FR2798403A1 - STEAM IRON ALL FABRICS WITH A SINGLE HEATING ELEMENT - Google Patents

Abstract

The invention concerns a steam iron whereof the soleplate consists of a moulded aluminium heating body (1) comprising the single heating element (3) of the iron, a temperature regulating thermostat and an evaporating chamber (4) coated on its wet surfaces with a coating layer (6) with low heat conductivity, and a top (18) in thermal and mechanical connection with the moulded body (1). The structure of the body (1), the top (18) and/or their contact surface are arranged such that the mean temperature of the body is at least 7 DEG C higher than that of the top, when the thermostat is adjusted for the mean temperature of the top to be less than 120 DEG C.

Description

The present invention relates to steam ironing irons.

These irons conventionally comprise a sole composed of a body generally made of cast aluminum, and a cap covering the lower part of this body and coming into contact with the clothes to be ironed. The sole body includes a heating element, an instantaneous water vaporization chamber, and channels for dispensing the steam produced to the steam ports directed to the laundry through the cap.

The body of the sole must ensure both the vaporization of the water and the temperature maintenance of the cap. If this condition is fairly well ensured by conventional irons for delicate fabrics ironed at high temperature, precautions should be taken for delicate fabrics such as synthetic fabrics that do not withstand high temperatures but that advantageously returns with a flow steam strong enough. Indeed, the steam ensures in all cases a significant heat transfer which facilitates the unwinding. At sole temperature high enough to produce enough steam, dexterity is needed to avoid damaging these delicate fabrics. If the temperature of the iron is lowered so as not to risk deterioration, the sole body is no longer hot enough to obtain a significant flow of steam and ironing is more difficult. Indeed, in conventional irons, thermal connection between the body and the cap is good and the average temperatures of one and the other are not very different.

Since the boiling temperature of the water is constant, the temperature of the wet heating surface of an evaporator varies only with the vaporization power and hence the steam flow rate. This surface temperature varies rather weakly around 110-130 C. In contrast, the temperature of the cap of the sole can be adjusted according to the tissues of the order of 80 C to 200 C. When the cap and the body are very hot, the vaporization chamber liner lowers the temperature of the wet surface which solves the problem of calefaction, but when the cap and the body are at low temperature, vaporization is difficult. We then understand the successive improvements that all tend to thermally decouple the best and independently control the evaporator and headdress iron for comfortable ironing of all fabrics and particularly delicate fabrics.

Thus, US3110975 discloses a steam iron having a vaporization chamber independent of the ironing surface itself molded. The patent FR2523164 describes a nearby building iron but with a water supply external to iron. EP0232924 discloses an iron wherein the steam is produced by an internal boiler thermally independent of the surface in contact with the laundry. Incidentally there is a partial thermal decoupling between the body and the cap of the soleplate described in patent US5613309 where the two parts are locally separated by empty spaces or filled with an adhesive of low thermal conductivity, empty spaces that can serve as channels of steam distribution to the apertures of the cap. However, this decoupling is only sufficient to improve the thermal distribution of the cap by avoiding causing hot spots or cold spots. EP0813627 also shows between the body of the cap a variable adhesive thickness. However, these different thicknesses only have the effect of improving the endurance resistance of the adhesive bond. The patent FR2766502 describes an iron for comfortably ironing all fabrics and having compared with the aforementioned irons the advantage of a unique temperature control for the body and cap of the sole. However the extra cost compared to a conventional iron remains important because of the necessary presence additional heating element.

The subject of the invention hereinafter is an iron capable of ironing all the fabrics without risk with a flow of steam, both the delicate fabrics with a low sole temperature and the fabrics requiring a high ironing temperature, and this with a construction more economical than known irons of the same characteristics. This object is achieved by a steam iron whose sole is composed on the one hand of an aluminum heating molded body comprising the only iron heating element, a temperature control thermostat, and a vaporization chamber coated on its wet faces a layer of a low thermal conductivity coating, and other a cap in thermal and mechanical relationship with the molded body, that the body structure, the cap and / or their face of These contacts are established so that the average body temperature is at least 7 C higher than that of the cap when the thermostat is set for a mean cap temperature of less than 120 ° C.

This setting of an "average cap temperature below 120 C" measured at the center of the cap corresponds to the thermostat in the low minimum position for ironing delicate textiles.

In fact, the operating temperature can oscillate around 10 C around the average value during a control cycle. other words, according to the invention, the minimum temperature of the cap then reached when the thermostat switches on when the body temperature is higher minus 7 C, and this measured when the iron is at rest on a horizontal support and not vaporize, this body temperature being measured by means of a thermocouple placed against the body and the thermostat sensor. For these measurements are used the rules of the art in the field defined by the protocol of IEC 60311 of 1997 published by the Technical Union of Electricity.

thermal flow to the cap being thus judiciously limited by this structure and its arrangement, the heating body sees its temperature rise sufficiently to ensure vaporization even when the cap is at a minimum temperature allowing ironing delicate fabrics. At this coldest time, the vaporization chamber can still provide a generous vapor.

