EP3559332B1

EP3559332B1 - Steam iron with increased water head

Info

Publication number: EP3559332B1
Application number: EP17821935.8A
Authority: EP
Inventors: Shenghuai Calvin LIN; Hee Keng CHUA; Milind Vishwas DATE; Hee Poh SIN
Original assignee: Koninklijke Philips NV
Current assignee: Koninklijke Philips NV
Priority date: 2016-12-22
Filing date: 2017-12-22
Publication date: 2020-05-13
Anticipated expiration: 2037-12-22
Also published as: EP3559332A1; RU2019123104A3; WO2018115518A1; CN110168160B; CN110168160A; RU2019123104A; RU2750373C2

Description

FIELD OF THE INVENTION

The present invention relates to a garment steaming device and more specifically to a garment steaming device being a steam iron.

BACKGROUND OF THE INVENTION

Garment steaming devices, such as steam irons, generate steam for removing creases and wrinkles from fabric. The most common method of producing steam is to dose water from a reservoir through a controlled orifice into a steam generator where it is heated to generate steam. The reservoir is normally above the steam generator in an operational position of the garment steamer so that gravity influences the flow of water from the reservoir into the steam generator.
Water dosed into the steam generator is evaporated. The volumetric expansion that takes place can cause instances of relatively high pressure to occur. This high pressure in the steam generator can exceed the pressure at the orifice caused by the hydraulic head of water in the reservoir above the steam generator, especially when the steam vents through which steam is ejected onto a fabric being treated are blocked or covered by the fabric. When this occurs, the dosing of water into the steam generator through the orifice is restricted until the pressure in the steam generator falls below the pressure at the orifice generated by the hydraulic head of water in the reservoir. As water is restricted from entering the steam generator, the rate at which steam is produced is reduced compromising performance of the device.
In an attempt to address the temporary restriction in the flow of water into the steam generator from the reservoir, it is known to, for example, shape the surface of the device and configure the vents through which steam is ejected onto the fabric so that not all the steam vents will be covered or will become at least partially blocked by the fabric during use. However, although this can effectively reduce the back pressure in the steam generator, steam is ejected into the atmosphere without passing through the fabric and so is wasted. It is also known to provide the device with a pump to force water into the steam generator from the reservoir through the orifice against any back pressure. However, the provision of a pump increases the weight, size and cost of the device and increases its complexity.
Patent US 4484399 A , which is considered as the closest state of the art, discloses a steam iron having a heated soleplate and a water reservoir with at least one manually operable passageway for the measured delivery of water into a vaporisation cavity adjoining the soleplate.
Patent US 2016/122937 A1 discloses the use of two water chambers in a cordless steam iron to prevent excessive unwanted condensation.
Patent US 2 700 236 discloses a water reservoir having a horizontal extension that extends over the cover plate. Ejection of steam is controlled by the operator by means of pump lever that is engaged with a pump cylinder, when actuated water is passed from the water reservoir via the pump cylinder into the steam generating chamber.
Patent JP H03 77586 A discloses a water tank formed of a first storage water chamber in a front section of the iron and a second storage water chamber in a rear section of the tank to ensure that water is fed smoothly into the evaporation chamber.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a garment steaming device, the device being a steam iron, which substantially alleviates or overcomes one or more of the problems mentioned above.
The invention is defined by the independent claim. The dependent claims define advantageous embodiments.
According to the present invention, there is provided a garment steaming device being a steam iron and comprising:

a first water chamber;
a second water chamber situated in a heel portion of the garment steaming device;
a steam generator situated below the first water chamber in an operational orientation of the garment steaming device;
a first fluid path connecting the first water chamber and the steam generator; and
a vent pipe connected to a top part of the second water chamber by its first end and open to the atmosphere at its second end , the second end of the vent pipe extending at least as far as the maximum water level height of the first water chamber when the garment steaming device is in a non-operational orientation;
characterized in that a second fluid path connects a bottom end of the first water chamber to a lower part of the second water chamber, the cross-sectional diameter of the second fluid path is in the range of 2 mm to 15 mm, and the second water chamber is arranged wholly above the first water chamber in the operational orientation so that a water level height of the second water chamber is higher than a water level height of the first water chamber in said operational orientation, so that the water head in the first fluid path generated by the fluid coupling the second water chamber and the first water chamber is increased to obtain an increased steam rate when the garment steaming device is in the operation orientation.

