A garment care system with water pump

FIELD OF THE INVENTION

The invention relates to a garment care system. The invention more particularly relates to a garment care system comprising an iron and a separate base unit. BACKGROUND OF THE INVENTION

The core function of a garment care steam appliance is to generate steam for garment treatment. Steam is the key element to deliver result, and, most of the time, performance of a garment care steam appliance is rated by steam performance. There are many ways for a garment care steam appliance to indicate steam performance, however, to an ordinary user, the time delay in the steam start is one of the most obvious factor for him/her to judge product performance.

Typically, a garment care steam appliance comprises a steam engine in which water is supplied, wherein the steam engine converts the water into steam instantaneously. In such an appliance, water dosing performance plays an important role in steam generation performance. Dosing can be simply done by gravity, but, for fast steam response and higher steam pressure, special technical solutions are normally used including water pumps, in order to achieve fast, pressured, and controllable water dosing. In such application, to improve water delivery performance becomes the key path of improving overall product performance.

Published patent WO 2007/013002 A2 discloses a steam ironing device having a pressurized water tank, for example, a spring-loaded water tank.

Published patent FR 2 853671 Al relates to steam irons in which a water pump in a base unit supplies pressurized water to a vaporization chamber.

SUMMARY OF THE INVENTION

It is an object of the present invention to propose an improved garment care system that substantially alleviates or overcomes one or more of the problems mentioned above. The invention is defined by the independent claims. The dependent claims define advantageous embodiments.

According to a first aspect of the invention, there is provided a garment care system comprising an iron and a base unit connected via a hose cord. The iron comprises a steam engine for receiving water from the base unit via the hose cord. The base unit comprises a water tank for storing water, a volume deformable container, an electric valve arranged between the hose cord and the volume deformable container, and a water pump for pumping water from the water tank into the volume deformable container, wherein an open state and closed state of the electric valve is controllable from the iron so that in a closed state of the electric valve, a water pressure is built up in the volume deformable container by actuating the water pump, and in an open state of the valve, pressurized water in the volume deformable container is delivered into the hose cord.

By using an electric valve, the valve can be controllable from the iron while being arranged in the base unit. This will reduce the space needed for components in the iron itself. It is noted that more components are arranged inside the base unit as compared to the state of the art systems. However, this will not give any problems, since the base unit is normally not move by the user, and can be designed so as to provide sufficient space for additional components.

Preferably, the volume deformable container is an elastically deformable tube arranged in the base unit between the water pump and the electric valve.

Preferably, the base unit comprises a deformable reservoir in fluid communication with an output of the water pump and an input the electric valve.

Preferably, the hose cord comprises an electrical wire to carry an electrical control signal for controlling the opening/closing of the electric valve.

Preferably, the base unit comprises a control unit connected to the electrical wire.

Preferably, the control unit is adapted, upon receiving the electrical control signal, to open the electric valve, and activate the water pump.

Preferably, the base unit further comprises a pressure regulator for regulating water pressure in the volume deformable container.

Preferably, the pressure regulator comprises a pressure relief valve arranged to release water out of the volume deformable container into the water tank, if water pressure in the volume deformable container exceeds a given threshold (TH1).

Preferably, the pressure regulator comprises a pressure sensor for measuring water pressure in the volume deformable container, the pressure sensor being connected to the control unit, the control unit being adapted to generate a control signal to the water pump for stopping the water pump if the water pressure in the volume deformable container exceeds a given threshold (TH2). Preferably, the pressure regulator corresponds to a pressure switch connected to the water pump, the pressure switch being arranged for switching off the water pump if the water pressure in the volume deformable container exceeds a given threshold (TH3).

Preferably, the pressure regulator corresponds to a pressure switch connected to the water pump, the pressure switch being arranged for switching on the water pump if the water pressure in the volume deformable container drops below a given threshold (TH4).

Detailed explanations and other aspects of the invention will be given below. BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will be apparent from and elucidated further with reference to the embodiments described by way of example in the following description and with reference to the accompanying drawings, in which

Figure 1 shows a garment care system according to an embodiment of the invention;

Figure 2 shows a garment care system according to a further embodiment of the invention;

Figure 3 shows an embodiment wherein the pressure regulator comprises a pressure relief valve arranged to release water out of the volume deformable container;

Figure 4 shows an embodiment wherein the pressure regulator comprises a pressure sensor for measuring water pressure;

Figure 5 shows an embodiment wherein the pressure regulator corresponds to a pressure switch connected to the water pump;

Figure 6 shows an embodiment wherein the base unit comprises a deformable reservoir;

Figure 7 shows a flow chart of a simplified control flow of a typical garment care system having no electric valve, and

Figure 8 shows a flow chart of an improved control flow of a typical garment care system having an electric valve.