Conversely when the cap is very hot, the heating body is even hotter, but the insulating coating of the chamber allows the temperature of the wet surface to remain at a value compatible with good vaporization without calefaction, wet surface adjusting with the flow of water and the heat flow. The power of the heating element is used approximately for about a quarter by the cap, which justifies the high thermal resistance advantageously achieved between the body and the cap in order to control its temperature for all uses.

Preferably the body is in contact with the cap on an area measuring between 8 and 30% of the projected surface body on the cap.

The contact areas and their extent are adjusted to provide a controlled distribution of heat and temperature of the cap.

The thermal contact may possibly be stabilized by a very thin adhesive crushed between the two parts. The rest of the surface of the cap facing the body is surmounted by a vacuum that can be used for steam distribution or locally receives low conductive resin for bonding and sealing by a thick bonding, low conductive, two parts . This solution has the advantage of preserving the usual connecting means between the heating body and the cap.

Preferably the contact area between the body and the cap is distributed between a distribution channel wall contact and one or more predetermined heat transfer pad contacts.

The lower part of the body has ribs that materialize the channels and distribution chambers. The thermal contact thus limited to the top of these ribs is adjusted by means of additional pads located under the body and coming into contact with the cap.

The area of contact between the body and the cap is 80 to 95% by the contact of the channel walls.

The predetermined heat transfer pad or pads are arranged on or around the center line of the cap.

The front zone of the iron is a zone of usually high temperature where the thermal transfer of the body towards the cap can be limited by small surfaces in contact. The rear part of the cap is a usually cooler zone and the heat transfer can be favored by larger contact areas. This has the result of homogenizing the temperature of the cap.

In another version, the temperature drop between the body and the cap is obtained by the interposition between the body and the cap of a sheet of material which is weakly heat conducting and rigid in thickness.

This sheet is a part assembled to the construction of the sole. This arrangement allows to properly calibrate and control the thickness of the material which can reach 1 mm or more depending on its conductivity.

Preferably, the weakly conductive material comprises a film or a fabric such as a polyamide film or a glass sheet or a glass fabric whose conductivity is such that the power transmitted by this material attached to the surface of the cap is less than 230 W / M2 for a degree of separation between the body and the cap.

By surface of the cap is meant the useful surface in contact with the ironed fabrics excluding raised edges. The film can be hot glued on one side against the heating body and on its other face against the cap so as to control the thermal and mechanical connection. perforations are provided in correspondence with the steam orifices the cap.

The invention will be better understood from the examples described below and the accompanying drawings in which Figure 1 is a longitudinal sectional view by vertical plane of a sole according to the invention Figure 2 is a view in a horizontal plane of the zones of body contact and the cap as well as outer contours of the cap and body. Figure 3 is a longitudinal section through a vertical plane of another sole according to the invention.

Figure 4 is an enlarged detail view of Figure 3.

In a preferred version of the invention, FIGS. 1, 2 the iron soleplate comprises a molded aluminum body 1 whose outline is represented at 2 in FIG. 2. The body 1 includes an overmolded tubular heating element 3 whose power can reach 2000 watts and that is the only powerful heating element of the iron. The shapes of the body 1 generate vaporization chambers 4,5 which are coated with a poor thermal conductor deposit, such as the deposit 6 whose relative thickness is exaggerated in Figure 1. Channels such as 7 ensure the distribution of steam to the fabric ironed through holes such as 8 or to other channels distribution chambers 9 at the lower part of the body 1. The vapor then escapes to the fabric through other holes 10.

spray chambers 4.5 and the distribution channels 7 are closed at the upper part of the body 1 by a closure plate 11 having orifices 12, 13 for the admission of the water to be vaporized. Preferably, main chamber 4 receives the water by means of a drip device and the secondary chamber 5 receives the water injected by a pump.

sole comprises under the body 1 a metal cap 18 for example aluminum, enamelled steel, stainless steel but preferably aluminum sheet. Preferably, the cap is coated on its lower ironing face to improve contact with the fabric. The coating may be obtained by plasma spraying, electrolytic or chemical or by any other known technique. Preferably the coating is an enamel. This flat cap with raised edges comprises cures allowing the vapor to pass in correspondence with the holes 8 and holes such as 10 in correspondence with steam distribution chambers or channels such as 9.

