Iron with foam moistening means

The invention relates to an iron having means for moistening fabric to be ironed. According to the invention, the moistening means comprise a device for generating foam and means for applying said generated foam to the fabric. For example, foam may be generated by means of a nozzle (21) having a first inlet (8) for a foaming liquid (6) and a second inlet (12) for supplying pressurized air to the nozzle so as to mix air with said liquid, thereby creating foam (42). Applying foam to the fabric (50) can be realized by means of a doctor blade (51) to break up the foam.

The invention relates to an iron having a soleplate, heating means for heating said soleplate, and means for moistening fabric to be ironed.

To improve the ironing result it is generally known to moisten fabric before it is ironed. Moistening can, for example, be done by spraying water on the fabric. The fabric will absorb the water and after a while the fabric is moistened. Water can be sprayed from a separate container or from a spraying device provided on an iron. Whether the fabric is moistened more or less evenly depends on the user's skill. In general, a homogeneous moistening of the fabric will not occur. Another manner to moisten fabric is by means of steam. Steam irons are well known. During ironing steam penetrates the fabric, making the removal of wrinkles easier during the subsequent ironing stroke(s). This manner of moistening is more convenient for the user but the moistening itself is not very satisfactory. Water evaporates too quickly because the temperature of the fabric is high, often about 100° C. Often part of the steam goes through the fabric, moistening the cover layer of the ironing board, which is, of course, not desired.

It is an object of the invention to provide an iron as described in the opening paragraph with means for improving the moistening of the fabric during ironing.

According to the invention, this object is achieved in that the moistening means comprise means for generating foam and means for applying said generated foam to the fabric. The main advantage of using foam is that the fabric is moistened very homogeneously. Less water is necessary for effectively moistening fabric by means of foam than by means of steam. Moistening by foam not only saves water, but it also saves energy, because less heat is necessary for drying the fabric.

In general, foam can be generated either by means of air or by vapor. If air is used, a preferred embodiment of the iron is characterized in that the means for generating foam comprise at least one nozzle having a first inlet for a foaming liquid and a second inlet for air, and pressure means for supplying pressurized air to the nozzle via the air inlet so as to mix air with said liquid, thereby creating said foam. The nozzle comprising the pressure means in the form of a simple air pump, such as an aquarium pump, can be made very small, which is necessary because the space in an iron is limited. The liquid may contain an additive for improving, for example, the gliding performance during ironing or the wrinkle resistance.

In a further preferred embodiment of the iron, the nozzle comprises an outlet having at least one body of perforated material for generating a fine foam. Such a body may be, for example, a mesh. If the bubbles of the foam generated by the nozzle are too big, the outlet of the nozzle may be provided with one of more meshes, for example, a first, coarse mesh and behind that a second, fine mesh. Applying a fine foam on the fabric results in a better distribution of the foam over the fabric and thus a better moistening of the fabric.

In another embodiment, the means for generating foam comprise a chamber having a supply of foaming liquid and a supply of air, and agitating means for effecting a mixing of air and foaming liquid. The agitating means used could be a motor-driven impeller arranged in said chamber.

In the case of vapor being used, an embodiment of the iron above described is characterized in that the means for generating foam comprise a first reservoir containing a mixture of a liquefied propellant and a concentrated foaming liquid under pressure and a second reservoir containing water, each of said reservoirs having an outlet connected to the other one so as to form one single outlet for mixing said propellant/foaming liquid with said water, thereby creating said foam. The liquefied propellant, mostly a low-boiling alkane, is dissolved in a concentrated foaming liquid under pressure. When the propellant/foaming liquid are mixed with water, the propellant will evaporate resulting in an expansion in volume of the liquid, which thus becomes a foam.

To apply the generated foam to the fabric, the iron is preferably provided with at least one cavity at the lower side of the iron, said cavity having an outlet opening in the soleplate. The cavity enables the foam to expand, thereby facilitating delivery of the foam.

A further improvement in the application of the generated foam to the fabric is obtained by providing the iron with a doctor blade, an edge thereof being located at substantially the same level as an ironing surface of the soleplate. The doctor blade breaks up the foam and spreads the foam more uniformly over the fabric.

