Patent Publication Number: US-2017370572-A1

Title: Steam generating system with detachable cover

Description:
FIELD OF THE INVENTION 
     The present invention relates to a steam generation system, in particular to a steam generating system with a detachable cover to provide access for maintenance and cleaning. 
     BACKGROUND OF THE INVENTION 
     Steam generation devices designed to substantially raise the temperature of a body of water to generate steam are known to be prone to deposits of scale forming on the heat source. 
     Scale is formed when dissolved solids in the water, such as sulphates or carbonates of calcium and magnesium, are deposited as the water is turned to steam. Scale deposits form an insulating layer around the heat source resulting in a decline in the rate at which heat is transferred from the heat source to the water. If the heat source is not cleaned of scale, the rate and efficiency of steam generation will decline through the operational life of the steam generation unit. Furthermore, the insulating layer of scale can cause the heat source to accumulate excess heat so that the temperature of the working components exceeds that required for safe and reliable operation. 
     Small amounts of scale are known to break away from the insulating layer to become suspended in the water. As steam is generated, some portion of these suspended particles of scale will be transported by the steam and then deposited when the steam condenses. Scale particles that are entrained in the steam reduce the quality of the steam. Low quality steam is particularly problematic in the example of a steam iron, where entrained scale may become deposited on the garment to be treated by the steam iron dirtying or staining the garment. 
     Scale is especially problematic for domestic steam generation devices as domestic water sources often have a high count of scale forming dissolved solids. Unless these devices are cleaned of scale they will be subject to the above mentioned problems. 
     Domestic steam generation devices generally comprise a housing with a heat source, such as a heating element, disposed therein to form a steam generation chamber. In order to provide steam, as well as to ensure the user&#39;s safety, the housing will enclose the heating element, with the steam and water provided through a small aperture. This makes access to the heating element difficult, if not impossible, for removing the scale. 
     It is known from U.S. Pat. No. 3,078,605 to provide an opening directly over the steam chamber of a steam iron to allow the user access to the sole plate (heating element) for cleaning. A cap designed to be received in the opening encloses the steam chamber. The cap may be removed completely from the iron by unthreading a securing screw. U.S. Pat. No. 3,078,605 teaches the use of a scraper for removing scale from the steam chamber. Scale can also be removed by cleaning with a weak acid. 
     The requirement to unthread a securing screw in order to access the steam chamber necessitates the use of a tool, therefore adding a step to the cleaning process. 
     DE 198 47 670 A1 discloses a boiler for a domestic electrical appliance comprising a body forming a steam chamber and a plate crimped to the body and forming the base of the body. 
     U.S. Pat. No. 6,243,535 B1 discloses a steam generator for a domestic apparatus comprising a body including a steam receptacle and a cover secured to the body by means of studs. 
     WO 90/13771 A1 discloses a steam generator for use in a wallpaper steamer, comprising a base having a central depression and a lid for closing the base. 
     U.S. Pat. No. 3,538,306 A, U.S. Pat. No. 4,243,870 A, WO 96/22004 A1 disclose vaporisers having a steam reservoir and a cover for closing the steam reservoir. 
     OBJECT AND SUMMARY OF THE INVENTION 
     It is an object of the invention to propose a system for generating steam which substantially alleviates or overcomes the problems mentioned above. 
     The invention is defined by the independent claims. The dependent claims define advantageous embodiments. 
     According to the present invention there is provided, a system for generating steam. The system comprises a wall structure forming a steam chamber. The system comprises an opening formed in a wall portion of said wall structure. The system comprises a cover member cooperating with said wall portion such that the cover member can take a first position where the cover member covers the opening and a second position where the cover member uncovers the opening. The opening has a cross-section surface being at least 50% of the cross-section surface of said wall portion. The cover member comprises a steam outlet and the system comprises a nozzle, such that when the cover member is in said first position, the steam outlet faces said opening and said nozzle fluidly couples the opening with the steam outlet to provide a passage configured to direct the steam from the steam chamber to the steam outlet. 
