Garment steamer with improved steaming performances and functionalities

Abstract

The invention relates to a garment care device comprising a steam generator having improved steaming performances and functionalities.

Description

FIELD OF THE INVENTION The invention relates to a garment steamer with improved steam performances. The invention may be used in the field of garment care. BACKGROUND OF THE INVENTION Typically, steam generators used in irons and some steamer products utilise flash boiling to produce steam, whereby water which is dosed onto a hot steaming surface at one point or in some cases at two points, is instantaneously steamed off. In some other steam generators, especially in steamer products, a labyrinth design is used for limiting water spreading and improving steam generation. However, spreading of the water onto the main steaming surface is affected by the labyrinth design and protrusions on the steaming surface. The so-called “open” steam generator design concepts can be used to address to some extent the problem of the limited steam rate and scaling life. By the term “open”, it is referred to a flat steaming surface without labyrinth extending onto it. As illustrated in Fig.l, known open steam generator design utilises an open steaming surface to generate steam which will pass through one or more side steam channel before steam is emitted out of the steam vents. However, the side steam channel requires quite some space on the steam generator which could otherwise be used to generate more steam. There is also the problem of hot spots generation due to lower or slower heat transfer rate in areas around the steam channel which are difficult for dosed water to reach, as illustrated in Fig.2. When steaming orientation is sideways especially towards right side, as illustrated by Fig.3, the effective steam area is greatly reduced due to orientation and the area occupied by the steam channel. This requires the steam generator to reduce the steam rate by a significant amount when used at such unfavourable orientation, which would otherwise lead to undesired spitting of water during usage. Steam output may also be perceived by user as inconsistent due to the step down. To detect usage orientation, an orientation sensor would also be required for angle detection, leading to increased manufacturing costs. In other words, in the current known labyrinth steam generator designs, like the one shown in Fig.4, the limitations arise from: - Limescale buildup clogging labyrinth steam generator paths, - Limited instantaneous steaming area. Depends on water travelling through the labyrinth path. This results in lower steam rate and weaker steam perception. -  Steam perception will be poor and high chances of water leaking in labyrinth design in different orientations. This will lead to poor steam perception and spitting. The disadvantages of the current handheld steamer products are already known and that is the reason why there are sometimes weak, short limescale life and low steaming performance currently for products on the market. OBJECT AND SUMMARY OF THE INVENTION It is an object of the invention to propose a garment care device that avoids or mitigates the above-mentioned problems by, among other, generating more powerful steam at any angle. The invention is defined by the independent claims. The dependent claims define advantageous embodiments. The garment care device (GCD) according to the invention comprises: - a steam generator (SG) comprising an ironing plate (IP) with steam vents (SV), a bottom steam plate (SP) being heated, a peripheral wall (PW) protruding from a periphery of the steam plate, a cover (CC) arranged on top of the peripheral wall, the steam generator forming an internal volume (W) free of constrained steam paths above a central area (CA) of the steam plate, - at least one water dosing point (WDP1, WDP2) arranged in the cover, to provide water onto the steam plate, resulting in water being vaporized by the steam plate, - a hollow chimney (CH) protruding from the steam plate and arranged at proximity of the peripheral wall, to carry steam generated by the steam plate towards a steam channel (SC) being arranged below the steam plate, the steam channel being fluidly connected with the steam vents. This solution allows increasing the steam rate by using an open steaming chamber structure for smaller steamer products, as well as extending the product lifespan. 