Abstract:
A steam iron having a bipartite steam rate control, based on a combination of a user-control, which allows a user to consciously set a desired steam rate, and an intuitively operated handle, which may conditionally provide the steam rate control assembly with corrective, energy saving input.

Description:
FIELD OF THE INVENTION 
     The invention relates to steam irons, and more in particular to the control of steaming functions of such irons. 
     BACKGROUND 
     A domestic steam iron has the capability to generate steam and to subsequently release this steam through outlet openings provided in the soleplate of the iron. The steam, which is applied directly to a garment being ironed, helps to diminish the ironing effort and to improve the ironing result. 
     Modern steam irons may come equipped with a steam rate control, for example in the form of a turnable knob or a slider provided on the iron housing. While a low steam rate setting may suffice for efficiently ironing moderately creased clothes (or patches thereof), a high steam rate setting may be selected to aid in the removal of tough wrinkles. The control allows the user at any time to select the steam rate setting that is appropriate for the (patch of) garment at hand. Practice shows, however, that some if not most users do not bother to adjust the steam rate once they have started an ironing session. Accordingly, when the maximum steam rate has been selected initially, the iron may remain set to produce larger amounts of steam than necessary for achieving a proper ironing result. Moreover, many users tend to park an iron horizontally between different ironing strokes, e.g. during garment changing or rearrangement, which results in continuation of maximum steam production during idle time. 
     In an attempt to put a curb on the energy wastage that is associated with such use of a steam iron, it has been suggested to fit the iron with an intuitively operated handle that controls the steam rate. See for an example of such an iron FR602293. The working of an intuitive handle may rely on the downward force that is exerted by a user&#39;s hand as he steers the iron across a garment. In general, a user will intuitively apply a larger downward force on the handle as the degree of wrinkling in a garment increases. The applied force may thus be taken as a measure of the desired steam rate. When no force is applied, for example when the iron is parked on an iron rest, the production and/or release of steam may be halted. 
     Although the intuitive handle seems to provide a solution to the problem of energy wastage due to unnecessary steam production, research has shown that the range of forces exerted on a handle by an ironing user varies per individual. This means, inter alia, that the minimum force that is applied during an ironing session is individual-dependent. In addition, individual users do not display consistent force-exertion behaviour across different ironing sessions either. As an intuitive handle has a minimum force threshold that must be exceeded in order to activate it, users of an iron with such a handle may not, or not at all times, automatically apply sufficient force on the handle to bring about the release of steam. Furthermore, even though the handle may thus work unsatisfactorily, it may not be possible to put the handle out of action or to override it, and to specify the desired steam rate in a different manner. 
     SUMMARY 
     It is an object of the present invention to provide for a steam iron that overcomes or mitigates one or more of the above-described problems. 
     To this end, a steam iron is provided that includes a handle, moveable between a first handle position and a second handle position, whereby a biasing mechanism is provided to bias the handle into the first handle position. The steam iron also includes a user-control, adjustable between a first state and a second state, and a steam rate control assembly, operatively connected to the handle and the user-control, and configured to set a steam rate of the steam iron. The steam rate control assembly is configured such that the steam rate is set based on the user-control, irrespective of the position of the handle, when the user-control is in the first state; and such that the steam rate is set based on at least a position of the handle when the user-control is in the second state. 
     A steam iron according to the present invention provides a bipartite steam rate control, based on the synergetic combination of the two controls discussed above: a user-control, which allows a user to consciously set a desired steam rate, and an intuitively operated handle, which may conditionally provide the steam rate control assembly with corrective, energy saving input. Advantageously, the user-control enables the user to put the intuitive handle out of action in case it does not function satisfactorily, e.g. when ironing only mildly creased clothes, or in case its operation is not required, e.g. when no steaming is desired at all. Depending on the desired functionality, the first state of the user-control may comprise two or more selectable user-control positions, each of which may be associated with its own steam rate. The more first-state user-control positions, the wider the choice available to the user to unambiguously select the desired steam rate, independent of the handle position. 
     In an advantageous embodiment, the steam rate control assembly is configured such that a steam rate that is set when the user-control is in its first state is smaller than a steam rate that is set when the user-control is in its second state. 