As the water head from the second water chamber and the first water chamber to the steam generator is increased due to the increased distance between the water level in the second water chamber to first fluid path, an elevated steam pressure in the steam generator is overcome by the water head to maintain a consistent flow of water from the reservoir to the steam generator and therefore a generally constant steam generation rate. The second water chamber is arranged wholly above the first water chamber in the operational orientation.
Therefore, as long as there is water in the second water chamber the water head will be greater than the water head provided by water contained in the first water chamber alone, and so an improved or more consistent steam generation rate is achieved when the garment steaming device is in its operational orientation.
Advantageously, the second water chamber and the first water chamber are arranged such that when the garment steaming device is moved into its non-operational orientation from the operational orientation, water is displaced from the first water chamber into the second water chamber through the second fluid path until the water level heights in the first water chamber and the vent pipe are the same.
Therefore, the ability to replenish the second water chamber, by moving the garment steaming device into its non-operational orientation, allows an increased water head to be re-established once the garment steaming device is returned to its operational orientation for further use. This means that an increased steam generation rate can be maintained for longer periods without user intervention other than by moving the device between operational and non-operational orientations.
The first fluid path may be arranged higher than the maximum water level height of the first water chamber when the garment steaming device is in the non-operational orientation to allow the air in the steam generator to pass into the first water chamber through the first fluid path as the water is displaced from the first water chamber into the second water chamber.
Therefore, the first water chamber, the second water chamber, and the vent pipe can act as communicating vessels so that the water level in the first water chamber and the second water chamber or the vent pipe is the same. This allows more water to flow through the second fluid path and be retained in the second water chamber to provide an increased water head when the garment steaming device is returned to its operational orientation allowing an increased steam generation rate to be maintained.
Preferably, the first water chamber, the second fluid path, the second water chamber, and the vent pipe are conjointly formed into a substantially "U"-shaped construction.
Advantageously, the capacity of the second water chamber is in the range of 5 ml to 50 ml.
A smaller second water chamber capacity provides a shorter duration during which an increased water head is provided before the device needs to be moved into its non-operational position to refill the second water chamber. A larger second water chamber provides a longer duration during which an increased water head is provided. The capacity of the second water chamber can be tailored to the steam generator to ensure that the increased water flow rate through the first fluid path caused by the increased water head provided by the second water chamber does not overfill the steam generator and cause it to cool to a temperature which is too low to generate steam.
The cross-sectional diameter of the second fluid path is in the range of 2 mm to 15 mm.
Therefore, the effective flow path resistance during replenishment of the second water chamber can be controlled. The smaller the cross-sectional diameter of the second fluid path, the larger the flow resistance and so the longer it takes to replenish the second water chamber.
The second fluid path may be formed into a right angle-shaped construction between the first water chamber and the second water chamber.
Advantageously, the second fluid path is formed integrally with or separately from the first water chamber and/or the second water chamber.
Preferably, the first water chamber comprises a water inlet and a sealing member located on the sidewall thereof, the water inlet being configured to allow the first water chamber and the second water chamber to be filled with water in the non-operational orientation, the sealing member being configured to seal the water inlet once the first water chamber and the second water chamber have been filled and prior to the movement of the garment steaming device into the operational orientation.
Therefore, the steam iron can be easily filled with water when in the non-operational orientation so that it is filled to the maximum water level height. Sealing of the water inlet traps air in the first water chamber when the garment steaming device is moved into the operational orientation so that water held in the second water chamber cannot fill the first water chamber and the increased water head is maintained.
The garment steaming device is a steam iron.
