Patent Description:
Wet floor cleaning machines are adapted for cleaning the floor with cleaning fluid such as water. A wet floor cleaning machine typically comprises a brush roller, a fluid delivery unit and a fluid recovery unit. When the wet floor cleaning machine is in operation, the fluid delivery unit supplies the brush roller with the cleaning fluid, which is used to clean the surface to be cleaned, and the fluid recovery unit draws and stores the spent cleaning fluid and debris from the surface to be cleaned in its own recovery tank. As the brush roller is in directly contact with the surface to be cleaned, it inevitably adheres to the spent cleaning fluid and debris from the surface to be cleaned. In order to prevent the brush roller getting mouldy and to maintain the cleaning effect of the floor cleaning machine and the life of the brush roller, parts of the fluid recovery unit, including the brush roller, need to be cleaned after the floor cleaning machine has finished its cleaning work.

A floor cleaning system is disclosed by <CIT>.

The invention provides a floor cleaning system comprising a floor cleaning machine and a self-cleaning station ,wherein the floor cleaning machine includes a cleaning base movable over a surface to be cleaned and including at least one brush roller; a fluid delivery unit configured to deliver a cleaning fluid to the at least one brush roller and comprising a supply tank for storing the cleaning fluid and a fluid dispenser in fluid communication with the supply tank; a fluid recovery unit comprising a recovery tank; a rechargeable battery configured to power energy-consuming components of the floor cleaning machine; a first control unit controlling the floor cleaning machine to perform cleaning operations and self-cleaning operations; and a first charging interface electrically coupled to the rechargeable battery; and the self-cleaning station includes a station body configured to receive and hold at least a portion of the base, a power plug provided on the station body and having ability to be electrically coupled to an external power source, a self-cleaning switch operably provided on the station body, a second charging interface configured to electrically contact to the first charging interface, and a second control unit communicatively coupled with the self-cleaning switch and the second charging interface; wherein the first control unit is in signal communication with the second control unit via an electrical pathway passing through the first charging interface and the second charging interface when the first charging interface is electrically contacted with the second charging interface, such that the self-cleaning operation is performed in response to an indication that the self-cleaning switch has been turned on.

Preferably, the floor cleaning machine comprises a charging control circuit controlling the charging of the rechargeable battery, wherein the charging control circuit is disabled when the first control unit controls the floor cleaning machine to perform the self-cleaning operation.

In a preferred embodiment, the self-cleaning switch is foot operated.

Preferably, the floor cleaning machine comprises a cleaning switch configured to be operable, and the cleaning switch is communicatively coupled to the first control unit for initiating the cleaning operation in response to an indication that the cleaning switch has been turned on.

Preferably, the floor cleaning machine comprises a power monitoring device configured to monitor the remaining power of the rechargeable battery and be in signal communication with the first control unit, and the first control unit is configured to perform the self-cleaning operation in response to an indication that the self-cleaning switch has been turned on when the power monitoring device detects the remaining power of the rechargeable battery being satisfied.

Preferably, the floor cleaning machine comprises a cleaning fluid monitoring device being in signal communication with the first control unit and configured to monitor the flow of the cleaning fluid in the fluid delivery unit.

It is preferred that the floor cleaning machine comprises a level monitoring device being in signal communication with the first control unit for monitoring the level in the recovery tank.

Preferably, the floor cleaning machine comprises a turbidity monitoring device being in signal communication with the first control unit for monitoring the turbidity of the fluid in the fluid recovery unit.

Preferably, the cleaning base comprises a brush- roller motor for rotating the at least one brush roller, the fluid delivery unit includes a liquid pump between the supply tank and the at least one brush roller, and the brush- roller motor and the pump are both communicatively coupled to the first control unit.

It is preferred that the fluid recovery unit comprises a suction motor in fluid communication with the recovery tank and communicatively coupled to the first control unit.

Additional aspects and advantages of the invention will be given in part in the following description, and will in part become apparent from the following description, or from the practice of the invention.

