EP0923656A1

EP0923656A1 - Electric iron with a soleplate

Info

Publication number: EP0923656A1
Application number: EP97918989A
Authority: EP
Inventors: Klaus Höfer; Andreas Walther
Original assignee: Rowenta Werke GmbH
Current assignee: Rowenta Werke GmbH
Priority date: 1996-08-24
Filing date: 1997-08-20
Publication date: 1999-06-23
Anticipated expiration: 2017-08-20
Also published as: DE19735214C2; US6035563A; DE19735214A1; EP0923656B1; RU2149935C1; WO1998007919A1; ES2185007T3; DE59708450D1

Abstract

An electric iron has a soleplate with a front tip and at least one passage for a liquid stored in a liquid tank system for wetting an article to be ironed. The passage is arranged in the area of the front tip symmetrically to a central line which starting from the front tip divides the soleplate in the middle. The liquid exits the passage in the form of liquid droplets generated by a piezo-electrically driven sprayer arranged above the soleplate. The electric iron is characterised in that the sprayer (12, 13, 14, 29) has at least one piezo-electrically driven thin membrane plate (12) with a plurality of spraying holes (24) associated with the respective passage (11) of the soleplate (6) and having a mean clear width from 30 to 100 νm. The number of spraying holes (24) is selected to ensure that the amount of liquid dispensed through the soleplate (6) does not exceed about 8 g/minute. The passages (11) are maximum 10 mm wide, whatever their length.

Description

P A T E N T A N M E L D U N G

"Electric iron with an iron soleplate"

The present invention relates to an electric iron with a soleplate that has a soleplate tip, and with at least one symmetrical to a center line that starts from the soleplate tip and divides the soleplate in the middle, in the area of the soleplate tip in the soleplate for the passage of a hole in a liquid tank system stored liquid for moistening an item to be ironed, the liquid in the form of liquid droplets, generated by means of a piezo-electrically excited atomizing device above the soleplate, emerging from the opening.

An electric iron of the type mentioned above is known from DE-A1 43 10 273.

The best ironing results, i.e. Optimal smoothness in the shortest possible time, achieved with steam irons or steam ironing stations. The steam output of the steam iron is 20 - 30 g / minute and that of the steam stations up to 60 g / minute. The steam generated serves both as a convective heat transporter and for moistening the ironing material, which is essential for smoothing natural fibers such as cotton, linen and wool. For an optimal ironing result, however, a so-called ironing moisture of about 15% by weight is required.

CONFIRMATION COPY These results can only be achieved with the very complex traditional sprinkling of the laundry by hand before ironing. In turn, the uneven distribution and the difficult dosage are disadvantageous.

With conventional steam ironing machines, the ironing moisture required for an optimal ironing result is not achieved even with a high steam output, since from a temperature of 100 ° C in the fabric, which is also significantly exceeded when the iron is passed over, there is no longer any condensation. Furthermore, the majority of the steam passes the ironing material unused and usually leads to an unpleasant working atmosphere.

Another disadvantage of the steam iron is that the user has to apply so-called ironing aids, such as starch, slip improvers, fragrances, finishes, etc., to the ironing material in a separate operation.

A direct introduction of these ironing aids into the water tank for steam generation is not possible, since these aids become ineffective due to the evaporation. Furthermore, the resulting deposits would permanently destroy the evaporator chamber of the devices.

In order to avoid all these disadvantages, liquid droplets are generated in the iron known from DE-A1 43 10 273 with a piezoelectric transducer. The liquid droplets are generated in a large-sized atomization chamber which is open on the side of the ironing surface and which is surrounded by the heated soleplate in a frame-like manner. A disadvantage of this known iron, however, is that, due to the very large atomization chamber, the heated part of the soleplate is insufficient in terms of area to smooth the difficult-to-smooth natural materials and to dry the moistened fabric ready for the cabinet. Another disadvantage is that when ironing in the atomization chamber objects attached to the items to be ironed, e.g. Buttons, get caught and tear off.