Advantageously, the non-operational orientation indicates an orientation in which the steam iron may be rested on its heel portion on a countertop. Therefore, a user can leave the steam iron to stand unsupported whilst the second water chamber is replenished by the first water chamber. Alternatively, the iron may be held in the hand of a user in its non-operational orientation whilst the second water chamber is replenished by the first water chamber.
Preferably, the second water chamber is arranged in the heel portion behind a back cover. Therefore, when the steam iron is placed on its heel portion, the water flows from the first water chamber to the second water chamber under the influence of gravity.
Conveniently, the vent pipe may be arranged inside a handle of the steam iron.
Preferably, there is a soleplate situated against the steam generator in which water is converted into steam, the soleplate having multiple steam venting holes therein and facing the garment to be ironed once the garment steaming device is moved into the operational orientation from the non-operational orientation.
Therefore, the steam, generated at an increased or consistent rate, can be directed onto the garment to be treated. A consistent steam rate will increase the steam iron's performance and help to remove creases.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Fig. 1 shows a schematic side view of an embodiment of a garment steaming device according to the present invention;
Fig. 2a shows a schematic side view of the embodiment shown in Fig. 1 in its non-operational orientation prior to a first and second water chamber being filled with water;
Fig. 2b shows a schematic side view of the embodiment shown in Fig. 2a after the water chambers have been filled;
Fig. 2c shows a schematic side view of the embodiment shown in Fig. 2b having been moved into its operational orientation;
Fig. 2d shows a schematic side view of the embodiment shown in Fig. 2c after some of the water has been turned into steam;
Fig. 2e shows a schematic side view of the embodiment shown in Fig. 2d moved into its non-operational orientation to recharge/refill the second water chamber;
Fig. 2f shows a schematic side view of the embodiment shown in Fig. 2e moved into its operational orientation;
Fig. 2g shows a schematic side view of the embodiment shown in Fig. 2f when the water in the water chambers is substantially depleted;
Fig. 3a shows a schematic side view of the garment steaming device comprising a steam iron in its operational orientation;
Fig. 3b shows a schematic side view of the garment steaming device comprising the steam iron shown in Fig. 3a in its non-operational orientation; and
Fig. 4 shows a table illustrating the correlation between hydraulic head and the steam rate.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Fig. 1 shows a garment steaming device 1 comprising a first water chamber 2, a second water chamber 3 situated in a heel portion 4, shown in Figs. 3a and 3b, of the garment steaming device 1, and a steam generator 5 situated below the first water chamber 2 in an operational orientation A of the garment steaming device 1.
A first fluid path 6 fluidly communicates the first water chamber 2 and the steam generator 5.
A second fluid path 7 fluidly communicates, via a second fluid path inlet 8, a bottom end of the first water chamber 2 with a lower part of the second water chamber 3, via a second fluid path outlet 9. The second fluid path inlet 8 is preferably arranged at the lowest point of side wall 25, but could also be arranged at any heights in the side wall 25 of the first water chamber 2. The second fluid path outlet 9 is preferably arranged in the bottom wall 26, but could also be arranged at any heights in the side wall 27 of the second water chamber 3, for example in the lower half part of the side wall 27.
A vent pipe 10 is connected to a top part of the second water chamber 3 by its first end 11 and is open to the atmosphere at its second end 12, including when the garment steaming device 1 is in a non-operational orientation B, as shown in Fig. 2b. The first end 11 is preferably arranged in the top wall 18, but could also be arranged at any heights in the side wall 27 of the second water chamber 3, for example in the upper half part of the side wall 27.
The second end 12 is preferably arranged higher than the first end 11 when the device is in the operational position A. For example, as illustrated, this can be achieved by arranging a "L" shape portions in the pipe 10 at the proximity of the first end 11 and the second end 12. Alternatively, the pipe can be straight, but inclined between a lower point defined by the first end 11 and a higher point defined by the second end 12.
The second water chamber 3 is arranged higher than the first water chamber 2 in the operational orientation A so that a water level height of the second water chamber 3 can be higher than a water level height of the first water chamber 2 in said operational orientation A.