In order to illustrate in detail the technical content, the constructional features, the purpose achieved and the efficacy of the invention, the technical solutions in the embodiments of the present application are described below in conjunction with the accompanying drawings in the embodiments of the present application, it being clear that the embodiments described are only a part of the embodiments of the present application and not all of them.

<FIG> illustrates an external view of a floor cleaning system <NUM>, according to one embodiment of the invention. In this embodiment, the floor cleaning system <NUM> is capable of performing cleaning operations and self-cleaning operations. The floor cleaning system <NUM> comprises a floor cleaning machine <NUM> and a self-cleaning station <NUM>. The floor cleaning machine <NUM> is adapted to move over the surface to be cleaned. The self-cleaning station <NUM> is capable of receiving and holding at least a part of the floor cleaning machine <NUM>. The floor cleaning machine <NUM> can perform the self-cleanings or recharge while the floor cleaning machine <NUM> is supported on the self-cleaning station <NUM>.

As shown in <FIG> and <FIG>, the floor cleaning machine <NUM> comprises a cleaning base <NUM> adapted for movement across a surface to be cleaned , an upright body <NUM> rotatably coupled to the cleaning base <NUM>, a fluid delivery unit (not shown) for delivering a cleaning fluid to the cleaning base <NUM>, a fluid recovery unit <NUM> for recovering a spent cleaning fluid and debris from the surface to be cleaned , and a first control unit <NUM> (<FIG>)controlling the floor cleaning machine <NUM> to perform the cleaning operations and the self-cleaning operations.

The cleaning base <NUM> comprises a housing <NUM>, an upper cover <NUM> removably provided on the housing <NUM>, a brush roller <NUM> rotatably provided in the housing <NUM>, moving wheels <NUM> for carrying the base11 over the surface to be cleaned and a brush-roller motor <NUM> for driving the rotation of the brush roller <NUM>. The wheels <NUM> are configured to contact with the surface to be cleaned. Some wheels <NUM> are provided to the rear end of the housing <NUM>.

A suction chamber <NUM> located at the front of the cleaning base <NUM> is defined by the housing <NUM> and the upper cover <NUM>. The suction chamber <NUM> has a lower opening (not shown) towards the surface to be cleaned. The brush roller <NUM> is rotatably supported in the suction chamber 116by a support member (not shown). The lower end of the brush roller <NUM> passes through the lower opening to contact with the surface to be cleaned. In other embodiments, the housing and the upper cover may be provided as an integral, or the housing and the upper cover may be fixedly connected to each other.

The upright body <NUM> comprises a handle assembly <NUM> at the top, a joint assembly <NUM> rotatably hinged to the cleaning base <NUM>, and a frame <NUM> between the handle assembly <NUM> and the joint assembly <NUM>. The handle assembly <NUM> is configured to be hand carried by a user for operating the floor cleaning machine <NUM>. The handle assembly <NUM> includes a cleaning switch <NUM> (<FIG>), which is used by the user for initiating the cleaning operation of the floor cleaning machine <NUM>. The cleaning switch <NUM> can be a individual switch or can be replaced by a main power switch (such as an on-off switch) of the floor cleaning machine.

The fluid delivery unit comprises a supply tank <NUM> for storing the cleaning fluid, a fluid delivery pathway (not shown) between the supply tank <NUM> and the brush roller <NUM>, and a liquid pump <NUM> located in the fluid delivery pathway. The supply tank <NUM> is removably mounted to the frame <NUM>. The fluid delivery pathway passes inside the upright body <NUM>, and some of the fluid delivery pathway is configured to pass through the joint assembly <NUM> to the cleaning base <NUM>. An outlet of the fluid delivery pathway is defined by a fluid dispenser (not shown) located on the upper side of the brush roller <NUM>. The dispenser is configured to evenly dispense the cleaning fluid to the outer circumferential surface of the brush roller <NUM>. A cleaning fluid monitoring device <NUM> (<FIG>) for monitoring the flow of the cleaning fluid through the delivery pathway is provided.