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.l depicts a known steam generator having a side steam channel, Fig.2 depicts a known steam generator having a side steam channel with hot spots arising along the side steam channel, Fig.3 depicts a known steam generator having a side steam channel when inclined towards the side steam channel, Fig.4 depicts a known steam generator having two lateral side steam channels, with labyrinth steam path, Figs.5 to 20 depict various embodiments according to the invention. DETAILED DESCRIPTION OF THE INVENTION Figs.5 to 20 depict various embodiments according to the invention. The garment care device (GCD) according to the invention comprises: - a steam generator (SG) comprising an ironing plate (IP) with steam vents (SV), a bottom steam plate (SP) being heated, a peripheral wall (PW) protruding from a periphery of the steam plate, a cover (CC) arranged on top of the peripheral wall, the steam generator forming an internal volume (W) free of constrained steam paths above a central area (CA) of the steam plate, - at least one water dosing point (WDP1, WDP2) arranged in the cover, to provide water onto the steam plate, resulting in water being vaporized by the steam plate, - a hollow chimney (CH) protruding from the steam plate and arranged at proximity of the peripheral wall, to carry steam generated by the steam plate towards a steam channel (SC) being arranged below the steam plate, the steam channel being fluidly connected with the steam vents. This core structure solves the problem of limited steaming area and hot spots found in prior art side-channel designs. By moving the steam channel below the steam plate, the entire top surface is freed up for efficient steam generation. The hollow chimney provides a dedicated collection point for this steam, leading to a higher steam rate, more even heat distribution, and a more compact overall design. The steam plate defines a plain surface which does not comprise any structures forcing steam to follow a given path (i.e. no labyrinths / paths / channels...). In other words, the internal volume is primarily non-obstructed. In this solution, the steam channel is designed so as to be located below the steam plate, and utilises a wall and chimney construction at the steam channel inlet to prevent water droplets that would have not been vaporized by the steam plate, to spit during dynamic steaming movement. The main advantages of the improved design construction are to include a larger available steaming surface which effectively increases the steam rate and limescale life of the steam generator. The steam generator also operates with lower peak temperature as heat is more effectively extracted from a larger steaming surface. Generated steam by the steam plate travels towards the chimney and through the steam channel, before being emitted out via the steam vents. Some excess water that flows towards the scale deposition zone at the base of the chimney will also be trapped at the bottom of the chimney. The chimney height prevents excess water (that would not have been vaporized by the steam plate) from entering the inlet of the steam channel. The large opening of the chimney also prevents from limescale clogging thereby extending the product lifespan. The ironing plate is preferably parallel to the steam plate and has a substantially similar outer shape. The ironing plate IP is for example rectangular, as illustrated. It could also have different shape, such as oval or any other shape. Garment care device may comprise a handle (HAN) to move the device against the garment to be treated by steam. If the longitudinal axis xx of the steam plate is oriented parallel, or axis yy of the steam plate is oriented perpendicular, to the longitudinal axis hh of the handle, the steam plate is said to be oriented in “portrait orientation”, as illustrated in Fig.5, 16 & 18. If the longitudinal axis xx of the steam plate is oriented perpendicular, or axis yy of the steam plate is oriented perpendicular, to the longitudinal axis hh of the handle, the steam plate is said to be oriented in “landscape orientation”, as illustrated in Fig.8, 15 & 19A. The handle is indirectly coupled to the steam plate via a housing of the device. The steam channel is positioned below the steam plate instead of along the side of the engine body. This effectively increases the steaming area which can be used to generate more steam instantaneously. This position of the steam channel prevents having hot spots at the periphery of the steam channel. The front half of the steam channel comprises a curved top surface to increase the velocity of the steam coming from the chimney. Preferably, the steam generator further comprises a substantially “U”-shaped heating element (HE) being in thermal heat transfer with said steam plate, wherein said chimney is arranged at the proximity of two open terminals (Tl, T2) of the “U”-shaped heating element. This is illustrated in Fig.8 In another embodiment, the heat of the steam plate is transferred to the ironing plate IP via a lateral thermal bridge arranged in-between. In such embodiment, the lateral thermal bridge is provided between the bottom steam plate and the ironing plate. The thermal bridge transfers heat efficiently, thereby ensuring faster heating of the ironing plate and maintaining a stable ironing temperature during use. This feature adds a dry-ironing functionality to the steamer. The thermal bridge provides a dedicated and efficient conductive path to transfer heat from the directly heated steam plate to the ironing plate, ensuring the ironing plate reaches and maintains a temperature effective for pressing wrinkles meanwhile not burning