     By allowing the opening to be uncovered, the sure may gain access to the inside part of the steam generator through the opening to clean the steam generator of scale. 
     Preferably, a seal gasket is disposed between the cover member and said wall portion. 
     This allows for high pressure steam generation without the risk of steam being expelled in an unexpected manner and causing injury to the user. 
     Preferably, the cover member comprises a first attachment element and the wall portion comprises a second attachment element, the first attachment element and the second attachment element being configured to engage and disengage with each other by manual action of the cover member relative to the wall portion. 
     The attachment elements allow the cover member to cooperate with the wall portion so that the cover member may cover the opening in the wall portion without the use of separate fastening components, such as a screw. 
     Preferably, the first attachment element comprises a first elongate rail disposed on the cover member and the second attachment element comprises a corresponding second elongate rail disposed on the wall portion, wherein the first rail comprises a first ledge and the second rail comprises a second ledge, the first ledge and second ledge extending along at least a portion of the corresponding rail, so that when the cover member is in said first position, the respective ledges overlap and abut. 
     Preferably, the wall portion includes a further second attachment element comprising a sprung catch arranged so as to engage with the cover member when the cover member takes said first position. 
     Preferably, according to the present invention there is provided a system for generating steam, comprising a release button moveably mounted to the wall portion and mechanically coupled to the sprung catch, such that when the release button is actuated the sprung catch is caused to disengage the cover member to allow the cover member to be detached from the wall portion. 
     Preferably, the first elongate rail extends along one side of the cover member and the second elongate rail extends along a corresponding side of the wall portion, the sprung catch being disposed on the wall portion so as to engage the opposite side of the cover member to that side of the cover member where the first elongate rail is disposed. 
     Preferably, the cover member is slideable relative to the wall portion to engage and disengage the first attachment element and second attachment element to attach and detach the cover member to the wall portion, respectively. 
     Preferably, at least one of the first attachment element and second attachment element is resiliently deformable to enable engagement with and disengagement from the/or each other attachment element. 
     Preferably, the cover member can be manually detached from the wall portion from said first position to said second position, and can be manually attached to the wall portion from said second position to said first position, without the use of a tool. 
     Preferably, the first elongate rail and the corresponding second elongate rail are curved along their length, so that they may be moved into and out of engagement to attach and detach the cover member to the wall portion by rotational movement of the cover member relative to the wall portion. 
     Preferably, at least one of the first elongate rail and second elongate rail is tapered such that the thickness of the rail increases along the length of the rail, such that when the elongate rails are moved into engagement, the rotational movement of the cover member relative to the wall portion causes the cover member to be drawn towards the wall portion. 
     Preferably, according to the present invention there is provided a system for generating steam comprising a housing at least partly enveloping the steam chamber, and wherein the cover member cooperates with the housing to move the cover member between the first position and the second position. 
     Preferably, the cover member is adapted to allow the passage of a water inlet entering said steam chamber. 