     That is to say, the first state of the user-control corresponds to one or more relatively low steam rates, while the second state of the user-control corresponds to one or more medium or high steam rates. Since the user-control is operated consciously, a user may determine whether he desires a low or a high steam rate. When a low steam rate is selected, the iron&#39;s energy consumption is moderate, and there is little need for corrective, energy saving input from the intuitive handle. Besides, the selection of a low steam rate indicates that only mildly creased garments are being ironed, such that the force that is intuitively exerted on the handle might easily be too small to activate it anyway. When the need for energy saving action arises, however, i.e. when a medium or high steam rate is selected, the steam rate control assembly will automatically involve input from the intuitive handle in setting the steam rate. As the conscious selection of a high steam rate indicates that more heavily wrinkled garments are being ironed, the force exerted on the intuitive handle will typically suffice to activate it. 
     The arrangement may be such that the user-control is primarily concerned with the selection a desired base steam rate. When the steam rate set by the user-control exceeds a certain threshold, whereby the user-control passes into its second state, the base steam rate may be fixed at the threshold value and the intuitive handle may be put in action to provide an extra dosage of steam in dependence of the force exerted thereon. Release of the handle will then ensure a return to the base steam rate to save energy. 
     These and other features and advantages of the invention will be more fully understood from the following detailed description of certain embodiments of the invention, taken together with the accompanying drawings, which are meant to illustrate and not to limit the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a schematic side view of an exemplary steam iron according to the present invention; 
         FIG. 2  is a schematic side view of a steam rate control assembly as shown in  FIG. 1 ; 
         FIGS. 3 and 4  illustrate the operation of the exemplary mechanical steam rate control assembly shown in  FIG. 2  when the user-control is in its first state; and 
         FIGS. 5 and 6  illustrate the operation of the exemplary mechanical steam rate control assembly shown in  FIG. 2  when the user-control is in its second state. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  schematically shows an exemplary embodiment of a steam iron  1  according to the present invention. It will be appreciated that several components of the iron which are well known and have no particular relevance to the present invention are omitted for reasons of clarity. 
     Steam iron  1  comprises a housing  2  that is fitted with an intuitively operated handle  4 . Handle  4  is pivotable between a first, elevated position and a second, lower position around a hinge  6  that connects the handle  4  to the housing  2 . In  FIG. 1 , the handle  4  is hinged near its front end, though in other embodiments it may be hinged at other points, such as its middle or its back end. Due to the action of a biasing mechanism  8 , handle  4  resides in its first position when no external, downward force is applied thereto. The biasing mechanism may, for example, be integrated in hinge  6  in the form of a spring hinge, as shown in  FIG. 1 . Alternatively, it may be provided in a fulcrum  38  of a lever  34  (to be discussed hereafter) that is connected to the handle. Handle  4  is operably connected to a steam rate control assembly  30 . The steam rate control assembly  30  includes a valve  32 , that is disposed in a water channel  10  that leads from a refillable water reservoir  12  to outlet openings  14  in the heated soleplate  16 . When valve  32  is in an open position, water is allowed to flow from reservoir  12 , through valve  32 , to a heated steam chamber  18 . In steam chamber  18 , the water is converted from its liquid form into steam, after which it is released through outlet openings  14  in soleplate  16 . Naturally, when the valve  32  is in a closed position, no water flows from the water reservoir to steam chamber  18 , and no steam is produced or released. 
     Although  FIG. 1  depicts a steam iron  1  with an integrated water reservoir  12 , i.e. a water reservoir integrated into the housing  2  that is purposefully moveable by the user during ironing, it is noted that in another embodiment of the steam iron the water reservoir may be arranged external to said housing  2  in a stationary body. This arrangement is common in so called system iron, which, as a rule, feature a relatively large water reservoir and a pressurized steam chamber upstream of the handle-operated valve  32 . In contrast to the embodiment of  FIG. 1 , in which the valve  32  controls a flow of liquid water, the valve in these steam iron systems may control a flow of steam. This is a result of the fact that heating of the water in the former embodiment tends to be taken care of downstream of the valve  32 , in steam chamber  18  near the soleplate  16  of the iron  1 , while in the latter embodiment heating is provided for in the aforementioned external, pressurized steam chamber. 
     Attention is now invited to the construction and operation of the steam rate control assembly  30 . The construction of the steam rate control assembly  30  will be described first with reference to  FIG. 2 . Subsequently its operation will be clarified with reference to  FIGS. 3-6 . 