the fabric. In an embodiment of the invention, a water shield (WS) is provided in the form of at least one rib extending downwards from a lower surface of the cover. The water shield is configured to prevent water droplets from entering the chimney, thereby reducing the risk of water spitting and ensuring dryer, more consistent steam output. Preferably, the water shield, taking the form of protruding ribs, extends downwards from a below-surface of the cover, to prevent water droplets carried by steam from directly entering the chimney. This is illustrated in Fig.9, and also again Fig. 11 wherein the cover being shown up-side-down. The water shield acts as a baffle to improve steam quality. It forces the turbulent steam to follow a more complex path before entering the chimney. This causes heavier, unvaporized water droplets to impact the shield and fall back onto the hot plate, preventing them from being ejected through the steam vents and causing spitting. The height of the water shield is greater than 2.4 mm to defeat the capillary effect. In a preferred embodiment, this height is between 2.4 mm and 7 mm but more preferably 2.4 mm and 5 mm. Preferably, a first wall (Wl) is arranged between said at least one water dosing point and the chimney, the first wall extending vertically between the steam plate and the cover. The first wall is arranged in front of the chimney to block water droplets entering the chimney. This wall acts as a primary splash guard. When water is first dosed onto the hot plate, it can splash. The first wall provides a direct physical barrier that blocks these initial, large droplets from being thrown directly into the inlet of the hollow chimney, which is the first line of defense against spitting. This is illustrated in Fig.9. Preferably, the garment care device further comprises at least one second wall (W2_P1, W2 P2) arranged adjacent to said first wall, the at least one second wall extending vertically at a height lower than the height of the first wall. This creates a two-stage labyrinth or weir system for separating steam from water. While the first wall blocks the initial splash, the lower second wall allows lightweight steam to easily flow over it while still blocking any lower-traveling water that might have gotten past the first wall. This provides a more sophisticated and effective separation, further enhancing steam quality. The second wall aims to partially block water droplets entering the chimney, while allowing steam generated by the steam plate to flow towards the chimney’s input. This is illustrated in Figs.9. Preferably, the second wall has a first portion (W2P1) on the left side of the first wall, and a second portion (W2 P2) on the right side of the first wall, respectively. In a preferred embodiment, the height of the at least one second wall is between 2.4 mm and 7 mm but more preferably 2.4 and 6 mm but more preferably 2.4 mm and 5.2mm. The height of the at least one second wall must be greater than 2.4 mm to defeat the capillary effect of water. Preferably, the garment care device further comprises a first area (Al) being recessed compared to said steam plate, the first area being arranged between said at least one of the second wall and said at least one water dosing point. This recessed area acts as a local reservoir or sump. It is designed to trap any excess water that is dozed onto the plate but does not instantly vaporize. By holding the water in this hot, recessed zone, it gives the system more time to turn the water into steam, increasing efficiency and preventing liquid water from flowing uncontrollably towards the chimney. The first area aims to trap water that would not have all be vaporized and thus prevent water from flowing towards the chimney. This is illustrated in Figs.9. Preferably, the first area can be split into two sub-areas arranged in front of the first portion and the second portion of the second wall. Preferably, the garment care device further comprises a second area (A2) being recessed compared to said steam plate, the second area being arranged around a bottom part of the chimney. This feature provides two distinct benefits. First, it acts as a final trap for any water droplets that have managed to travel across the steam plate, preventing them from entering the chimney. Second, as stated in the description, it serves as a dedicated collection zone for limescale particles that flake off the plate, which prevents the steam channel from becoming clogged and makes periodic descaling easier. Also descaling can be postponed, thereby improving user experience. Preferably, the at least one water dosing point comprises a first water dosing point and a second water dosing point. The first water dosing point and the second water dosing point separate the steam plate into two interconnected heating zones (Zl, Z2) to enhance water distribution and steam production, as illustrated in Fig. 12. In other words, the steaming surface is provided with two hot steaming zones to enable dual dosing resulting in faster steam generation, lower