FIELD OF THE INVENTION

The invention relates to a method of water priming a garment care device.

The invention also relates to a garment care device implementing such a method.

The invention may be used in the field of garment care.

BACKGROUND OF THE INVENTION

It is known garment care devices comprising: a mobile unit comprising a steam generator, a base, a cord for connecting the base and the mobile unit, a water tank and a pump arranged in the base for pumping water from the water tank to the steam generator via the cord.

In those known garment care devices, after a user action on a steam trigger arranged on the mobile unit, water is pumped from the water tank to the steam generator in order that steam is generated by the mobile unit.

For example, the generated steam is used to treat garments, such as removing wrinkles.

The above-mentioned garment care devices have technical limitations in the sense that after the user has actuated the steam trigger arranged on the mobile unit, there is a relatively long delay before steam is finally generated by the steam generator. In other words, such types of garment care devices lack responsiveness in steam generation, which may affect the efficiency of garment treatment, as well as result in a negative user experience.

CN 103 374 812 A discloses a steam-type electric iron, and a control method for controlling the iron. US 2009/084007 A1 discloses a steam iron comprising a base, a main body, and a control board. The base comprises a water tank, a steam generator, and a pump that is connected between the water tank and the steam generator.

WO 2005/054564 A1 discloses a method for ironing a textile item, and an apparatus for carrying out the method.

OBJECT AND SUMMARY OF THE INVENTION

It is an object of the invention to propose a method of water priming a garment care device that avoids or mitigates above-mentioned problems.

The invention is defined by the independent claims. The dependent claims define advantageous embodiments.

To this end, the method according to the invention is for water priming a garment care device comprising a mobile unit comprising a steam generator and a temperature sensor, a base, a cord for connecting the base and the mobile unit, a water tank and a first pump arranged in the base for pumping water from the water tank to the steam generator via the cord.

The method according to the invention comprises the following steps: a step of starting the heating of the steam generator, a first step of detecting, using the temperature sensor, that the steam generator has a temperature equal or larger than a given first increased temperature, after the steam generator has a temperature equal or larger than said given first increased temperature, a step of starting the first pump, a second step of detecting, using the temperature sensor, that the steam generator has a temperature equal or larger than a given second increased temperature, said second increased temperature being equal or larger than said first increased temperature, after the steam generator has a temperature equal or larger than said given second increased temperature, a step of stopping the heating of the steam generator, a step of measuring, using the temperature sensor, at least one rate of temperature decrease for the steam generator, after the at least one rate of temperature decrease of the steam generator has exceeded a certain threshold, a step of stopping the first pump. This method allows that before the garment care device is used by the user for treating garments, the water circuit carrying water between the base and the steam generator arranged in the mobile unit is already primed with water. This method is thus preferably implemented during the start-up phase of the device, right after the user has switched-on the device, and before the time the device indicates to the user that the start-up phase is finished and that the device is ready to be used.

In particular, the water circuit may comprise a water pipe arranged in the cord, as well as other water pipe portions or water path arranged in the base and/or in the mobile unit for carrying water between the base and the steam generator.

The water circuit carrying water between the base and the steam generator arranged in the mobile unit is primed with water when a significant decrease of temperature of the steam generator is detected, reflecting that the water circuit is filled-in with water, and that water has now reached the steam generator.

As a result, when the user actuates the steam trigger, the water circuit is already filled-in with water (i.e. all air has been replaced by water), so that water can be instantaneously dosed into the steam generator, and generate steam also instantaneously. In other words, there is no delay between actuating the steam trigger, and the steam generation.

Moreover, when the water circuit is used to carry water from the base to the mobile unit with the goal to fast-cooling the temperature of the steam generator and a soleplate attached to the steam generator, for example linked to a safety feature in the device having detected the need to decrease the temperature of the soleplate, this goal can be achieved quickly.

The invention also relates to a garment care device implementing steps of the above method.

The invention also relates to a computer program product comprising instructions codes for implementing steps of the above method.

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

Particular aspects of the invention will now be explained with reference to the embodiments described hereinafter and considered in connection with the accompanying drawings, in which identical parts or sub-steps are designated in the same manner :

Fig.1 depicts a garment care device according to the invention,

Fig.2 depicts a flow chart of a method according to the invention,

Fig.3 depicts a first series of signals when a method according to the invention is used, Fig.4 depicts a second series of signals when a method according to the invention is used.

DETAILED DESCRIPTION OF THE INVENTION

Fig.1 depicts a garment care device 100 according to the invention.

The garment care device 100 comprises: a mobile unit 101 comprising a steam generator 102 and a temperature sensor, a base 103, a cord 104 for connecting the base 103 and the mobile unit 101, a water tank 105 and a first pump PI arranged in the base 103 for pumping water from the water tank 105 to the steam generator 102 via the cord 104.

The cord 104 may correspond to a hose cord comprising at least one water pipe to carry water from the water tank 105 to the steam generator 102.

The temperature sensor may detect a temperature of the steam generator, such as a temperature within the steam generator. The temperature sensor may, for instance, comprise or consist of a thermistor.