Another iron is known from DD-PS 214 404. This iron is in a separate aerosolization room, in which an electro-mechanical Ultrasonic atomization system is arranged, atomized. The aerosol is then fed via an externally controllable conveying device to a further distribution space and from there to individual aerosol distribution channels which end in aerosol outlet openings located in the soleplate. With such an arrangement, there is a risk that the aerosol condenses on the walls of the flow channels along the flow path of the aerosol from the aerosolization space to the outlet openings, or that the individual aerosol droplets assemble to form larger drops, so that large ones emerge from the outlet openings in the soleplate Drops of liquid can escape and cause wet spots on the items to be ironed, which will not dry again during normal ironing.

From DE-AS 10 87 107 a steam iron with a pot evaporator, which is designed as a disc, is known. The steam is guided in the iron in such a way that, even in the different positions of the iron, the water supply cannot reach the openings or openings in the soleplate from which the steam emerges. The openings in the soleplate from which the steam emerges when ironing are arranged on a circle with circular cross sections or cross sections in the form of an elongated hole.

EP-A1 0 358 310 is concerned with steam irons, in which the openings in the soleplate are distributed in such a way that they either lie on a center line which, starting from the tip of the soleplate, divides the soleplate in the middle, or run parallel to this line. These breakthroughs are provided in the form of elongated holes or slots; in one embodiment, a single opening is also arranged approximately in the middle of the soleplate.

Based on the prior art specified above, the invention has for its object to provide an electric iron in which the disadvantages mentioned above are avoided and which in particular ensures a defined application of moisture to the items to be ironed, without causing heavily soaked spots can, and in all Direction of movement of the soleplate of the iron on the item to be ironed achieves comparably good ironing results.

The above object is achieved, starting from the generic state of the art mentioned at the outset, in that the atomizing device comprises at least one piezo-electrically excited, thin membrane plate which has a plurality of atomizing openings assigned to the respective opening of the soleplate, each of which has a central one have an opening width of 30 to 100 μm, the number of atomizing openings being selected so that liquid discharge of up to approximately 8 g / minute is ensured via the soleplate and the openings, regardless of the length, have a maximum width of 10 mm.

As a result of the construction according to the invention, the liquid is atomized directly in the area of the soleplate, specifically at the atomizing openings which are arranged directly at the openings above the soleplate. The atomizing openings are dimensioned with an average opening width of 30 to 100 μm in such a way that no liquid can escape from the openings when the atomizing device is not actuated. In addition, however, the number of atomizing openings is designed so that a liquid delivery of up to about 8 g / minute is guaranteed. About 70 to 100 atomization openings are required for this, depending on the mean opening width in the range from 30 to 100 μm, which in turn leads to fine atomization. Since the individual openings are arranged symmetrically to the center line, which starts from the tip of the soleplate and divides the soleplate in the center, it is ensured that uniform moistening and subsequent smoothing takes place in all directions of movement of the iron over the ironing material while drying the ironing material. The openings can be made relatively long, but it must be ensured that they have a maximum width of 10 mm, so that no parts present on the items to be ironed, such as buttons, can get caught in these openings in such a way that damage to the items to be ironed is achieved can be caused. In addition, the openings in the transition area to the soleplate surface are rounded. The fact that the individual atomizing openings of the If the soleplate is spaced apart, the liquid atomized at the atomizing openings can initially spread unhindered into the openings in the soleplate before the liquid particles hit the material to be ironed.

With this type of humidification, up to 50% better ironing results than with conventional steam irons can be achieved with conventional textiles such as linen, cotton, silk, synthetic fibers and blended fabrics or, based on the same ironing smoothness, up to 50% of the ironing time can be saved become. In particular, however, the stirrup arrangement according to the invention is distinguished by the uniform distribution of the liquid in the finest droplets which reach the material to be ironed, passing through the openings.

A further advantage is that the user of the iron can introduce any kind of suitable additives, such as, for example, finishes, starches, brighteners, fragrances, lubricants, disintegrators, disinfectants, etc., into the liquid tank, which then rain with the droplets can be finely distributed from the atomizing openings onto the ironing material without the additives from the liquid, usually distilled water, being able to separate or premature evaporation of certain constituents, which is the case when such additives are used in conventional steam irons .