     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. 1A  is a schematic view of a first embodiment of the invention in a closed position; 
         FIG. 1B  is a schematic view of the first embodiment of the invention in an open position; 
         FIG. 1C  is a schematic cross sectional view along the line X-X in  FIG. 1A  of the first embodiment of the invention with a closure structure schematically shown; 
         FIG. 2A  is a schematic view of a second embodiment of the invention in a closed position; 
         FIG. 2B  is a schematic view of the second embodiment of the invention in an open position; 
         FIG. 3A  is a schematic view of a third embodiment of the invention in a closed position; 
         FIG. 3B  is a schematic view of the third embodiment of the invention in an open position; 
         FIG. 3C  is a schematic cross sectional view along the line Y-Y in  FIG. 3A  of the third embodiment of the invention with a closure structure schematically shown; 
         FIG. 3D  is a schematic view of a variant of the third embodiment of the invention in a closed position; 
         FIG. 3E  is a schematic view of the variant of the third embodiment of the invention shown in  FIG. 3D , in an open position; 
         FIG. 4A  is a schematic view of a fourth embodiment of the invention in a closed position; 
         FIG. 4B  is a more detailed isometric cross section view of a first implementation of the fourth embodiment of the invention shown in  FIG. 4A ; 
         FIG. 5A  is a partial isometric view of the implementation of the fourth embodiment of the invention shown in  FIG. 4B , in a closed position; 
         FIG. 5B  is a partial isometric view of the arrangement of the fourth embodiment of the invention of  FIG. 5A , in an open position; 
         FIG. 6  is a partial isometric view of a cover member of the implementation of the fourth embodiment of  FIGS. 5A and 5B ; 
         FIG. 7  is a partial isometric cross sectional view of a second implementation of the fourth embodiment of the invention shown in  FIG. 4A ; 
         FIG. 8  is a partial isometric cross sectional view of a third implementation of the fourth embodiment of the invention shown in  FIG. 4A ; 
         FIG. 9  is a partial isometric view of an embodiment of a cover member for use with implementations of the fourth embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     In all embodiments of the present invention, shown in  FIGS. 1 to 9 , there is provided a system ( 1 ) for generating steam, the system comprising:
         a wall structure ( 3 ) forming a steam chamber ( 3 A);   an opening ( 4 ) formed in a wall portion ( 3 B) of said wall structure ( 3 ); and   a cover member ( 5 ) cooperating with said wall portion ( 3 B) such that the cover member ( 5 ) can take a first position (P 1 ) where the cover member ( 5 ) covers the opening ( 4 ) and a second position (P 2 ) where the cover member ( 5 ) uncovers the opening ( 4 ), wherein said opening ( 4 ) has a cross-section surface being at least 50% of the cross-section surface of said wall portion ( 3 B).       

     It shall be appreciated that in all embodiments of the invention, the size and shape of the opening ( 4 ) provided in the steam chamber ( 3 A) is configured to provide access to the inside part of the steam chamber ( 3 A), such that it can be manually cleaned of scale by the user; this may be achieved by rinsing or scraping the scale deposits away. 
     Such embodiments of the invention cover any household steam appliance and may include, but are not limited to, a steam iron, a floor steamer or a steam generator. 
     In a first embodiment of the invention, shown in  FIGS. 1A to 1C , the wall structure ( 3 ) forms a steam chamber ( 3 A). It is intended that the steam chamber ( 3 A) is a parallelepiped, though other shapes are included within the scope of the invention. A water inlet (F 1 ) is provided in a wall of the steam chamber ( 3 A) for introducing water into the steam chamber ( 3 A). A heated surface (not shown) disposed within the steam chamber, and arranged facing the water inlet, is configured to provide the necessary heat to convert water into steam. A steam outlet (F 2 ) is formed in another wall of the steam chamber ( 3 A) to allow for the passage of steam from the steam chamber ( 3 A). In operation, water introduced through the water inlet (F 1 ) is directed onto the heated surface and evaporated to steam, whereupon it is directed out of the steam outlet (F 2 ). In this first embodiment, the opening ( 4 ) is formed in a separate wall to either the water inlet (F 1 ) or the steam outlet (F 2 ). 
     The cover member ( 5 ) is configured to attach to the steam chamber ( 3 A) by cooperating attachment elements. First attachment elements ( 8 ) provided on the cover member ( 5 ) comprise first elongate rails ( 8 A) upstanding perpendicularly from a face of the cover member ( 5 ). In this embodiment, two elongate rails ( 8 ) are provided that run in parallel. The cover member ( 5 ) further comprises first ledges ( 8 B) that extend from the upper edges of the first elongate rails ( 8 A) so that the first attachment element ( 8 ) is L shaped in section. 
     Second attachment elements ( 9 ) are provided on the steam chamber ( 3 A) and comprise second elongate rails ( 9 A) upstanding perpendicularly from the outer face of the wall of the steam chamber ( 3 A) in which the opening ( 4 ) is formed. In this embodiment, two second elongate rails ( 9 A) are provided that run in parallel and are disposed either side of the opening ( 4 ). The steam chamber ( 3 A) further comprises second ledges ( 9 B) that extend from the upper edges of the second elongate rails ( 9 A) so that the second attachment element ( 9 ) is L shaped in section. 