     Referring primarily to  FIG. 2 , the exemplary steam rate control assembly  30  comprises a support structure  31  to which a steam shaft  58 , a switch  42  and a lever  34  are moveably connected. A lower end of the steam shaft  58  coincides with the aforementioned valve  32 . Said lower end normally extends through a valve opening  33  (see  FIG. 1 ) and tapers off to a point. When the steam shaft  58  is in its lowest position, its lower end may block the valve opening  33  completely. However, when the steam shaft  58  is raised, the valve opening  33  is gradually freed as the tapered end  32  retreats therefrom. This allows for an increasing flow of water from the water reservoir  12  to the steam chamber  18 . The higher end of the steam shaft  58  is formed by a steam shaft bracket  56 , which is slideably moveable in a generally vertical direction within the support structure  31 . The steam shaft bracket  56  is spring-loaded by a spring  60  that forces the steam shaft bracket  56 , and hence the steam shaft  58  as a whole, upwards. The highest position that may be occupied by the steam shaft bracket  56  at any time is restricted by one of the switch  42  and the lever  34 . 
     The switch  42  comprises a selector pin  44 , a guide slit  46  and a spring-loaded switch body  48 . The selector pin  44  may be operatively connected to a user-control that is accessible from the outside of the housing  2  of the steam iron  1 . Said user-control may take any suitable form, and for example be a turnable knob, a dial, a slider, etc. Alternatively, when the selector pin  44  is itself suitably shaped and positioned, the selector pin  44  may be identified with a user-control. The selector pin  44  is slideably moveable within the guide slit  46  that is provided in the support structure  31 . The guide slit  46  extends slantingly upwards, as can be best seen in  FIG. 3 . The switch body  48  is also slideably moveable within the support structure  31 , in a generally vertical direction. It deserves notice that this direction has a component that is perpendicular to the direction in which the guide slit  46  extends. The switch body  48  is spring-loaded by a spring  54  and serves, inter alia, to define a number of selectable selector pin positions, each of which is associated with its own steam rate. To this end, a top surface of the switch body  48  is provided with serrations  50  between any two of which the selector pin  44  is partly receivable. The spring action of spring  54  forces the switch body  48  upwards to lock the selector pin  44  in place between a selected pair of serrations  50  and an upper edge of the guide slit  46 . The selected position of the selector pin  44  determines the vertical position of the switch body  48 . Depending on its vertical position, an arm  49  of the switch body  48  may contact a top end of the spring-loaded steam shaft bracket  56  to restrict the upward movement thereof. Typically, such restricting contact occurs only when the selector pin  44  occupies one of the more left selector pin positions, which correspond to a relatively low vertical position of the switch body  48 . When the upward movement of the spring-loaded steam shaft bracket  56  is not restricted by the arm  49  of the switch body  48 , it may be restricted by contact with the lever  34  instead. 
     The lever  34  comprises a lever effect end  36 , a lever load end  40  and a lever fulcrum  38 . The lever effect end  36  is operably connected to the intuitive handle  4 , either directly or through the intermediation of an optional link mechanism. The connection is such that a downward movement of the handle  4  towards its second, lower position corresponds to a clockwise rotation of the lever  34  around the fulcrum  38 . It is understood that the clockwise rotation of the lever  34  involves the lifting of the lever load end  40 . When no downward force is exerted on the handle  4 , the biasing mechanism  8  will force the handle  4  into its first, elevated position such that the lever  34  is rotated in a counter-clockwise direction and the lever load end  40  is lowered. The counter-clockwise rotation of the lever  34  may be halted when the handle  4  reaches its first position or when the lever effect end  36  contacts a stop  62  provided by the support structure  31 . The lever load end  40  may interact with the steam shaft bracket  56  at the stop  57  provided thereon. Contact with the stop  57 , however, will not halt a counter-clockwise rotation of the lever as the biasing mechanism  8  is configured to overcome the spring action of spring  60 . 
     With regard to the terminology, it is noted that the positions of the selector pin  44  that effect a situation wherein the upward motion of the steam shaft bracket  56  is restricted by the switch body  48 , and not by the lever load end  36  in its lowest position, may define the first state of the user-control. Any position of the selector pin  44  that effects a situation wherein the lever load end  36  in its lowest position restricts the upward motion of the steam shaft bracket  56 , on the other hand, corresponds to a user-control in its second state. 