The active heating of the entire iron surface, which is enclosed by the openings, by means of suitable heating elements and the thermally conductive connection of this surface via webs with the likewise heated surface of the soleplate outside the part enclosed by the openings, is advantageous, so that the entire iron surface is uniform Has heat distribution. For this reason, in a preferred embodiment, the individual openings in the soleplate and thus also the atomizing openings assigned to these openings are arranged in a circle, so that the area of the soleplate which is surrounded by the circle of openings represents a sufficient area around this area Assign heating element. If individual breakthroughs are so spaced from each other that between these breakthroughs, wherein oblong holes are preferably used, webs remain, the heating elements can be guided along these webs on the inside of the soleplate.

It has been shown that the openings should preferably be formed as elongated holes or circular sections with a preferred, maximum number of openings in the soleplate of 6, preferably 3 or 4. This ensures that in all directions when moving the iron on the The material to be ironed is uniformly moistened because when the ironing base is moved on the ironing material, the areas that are covered by webs between adjacent openings and are not moistened are then surely swept over by the subsequent opening seen in the direction of displacement of the soleplate and thus moistened.

If three openings are provided, they should each occupy a radial section of the circle with respect to the center of the circle on which the openings lie, up to 100 ° in each case. This then results in a free space between adjacent openings, which takes up an angular section with respect to the center of 20 °.

In order to additionally ensure that, when no moistening is to take place during ironing, no liquid droplets emerge from the atomizing openings, a negative pressure should be maintained in the area above the liquid-covered membrane plate during ironing. Such a vacuum can be built up, for example, via the ventilation of the tank, from which liquid is removed during ironing.

While the atomizing openings can have an average opening width of 30 to 100 μm, an opening width of 45 to 60 μm is preferred, an area which ensures that on the one hand sufficient amounts of liquid are dispensed from the openings, but on the other hand the size of the liquid droplets is sufficiently small and that it is also prevented that liquid can escape from the atomization openings without actuation of the atomization device. In order to achieve a uniform moistening on the one hand, but on the other hand to obtain a quick drying and smoothing of the ironing material, the breakthroughs should be arranged on a circle with a diameter of 50 to 100 mm, preferably of approximately 70 mm. Under the usual dimensions of the soleplate, a sufficient edge area remains on all sides around these openings up to the edge of the soleplate, which is heated and glides over the moistened ironing material.

For a quick and immediate dispensing of the liquid onto the ironing material, the internal structure of the atomizing arrangement is selected so that in the basic position of the iron, i.e. during the ironing, the membrane plate or the membrane plates limits or limit the liquid supply as a wall part. This means that directly above the membrane plate and thus above the atomizing opening or even in the atomizing openings itself is the liquid which then, with the membrane plates vibrating, emerges from the atomizing openings without any time delay.

To ensure that there is always a sufficient liquid level above the membrane plate that can be atomized directly from the openings during the ironing, if the iron is moved back and forth or is inclined differently, and this with the actuation of the atomizing device Liquid supply and the liquid discharge from the membrane plate are damped, for which purpose corresponding flow resistances in the form of narrowed channels or the like can be provided.

Embodiments of the invention are shown in the drawings and are described below.

Show in the drawings

FIG. 1 shows an exploded view of an iron according to the invention with a schematically illustrated liquid outlet from the soleplate, FIG. 2 shows a top view of an iron soleplate with openings, although in contrast to the arrangement in FIG. 1, three openings are provided,

3 shows a plan view of an iron soleplate, comparable to FIG. 2, but with six elongated holes,

FIG. 4 shows a further top view of a soleplate with circular openings arranged on a circle, and

5 shows a section along the section line A-A in FIG.

The iron, as shown in the exploded view in FIG. 1, has a main housing 1 with a mains connection 2 for the electrical supply, which has a handle 3 formed on its upper side. The main housing 1 comprises a central housing extension part 4, around which a U-shaped front housing section 5, which serves, among other things, serves as a water reservoir. This front housing section 5 is clamped to the main housing 1 with elements (not shown).