     The first attachment elements ( 8 ) are spaced apart corresponding to the spacing of the second attachment elements ( 9 ), such that the first ledges ( 8 B) overlap the second ledges ( 9 B) when the cover member ( 5 ) is in the first position (P 1 ), the first ledges ( 8 B) being disposed between the respective second ledges  9 B and the housing ( 2 ), so that the cover member ( 5 ) can only be separated from the steam chamber ( 3 A) by a sliding action of the cover member ( 5 ) relative to the steam chamber ( 3 A) in a direction parallel to the attachment elements ( 8 , 9 ). 
     A second embodiment of the invention is shown in  FIGS. 2A and 2B  and differs from the first embodiment in that a steam outlet ( 6 ) is formed in the cover member ( 5 ). When the cover member ( 5 ) is in the first position (P 1 ), so that the cover member ( 5 ) covers the opening ( 4 ), the steam outlet ( 6 ) formed in the cover member ( 5 ) communicates with the inside of the steam chamber ( 3 A) to allow for the passage of steam from the steam chamber ( 3 A). The cover member ( 5 ) is attached to the steam chamber ( 3 A) by the same configuration of attachment elements ( 8 , 9 ) as described above. 
     A third embodiment of the invention is shown in  FIGS. 3A to 3E . In this embodiment, the cover member ( 5 ) is adapted so that the water inlet (F 1 ) may pass through the same wall of the steam chamber ( 3 A) as the opening ( 4 ). In one example of this embodiment, shown in  FIGS. 3A to 3C , the cover member ( 5 ) cooperates with the steam chamber ( 3 A) so that, when the cover member is in the first position (P 1 ), the cover member is disposed adjacent to the water inlet (F 1 ). In another example of this embodiment, shown in  FIGS. 3D to 3E , the cover member ( 5 ) is provided with an aperture ( 25 ) so that, when the cover member ( 5 ) is in the first position (P 1 ), the aperture ( 25 ) aligns with the water inlet (F 1 ) so as to allow for the passage of water through the aperture ( 25 ) and water inlet (F 1 ) and into the steam chamber ( 3 A). The cover member ( 5 ) is attached to the steam chamber ( 3 A) by the same configuration of attachment elements ( 8 , 9 ) as described above, shown in  FIG. 3C . 
     A fourth embodiment of the invention is shown in  FIG. 4A , and a first implementation of the fourth embodiment is shown in  FIG. 4B . The system further comprises an outer housing ( 2 ), wherein the housing ( 2 ) may be configured to partly envelop the steam chamber ( 3 A) so that at least one side of the steam chamber ( 3 A) is covered by the housing ( 2 ). In the first implementation of the fourth embodiment shown in  FIGS. 4A and 4B , an opening ( 4 A) is provided in the housing ( 2 ), the opening ( 4 A) in the housing ( 2 ) being formed around the opening ( 4 ) in the steam chamber ( 3 A), such that the opening ( 4 A) in the housing communicates with the inside of the steam chamber ( 3 A). 
     In this embodiment, the second attachment elements ( 9 ) are provided on the housing ( 2 ), with second elongate rails ( 9 A) running parallel either side of the opening ( 4 A) provided in the housing ( 2 ). As above, the first attachment elements ( 8 ) are spaced apart corresponding to the spacing of the second attachment elements ( 9 ), such that the first ledges ( 8 B) are in overlapping relation with the second ledges ( 9 B) when the cover member ( 5 ) is in the first position (P 1 ). Therefore, the cover member ( 5 ) can only be separated from the steam chamber ( 3 A) by a sliding action of the cover member ( 5 ) relative to the housing ( 2 ) in a direction parallel to the attachment elements ( 8 , 9 ). 
