said air flow passing between said suction unit and outlet 170, and further configured to individually activate or deactivate said electric motors 150 to meet said user defined threshold value in response to air flow data received from said sensor unit 160. The user input is here shown to be received via a multistep switch 184 with five steps configured for variably adjusting the threshold value of the air flow passing between said suction unit and outlet 170. If it is not possible for the control unit 180 to obtain the user chosen threshold air flow value, the control unit 180 may be configured to send an audible and / or visible alarm as exemplified with an audible piezo electric beeper 182. Alternatively, or in combination, a lamp (not shown) could be used as a visible alarm.References

[0028] 100Vacuum cleaner 110Suction hose 120Particle collection chamber 130Air filter unit 140Air pump 150Electric motor 160Sensor unit 170Air outlet 180Control unit 182Piezo electric beeper 184Multistep switch 190Power grid

Claims

1. A mobile vacuum cleaner (100) comprising: - a suction hose (110); - a particle collection chamber (120) in air communication with said suction hose (110); - an air filter unit (130); - a suction unit in air communication with said particle collection chamber (120) through said air filter unit (130), and comprising an electric motor (150) configured for driving at least one air pump (140); - an air outlet (170) in air communication with said suction unit; - a sensor unit (160) adapted for measuring the air flow passing between said suction unit and said outlet (170); and - a control unit (180) in communication with said sensor unit (160) and configured to receive user input about a threshold value of said air flow passing between said suction unit and said outlet (170); characterized in that the suction unit comprises at least three electric motors (150) configured for driving at least one air pump (140), wherein the sensor unit (160) comprises a sensor configured for measuring the actual airflow passing between said suction unit and said outlet (170), and wherein the control unit (180) is configured to individually activate or deactivate said electric motors (150) to meet said user defined threshold value in response to air flow data received from said sensor unit (160).

2. The vacuum cleaner (100) according to claim 1, wherein the control unit (180) further comprises a rotary potentiometer, a multistep switch (184), or the like for variably adjusting said threshold value of said air flow passing between said suction unit and said outlet (170).

3. The vacuum cleaner (100) according to any one of the claims 1-2, wherein the sensor unit (160) is selected from the group consisting of: a hot wire anemometer, a vane anemometer, an ultrasonic anemometer, an acoustic resonance anemometer, an air flow meter based on the pressure drop over an orifice, an air flow meter based on an orifice or a venturi, and the like.

4. The vacuum cleaner (100) according to any one of the claims 1-3, wherein the control unit (180) is configured to prioritize which of said electric motors (150) that should be activated at a given time based on information about each of said motors' operating time.

5. The vacuum cleaner (100) according to claim 4, wherein the prioritization is performed by continuously keeping track of said electric motors' accumulated operating time and / or listing said electric motors according to their accumulated operating time, and at any given time selecting the electric motor to be activated with the shortest accumulated operating time.

6. The vacuum cleaner (100) according to any one of the claims 1-5, wherein the control unit (180) is configured to prioritize which of said electric motors (150) that should be deactivated at a given time based on information about each of said motors' accumulated operating time.

7. The vacuum cleaner (100) according to claim 6, wherein the prioritization is performed by continuously keeping track of said electric motors' accumulated operating time and / or listing said electric motors to be deactivated according to their accumulated operating time, and at any given time selecting the electric motor with the longest total operating time.

8. The vacuum cleaner (100) according to any one of the claims 4-7, wherein the prioritization includes disregarding an electric motor (150) that is determined to be out of order.