An iron soleplate 6, on the inside of which a heating element support plate 7 is placed, which in turn carries a coiled electric heating element 8, is screwed against the underside of the main housing 1 and the front housing section 5. Two connecting lugs 9 are provided for the electrical contacting of the electrical heating element 8.

In the area of the front third of the soleplate 6, four openings 11 are provided symmetrically to a center line, which is indicated by the dash-dotted line 10 in FIG. 1, which penetrate the entire soleplate 6. These four openings 11 are assigned a membrane plate 12, which is held on a round support part 13. This membrane plate 12 is held at its edge in the carrier part 13 in such a way that it can vibrate freely, at least in the area of the openings 11, which are also provided in the carrier part 13. On the membrane plate 12 is a piezoelectric element 14, which is constructed in the form of a circular ring, arranged, which can be connected to an excitation part, not shown, which is arranged in the main housing 1, via an electrical connecting line 15.

Various arrangements of the openings 11, which are suitable in connection with the atomization of liquid in the soleplate 6 by means of the piezoelectric element 14, are also shown in FIGS. 2, 3 and 4. The arrangement of the openings 11 is basically essentially symmetrical to the center line 10 and lying on a circle, the center of which is designated by the reference number 16 in FIGS. 2 to 4.

The number of openings 11 corresponding to the embodiment in FIG. 2 is three, these individual openings being constructed as curved elongated holes, each of which occupies a segment of a circle with respect to the center point 16 of approximately 100 °. The ends 17 of the respective openings 11 are spaced apart from one another such that a web 18 remains between them, which connects the sole region 19, which is enclosed by the openings 11, to the further sole region or the sole surface 20.

In a third embodiment of the openings 11, which is shown in FIG. 3, a total of six openings are provided, which in turn run symmetrically to the center line 10. However, in contrast to the embodiments in FIGS. 1 and 2, there are straight elongated holes which tangentially distribute an imaginary circle with the center, which is designated by the reference number 16.

Finally, FIG. 4 shows an arrangement of the openings 11, which, however, is not to be regarded as preferred, in the form of circular bores, namely a total of 16 bores which are arranged on a circle with the center 16. The diameter of the circle on which the respective openings 11 are aligned in the center or tangent to them with their center line is approximately 60 to 65 mm. The width of the openings in each case, designated by the reference symbol 21, ie the dimension transverse to the longitudinal extent of the individual elongated holes, is approximately 5 mm; this small width ensures that no parts of the items to be ironed, such as buttons, can get caught in these openings when ironing. On the other hand, this dimension of the openings is sufficient to achieve the required liquid discharge.

In one embodiment, as shown in FIG. 5, a tank system 22, which can be the front housing section 5, is arranged above the soleplate 6. This tank system 22 comprises a carrier plate which is comparable to the carrier part 13 in FIG. 1 and which in turn comprises openings 23 which correspond in size to the openings 11 in the soleplate 6. The membrane plate 12, as is also shown in FIG. 1, is placed on the top of this carrier part 13 and in turn has a large number of atomizing openings 24. This membrane plate 12 is relatively thin, so that it, held on the edge of the carrier part 13, can vibrate in the region of the openings 23 with appropriate piezoelectric excitation. Immediately above this membrane plate 12 there is a space 25 which contains part of the liquid with which the items to be ironed are to be moistened. Another liquid reservoir 26, which is the main liquid reservoir in the iron, is provided above the space 25, separated from the space 25 by a partition wall 27.

The space 25 and the main reservoir 26 are connected to one another via a connecting channel 28. In order to ensure that suitable pressure conditions are present in the space 25, a pump 29 or another suitable device can be provided in the connecting channel 28. On the one hand, this conveys liquid in all operating states of the iron from the main reservoir 26 to the space 25, indicated by the arrow 32, so that the space 25 is preferably completely filled with liquid. On the other hand, suitable pressure ratios for dispensing liquid droplets 30 are achieved, which, as can also be seen in FIG. 1, are dispensed perpendicular to the soleplate surface, indicated by the directional arrow 31.