The fluid recovery unit <NUM> comprises a recovery tank <NUM> for receiving and storing the spent cleaning fluid and debris, a suction motor <NUM> mounted on the upper side of the recovery tank <NUM>, and a fluid recovery pathway <NUM> between the suction chamber <NUM> and the recovery tank <NUM>. In this embodiment, the suction motor <NUM> is installed inside the frame <NUM> and located underneath the supply tank <NUM> and. The recovery tank <NUM> is removably mounted to the frame <NUM>, too. The recovery tank <NUM> is configured to be in fluid communication with the suction motor <NUM>. The fluid recovery pathway <NUM> passes inside the upright body <NUM>. Some of the fluid recovery pathway <NUM> passes through the joint assembly <NUM> to the cleaning base <NUM>. The fluid recovery pathway <NUM> is in fluid communication with the suction chamber <NUM> and the recovery tank <NUM>.

A level monitoring device <NUM> (<FIG>) for monitoring the level of the recovery tank <NUM> and a turbidity monitoring device <NUM> (<FIG>) for monitoring the turbidity of the recovery fluid in the fluid recovery pasthway143 are provided in the fluid recovery unit <NUM>. The lower the turbidity of the recovery fluid is, the higher the clarity of the recovery fluid is. In this embodiment, the turbidity monitoring device <NUM> is set in the fluid recovery pathway <NUM>.

The floor cleaning machine <NUM> also comprises a rechargeable battery <NUM>, a first charging interface <NUM>, and a charging control circuit <NUM> between the rechargeable battery <NUM> and the first charging interface <NUM> (<FIG> and <FIG>). The charging control circuit <NUM> is in signal communication with the first control unit <NUM> and is controlled by the first control unit <NUM>. The rechargeable battery <NUM> is located on the rear side of both the recovery tank <NUM> and the suction motor <NUM>. The rechargeable battery <NUM> is configured to be inside the upright body <NUM>. The rechargeable battery <NUM> is electrically coupled with the brush-roller motor <NUM>, the liquid pump <NUM>, the suction motor <NUM> and the first control unit <NUM> to power them.

The charging control circuit <NUM> is constructed to conduct and disconnect the electrical connection of the rechargeable battery <NUM> to the first charging interface <NUM>. The charging control circuit <NUM> is always on; however, the charging control circuit <NUM> is controlled by the first control unit <NUM> to disconnect the electrical connection between the first charging interface <NUM> and the rechargeable battery <NUM> when the floor cleaning machine <NUM> is activated and the self-cleaning operation is carried out. The first charging interface <NUM> is exposed to the upright body <NUM> for connection to an external charging interface (for example, the second charging interface of the self-cleaning station <NUM> mentioned below). In this embodiment, the floor cleaning machine <NUM> also has a power monitoring device <NUM> (<FIG>), which is used to monitor the remaining power of the rechargeable battery <NUM>.

The first control unit <NUM> is within the floor cleaning machine <NUM> and is pre-stored with a cleaning control procedure for cleaning operations and a self-cleaning control procedure for self-cleaning operations. The cleaning switch <NUM>, the cleaning fluid monitoring device <NUM>, the level monitoring device <NUM>, the power monitoring device <NUM> and the turbidity monitoring device <NUM> are all communicatively coupled to the first control unit <NUM> for sending relevant signals to the first control unit <NUM>. The first control unit <NUM> is in signal communication with the brush roller motor <NUM>, the liquid pump <NUM>, the charging control circuit <NUM> and the suction motor <NUM> to control the operations of the floor cleaning machine <NUM>.