This results in that the water head in the first fluid path 6 generated by the fluid coupling of the second water chamber 3 and the first water chamber 2 to the steam generator 5 under gravity is increased. Because the water pressure is increased in the first fluid path 6 when the garment steaming device 1 is in the operational orientation A, the steam rate generated by the steam generator 5 is as a result also increased.
The steam generator 5 is in thermal contact with a heated plate 14 having a first end 15 and an opposing second end 16. In the present embodiment, the heated plate 14 extends in a horizontal direction when the garment steaming device 1 is in its operational orientation A. The heated plate 14 extends at an angle to the horizontal such that the first end 15 is above the second end 16 when the garment steaming device 1 is moved into a non-operational orientation B. The garment steaming device 1 may be moved between its operational and non-operational orientations A, B by rotating it in the hand of a user. In the non-operational orientation B, the water level in the first water chamber 2 is below the first fluid path 6 so no water can enter the steam generator 5, as shown in Fig. 2a, and as will be described in more detail hereinafter.
Referring back to Fig. 1, the steam generator 5 is configured to evaporate water dosed onto it from the first water chamber 2 via the first fluid path 6. The steam generator 5 further comprises a steam outlet (not shown) so that generated steam can be used to, for example, remove creases from fabric.
Furthermore, the second water chamber 3 is generally located proximate the second end 16 of the heated plate 14 above of the first water chamber 2. That is, a top wall 18 of the second water chamber 3 is positioned at a greater vertical distance from the steam generator 5 than a top wall 19 of the first water chamber 2. It will be understood that the second water chamber 3 may extend towards the first end 15 of the heated plate 14 above the first water chamber 2. In some embodiments, the whole of the second water chamber 3 may be arranged at a greater vertical distance from the steam generator 5 than the first water chamber 2 when the garment steaming device 1 is in its operational orientation A.
The second fluid path 7 fluidly communicates the first water chamber 2 and the second water chamber 3. The first water chamber 2 may comprise an orifice 21 to which the second fluid path inlet 8 is connected. The orifice 21 is configured to allow the flow of water from the second fluid path inlet 8 into the first water chamber 2 in the operational orientation A. Furthermore, the second water chamber 3 may comprise an orifice 22 to which the second fluid path outlet 9 is connected. The orifice 22 is configured to allow the flow of water from the second water chamber 3 into the second fluid path outlet 9 in the operational orientation A.
In one embodiment, the first fluid path 6 and the orifice 21 connected to the second fluid path inlet 8 are at opposing ends of the first water chamber 2. That is, the first fluid path 6 is proximate the end of the first water chamber 2 closest to the first end 15 of the heated plate 14 and the orifice 21 is closest to the second end 16 of the heated plate 14. The first fluid path 6 is formed in a bottom wall 24 of the first water chamber 2 so that it is below the water level in the first water chamber 2 when the garment steaming device 1 is in its operational orientation A until substantially all the water has been dosed into the steam generator 5.
Furthermore, the second fluid path inlet 8 and the orifice 21 are positioned so that when the garment steaming device 1 is in its operational orientation A, the second fluid path inlet 8 and the orifice 21 will be below the water level in the first water chamber 2 until the water in the first water chamber 2 is substantially depleted. Therefore, the orifice 21 that is connected to the second fluid path 7 is located in a wall of the first water chamber 2 proximate to the heated plate 14. That is, the orifice 21 is located in the bottom wall 24 or a side wall 25 proximate the bottom wall 24, as shown in Fig. 1, of the first water chamber 2. Therefore, the orifice 21 is near the bottom of the first water chamber 2 when the garment steaming device 1 is in its operating orientation A.
The second fluid path outlet 9 and the orifice 22 in the second water chamber 3 are positioned so that when the garment steaming device 1 is in its operational orientation A, the orifice 22 will be below the water level in the second water chamber 3 until the water in the second water chamber 3 is substantially depleted. Therefore, the orifice 22 is located in a wall of the second water chamber 3 proximate the heated plate 14. That is, the orifice 22 may be located in a bottom wall 26, as shown in Fig. 1, or a side wall 27 proximate the bottom wall 26 of the second water chamber 3 when the garment steaming device 1 is in its operating orientation A.
The vent pipe 10 is configured to fluidly connect the second water chamber 3 to the atmosphere. The vent pipe 10 is positioned so that when the garment steaming device 1 is in its operational orientation A, the vent pipe 10 extends from the second water chamber 3 proximate its top wall 18. That is, the vent pipe 10 extends from the top wall 18, as shown in Fig. 1, or from the side wall 27 proximate the top wall 18. In this way, the vent pipe 10 is normally above the water level in the second water chamber 3 when the garment steaming device 1 is in its operational orientation A.