Another preferred embodiment of the iron described above is characterized in that the means for generating foam comprise a pump having an inlet and an outlet, a reservoir for containing a foaming liquid and having an outlet, and a device for generating foam, having a first inlet for the foaming liquid, a second inlet for air, and an outlet connected to the inlet of said pump for sucking air and said foaming liquid from said reservoir into the foaming device, thereby generating foam, the outlet of said pump being connected to at least one discharge opening of the iron for applying the generated foam to the fabric by means of the pump. One single pump is used to suck in foaming liquid as well as air in a desired proportion into the foaming device, where the air is mixed with the liquid. The sucking force causes the mixture to turn into a foam. The dispensing rate of the generated foam can be controlled by means of a control unit for controlling the power of the pump. The liquid may contain an additive for improving, for example, the gliding performance during ironing or the wrinkle resistance.

A preferred embodiment of the iron described above is characterized in that the iron comprises a second reservoir for containing water and having an outlet which is connected to the outlet of the foaming liquid reservoir upstream of the foaming device. In this way the foaming liquid can be supplied in a concentrated form, so that the storage reservoir for the foaming liquid can be kept relatively small. The concentrated foaming liquid is diluted before it enters the foaming device. It is also possible that the iron comprises a second reservoir for containing water and having an outlet, and that the foaming device comprises a third inlet connected to the outlet of the water reservoir for water to be mixed with the foaming liquid and with air for creating said foam. In this case the foaming fluid is diluted in the foaming device.

In a further embodiment thereof, the inlet of the foaming device for foaming liquid comprises a shut-off valve. By closing the valve it is possible to clean the foaming device and tubes downstream of the foaming device by flushing with water.

In the first embodiment shown inFIG. 1, the iron comprises a housing1with a soleplate2which is heated by an electric heating element3. Foam is generated by means of a nozzle unit4, the working of which will be described hereinafter with reference toFIG. 2. The iron comprises a reservoir5containing a foaming liquid6under pressure. Reservoir5may be, for example, a removable cartridge. The foaming liquid contains a small amount of surfactant to reduce the surface tension. The surfactant concentration must be just above the Critical Micelle Concentration (CMC) for producing a foam. In practice this means that the concentration is about 0.2 to 0.5 percent by weight. The reservoir5has an outlet7which is connected to a first inlet8of the nozzle unit4via a duct9. If desired, the flowrate of the foaming liquid from the reservoir to the nozzle unit may be made adjustable. The iron further comprises an electric air pump10whose outlet11is connected to a second inlet12of the nozzle unit4via a duct13. The outlet11of the air pump is also connected to an upper part of the reservoir5via a duct14to put the foaming liquid6under pressure. If so desired, the airflow rate to the nozzle unit4may also be made adjustable. The pump10can be operated by an operating knob15on the iron.

The second embodiment shown inFIG. 2, is a modification of the first embodiment. In this embodiment, the iron comprises a second reservoir16which is a removable cartridge containing the foaming liquid6under pressure. The (first) reservoir5contains water17. The second reservoir16has an outlet18which branches into the duct9toward said first inlet8of the nozzle unit4. In this embodiment the foaming liquid6in the cartridge16is in a concentrated form. The concentrated foaming liquid is diluted with water17from the water reservoir5before it enters the nozzle unit4. As in the first embodiment, the air pump10is connected to the nozzle unit4.