As can be seen in FIG. 5, the liquid droplets 30 are generated directly in the area of the soleplate 6, ie in the openings 11 in the soleplate or in the openings 23 in the carrier part 13. In the embodiment of FIG. 1, the membrane plate 12, as can be seen in FIG. 5, is vibrated by a piezo-electric element 14, which is suitably arranged above the membrane plate 12, in order to release the liquid droplets 30 in defined amounts to achieve. In order to achieve a fine spray of liquid spray, the diameters of the individual atomizing openings 24 should be in the range from 30 to 100 μm, opening widths between 45 to 60 μm being preferred. Given this dimensioning and with a radius of the circle on which the openings 11 lie, of approximately 60 to 70 mm, the number of these atomizing openings is chosen such that a maximum of 8 g / minute of liquid is dispensed from the liquid container 25 onto the items to be ironed.

Due to the symmetrical arrangement of the openings to the center line 10 or on a circle with the center point 16, it is ensured that a defined zone on the material to be ironed is moistened when the soleplate is moved over the material to be ironed. Even with multiple changes of direction, constant moistening is ensured in each case, since a quasi-annular volume of liquid droplets emerges from the soleplate, as is indicated in perspective in FIG. 1. Furthermore, no cold surfaces of the soleplate 6 are formed since, as can also be seen in particular in FIG. 1, the heating element 8 is guided such that the sole area 19, which is enclosed by the openings 11, is also heated.

Claims

PATENT CLAIMS

1. Electric iron with an iron soleplate, which has an iron soleplate tip, and with at least one symmetrical to a center line, which starts from the iron soleplate tip and divides the iron soleplate in the center, in the area of the iron soleplate tip in the iron soleplate for the passage of a liquid stored in a liquid tank system Moistening an ironing material, the liquid in the form of liquid droplets, generated by means of a piezo-electrically excited atomizing device above the soleplate, emerging from the opening, characterized in that the atomizing device (12, 13, 14; 29) at least one piezo-electrically excited , comprises a thin membrane plate (12) which has a plurality of atomizing openings (24) associated with the respective opening (11) of the soleplate (6), each having an average opening width of 30 to

Have 100 microns, the number of atomizing openings (24) is selected so that a liquid delivery up to about 8 g / minute is guaranteed via the soleplate (6), and wherein the openings (11), regardless of the length, a width of have a maximum of 10 mm.

2. Electric iron according to claim 1, characterized in that the openings (11) around a center (16) on the center line (10) of the soleplate (6) are arranged distributed.

3. Electric iron according to claim 1, characterized in that adjacent openings (11) via webs (18) are spaced apart.

4. Electric iron according to claim 3, characterized in that the openings (11) are arranged in a circle.

5. Electric iron according to claim 4, characterized in that the openings (11) are each formed as an elongated hole or as a circular section.

6. Electric iron according to claim 5, characterized in that the number of openings (11) in the soleplate (6) is a maximum of six, preferably three or four.

7. Electric iron according to claim 6, characterized in that three openings (11) are provided, which occupy a radial section of up to 100 ° from the center point (16) as seen.

8. Electric iron according to claim 6 or claim 7, characterized in that the area (19) of the iron soleplate (6) enclosed by the openings (11) is associated with a heating element (8).

9. Electric iron according to claim 1, characterized in that a vacuum is maintained during the ironing at least a region above the liquid-covered membrane plate (12).

10. Electric iron according to claim 1, characterized in that the opening width of the atomizing openings (24) is 45 to 60 microns.

11. Electric iron according to claim 4, characterized in that the openings (11) on a circle with a diameter of 50 to 100 mm, preferably of about 70 mm, are arranged.

12. Electric iron according to claim 1, characterized in that the openings (11) have a maximum width (21) of 6 mm.

13. Electric iron according to claim 1, characterized in that during the ironing the membrane plate (s) (12) limits the liquid supply (25) as a wall part (limit).

14. Electric iron according to claim 1, characterized in that the number of atomizing openings (24) is between 70 and 100.

15. Electric iron according to claim 1, characterized in that the liquid supply and the liquid discharge from the membrane plate (12) is damped.

16. Electric iron according to claim 1, characterized in that the openings (11) in the transition region to the soleplate surface (19, 20) are rounded.