Referring to Fig. 2b, the first and second water chambers 2, 3 are arranged such that, when the garment steaming device 1 is moved from its operational orientation A to its non-operational orientation B, water flows from the first water chamber 2 into the second water chamber 3 and vent pipe 10 through the second fluid path 7 until the water levels in the first water chambers 2 is are at the same level as the water in the second water chamber 3 or vent pipe 10. That is, in the non-operational orientation B, the second fluid path inlet 8 is configured to allow the flow of water from the first water chamber 2 into the second fluid path 7 and the second fluid path outlet 9 is configured to allow the flow of water from the second fluid path 7 into the second water chamber 3 and into the vent pipe 10.
In one embodiment, the first fluid path 6 is positioned at the end of the first water chamber 2 proximate the first end 15 of the heated plate 14 and therefore, may define an acceptable water level which is depicted by a horizontal dashed line in Fig. 2a. The acceptable water level is the level that the first water chamber 2 and vent pipe 10 can be substantially filled to before water looks like to begin to leak through the first fluid path 6 into the steam generator 5 or out of the second end 12 of the vent pipe 10, depending on the length of the vent pipe 10.
In one embodiment, the vent pipe 10 extends towards the first end 15 of the heating plate 14 by a distance at least as far as the maximum water level height of the garment steaming device 1 when in its non-operational orientation B. Therefore, water does not exit the second end 12 of the vent pipe 10 before it exits the first water chamber 2 via the first fluid outlet 6 when the garment steaming device 1 is in its non-operational orientation B. That is, the vent pipe 10 extends to the same height or higher than the maximum water level of the first water chamber 2 when the garment steaming device 1 is in its non-operational orientation B.
In one preferred embodiment, the garment steaming device 1 may comprise a 'snap-disc' mechanism (not shown) which is configured to control the flow of water through the first fluid path 6. The 'snap-disc' mechanism may be located at either end of or in the first fluid path 6. The state of the 'snap-disc' mechanism is dependent on the temperature of the steam generator 5. That is, if the steam generator 5 is sufficiently heated to evaporate water and produce steam, the 'snap-disc' mechanism will be in a state which opens the first fluid flow path 6 and allows water to flow through the first fluid path 6 from the first water chamber 2 into the steam generator 5. If the temperature of the steam generator 5 is not sufficient to evaporate water and produce steam, the 'snap-disc' mechanism will be in a state which closes the first fluid path 6 so that there is no flow of water to the steam generator 5. Therefore, before the garment steaming device 1 is heated up, the 'snap-disc' mechanism will close the first fluid path 6. Consequently, in the preferred embodiment, the position of the first fluid path 6 does not define the maximum water level in the first water chamber 2 in the non-operational orientation B and the vent pipe 10 may extend as far as the top end of the first water chamber 2 proximate the first end 15 of the heated plate 14. As a result, the first water chamber 2 may be completely filled with water in the non-operational orientation B before the garment steaming device 1 is turned on.
Furthermore, the garment steaming device 1 may further comprises another specific mechanism (not shown), such as a button, which is configured to override the 'snap-disc' mechanism so that it keeps the first fluid path 6 totally closed. Therefore, the garment steaming device 1 can be used for, for example, "dry ironing" (ironing without steam).
As shown in Fig. 2a, the first water chamber 2 further comprises a water inlet 29 configured to allow the first and second water chambers 2, 3 to be filled with water when the garment steaming device 1 is in its non-operational orientation B and a sealing member 30 configured to seal the water inlet 29 once the water chambers 2, 3 have been filled. The sealing member 30 may be, for example, but not limited to, a hinged door comprising an 'O'-ring to seal the door against the walls of the first water chamber 2. In order to facilitate filling the first water chamber 2 to its maximum water level, the water inlet 29 should be located closer to the end of the first water chamber 2 proximate the first end 15 of the heated plate 14 than the first fluid path 6. Preferably, the water is located in the side wall 25 of the first water chamber 2 closest to the first end 15 of the heated plate 14.