The nozzle unit4for generating foam is shown inFIG. 3. The nozzle unit comprises a housing consisting of three housing parts20a,20b, and20c. The housing accommodates a nozzle21and comprises the following parts: a hollow cylindrical outer housing22having a lower part23and a wider upper part24with a stepped portion25between said two parts, a cylindrical sleeve26, and a core27. The sleeve26is partly located inside the upper part24of the housing22such that an annular space28is formed between an outer wall29of the sleeve26and an inner wall30of the upper part24. Furthermore, a lower edge31of the sleeve26is located at a distance from the stepped portion25, leaving a circumferential opening32therebetween. The core27is located inside the sleeve26such that a thin annular space33is formed between an inner wall34of the sleeve26and an outer wall35of the core27. A cylindrical lower end part36of the core is positioned opposite said circumferential opening32. The circumferential opening32forms the connection between the two annular spaces28and33. The housing22of the nozzle is secured inside the housing part20aof the nozzle unit, the sleeve26is secured to the housing part20b, and the core27is secured to the housing part20c. When the three housing parts20a,20b, and20care assembled, the core27fits into the sleeve26and the sleeve26fits into the upper part24. The housing parts are fastened together by means of fasteners37. Sealings38between the housing parts make the parts airtight. Housing part20cis provided with said first inlet8for the foaming liquid6. A duct39connects the inlet8with the annular space33. Housing part20ais provided with said second inlet12for pressurized air40. A duct41connects the air inlet12with the annular space28.

Foam is generated as follows: foaming liquid6from the reservoir5(FIG. 1) or16(FIG. 2) is pressed via the first inlet8into the annular space33; air is pumped via the second inlet12into the annular space28, leaves said space via the circumferential opening32, and is radially forced into the foaming liquid6in the annular space33, thereby creating a foam42. Good results are obtained with a foaming liquid/air ratio of approximately 1:10. The generated foam is pressed to an outlet43of the nozzle21and then to a conical outlet44of the nozzle unit4. If the bubbles in the foam thus generated are too coarse, meshes may be arranged at the outlet43of the nozzle, for example two meshes, a first, coarse mesh45followed by a second, fine mesh46. In this way a very fine foam47is obtained at the outlet44.

The foam47flows from the conical outlet44into a cavity48located at the lower side of the iron. The cavity48has an outlet opening49in the soleplate2. The cavity serves as an expansion space for the foam to allow the foam to expand over the fabric50during ironing. In order to obtain a good penetration of the foam into the fabric, a doctor blade51is provided in the cavity48. The lower edge52of the blade51is located approximately at the same level as the ironing surface52of the soleplate2and extends perpendicularly to the ironing direction. The doctor blade breaks up the foam, thereby creating very fine liquid droplets which easily penetrate into the fabric in a uniform manner. It is also possible to use an airflow to improve the penetration of the foam into the fabric. Such an airflow may be obtained by means of the pump10which is present anyway. A duct53branches from the air duct13and issues into a groove54at the lower side of the soleplate2. The groove54extends perpendicularly to the ironing direction.

In the third embodiment shown inFIG. 4, foam is generated by means of an impeller55driven by a motor56. The impeller is accommodated in a chamber57which has an inlet58for foaming liquid and an inlet59for air. The inlet58is connected to the reservoir60containing a foaming liquid6. The chamber57is divided into two spaces61,62separated by a partition wall63. The spaces61,62are in communication with each other in the upper part64of the chamber. The inlet58for the foaming liquid6is connected to a first space61in which the impeller55is accommodated. The inlet59for air is arranged in the upper part64of the chamber. The second space62is provided with an outlet65which is connected to the cavity48. The impeller rotation mixes air and foaming liquid, thereby creating foam42in the upper part64of the chamber. The foam is pressed through the second space62toward the outlet65into the cavity48. Meshes (not shown) may be provided at the outlet65to obtain a fine foam.

In the fourth embodiment shown inFIG. 5, foam is generated by mixing a propellant with a concentrated foaming liquid. Inside the housing1there is first reservoir5containing water17, and a second reservoir66containing a mixture67of a liquefied propellant, such as a low-boiling alkane, and a concentrated foaming liquid. The second reservoir may be a removable cartridge. The mixture in the reservoir66is pressurized. Outlets68and69of said reservoirs are connected to each other in a mixing device70having a single outlet71. When the mixture of propellant and concentrated foaming liquid issues from the single outlet, the propellant vaporizes and causes an expansion in volume of the foaming liquid. At the same time water is added to make a stable foam. The addition of water offers the possibility to store the mixture of liquefied propellant and foaming liquid in a concentrated form, thus keeping the volume of the reservoir66small. Moreover, adding water makes the foam fireproof, which of course is absolutely necessary.