     In this embodiment, the cover member ( 5 ) further comprises a steam outlet ( 6 ), the steam outlet ( 6 ) communicates with the inside of the steam chamber ( 3 A) when the cover member ( 5 ) is in the first position (P 1 ) to allow for the passage of steam through the steam outlet ( 6 ) and out of the steam chamber ( 3 A). 
     Referring to  FIG. 4B , the cover member ( 5 ) comprises a silicon seal ( 7 ). When the cover member ( 5 ) is in the first position (P 1 ), the seal ( 7 ) is disposed around the opening ( 4 ) in the steam chamber ( 3 A) and between the steam chamber ( 3 A) and the cover member ( 5 ). 
     A water inlet (not shown) is also provided to allow for the passage of water from a water tank (not shown) to the inside part of the steam chamber ( 3 A). It is envisaged that the water tank is formed integrally with the housing ( 2 ); in one such example, the water tank comprises a separate chamber formed in the housing ( 2 ) to store water and deliver water through the water inlet by any suitable means. 
     The cover member ( 5 ) comprises a flat plate ( 16 ) wherein a plurality of apertures ( 6 A) is provided in the plate ( 16 ) for delivering steam from the steam chamber ( 3 A) when the device is operational. On the back of the plate ( 16 ) there is formed a surround ( 17 ) that is arranged to enclose the space between the housing ( 2 ) and the flat plate ( 16 ) when the cover member ( 5 ) is fitted to the housing ( 2 ). In more detail, the surround ( 17 ) is a wall that extends around the outer edge of the plate ( 16 ) and is upstanding therefrom, so that the plate&#39;s ( 16 ) surface on which the surround ( 17 ) is disposed lies entirely within the confines of the surround ( 17 ). A bracket ( 18 ) formed integrally with the surround ( 17 ) and extending from the inner face of the surround ( 17 ) is provided for retaining the seal ( 7 ). The bracket ( 18 ) comprises a second wall ( 18 A) that extends around the whole of the inner face of the surround ( 17 ) and into the region enclosed by the surround ( 17 ) to form an opening ( 4 A) disposed opposite the flat plate ( 16 ). A U-shaped channel ( 18 B) for retaining the seal ( 7 ) extends around the inner edge of the opening ( 4 A). With the cover member ( 5 ) in the first position (P 1 ), the opening ( 4 A) in the cover member ( 5 ) faces the opening ( 4 ) in the steam chamber ( 3 A) so that the seal ( 7 ) is disposed around the opening ( 4 ) in the steam chamber ( 3 A) so that a seal is made that is impermeable by steam or water. In operation of the system ( 1 ), steam passes through the openings ( 4 , 4 A) in the steam chamber ( 3 A) and cover member ( 5 ) respectively, and into the space enclosed by the surround ( 17 ) and the flat plate ( 16 ), before passing out through the apertures ( 6 A) formed in the plate ( 16 ). 
     The seal ( 7 ) may be held in place by compression of the seal ( 7 ) material; this may be achieved by sizing the seal ( 7 ) so as to be marginally larger than the space within the U shaped channel ( 19 ). Alternatively, the seal ( 7 ) may be held in place by a suitable adhesive. 
     A nozzle ( 7 A) is formed integrally with the seal ( 7 ), and comprises a wall that extends around the opening ( 4 A) provided in cover member ( 5 ) and into the surround ( 17 ), abutting the plate ( 16 ) to enclose the steam dispensing apertures ( 6 ). Therefore, with the cover member ( 5 ) disposed in the first position (P 1 ), the nozzle ( 7 A) fluidly couples the opening ( 4 ) formed in the steam chamber ( 3 A) with the apertures ( 6 A) formed in the plate ( 16 ) to provide a passage that directs the steam from the steam chamber ( 3 A) to the apertures ( 6 A) formed in the plate ( 16 ). Advantageously, the nozzle ( 7 A) helps to prevent steam from condensing inside the surround ( 17 ) by minimising the surface area inside the surround ( 17 ) to which steam is exposed, thus reducing the risk of condensate passing through the apertures ( 6 A) formed in the plate ( 16 ). 