hotspots, longer limescale life and higher steam rate without spitting. By simultaneously delivering water to both zones, the system generates more powerful, rapid, and voluminous steam. In other words, large amount of steam is generated instantaneously. This configuration also extends the product's lifespan by providing a larger surface area for scale accumulation, reducing the frequency of descaling. Water is dosed on the two zones simultaneously. Excessive water is expected to flow towards the first area and the second area. At side water retention pockets, the excess water will be trapped by the separation walls / ribs while the engine takes time to transfer heat to steam off the water. Preferably, in case the heating element comprises a neck portion (NP) in the overall U-shape, as illustrated in Fig. 8, the temperature sensor is arranged slightly offset compared to this neck portion. This helps to better sense the heating element being powered-ON or powered-OFF, as well as sense water being present or not on the steam plate, by balancing the energy in and out of the steam generator. Preferably, the steam plate forms a surface comprising a first grid pattern made of protruding truncated square pyramids. This surface texture solves two problems: it improves heat transfer and controls water flow. The pyramids increase the total surface area for faster vaporization and create micro-channels that promote even water spreading. They also act as baffles to slow down water runoff when the device is used vertically, ensuring the water has enough time to turn into steam. In the main steaming area of the steam plate, in particular zone Z1 and zone Z2, 1x1 millimetre truncated square pyramid grids of height 0.5mm with a spacing of 1mm are used for better water spreading in both horizontal and vertical, as illustrated in Fig. 13. The truncated square pyramids are also oriented in a manner that they are symmetrical in both landscape and portrait orientations of the rectangular steam plate for optimal water spreading regardless of orientation of the steam plate. The pyramids are oriented at an angle between 40° and 50° but more preferably at an angle of 45° to a vertical axis in both landscape and portrait orientations of the device. By means of this, water is spread efficiently in both orientations. The truncated square pyramid also helps that water which is dosed by the water dosing point spreads over the steam plate without too fast falling when the longitudinal axis xx of the steam plate is oriented vertically. The small size of the pyramids also helps that the scale that could build on the steam plate flakes more easily. Preferably, there is a first distance (DI) between neighboring pyramids which is less than 1.9 mm. At this distance, the water will climb up to the top of the truncated pyramid using its capillary action ability. In a most preferred embodiment, the first distance is between 0.75 mm and 1.5 mm. Preferably, the second area forms a surface comprising a second grid pattern made of protruding square pyramids. This specific texture makes the second area more effective at its job. The rough, high-surface-area pyramids are excellent at "catching" and retaining solid scale particles. They also help to quickly vaporize any final stray droplets of water that reach this area before the chimney inlet. The first distance also applies to the square pyramids. Namely, first distance between neighboring pyramids is first distance is between 0.75 mm to 1.5 mm. In the second area around the chimney, full height square base pyramids (i.e. non-truncated pyramids) are used with the same density as for the steam plate, as illustrated in Fig. 14. Since non-truncated pyramids are taller compared to truncated pyramids, this makes it difficult for water accumulated in the second area to climb and be directed towards the chimney. Moreover, non-truncated pyramids will help scale to accumulate in this second area, as the contact surface is larger than truncated pyramids. Second area acts as a scale accumulation area. Preferably, the garment care device according to the invention comprises a pump (WP). Preferably, the water pump is a piston pump. Indeed, piston pumps (>=1 bar max pressure), capable of generating higher pressure, are better suited for this application as they can effectively displace air bubbles, ensuring consistent water flow. In one embodiment, a second distance (D2) between the chimney and the cover or peripheral 5 wall is between 2.4 mm and 8 mm, and preferably between 2.4 mm and 5.5 mm. The lower limit of 2.4 mm is critical, as it represents the minimum spacing required to overcome the capillary effect of water, thereby preventing water from climbing between these components. It is noted that various features of the invention can also be combined differently together or used 10 in isolation. 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 detail referring to the preferable embodiments, those skilled in the art will understand that the technique 15     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.