The temperature sensor may be in thermal contact with the steam generator. For example, the temperature sensor may be mounted on or in a wall of the steam generator.

Preferably, as illustrated, the mobile unit 101 is a steam iron 101 or a steamer head (not shown). Preferably, as illustrated, the base 103 further comprises a second steam generator 106 supplied in water by a second pump P2 from the water tank 105, for generating steam carried from the base 103 to the mobile unit 101 via the cord 104.

The base 103 comprises a micro controlling unit MCU adapted to actuate the pump PI and/or P2, retrieve a temperature signal from the temperature sensor, and perform various measurements and calculations, by running a computer program product comprising instructions codes implementing steps of the method according to the invention that will be described in the following.

Fig.2 depicts a flow chart of a method according to the invention.

The various steps of the method will also be described along with Fig.3 which depicts a first series of signals when a method according to the invention is used.

The method comprises a step SI of starting the heating of the steam generator 102. This step is started at time tO. At that time, the temperature T of the steam generator 102 is TO, which may for example be close to the ambient room temperature where the device is located. After the heating of the steam generator 102 has started, the temperature of the steam generator 102 increases, more or less linearly depending on the characteristics of the steam generator 102.

The method also comprises a first step S2 of detecting that the steam generator 102 has a temperature T equal or larger than a given first increased temperature Tl. This implies that a temperature measurement of the steam generator 102 is performed regularly, for example every second. In the diagram of Fig.3, the steam generator 102 has a temperature T equal or larger than said given first increased temperature Tl at time tl. Preferably, the given first increased temperature Tl is a value in the range [90; 150] degrees Celsius, for example 120 degrees Celsius.

After the steam generator 102 has a temperature T equal or larger than said given first increased temperature Tl, the method also comprises a step S3 of starting the first pump PI. In the diagram of Fig.3, this may happen at time tl or slightly later. Water is thus pumped from the water tank 105, and water starts to flow along the water circuit formed by: a water pipe portion between the water tank 105 and the first pump PI, - the inside of the first pump P 1 , a water pipe portion in the base 103 being downstream the first pump PI, a water pipe portion in the hose cord 104, a water pipe portion in the mobile unit 101 being upstream the steam generator 102.

This is typically the path followed by water for the first time the garment care device is used.

In case the water circuit would already be partly filled-in with water, for example if the user has recently used the garment care device, water will continue to flow along the water circuit from the point where water had drained out or had evaporated.

The method also comprises a second step S4 of detecting that the steam generator 102 has a temperature T equal or larger than a given second increased temperature T2, the second increased temperature T2 being equal or larger than said first increased temperature Tl. This implies that a temperature measurement of the steam generator 102 is performed regularly, for example every second. In the diagram of Fig.3, the steam generator 102 has a temperature T equal or larger than said given second increased temperature T2 at time t2. Preferably, the given second increased temperature T2 is a value in the range [130; 190] degrees Celsius, for example 150 degrees Celsius.

After the steam generator 102 has reached said given second increased temperature T2, the method also comprises a step S5 of stopping the heating of the steam generator 102. At this point in time, this given second increased temperature T2 is deemed a sufficiently high temperature for the steam generator 102 in terms of for example being able to generate a sufficient amount of steam as soon as the start-up phase of the device will be elapsed.

The method also comprises a step (S6) of measuring at least one rate of temperature decrease for the steam generator (102).

Since the supply of energy to the steam generator 102 is stopped, the temperature of the steam generator 102 will in turns decrease step by step. It is noted that right after the heating of the steam generator 102 has been stopped, the temperature of the steam generator 102 might still increase little bit until the hottest areas of the steam generator 102 have balanced in temperature with cooler areas of the steam generator 102. This is illustrated in Fig.3 by a temperature overshoot OV. Anyway, the presence of this overshoot OV does not affect the robustness of the measurements and calculations conducted by the method according to the invention.

As long as the water pumped from the water tank 105 has not reached the steam generator 102, the temperature of the steam generator 102 will in general decrease relatively slowly, mainly via loss of energy by thermal convection in the surrounding ambient air, and/or by thermal conduction if the mobile unit 101 is placed on a support during the start-up phase. On the contrary, when the water pumped from the water tank 105 reaches the steam generator 102, the rate R of temperature decrease of the steam generator 102 will be higher, in particular when exceeding a certain threshold TH. The method according to the invention uses this approach to identify that water pumped from the water tank 105 has reached the steam generator 102. This implies that a measurement of the rate R of temperature decrease of the steam generator 102 is performed regularly, for example every second.

After the at least one rate R of temperature decrease of the steam generator 102 has exceeded said certain threshold TH, the method also comprises a step S7 of stopping the first pump PI. In the diagram of Fig.3, the step S7 of stopping the first pump PI happens at time t3.

Preferably, said at least one rate R of temperature decrease is measured as an elapsed time for a given amount of temperature decrease.