     In the first to fourth embodiments, the cover member ( 5 ) is configured so as to be removable from the housing ( 2 ) by a sliding action, as depicted in detail in  FIGS. 5A and 5B , to provide the user with access to inside surfaces of the steam chamber ( 3 ) through the opening ( 4 ) provided in the steam chamber ( 3 A). 
     An example cover member ( 5 ) is shown in  FIG. 6 . In this example, the first attachment elements ( 8 ) are disposed either side of the opening ( 4 A) and are arranged parallel to allow the cover member ( 5 ) to be slideably engaged with the housing ( 2 ). It is intended that the second attachment elements ( 9 ) conform to substantially the same shape as the first attachment elements ( 8 ) but are offset so as to lie within the first attachment elements ( 8 ) when the cover member is in the first position (P 1 ). 
     In further implementations of the fourth embodiment, shown in  FIGS. 7 and 8 , the first attachment element ( 8 ) is provided along one side of the upper edge of the surround ( 17 ) only, with the second attachment element ( 9 ) being provided along a corresponding side of the housing ( 2 ). To attach the cover member ( 5 ) to the housing ( 2 ), the first attachment element ( 8 ) and second attachment element ( 9 ) are engaged such that the respective first and second ledges ( 8 B,  9 B) overlap; the opposite sides of the cover member ( 5 ) and housing ( 2 ) are then brought together and secured in place by a sprung catch ( 14 ) such that the cover member ( 5 ) is in the first position (P 1 ). 
     The sprung catch is a cantilevered tab ( 14 ) with a V-shaped bend ( 14 A) disposed in the free end such that an element of the tab ( 14 ) extends from the main body of the tab ( 14 ). The tab may be made from steel or any suitable resiliently deformable material. The fixed end of the tab ( 14 ) is located permanently on the housing ( 2 ), with the free end protruding into overlapping relation with the top of the surround ( 17 ). To engage with the tab ( 14 ), there is provided a recess formed in the inside face of the upper edge of the surround ( 17 ) into which the V-shaped bend ( 14 A) of the tab ( 14 ) is received. Optionally, to disengage the V-shaped section from the recess, the user is required to pull the two components apart by exerting a force not normally encountered during normal operation of the steam system ( 1 ), in this way the corresponding edge of the surround ( 17 ) is prevented from becoming separated from the housing ( 2 ) during normal operation of the steam system ( 1 ). It shall be appreciated that alternative bend shapes can be envisaged that prevent separation of the cover member ( 5 ) from the housing ( 2 ) by a force acting to pull the two components apart 
     In the implementation of the fourth embodiment shown in  FIG. 8 , a button ( 15 ), shown in  FIG. 8 , may be provided to release the tab ( 14 ). The button ( 15 ) is moveably mounted to the housing ( 2 ) and mechanically coupled to the tab ( 14 ), such that when the button ( 15 ) is depressed the tab ( 14 ) is caused to disengage the cover member ( 5 ) so that the cover member ( 5 ) is free to move from the first position (P 1 ) to the second position (P 2 ) 
     The button ( 15 ) is received in an opening formed in the housing ( 2 ) adjacent to the fixed end of tab ( 14 ). One end of the button ( 15 ), herein referred to as the operable end ( 15 A), is disposed so as to protrude from the outer surface of the housing ( 2 ) when the tab ( 14 ) is in an initial position; the other end of the button ( 15 ), herein referred to as the distal end ( 15 B), is in abutting relation with the tab ( 14 ). When the user presses on the operable end ( 15 A) of the button ( 15 ), the button ( 15 ) is displaced and the distal end ( 15 B) acts against the tab ( 14 ) to cause it to bend along its unfixed length from the initial position to a displaced position. The inherent elasticity of the material used to form the tab ( 14 ) causes the bending of the tab ( 14 ) to be reacted. As the user releases pressure on the button ( 15 ), the tab ( 14 ) moves from the displaced position to the initial position, acting on the distal end ( 15 B) of the button to cause the button&#39;s operable end ( 15 A) to be restored to a protruding position from the outer surface of the housing ( 2 ). The button ( 15 ) and the opening in which it is received are shaped so that the button ( 15 ) is constrained by the housing ( 2 ) when the tab ( 14 ) is in its initial position. For example, this may be achieved by tapering the button ( 15 ) such that the distal end ( 15 B) is larger in section than the operable end ( 15 A), with the opening in the housing ( 2 ) having an internal surface that substantially matches the shape of the button&#39;s ( 15 ) exterior surface. In this example, the tab ( 14 ) acts against the button ( 15 ) so that the button ( 15 ) is held against the interior surface of the opening in the housing ( 2 ). 