Claims

1. A Garment care device (GCD) comprising:- a steam generator (SG) comprising an ironing plate (IP) with steam vents (SV), a bottom steam plate (SP) being heated, a peripheral wall (PW) protruding from a periphery of the steam plate, a cover (CC) arranged on top of the peripheral wall, the steam generator forming an internal volume (W) free of constrained steam paths above a central area (CA) of the steam plate,- at least one water dosing point (WDP1, WDP2) arranged in the cover, to provide water onto the steam plate, resulting in water being vaporized by the steam plate,- a hollow chimney (CH) protruding from the steam plate and arranged at proximity of the peripheral wall, to carry steam generated by the steam plate towards a steam channel (SC) being arranged below the steam plate, the steam channel being fluidly connected with the steam vents.

2. The garment care device as claimed in claim 1, wherein the steam generator further comprises a substantially “U”-shaped heating element (HE) being in thermal heat transfer with said steam plate, wherein said chimney is arranged at proximity of two open terminals (Tl, T2) of the “U”-shaped heating element.

3. The garment care device as claimed in any one of the preceding claims, further comprising a lateral thermal bridge arranged between the bottom steam plate and the ironing plate configured to transfer heat between them.

4. The garment care device as claimed in any one of the preceding claims, wherein the steam plate forms a surface comprising a first grid pattern made of protruding truncated square pyramids.

5. The garment care device as claimed in claim 4, wherein the protruding truncated square pyramids are oriented at an angle between 40° and 50°, more preferably 45°, to a vertical axis in both landscape and portrait orientations of the device.

6. The garment care device as claimed in claim 4 or 5, wherein a first distance (DI) betweenneighboring pyramids is smaller than 1.9 mm, more preferably between 0.75-1,5mm.

7. The garment care device as claimed in any one of the preceding claims, further comprising a water shield (WS) in the form of at least one rib extending downwards from a lower surface of the cover, configured to prevent water droplets from entering the hollow chimney.

8. The garment care device as claimed in claim 7, wherein the height of the water shield is between 2.4 mm to 7 mm, more preferably 2.4 mm to 5 mm.

9. The Garment care device as claimed in any one of the preceding claims, further comprising a first wall (Wl) arranged between at least one water dosing point and the chimney, the first wall extending vertically between the steam plate and the cover.

10. The garment care device as claimed in claim 9, further comprising at least one second wall (W2 P1, W2 P2) arranged adjacent to said first wall, the at least one second wall extending vertically at a height lower than the height of the first wall.

11. The garment care device as claimed in claim 10, wherein the height of at least one second wall (W2 P1, W2 P2) is between 2.4 mm and 7 mm but more preferably 2.4 and 6 mm but more preferably 2.4 mm and 5.2mm.

12. The Garment care device as claimed in claim 10 or 11, further comprising a first area (Al) being recessed compared to said steam plate, the first area being arranged between said at least one second wall and said at least one water dosing point.

13. The garment care device as claimed in any one of the preceding claims, further comprising a second area (A2) being recessed compared to said steam plate, the second area being arranged around a bottom part of the chimney.

14. The garment care device as claimed in claim 13, wherein the second area forms a surface comprising a second grid pattern made of protruding square pyramids.

15. The garment care device as claimed in any one of the preceding claims, wherein a second distance (D2) between chimney and the cover or peripheral wall is between 2.4 and 8 mm but more preferably between 2.4 and 5.5mm.

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