The method of using the garment steaming device 1 will now be described with reference to Figs. 2a to 2g. Referring to Fig. 2a, once the first water chamber 2 has been substantially depleted, the garment steaming device 1 is moved from its operational orientation A, shown in Fig. 1 to its non-operational orientation B in which the first end 15 of the steam generator 5 is above the second end 16. The sealing member 30 covering the water inlet 29 of the first water chamber 2 is opened to allow the garment steaming device 1 to be refilled with water.
Whilst filling the garment steaming device 1 with water, the first water chamber 2 is fluidly connected to the atmosphere via the open water inlet 29 and the first fluid path 6, and the second water chamber 3 is fluidly connected to the atmosphere via the second end 12 of the vent pipe 10. Therefore, the first and second water chambers 2, 3 act as communicating vessels and so the water level in the first water chamber 2 and the vent pipe 10 are always at the same height.
Referring to Fig. 2b, the first and second water chambers 2, 3 are filled with water until the water level is just below the first fluid path 6 whilst the garment steaming device 1 is in its non-operational orientation B and the water inlet 29 is sealed closed by the sealing member 30. At this point the first water chamber 2 is open to the atmosphere via the first fluid path 6.
Referring to Fig. 2c, with the water inlet 29 sealed closed, the garment steaming device 1 is moved back into its operational orientation A in which the steam generator 5 extends horizontally. Because the orifice 21 connected to the second fluid path inlet 8 is below the water level in the first water chamber 2, the air in the first water chamber 2 becomes trapped. The air in the first water chamber 2 is sealed under pressure by the hydraulic head achieved by the water in the second water chamber 3 being at a greater vertical height from the steam generator 5 than the water in the first water chamber 2. The larger the height of the water level in the second water chamber 3 from the first fluid path 6 the larger the hydraulic head. As shown in Fig. 2c, water may be in the vent pipe 10 when the garment steaming device 1 has just been filled and will contribute to the overall water head.
The greater hydraulic head achieved by the second water chamber 3 holding water above the water level in the first water chamber 2 causes a higher pressure at the first fluid path 6 than would occur without water in the second water chamber 3. Therefore, a higher dosing rate can be achieved which results in a larger steam rate. Furthermore, water can be forced through the first fluid path 6 in instances of higher pressure created by the volumetric expansion of water in the steam generator 5. This helps to overcome the prevention of water dosage into the steam generator 5 that is encountered in previous steam generating devices. In addition, the hydraulic head can prevent the back flow of steam from the steam generator 5 into the first water chamber 2.
Referring now to Fig. 2d, as steaming continues water from the first water chamber 2 is directed through the first fluid path 6 and into the steam generator 5. The air in the first water chamber 2 remains sealed and under pressure caused by the hydraulic head achieved in the second water chamber 3. Therefore, the water that exits the first water chamber 2 into the steam generator 5 is replaced by water from the second water chamber 3. As steam is continually generated, the water level in the second water chamber 3 becomes lower which results in a lower hydraulic head and therefore, a slowing steam rate as the difference in pressure between the first fluid path 6 and the steam generator 5 decreases. As the water level in the second water chamber 3 becomes lower air enters via the vent pipe 10 at atmospheric pressure.
To prevent excessive amounts of water entering the steam generator 5 and offsetting the energy balance, i.e. cooling the heated plate 14 sufficiently so that steam can no longer be generated, the capacity of the second water chamber 3 must be chosen carefully to fit the garment steaming device 1. The second water chamber 3 may have a capacity of between 5 and 50 ml. Preferably, the second water chamber 3 has a capacity of 20 ml. The larger the second water chamber 3, the longer the duration of a higher steam rate whilst the garment steaming device 1 remains in its operational orientation.
It will be understood that depending on the placement of the vent pipe 10, the capacity of water that the second water chamber 3 can hold and the volume of the second water chamber 3 may differ. Another parameter that can be controlled is the effective flow path diameter of the water. The minimum cross-sectional diameter of the second fluid path 7 is between 2 to 15 mm. Preferably, the minimum cross-sectional area is 5 mm².
Once the water level in the second water chamber 3 or the second fluid path 7 reaches the same level as the water level in the first water chamber 2, the steam rate is no longer increased above what the first water chamber 2 can achieve on its own.