The figures are purely diagrammatic and not drawn to scale. In the Figures, elements which correspond to elements already described may have the same reference numerals. DETAILED DESCRIPTION OF EMBODIMENTS

Figure 1 shows a garment care system 1 according to an embodiment of the invention. The garment care system 1 comprises an iron 2 and a base unit 3 connected via a hose cord 41. The iron 2 comprises a steam engine 21 for receiving water from the base unit 3 via the hose cord 41. The base unit 3 comprises a water tank 31 for storing water, a volume deformable container 32, and an electric valve 33 arranged between the hose cord 41 and the volume deformable container 32. The base unit also comprises a water pump 34 for pumping water from the water tank 31 into the volume deformable container 32.

The electric valve has an open state and a closed state. In the closed state of the electric valve 33 a water pressure is built up in the volume deformable container 32 by actuating the water pump 34, and in the open state of the valve, pressurized water in the volume deformable container 32 is delivered into the hose cord 41.

In the embodiment of Figure 1, the hose cord 41 comprises an electrical wire 42 to carry an electrical control signal for controlling the opening/closing of the electric valve 33. The iron 2 comprises a user-actuated element 22 to generate the electrical control signal. For example, the user-actuated element 22 is an on/off switch, or a sensor for detecting the presence of a user, or the motion of the iron.

The base unit 3 comprises a control unit 35 connected to the electrical wire 42. The control unit 35 is arranged to control the electric valve 33 and the water pump 34. The open state and closed state of the electric valve 33 is controllable from the iron 2 indirectly via the control unit 35, by actuating the user-actuated element 22.

Alternatively (not shown), the electrical wire 42 is directly connected to the electric valve 33 to control its open state and closed state, by actuating the user-actuated element 22. In this case, the time response to open or close the electric valve 33 may be faster, for example faster by a few tens of milliseconds, as compared to indirectly controlling the electric valve 33 via the control unit 35.

Control of the valve may be implemented by any suitable mechanism. For example, the control may be implemented directly from the user-actuated element 22 so that the control unit 35 controls the pump and the user-actuated element 22 directly controls the valve 33.

If the electric valve is opened, water immediately flows from the deformable container 32 through a connection pipe 37 arranged in the base unit 3 into a water pipe 44 arranged in the hose cord 41. It is noted that pipe 37 can be part of pipe 44, meaning that pipe 37 and pipe 44 form a same pipe. The water will flow through the water pipe 44 into the steam engine 21 so as to create steam, which will leave the iron via one or more openings (not shown in Figure 1).

In the embodiment of Figure 1, the volume deformable container 32 is an elastically deformable tube arranged in the base unit 3 between the water pump 34 and the electric valve 33. If the electrical valve 33 is closed, and the water pump 34 is activated, a water pressure is built up in the volume deformable container 32.

Figure 1 also shows a power plug 5 for connection to a power supply. By plugging in the power plug 5, the components of the base unit 2 can be powered as well as the components of the iron 2, which receive the electrical power via a power line 43 arranged in the hose cord 41.

Figure 2 shows a garment care system 1 according to a further embodiment of the invention. Figure 2 corresponds to Figure 1 except for an additional pressure regulator 36 for regulating water pressure in the volume deformable container 32.

The base unit 3 functions as a water delivery system for the iron 2 which is able to generate steam instantaneously via dosing water into its steam engine 21. In the water delivery system, during its working cycles, a certain amount of water can be stored under pressure, which can be used to create fast water release, a jet water dosing effect, when discharged. The base unit 2 may have the following working cycles.

I) The controller 35 closes the electric valve 33 and keeps the water pump 34 running for a certain time with a certain rate, and then, a certain amount of water is pushed into deformable tube 32 by the pumping action. The deformed volume size of the deformable tube 32 determines the amount of stored water; energy is stored by this deformation caused by additional pumping when the electric valve 33 is closed; the chamber formed by the deformed tube applies pressure onto stored water ; and the pressure regulator determines the pressure level.

II) When water supply is requested to do steam generation, the controller 35 opens the electric valve 33 and turns on the water pump 34. Thanks to above mentioned setup, a very fast moving water stream is generated immediately by the pre-stored water in the deformable tube 32 under the pre-stored pressure. The generation of the water stream is instantaneous once the electric valve 33 is opened, which is independent from pumping action and its momentum and volume also help to compensate negative effects from resistance and absorption by piping line. Eventually, the fast response water stream creates a fast dosing into steam engine 21 to achieve fast steam start, meanwhile, following water flow pushed by pump catches up and keep steam running as per request.