       FIGS. 3-6  illustrate the operation of the steam rate control assembly  30  shown in  FIG. 2 .  FIGS. 3 and 5  show the steam rate control assembly  30  with the lever  34  in its rest position, while  FIGS. 4 and 6  show the assembly  30  with the lever  34  in a rotated position that corresponds to a pressed-down intuitive handle  4 . 
     In  FIGS. 3 and 4 , the steam rate control assembly  30  is shown at a low steam rate setting. The selector pin  44  occupies a position between the two leftmost serrations  50  of the switch body  48 , which position corresponds to a user-control in its first state. As can be seen, the lever load end  40  does not contact the stop  57 , and the upward movement of the steam shaft bracket  56  is restricted by the contact between its upper end and the arm  49  of the switch body  48 . As shown in  FIG. 4 , a clockwise rotation of the lever  34  merely increases the gap between the lever load end  40  and the stop  57 . The rotation does not influence the position of the steam shaft  58 . Accordingly, the steam rate of the iron is determined only by the position of the selector pin  44 . In an embodiment of the steam iron, the handle  4  may be locked in place when the user-control is in the first state. This would prevent the handle  4  from pivoting idly, i.e. without controlling the position of the steam shaft  58 , which might lead a user to think that the user-control is actually in the second state and not functioning. The locking of the handle may be effected in numerous ways, as will be apparent to one skilled in the art. 
     Departing from the situation shown in  FIGS. 3 and 4 , the steam rate of the iron may be increased by sliding the selector pin  44  in an oblique, upward right direction through the guide slit  46 . The selector pin  44  will consecutively lock in place between different serrations  50  of the switch body  48 , which at the same time causes the spring-loaded switch body  48  to be moved upward. The upward motion of the switch body  48 , and in particular its arm  49 , allows the spring-loaded steam shaft  58  to rise as well. Since elevation of the steam shaft  58  lifts the tapered end  32  thereof from the valve opening  33 , an upward right movement of the selector pin  44  leads to an increased valve opening, and hence an increased steam rate of the iron  1 . 
     At some point, the sliding selector pin  44  will effect a situation wherein the steam shaft bracket  56  touches the lever load end  40  at stop  57 , and loses contact with the arm  49  at its top end. From that point on, the upward movement of the steam shaft  58  is no longer restricted by the switch body  48 , but by the lever  34 . Accordingly, it is the position of the intuitive handle  4 , which is operably connected to the lever  34 , that determines whether the steam rate is increased any further or not. This situation, which is depicted in  FIGS. 5 and 6 , corresponds to a user control is in its second state. 
     The steam rate control assembly  30  shown in  FIGS. 1-3  is entirely mechanical, i.e. does not comprise any electric or electrically controlled components. Although a (partly) electric steam rate control assembly may be used in alternative embodiments, a mechanical construction is generally preferable as it is more economical in terms of manufacturing costs. 
     By way of example a number of embodiments of a steam rate control assembly featuring electric components will be described briefly. In one embodiment the steam rate control assembly may comprise an electric pump by means of which a water flow rate in the water channel  10  (see  FIG. 1 ) can be controlled. An advantage of an electric pump is that it allows for configurations wherein the flow of water from the water reservoir  12  to the outlet openings  14  in the soleplate  16  of the iron is not gravity-driven. In addition, a pump may allow for much higher steam rates than can be obtained using a merely mechanical steam rate control assembly. Compared to the mechanical embodiments discussed above, the electric pump may effectively replace the valve  32 . Other than that, the described steam rate control assembly  30  may be used without modifications when the flow rate of the pump can be adjusted mechanically, keeping in mind that the steam shaft  58  now adjusts the flow rate setting of the electric pump instead of the position of a valve. 
     Alternatively, the flow rate setting of the electric pump may be controlled electronically, for example by means of a certain electric signal having a variable voltage or frequency. In that case, the steam rate control assembly may comprise an electronic control unit, e.g. a processor. In addition, the user-control may be an electric control, e.g. an electronic switch, and the handle  4  may be fitted with a displacement sensor or a force sensor to register the displacement of or the force exerted on the handle. In an advantageous embodiment, the electronic control unit may be programmable by the user, such that the user may for example set the steam rates associated with different positions of the user-control precisely as desired. —It is noted that the electric pump, like the water reservoir  12 , need not to be integrated into the housing  2  of the iron, but may be disposed external thereto instead. 
     Although illustrative embodiments of the present invention have been described with reference to the accompanying drawings, it is to be understood that the invention is not limited to these embodiments. Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, it is noted that the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.