For example, the time elapsed for a given amount of temperature decrease of for example 3 degrees Celsius is measured, and this time elapsed is compared with a time threshold of for example 4 seconds. If the measured time elapsed (for example 3 seconds) is less than the time threshold, this means that water pumped from water tank 105 has reached the steam generator 102

Alternatively, said at least one rate R of temperature decrease is measured as a temperature decrease over a given duration of elapsed time.

For example, the temperature decrease for a given time elapsed of for example 4 seconds is measured, and this temperature decrease is compared with a temperature threshold of for example 3 degrees Celsius. If the measured temperature decrease (for example 4 degrees Celsius) is more than the temperature threshold, this means that water pumped from water tank 105 has reached the steam generator 102. Preferably, the at least one rate R of temperature decrease comprises a plurality of consecutive rates of temperature decrease exceeding said certain threshold (TH), preferably two or three consecutive rates of temperature decrease. This prevents from false detections of water reaching the steam generator 102. In other words, this improves the robustness of detecting that water has reached the steam generator 102 and that the water circuit is now fully filled-in with water (i.e. the water circuit is primed).

For example, if three consecutive rates of temperature decrease are used, when the heating of the steam generator 102 is stopped at time t2 with a temperature of 150 degrees Celsius, a first check of the rate (R) of temperature decrease is made when the steam generator 102 reaches 147, then a second check of the rate (R) of temperature decrease is made when the steam generator 102 reaches 144, then a third check of the rate (R) of temperature decrease is made when the steam generator 102 reaches 141. If each of those three checks are such that the rate R of temperature decrease of the steam generator 102 has exceeded a certain threshold TH, this means that water has reached the steam generator 102 and that the water circuit is now fully filled-in with water (i.e. the water circuit is primed).

Preferably, the step S6 of measuring at least one rate R of temperature decrease for the steam generator 102 is started either: immediately from the time said steam generator 102 has reached said second increased temperature T2 and the heating of the steam generator 102 has been stopped, or after a certain duration from the time said steam generator 102 has reached said second increased temperature T2 and the heating of the steam generator 102 has been stopped.

For example, if the at least one rate R of temperature decrease is measured as an elapsed time for a given amount of temperature decrease, the measured time elapsed is started from time t2, or a time delayed by a fixed value after time t2, for example two seconds.

For example, if the at least one rate R of temperature decrease is measured as a temperature decrease over a given duration of elapsed time, the measured temperature decrease is started from temperature T2 at time t2, or the temperature at a time delayed by a fixed value after time t2, for example two seconds. Preferably, the step S3 of starting the first pump PI comprises setting the water flow rate of the first pump PI in the range [3;30] g/mn.

Values in this range provides a good balance between having a sufficient flow rate making possible to finish the priming of the water circuit before the end of the start-up phase of the device, and not too high values of the flow rate that might have otherwise result in flooding the steam generator 102 before stopping the first pump PI.

For example, if the total water volume of the water circuit is about 20 cm3, a flow rate of 9 g/mn for the first pump PI can be selected.

For example, the water flow rate of the first pump (PI) may be set by varying the duty cycle of the activation of the first pump (PI).

Preferably, after the step S7 of stopping the first pump PI, the method further comprises a step S8 of setting the device in an operating mode allowing any of the following modes: decreasing the temperature of the first steam generator 102 by starting the first pump PI, and/or delivering a boost of steam by the first steam generator 102 by starting the first pump PI

Preferably, the method further comprises comprising a step S9 of stopping the first pump PI, if after a given duration Dmax starting from said step SI of starting the heating of the steam generator 102, the at least one rate of temperature decrease of the steam generator 102 has not exceeded said certain threshold TH.

This situation reflects a potential problem in the garment care device such as a water pipe broken or with leaking, water pipe stroked, pump deficient.... In that case, it is preferred to stop the first pump PI .

The given duration Dmax is counted from time tO. For example, Dmax = 3 mn.

Preferably, the method further comprises a step S10 of setting the device in an operating safe mode after the step S9 of stopping the first pump PI.

For example, the operating safe mode can be choose among the following:

- limiting the temperature of the steam generator 102 to a certain maximum temperature (e g. 150 degrees), - not activating the first pump PI with the goal of reducing the temperature of the steam generator 102.

Fig.4 depicts a second series of signals when a method according to the invention is used.

Fig.4 differs from Fig.3 is that the first increased temperature T1 has same value has the second increased temperature T2, for example 150 degrees Celsius.

The first pump PI is started much later than in the scenario of Fig.3. Indeed, the first pump PI is here started at time t2. In general, this means that less time will be available to complete the water priming of the water circuit.

This scenario is thus preferred in case of the water volume of the water circuit to prime is relatively smaller.

The above embodiments as described are only illustrative, and not intended to limit the technique approaches of the present invention. Although the present invention is described in details referring to the preferable embodiments, those skilled in the art will understand that the technique approaches of the present invention can be modified or equally displaced without departing from the protective scope of the claims of the present invention. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. Any reference signs in the claims should not be construed as limiting the scope.