EP0047695B1 - Electric steam iron - Google Patents

Description

The present invention relates to an electric steam iron of the kind comprising an injection device for letting a certain flow of water flow into a vaporization chamber from which the vapor formed escapes through openings formed under the sole.

Steam irons of this kind provide a moderate rate of steam, adjustable in a certain band, to perform routine ironing work. However, it happens that, for certain special works, one needs momentarily a significant surplus of vapor. To deal with this possibility, it is known to use an additional injection device which supplies water at the required flow rate.

If this relatively abundant excess of water is admitted directly into the vaporization chamber of a conventional iron, there is a risk of producing abundant scaling, with the risk of incomplete vaporization resulting in water on the laundry. , possibly with pieces of tartar. In addition, the projection of water droplets can cause stains.

To overcome this drawback, it has been proposed for example in patent FR-A-2,231,799 to carry out the additional injection in an auxiliary chamber constituted by a conduit of great length and small section, and provided with baffles. These provisions delay the flow of water and facilitate its total vaporization.

However, the abundant vaporization which occurs in a narrow baffle duct produces rapid scaling which is unacceptable as it is very difficult to eliminate.

The present invention aims to achieve a steam iron which allows to obtain a momentary surplus of steam with total and almost instantaneous vaporization, and without significant scaling.

According to the invention, the electric steam iron comprises a heating element overmolded in a boss of a soleplate, a main injection device linked to a water tank for injecting water into an adjacent vaporization chamber. to said boss, and an auxiliary injection device for injecting an additional flow of water in order to obtain a momentary surplus of steam. This auxiliary injection device opens into the vaporization chamber above the boss containing the heating element, and the iron is characterized in that, in the zone where the auxiliary injection opens, the metal of the boss is thinned so bringing the heating element closer to the metal surface.

The temperature of the metal at the drop point of the secondary injection is very high, which provides rapid vaporization.

The small amount of residual water then easily vaporizes in the vaporization chamber. There is therefore no risk of water being injected into the laundry.

According to an advantageous embodiment of the invention, the thinned area of the boss is substantially planar and has a downward slope towards the vaporization chamber.

In this way, the water that is not instantly vaporized easily flows into the vaporization chamber to complete vaporization there.

Preferably, the flat and thinned zone has a widening situated to the right of the auxiliary injection point.

This widening allows the secondary injection to always fall on the zone in question, even if the movements imprinted on the iron by the user disturb the fall of the water.

Other features and advantages of the invention will emerge from the detailed description which follows.

• - la figure 1 est une vue partielle en plan d'une semelle de fer conforme à l'invention;
• - la figure 2 est une vue en coupe suivant II-II de la figure 1; et
• - la figure 3 est une vue en perspective d'une partie de la semelle, montrant la zone de chute de l'injection auxiliaire.

In the accompanying drawings, given by way of nonlimiting example:

• - Figure 1 is a partial plan view of an iron soleplate according to the invention;
• - Figure 2 is a sectional view along II-II of Figure 1; and
• - Figure 3 is a perspective view of part of the sole, showing the drop zone of the auxiliary injection.

With reference to these figures, a soleplate 1 of steam iron comprises an armored electrical resistance 2 forming a heating element, arranged in a U and molded in a boss 3 integral with the soleplate.

The steam iron comprises, in known manner, a main water injection device (not shown), designed to drop water drop by drop into a vaporization chamber 4 located between the branches of the U of the heating element 2. The drop point of this main injection is located in the region of the base of the U, in the vicinity of point 5.

The iron according to the invention also comprises, in known manner, an auxiliary injection device (not shown) which can be operated independently of the main device, in order to temporarily obtain an excess of steam.

This auxiliary device is placed so that the injection takes place above a point 6 located on the boss 3.

In the area around point 6, the metal constituting the boss 3 is thinned, so that the shielding of the resistor 2 comes almost flush with the surface of the boss (Figure 2).

On the other hand, this thinned area 7 is flat. It is in relation to the chamber 4 and extends over a certain length of the boss. It has a downward slope towards the vaporization chamber 4.

Finally, the thinned zone 7 has, around the injection point 6, an enlargement 8 towards the vaporization chamber.

In normal operation, the main injection pale falls in the region of point 5 and partly vaporizes there. The non-vaporized water flows into chamber 4 and finishes vaporizing there. Due to the large dimensions of this chamber, scaling is distributed over a large area, therefore in a very small thickness.

To obtain a momentary surplus of steam, the auxiliary device is actuated which causes the water to fall on zone 7 in the vicinity of point 6. Due to the thinning of the metal of the boss, the surface of zone 7 is at a temperature very high, which causes almost instant vaporization of most of the water.

The non-vaporized water partially rebounds to fall as rain over the whole of zone 7 where it vaporizes, leaving a fairly thin distributed deposit of tartar. Due to the inclination of the zone 7, the rebound and the fallout tend moreover to take place preferentially towards the vaporization chamber 4.

The inclination also allows the non-vaporized water which wets the zone 7 to flow towards the chamber 4.

Finally, despite the movements printed on the iron by the user, the enlargement 8 allows the water fall to still be in the interior area.

The invention makes it possible to obtain a total vaporization of the auxiliary injection, possibly terminated in the vaporization chamber 4, and almost instantaneous.

Due to the bursting of the drop of water, and its projection onto a large surface, scaling is distributed and has only a very small thickness. Minimal scaling is also necessary to avoid the phenomenon of caulking.

On the other hand, a rather unexpected advantage has been found brought by the invention, namely that the auxiliary waterfall did not cause the boss 3 to cool, which could be felt by the thermostat fixed at 9 on this boss. a certain distance from the drop point 6. It may be thought that this phenomenon is due to the large decrease in section of the boss in its thinned part (FIG. 3), which decreases its thermal conductance. Of course, the invention is not limited to the example described, but covers any minor variant within the reach of ordinary skill in the art.

Claims (3)

1. An electric steam iron, comprising a heating element (2), cast in a boss (3) of a sole-plate (1), a main injection device (5) connected to a water reservoir for injecting water into a vaporization chamber (4) adjacent said boss, and an auxiliary injection device (6) for injecting a supplementary amount of water for obtaining an instantaneous surplus of steam, with said auxiliary injection device (6) emptying into the chamber of vaporization (4) above the boss (3) enclosing the heating element (2); characterized in that in the area (7) into which the auxiliary injection device empties, the metal of the boss (3) is thin in such a way as to bring the heating element (2) close to the metal surface.

2. An electric steam iron as defined in Claim 1, wherein the thin area (7) of the boss is substantially plane, in connection with the chamber of vaporization (4) and has a slope descending toward the vaporization chamber.

3. An electric steam iron as defined in Claim 2, wherein the thin, plane area (7) has an enlarged portion (8) situated in the area of the auxiliary injection point (6).

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