When the first control unit <NUM> executes the cleaning control procedure after the user turns on the cleaning switch <NUM>, the floor cleaning machine <NUM> starts to perform a cleaning operation. The first control unit <NUM> starts the brush-roller motor <NUM>, the liquid pump <NUM> and the suction motor <NUM> at the same time. The cleaning fluid in the supply tank <NUM> reaches the fluid distributor via the liquid pump <NUM> and it is distributed via the fluid distributor to the brush rollers <NUM>. The brush roller <NUM>, driven by the brush-roller motor <NUM>, uses the cleaning fluid to scrub the surface to be cleaned. The suction motor <NUM> at work creates a negative pressure in the recovery pathway <NUM> from the lower opening of the suction chamber <NUM> to the recovery tank <NUM>. The spent cleaning fluid and debris from the floor surface pass through the lower opening, the suction chamber <NUM> and the recovery path <NUM> in succession, arrive and are stored in the recovery tank <NUM> by the force of the negative pressure.

As shown in <FIG>, <FIG> and <FIG>, the self-cleaning station <NUM> comprises a station body <NUM>, a self-cleaning switch <NUM> operably provided at the rear of the body <NUM>, a second control unit <NUM> communicatively coupled to the self-cleaning switch <NUM>, and a second charging interface <NUM> capable of engaging with the first charging interface <NUM>. The second charging interface <NUM> is electrically coupled with the second control unit <NUM>. The self-cleaning station <NUM> is supported on the floor surface by its bottom surface or own legs (not shown). A power plug <NUM> (<FIG>) is provided with the station body <NUM>. The power plug <NUM> has ability to electrically couple to an external power source, such as a household outlet. The power plug <NUM> is arranged on the body <NUM> and is capable of directing current from the external power source to the second charging interface <NUM>.

The station body <NUM> comprises a column <NUM> extending in an upward and downward direction, and a tray <NUM> fixed to the lower part of the column <NUM>. The tray <NUM> has a portion <NUM> capable of receiving and holding the cleaning base <NUM> and an upright sidewall <NUM> formed by the upward extension of the edge wall surface of the portion <NUM>. The portion <NUM> comprises a recess <NUM> and a support part <NUM>. The recess <NUM> is provided on the front side of the support part <NUM>. The support part <NUM> has a flat surface sloping forward and downwards. The support part <NUM> is configured to receive and support parts of the bottom of the housing <NUM>, such as the wheels. The recess <NUM> is configured to receive and hold the brush roller <NUM>.

The second charging interface <NUM> is located at the top of the column <NUM>. The second charging interface <NUM> is electrically contacted with the first charging interface <NUM> when the floor cleaning machine <NUM> is placed on the self-cleaning station <NUM>. When the charging control circuit <NUM> is enabled, a charging current is continuously delivered to the rechargeable battery <NUM> via an electrical pathway passing through the first charging interface <NUM> and the second charging interface <NUM> to enable charging of the rechargeable battery <NUM>.

In this embodiment, the self-cleaning switch <NUM> is configured as a foot-operated switch. It is mounted at the rear of the tray <NUM>. It is for the user to activate the self-cleaning operations of the floor cleaning machine <NUM>. In other embodiments, the position of the self-cleaning switch can be changed as desired, such as provided on the front side of the recess, and the self-cleaning switch can also be provided as a hand-operated switch, such as a button or a slider.

As shown in <FIG> and <FIG>, the second control unit <NUM> is in signal communication with the second charging interface <NUM> and the self-cleaning switch <NUM>. When the second charging interface <NUM> is electrical contacted with the first charging interface <NUM>, the second control unit <NUM> is in signal communication with the first control unit <NUM> via an electrical pathway passing through the second charging interface <NUM> and the first charging interface <NUM>. Thereafter, it allows the second control unit <NUM> to send signals or messages to the first control unit <NUM> by the electrical pathway. For example, a signal from the self-cleaning switch <NUM> to the second control unit <NUM> can be further transmitted to the first control unit <NUM> by the electrical pathway.