FIG. 6shows an embodiment in which multiple cavities48are provided at the lower side of the iron. The foam outlet44of the nozzle unit4ofFIG. 1or2is connected to a duct72which has multiple outlets73ending in the respective cavities48. A similar construction may be applied to the third embodiment (FIG. 4) and fourth embodiment (FIG. 5). A more uniform foam distribution is obtained thereby.

In the fifth embodiment shown inFIG. 7, the iron comprises a housing101with a soleplate102which is heated by an electric heating element103. Foam is generated by means of a foaming device104. The iron comprises a reservoir105containing a foaming liquid106. The foaming liquid contains a small amount of surfactant to reduce the surface tension. The surfactant concentration must be just above the Critical Micelle Concentration (CMC) for producing a foam. In practice this means that the concentration is about 0.2 to 0.5 percent by weight. The reservoir105has an outlet107which is connected to a first inlet108of the foaming device104via a duct109. The iron comprises an air duct110, one end111thereof communicating with the open air112, the other end being connected to a second inlet113of the foaming device104. The iron further comprises an electric pump114with an inlet115and an outlet116. An outlet117of the foaming device is connected to the inlet115of the pump114via a duct118. The outlet116of the pump is connected to a cavity119via a duct120. The cavity119has a discharge opening121in the soleplate102. The pump114is electrically connected via line122to a control unit123for controlling the power of the pump114.

In operation, when the pump114is activated by means of a knob124, foaming liquid106and air are sucked into the foaming device104, thereby generating foam125. The generated foam is sucked via duct118to the pump and then via duct120to the cavity119and discharged through discharge opening121to the fabric126. The flowrate of the generated foam can be controlled by controlling the power of the pump114.

The cavity119serves as an expansion space for the foam to allow the foam to expand, i.e. to generate more bubbles. If the bubbles in the foam thus generated are too coarse, meshes may be arranged in the cavity119, for example two meshes: a first, coarse mesh127followed by a second, fine mesh128. In this way a very fine foam129is obtained at the discharge opening121.

The sixth embodiment shown inFIG. 8is a modification of the fifth embodiment. The same reference numerals are used for similar parts. In this embodiment the iron comprises a second reservoir130for containing water131. The (first) reservoir105contains the foaming liquid106in a concentrated form. Preferably, this reservoir105is a replaceable cartridge. The cartridge105is under atmospheric pressure and has a vent opening132. An outlet133of the second reservoir130is connected to a third inlet134of the foaming device104via a duct135. In operation, when the pump114is activated, the concentrated foaming liquid106, water131, and air112are sucked into the foaming device104, thereby generating foam. The concentrated foaming liquid106is diluted with water131in the foaming device104. The generated foam is pressed toward the discharge opening121by means of the pump114, similar to the operation of the iron ofFIG. 7as described above.

A shut-off valve136may be provided in duct109between the cartridge105and the foaming device104. When the valve136is closed and the pump is still operating, the foaming device104and all ducts downstream thereof can be cleaned by flushing with water. For example, this may be done after every moistening period, i.e. the pump may run for another few seconds when the knob123for activating the pump114is released.

The foaming device104may be arranged as a replaceable unit for cleaning purposes. It is also possible to integrate the foaming device104into the bottom137of the replaceable cartridge (first reservoir)105for the foaming liquid106. The foaming device will then be clean whenever an empty cartridge is replaced by a new, full cartridge.

The foaming device maybe a simple 3-to-1 fitting, i.e. a joint with three inlets and one outlet. The mixing ratio of the diluted foaming liquid may be achieved by a determination of the orifice sizes of the three inlets of the foaming device. The inlets may be provided with non-return valves to prevent reverse flow. Filters may be arranged at the inlets to avoid dirt particles to clog up the foaming device. The foaming device may be provided with meshes like those arranged in the cavity119to promote foam generation.

The iron may be provided with a heat insulation cover138to avoid heat conduction from the soleplate to the foaming device104, pump114, ducts118,120, and cavity119.