     It shall be appreciated that the sprung catch ( 14 ) may alternatively be mounted to the wall portion ( 3 B) and arranged so as to engage with the cover member ( 5 ) when the cover member ( 5 ) takes said first position (P 1 ) so that the cover member ( 5 ) mounts directly to the wall portion ( 3 B) (as per embodiments 1 to 3). Equally, the release button ( 15 ) may be moveably mounted on the wall portion ( 3 B) and mechanically coupled to the sprung catch ( 14 ), such that when the release button ( 15 ) is actuated the sprung catch ( 14 ) is caused to disengage the cover member ( 5 ) to allow the cover member ( 5 ) to be detached from the wall portion ( 3 B). 
     In another implementation of the fourth embodiment, the first and second attachment elements ( 8 , 9 ) are curved along their length to enable the cover member ( 5 ) to be attached to the housing ( 2 ) by rotation of the cover member ( 5 ) relative to the housing ( 2 ). An example cover member ( 5 ) with curved first attachment elements ( 8 ) is shown in  FIG. 9 . To mount the cover member ( 5 ) to the housing ( 2 ), the cover member ( 5 ) is positioned relative to the housing ( 2 ) so that the upper edge of the surround ( 17 ) and the respective face of the housing ( 2 ) are aligned. The cover member ( 5 ) is rotated around a central axis ( 26 ) to cause it to be attached to the housing ( 2 ). The first and second attachment elements ( 8 , 9 ) have radius of curvature equal to their distance from the central axis ( 26 ). First and second attachment elements ( 8 , 9 ) are positioned such that, as the cover member ( 5 ) is attached to the housing ( 2 ), their respective first and second ledges ( 8 B,  9 B) are slid into abutting overlapping relation by rotation of the cover member ( 5 ) about the central axis ( 26 ). 
     Optionally, the first attachment elements ( 8 ) have first ledges ( 8 B) that are tapered so that the thickness of the ledge ( 8 B) increases along the length of the ledge ( 8 B), such that when first and second attachment elements ( 8 , 9 ) are moved into engagement, the rotation of the cover member ( 5 ) relative to the housing ( 2 ) causes the cover member ( 5 ) to be drawn towards the housing ( 2 ). It shall be appreciated that the second ledge ( 9 B) may also, or alternatively, be tapered so as to achieve the same effect. It shall be appreciated that the first and second attachment elements ( 8 , 9 ) provided on the wall portion ( 3 B) in embodiments 1 to 3 may also be curved in the manner described hereinabove so that first and second attachment elements ( 8 , 9 ) may be moved into and out of engagement to attach and detach the cover member ( 5 ) to the wall portion ( 3 B) by rotational movement of the cover member ( 5 ) relative to the wall portion ( 3 B). 
     In all above embodiments of the invention, the size and shape of the opening provided in the steam chamber ( 3 A) is configured to provide access to the inside part of the steam chamber ( 3 A), such that it can be manually cleaned of scale by the user; this may be achieved by rinsing or scraping the scale deposits away. Rinsing can be achieved by introducing water into the steam generator through the water inlet (F 1 ), providing the advantage of delivering water to only the location where it is needed. 
     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.