Ill) Once steam generation is no longer needed, the controller 35 closes the electric valve 33 and lets the water pump 34 to refill the deformable tube 32 and rebuild the pressure, what is the repeat of the first step.

For example, in an embodiment, wherein capacity of the steam engine to generate steam is low, the water storage in the volume deformable container 32 is about 0.4g with a water pressure of 0.8bar, and it takes 0.5sec pumping time under ~225g/min pumping rate to build.

In another embodiment, wherein steam engine capability is high, the water storage in the volume deformable container 32 is about 2g with a water pressure up to 3bar, and it takes about lsec pumping time under about 225g/min pumping rate to build.

In an embodiment, shown in Figure 3, the pressure regulator 36 comprises a pressure relief valve 36a arranged to release water out of the volume deformable container 32 into the water tank 31, if water pressure in the volume deformable container 32 exceeds a given threshold TH1. By releasing water out of the volume deformable container 32 if a certain threshold is exceeded, this avoids that the pressure and volume become too high. In this way, unwanted damage to the volume deformable container 32 can be avoided, and pressure inside the volume deformable container 32 is regulated.

In another embodiment, as shown in Figure 4, the pressure regulator 36 comprises a pressure sensor 36b for measuring water pressure in the volume deformable container 32. The pressure sensor 36b is connected to the control unit 35, the control unit 35 is adapted to generate a control signal to the water pump 34 for stopping the water pump 34 if the water pressure in the volume deformable container 32 exceeds a given threshold TH2. The threshold TH2 can be a fixed value. Alternatively, the threshold TH2 is a variable parameter determined by the control unit 35. In another embodiment, as shown in Figure 5, the pressure regulator 36 corresponds to a pressure switch 36c connected to the water pump 34. The pressure switch 36c is arranged for switching off the water pump 34 if the water pressure in the volume deformable container 32 exceeds a given threshold TH3. In an embodiment, the pressure switch 36c is also arranged for switching on the water pump 34 if the water pressure in the volume deformable container 32 drops below a given threshold TH4. By the controlled switching on and off of the water pump 34, the water pressure in the volume deformable container 32 can be held within limits.

In above embodiments, value of TH1, TH2, TH3, TH4 can be the same.

In another embodiment depicted in Figure 6, the base unit 3 comprises a deformable reservoir 39 in fluid communication with an output of the water pump 34 and an input the electric valve 33. The deformable reservoir 39 is arranged to store and keep pressure for the water amount used for fast water stream generation. The deformable reservoir 39 can be container made out of a flexible material. Alternatively, the deformable reservoir 39 can comprises rigid walls, but having a movable biased part (e.g. a piston) so as to be provide for a variable volume depending on the pressure of its interior. Alternatively, the deformable reservoir 39 has a rigid outer wall and with compressible material inside (such as air) so as to be provide for a volume deformable storage depending on the pressure of its interior.

It is noted that the deformable reservoir 39 can be the only volume deformable container in the base unit 3. Alternatively, the tube 32 can be deformable as well. In that case, two volume deformable containers are arranged in the base unit 3. It is further noted that the pressure regulator 36 shown in Figures 2-5 could also be present in the base unit 3 with the deformable reservoir 39. The pressure regulator 36 could be arranged in the deformable reservoir 39 or in the deformable tube 32.

In an specific embodiment, the control unit 35 is adapted, upon receiving the electrical control signal from the actuated element 22, to open the electric valve 33, and activate the water pump 34. This allows delivering a flow of water in the hose cord 41, for example a continuous flow of water. The opening of the electric valve 33 and the activation of the water pump 34 are performed simultaneously. Alternatively, the electric valve 33 is opened just before the water pump 34 is activated.

The advantage of implementing the electric valve 33 in the garment care system and properly controlling the electric valve 33 and the water pump 34 will be further discussed with reference to Figure 7 and Figure 8.

Considering building blocks and cost constrain of a domestic garment care steam appliance, most likely only single core and single task processor will be used, also, its clock speed will not be too fast. In order to control multiple function units with limited processing power, some priorities have to be defined. In a typical control logic of a garment care steam appliance, in order to ensure proper core functionalities, processes related to temperature management normally take higher order than flow control. Most of the time, flow control decision is one of the result of temperature management decision. Counting process priorities and processing cycles, it easily takes about 0.1 sec before controller can give commands for water dispensing and about another 0.1 sec to decide how it should be dispensed in certain kind of way.

Figure 7 shows a flow chart of a method of controlling water flow in a known garment care system having no electric valve. The method steps can be performed by a controller arranged to control the water pump and a temperature control arranged in the system.

The method of controlling starts with receiving a request of steam triggering, see block 701.