Referring now to Fig. 2e, the garment steaming device 1 can be rotated back into its non-operational orientation B from its operational orientation A. In this orientation, water from the first water chamber 2 flows through the second fluid path inlet 8 into the second fluid path 7 and through the second fluid path outlet 9 into the second water chamber 3. As the first fluid path 6 fluidly communicates the first water chamber 2 with the atmosphere, air can enter the first water chamber 2, as shown by the arrow in Fig. 2e, and the water chambers 2, 3 can act as communicating vessels so that the water level in the first water chamber 2 and the second water chamber 3 or the vent pipe 10 become level. Pressure in the first water chamber 2 and the vent pipe 10 are both atmospheric once again.
When the garment steaming device 1 is subsequently moved back into its operational position A, shown in Fig. 2f, the same effects as described in reference to Fig. 2c occurs. Namely, because the second fluid path inlet 8 is below the water level in the first water chamber 2, the air in the first water chamber 2 becomes trapped and sealed under pressure by the hydraulic head caused by the water level in the second water chamber 3. The recovered hydraulic head will increase the steam rate once again. However, as shown in Fig. 2f, the water levels in both the first and second water chambers 2, 3 will be lower and so the maximum steam rate achievable after partially refilling the second water chamber 3 will be lower than previously.
Referring now to Fig. 2g, it can be seen that water from the second water chamber 3 and second fluid path 7 continue to replenish the water in the first water chamber 2 even once the water level in the second water chamber 3 or second fluid path 7 is below the water level in the first water chamber 2. This is because of the atmospheric pressure acting on the water in the second water chamber 3 or second fluid path 7. The atmospheric pressure acts on the water to try and keep the air trapped in the first water chamber 2 at atmospheric pressure.
However, due to the weight of the body of water, the water level in the first water chamber 2 may decrease slightly. Thus, the trapped air in the first water chamber 2 will be under less than atmospheric pressure and the water level in the second fluid path 7 or second water chamber 3 will rise slightly.
If the water head becomes insufficient to overcome the pressure in the steam generator 5, air and/or steam may leak through the first fluid path 6 from the steam generator 5 into the first water chamber 2. Furthermore, when the water level in the second fluid path 7 falls below the top of the second fluid path inlet 8, air may bubble through from the second fluid path 7 to the first water chamber 2 until the water level rises above the top of the second fluid path inlet 8 again.
Once the water level in the first water chamber 2 is the same as the water level in the second water chamber 3 or the second fluid path 7 and the water level is below the top of the second fluid path inlet 8, the air in the first and second water chambers 2, 3 fluidly communicate. Then once the first water chamber 2 is substantially depleted, the garment steaming device 1 can be placed back into its non-operational orientation B, as shown in Fig. 2a and the whole process can begin again.
Fig. 3a shows a garment steaming device 1 comprising a steam iron 35 in its operational orientation A. The steam iron 35 comprises a soleplate 36 which is heated by a heating element 37 and has steam venting holes 38 therein for the passage of steam from the steam generator 5 towards a fabric being ironed. The soleplate 36 may be equivalent to the heated plate 14 mentioned above. The steam iron 35 further comprises a housing 40 which has a handle 41 to allow a user to grip and manoeuvre the steam iron 35. As can be seen from Fig. 3a, the soleplate 36 extends substantially horizontally when the steam iron 35 is in its operational orientation A. The second water chamber 3 is located proximate the rear end of the steam iron 35 such that it is arranged behind a back cover 4a in the heel portion 4, and the vent pipe 10 extends through the handle 41.
Referring to Fig. 3b, it can be seen that the steam iron 35 is placed on its heel portion 4 during its non-operational orientation B. Fig. 3b also illustrates that the soleplate 36 extends at an angle to the horizontal when placed on its heel portion 4 in its non-operational orientation B.
In the present embodiment, shown in Figs. 3a and 3b, the steam generator 5 is located against the soleplate 36 and the second water chamber 3 is located in the heel portion 4.
Referring now to Fig. 4, a table is shown illustrating the correlation between hydraulic head and the steam rate. The hydraulic head is plotted on the X axis and is given in centimetres (cm). The steam rate is plotted on the Y axis and is given in grams of steam generated per minute (g/min). As is clear from the graph, the higher the water level is above the first fluid path 6, shown in Fig. 1, the more steam is created per minute.
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 scope of the invention as defined by the appended claims. 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.