When the second charging interface <NUM> is electrical contacted with the first charging interface <NUM> and the self-cleaning switch <NUM> is not turned on, the electrical pathway through the second charging interface <NUM> and the first charging interface <NUM> directly transmits a charging voltage signal by the control of the second control unit <NUM>; and at this moment, the first control unit <NUM> of the floor cleaning machine <NUM> receives a normal voltage wave signal corresponding to the charging voltage signal. For example, the charging voltage wave signal is received with a charging voltage of Vo at all times as shown in <FIG>; the waveform of the voltage wave is a straight line. Upon receipt of the normal voltage wave signal, the first control unit <NUM> controls the charging control circuit <NUM> is enabled, and the rechargeable battery <NUM> starts charging.

When the second charging interface <NUM> is electrical contacted with the first charging interface <NUM> and the self-cleaning switch <NUM> is turned on, the electrical pathway passing through the second charging interface <NUM> and the first charging interface <NUM> transmits a protocol voltage signal. The protocol voltage signal is different from the charging voltage signal. At this moment the first control unit <NUM> of the floor cleaning machine <NUM> receives an abnormal voltage wave signal corresponding to the protocol voltage signal. For example, the waveform of the received protocol voltage signal is rectangular as illustrated in <FIG>. Upon receipt of the protocol voltage waveform, the first control unit <NUM> controls the charging control circuit <NUM> is disabled, and the first control unit <NUM> executes the self-cleaning control procedure, a self-cleaning operation starts. After the self-cleaning operation is completed, the first control unit <NUM> controls the charging control circuit <NUM> is enabled again until charging the rechargeable battery <NUM> is complete. Before the self-cleaning control procedure starts to run, the first control unit <NUM> checks whether the charge of the rechargeable battery <NUM> meets the power requirements for the self-cleaning operation, whether the cleaning fluid in the supply tank <NUM> meets the requirements for the self-cleaning operation, and whether the recovery tank <NUM> is empty, based on the individual monitoring devices, and only starts when all these needs are met. In this embodiment, the protocol voltage waveform is designed as a "special-shaped" waveform that is temporarily inserted into the charging voltage waveform. This "special-shaped" waveform is typically short in duration and easily recognized by the first control unit <NUM>.

The application uses the electrical pathway through the second charging interface <NUM> and the first charging interface <NUM> to transmit the protocol voltage signal generated by turning on the self-cleaning switch, and a separate transmission signal wire between the self-cleaning station <NUM> and the floor cleaning machine 1is not necessary. It simplifies the electrical or signal connection structure between the floor cleaning machine <NUM> and the self-cleaning station <NUM>. The self-cleaning switch does not require a locking procedure for the self-cleaning switch to prevent in advertent operation compared to the previous solution of having the self-cleaning switch on the floor cleaning machine, which also simplifies the self-cleaning control procedure.

The working principle of the self-cleaning operations of the floor cleaning system <NUM> is described below. It should be noted that, in order to avoid power supply interruptions during the self-cleaning operation of the floor cleaning machine <NUM>, the first control unit <NUM> is pre-stored with a minimum power threshold based on the power required for the self-cleaning operation of the floor cleaning machine <NUM>. The first control unit <NUM> can only perform the self-cleaning operation of the floor cleaning machine <NUM>,if the power level monitored by the power monitoring device <NUM> is greater than the minimum power threshold.

When the user turns on the self-cleaning switch <NUM>, the second control unit <NUM>, which is communicatively coupled with the self-cleaning switch <NUM>, sends a protocol voltage waveform to the first control unit <NUM> via the electrical pathway through the second charging interface <NUM> and the first charging interface <NUM>, which are electrically contacted with each other. It can indicate the start of the self-cleaning operation of the floor cleaning machine <NUM>. When the first control unit <NUM> receives the protocol voltage wave signal, and on the one hand, it sends a signal to disable the charging control circuit <NUM>, the rechargeable battery <NUM> disconnects from the first charging interface <NUM>, and the rechargeable battery <NUM> pauses charging; on the other hand, it makes a pre-judgement on the self-cleaning conditions; and when all the conditions are met, it starts the brush-roller motor <NUM>, the liquid pump <NUM> and the suction motor <NUM> at the same time to perform the self-cleaning control procedure.