Next, a signal confirmation decision is made by the controller (preferably after filtering and noise cancellation processes), see 702. In this step, the controller confirms the signal which is received is a request, and not noise or interference. This can be normally done by software buffering and/or multiple sampling and comparing.

Then, a temperature check of the steam engine temperature is performed, see

703.

The next block 704 indicates a water dosing flowrate pattern decision, which is made based on the sensed temperature of the steam engine and a pre-determined look-up table, in order to perform certain water dosing flowrate pattern based on the temperature reading. Below table is an example of such a look-up table:

Next, the temperature control of the steam engine is adjusted to prepare for incoming water and use cases change, see block 705. Indeed, many garment care systems use dynamic control, i.e. system setting will change according to user behavior, like vertical mode, auto steam etc...and those garment care systems keep monitoring these status and make changes accordingly. It is followed by a pump start timing check 706, which is necessary to protect pump and its control circuit by switching around zero point of alternative current that drives the pump.

Next, a pump driving signal is output to a pump driving circuitry, see 707, so as to activate the water pump.

Other control processes, see 708, may follow not related to the pumping. First, the water pump primes (i.e. sucks water to fill its inlet and internal air vacancy), sucking water from water source, once received driving signal, see block 709. After that, water will start moving towards steam engine, see block 710.

In Figure 7, the arrow 715 indicates the time delay between the receiving of the trigger and the moving of the water. Since the water only starts to move after the controller has confirmed its working statue and has decided how it should react to the triggering demand, the time delay may be significant. In many state of the art systems, this delay can be up to a hundred micro-seconds (for example 200 micro-seconds), which negatively affects user experience, as indicated in the Background section of the invention.

Thanks to the introducing of electric valve as described above with reference to Figures 1-6, it is possible to provide for a short cut for early water movement. This will be explained with reference to Figure 8 which shows a flow chart of a method of controlling performed by the controller 35 according to the invention.

The improved method of controlling starts with receiving a request of steam triggering, see block 801.

Next, a signal confirmation decision is made by the controller (preferably after filtering and noise cancellation processes), see 802.

Then, the controller 35 outputs a electric valve ON signal, see block 803 to actuate the electric valve 33.

Then, a temperature check of the steam engine temperature is performed, similar to 703, see 804.

The next block 805 indicates a dosing pattern decision, similar to 704.

Next, the temperature adjustment is performed, similar to 705, see block 806, followed by a pump start timing check 807, similar to 706.

Next, a pump driving signal is output to the water pump driving circuitry, similar to 707, see 808, so as to activate the water pump. Other control processes, similar to 708, see 809, may follow not related to the pumping.

Due to the limited number of steps required to operate the electric valve, early electric valve ON signal can be output, see block 803. The electric valve 33 will thus be activated quickly after that, see 810, and the water will start moving before the pump is activated, see block 811, which refers to the 'leading water moving'. Movement of the water before the pump is activated is possible, since the water in the volume deformable container 32 was put under pressure in earlier operating steps (not shown in Figure 8).

Similar to the processes of Figure 7, Figure 8 shows that due to the pump driving signal, see the block 808, the water pump is primed, see block 812, and the following water will start moving, see block 813.

In Figure 8, the arrow 815 indicates the time delay between the receiving of the trigger and the moving of the (leading) water. Since this water already start to move after the controller has confirmed its working statue, the time delay is less than in Figure 7. The water already starts to move before controller 35 makes any other fundamental decision, see blocks 804-807.

The present of the electric valve 33 together with its operating in advance scheme thanks to its simple activation process, see Figure 8, water starts to move much earlier compared to that in original systems. Although there is only limited amount of 'leading water', it's sufficient to cover the time delay caused by processing time. Since steam generation is started earlier, steam response becomes faster and total steam start delay will be less, which is beneficial for the user ironing experience.

It will be appreciated that the above description for clarity has described embodiments of the invention with reference to different functional units and processors.

However, it will be apparent that any suitable distribution of functionality between different functional units or processors may be used without deviating from the invention. For example, functionality illustrated to be performed by separate units, processors or controllers may be performed by the same processor or controllers. Hence, references to specific functional units are only to be seen as references to suitable means for providing the described functionality rather than indicative of a strict logical or physical structure or organization.

It is noted, that in this document the word 'comprising' does not exclude the presence of other elements or steps than those listed and the word 'a' or 'an' preceding an element does not exclude the presence of a plurality of such elements, that any reference signs do not limit the scope of the claims, that the invention may be implemented by means of both hardware and software, and that several 'means' or 'units' may be represented by the same item of hardware or software, and a processor may fulfil the function of one or more units, possibly in cooperation with hardware elements. Further, the invention is not limited to the embodiments, and the invention lies in each and every novel feature or combination of features described above or recited in mutually different dependent claims.