Claims

A steam iron (1) comprising:
- a first water chamber (2);

- a second water chamber (3) situated in a heel portion (4) of the steam iron (1);

- a steam generator (5) situated below the first water chamber (2) in an operational orientation (A) of the steam iron (1);

- a first fluid path (6) connecting the first water chamber (2) and the steam generator (5); and

- a vent pipe (10) connected to a top part of the second water chamber (3) by its first end (11) and open to the atmosphere at its second end (12), the second end (12) of the vent pipe (10) extending at least as far as the maximum water level height of the first water chamber (2) when the steam iron (1) is in a non-operational orientation (B);

- characterized in that a second fluid path (7) connects a bottom end of the first water chamber (2) to a lower part of the second water chamber (3) in the operational orientation (A), the cross-sectional diameter of the second fluid path (7) is in the range of 2 mm to 15 mm, and the second water chamber (3) is arranged wholly above the first water chamber (2) in the operational orientation (A), so that so long as there is water in the second water chamber (3) a water level height of the second water chamber (3) is higher than a water level height of the first water chamber (2) in said operational orientation (A), so that the water head in the first fluid path (6) generated by the fluid coupling the second water chamber (3) and the first water chamber (2) is increased to obtain an increased steam rate when the steam iron (1) is in the operational orientation (A).
The steam iron (1) according to claim 1, wherein the second water chamber (3) and the first water chamber (2) are arranged such that when the steam iron (1) is moved into the non-operational orientation (B) from the operational orientation (A), water is displaced from the first water chamber (2) into the second water chamber (3) through the second fluid path (7) until the water level heights in the first water chamber (2) and the vent pipe (10) are the same.
The steam iron (1) according to claim 2, wherein the first fluid path (6) is arranged higher than the maximum water level height of the first water chamber (2) when the steam iron (1) is in the non-operational orientation (B) to allow the air in the steam generator (5) to pass into the first water chamber (2) through the first fluid path (6) as the water is displaced from the first water chamber (2) into the second water chamber (3).
The steam iron (1) according to any preceding claim, wherein the first water chamber (2), the second fluid path (7), the second water chamber (3) and the vent pipe (10) are conjointly formed into a substantially "U"-shaped construction.
The steam iron (1) according to any preceding claim, wherein the capacity of the second water chamber (3) is in the range of 5 ml to 50 ml.
The steam iron (1) according to any preceding claim, wherein the minimum cross-sectional area of the second fluid path (7) is 5 mm².
The steam iron (1) according to any preceding claim, wherein the second fluid path (7) is formed into a right angle-shaped construction between the first water chamber (2) and the second water chamber (3).
The steam iron (1) according to any preceding claim, wherein the second fluid path (7) is formed integrally with or separately from the first water chamber (2) and/or the second water chamber (3).
The steam iron (1) according to any preceding claim, wherein the first water chamber (2) comprises a water inlet (29) and a sealing member (30) located on a sidewall thereof, the water inlet (29) being configured to allow the first water chamber (2) and the second water chamber (3) to be filled with water in the non-operational orientation (B), the sealing member (30) being configured to seal the water inlet (29) once the first water chamber (2) and second water chamber (3) have been filled and prior to the movement of the steam iron (1) into the operational orientation (A).
The steam iron (1) according to any preceding claim, wherein the non-operational orientation (B) indicates the orientation in which the steam iron rests on its heel portion (4) against a countertop.
The steam iron (1) according to any preceding claim, wherein the second water chamber (3) is arranged in the heel portion behind a back cover (4a).
The steam iron (1) according to any preceding claim, wherein the vent pipe (10) is arranged inside a handle (41) of the steam iron (35).
The steam iron (1) according to any preceding claim, wherein there is a soleplate (36) situated against the steam generator (5) in which water is converted into steam, the soleplate (36) having multiple steam venting holes (38) thereon and facing the garment to be ironed once the garment steaming device (1) is moved into the operation orientation (A) from the non-operational orientation (B).