The cleaning fluid in the supply tank <NUM> is pumped by the liquid pump <NUM> through the fluid delivery pathway to the fluid distributor and distributed via the fluid distributor to the brush roller <NUM>. The brush roller <NUM>, driven by the brush-roller motor <NUM>, uses the cleaning fluid to wash itself. The suction motor <NUM> creates a negative pressure in the recovery pathway <NUM> from the suction chamber <NUM> to the recovery tank <NUM>, and the spent cleaning fluid and debris from the brush roller <NUM> flows along the fluid recovery pathway <NUM>, reaches and stores in the recovery tank <NUM>.

The first control unit <NUM> also pre-stores a cut-off flow rate threshold corresponding to the flow rate of cleaning fluid, a cleanliness threshold corresponding to the turbidity of the spent cleaning fluid and debris, and a level threshold corresponding to the level of the recovery tank <NUM>. During the self-cleaning operation of the floor cleaning machine <NUM>, the first control unit <NUM> interrupts the self-cleaning operation and reminds the user to add new cleaning fluid if the cleaning fluid flow rate monitored by the cleaning fluid monitoring device <NUM> is lower than the cut-off flow rate threshold; if the level monitored by the level monitoring device <NUM> is higher than the full-level tank threshold, the first control unit <NUM> interrupts the self-cleaning operation and reminds the user to dump the fluid in the recovery tank <NUM>; If the turbidity level monitored by the turbidity monitoring device <NUM> is below the cleanliness threshold, the first control unit <NUM> ends the self-cleaning operation and the self-cleaning operation of the floor cleaning machine <NUM> is finished. In other embodiments, the floor cleaning machine can also cancel the turbidity monitoring device, and the first control unit can be equipped to automatically end the self-cleaning of the floor cleaning machine after the self-cleaning operation has been carried out for a pre-set period of time.

Claim 1:
A floor cleaning system, comprising:
a floor cleaning machine (<NUM>) including:
a cleaning base (<NUM>) movable over a surface to be cleaned and having at least one brush roller (<NUM>);
a fluid delivery unit configured to deliver a cleaning fluid to the at least one brush roller (<NUM>) and comprising a supply tank (<NUM>) for storing the cleaning fluid and a fluid dispenser in fluid communication with the supply tank (<NUM>);
a fluid recovery unit (<NUM>) comprising a recovery tank (<NUM>);
a rechargeable battery (<NUM>) configured to power energy-consuming components of the floor cleaning machine (<NUM>);
a first control unit (<NUM>) controlling the floor cleaning machine (<NUM>) to perform cleaning operations and self-cleaning operations;
a first charging interface (<NUM>) electrically coupled to the rechargeable battery (<NUM>);
a self-cleaning station (<NUM>) including:
a station body (<NUM>) configured to receive and hold at least a portion of the base (<NUM>);
a power plug (<NUM>) provided on the station body (<NUM>) and having ability to be electrically coupled to an external power source;
a second charging interface (<NUM>) configured to electrically contact to the first charging interface (<NUM>) ;
wherein the self-cleaning station (<NUM>) comprises a self-cleaning switch (<NUM>) operably provided on the station body (<NUM>), characterized in that
the self-cleaning station (<NUM>) further comprises a second control unit (<NUM>) communicatively coupled with the self-cleaning switch (<NUM>) and electrically coupled with the second charging interface (<NUM>), and the first control unit (<NUM>) is in signal communication with the second control unit (<NUM>) via an electrical pathway passing through the first charging interface (<NUM>) and the second charging interface (<NUM>) when the first charging interface (<NUM>) is electrically contacted with the second charging interface (<NUM>), such that the self-cleaning operation is performed in response to an indication that the self-cleaning switch (<NUM>) has been turned on .