body 1 has at its lower portion ribs 14,15,20 which form between them a chamber or channel 16 which surrounds the holes 8 and isolates other groups of steam holes formed in the cap, such as the holes 10. The Chamber 16 is filled with a curable binder 17 the body 1 being laid flat on the back, the whole being returned to the cap 18 as shown in Figure 1. The lower edges of the ribs 14,15,20 are then in contact with the cap 18 and the binder 17 trapped ribs 14,15,20 flows on the cap between these ribs. Cavities 19 can then appear in the bottom of the chamber 16. The binder 17, preferably a silicone, provides after polymerization the vapor tightness of the distribution chambers and the seal between the holes. It participates in the mechanical connection of the body 1 on the cap This connection is perfect by crimping the cap 18 in holes such as 8. More particularly according to the invention the heat produced by the heating element 1 flows for a part towards the cap by the top of the ribs 14,15,20 delimiting the channels and binder distribution chambers and steam. The thickness of these ribs can be adjusted to obtain a correct distribution of the temperature of the cap. Additional studs or bearings 21,22 of the body 1 on the cap are provided to adjust the heat passage section towards the cap 18 especially in areas where the cap tends to be colder. In the described embodiment round section reach 21 is provided between the center and the back of the sole, as well as another 22 at the tip of the sole.

Other arrangements of studs could be envisaged, for example it is possible to make a mesh of smaller studs such as those shown in dotted lines in FIG. 2, in square, diamond or rectangle mesh, the total contact surface of the studs with the cap does not exceed 5 'of the total contact area.

In this embodiment the surface of the body 1 in contact with the cap is of the order of 20% of the projected surface of the body 1 on the cap, the projection of the body 1 being shown in Figure 2 by the surface enclosed by the contour 2 If necessary, the metal-to-metal contact can be improved by binder coating which crushes when the two pieces are placed against each other, thus not affecting heat exchange. It is also possible to improve the metal contact by bonding the parts by other means, for example by laser welding.

In the example described, the thermostat (not shown) is situated longitudinally substantially at the rear third of the sole, on the side of the heel, and near the heating tube 3.

When the sole works for delicate textiles, the thermostat regulates the temperature of the body 1 to a minimum value greater than 1, for example between 110 C and 128 C. The passage of heat passage to the cap being reduced, it occurs in this section a temperature drop that allows during the ironing at the cap 18 to be at a significantly lower temperature, compatible with delicate fabrics. When not ironing, there is still an average temperature drop of 9 C between the body 1 and cap 18. The body 1 dissipates most of its heat to the vaporization chamber 4 which receives a flow of water orifice 12. The heat passes through the deposit 6 on a large wet surface this allows a low temperature drop in this deposit and a good vaporization of the water flow.

When the sole works for textiles requiring a high ironing temperature, the body 1 is regulated at a very high temperature, for example 250 C, but most of the power is always directed to the vaporization chamber. Natural regulation occurs: at a constant water flow rate, the wetted surface of the chamber 4 decreases, accentuating the drop in temperature in the deposit 6, which allows the vaporization surface to remain at a temperature compatible with vaporization without calefaction.

The sole thus designed makes it possible to iron all textiles safely and economically.

In another version 3, the sole comprises a molded aluminum body enclosing an overmoulded heating tube 3, and a cap The body 1 includes an overmolded tubular heating element 3, the only power heating element of the iron. The shapes of the body 1 generate vaporization chambers 4,5 which are coated with a poor thermal conductor deposit such as the deposit 6. Channels such as 7 ensure the distribution of steam to holes or other channels or chambers. distribution from where it escapes to the tissue through the perforated cap 18.

The body 1 has at its lower part a flat surface of large area facing the cap 18 from which it is separated by a plate 30 of poor thermal conductor material. This plate is preferably cut from a sheet of insulating material such as a polyimide whose thickness is well calibrated. The plate 30 can be glued on its two faces against the body 1 on the one hand and on the other hand the cap 18. If necessary, the assembly comprises studs welded to the cap and passing through the body 1 which ensure the tightening of the cap against the plate 30 and the body 1.

When the sole works for delicate textiles, the thermostat (not shown) regulates the temperature of the body 1 such that the cap is at a lower value on average at 120 C. However the passage of heat through the plate 30 being difficult, it a temperature drop occurs in this plate 30 which allows the body 1 to be at a higher temperature and to be able to ensure a generous vaporization.

When the sole works for ironing textiles requiring a high sole temperature, the operation similar to that of the previous embodiment. There is therefore a second embodiment for ironing all textiles without risk and with an economical construction.

It is possible to envisage a combination of the two preceding variants consisting in locally enlarging the contact surface by the top of the ribs 14, 15, 20, FIG. 2, but by inserting according to FIG. 3 a plate made of a poor thermal conductor material between the cap and the body. . The magnification can be done preferentially in the coldest areas of the cap so as to better distribute the temperature.

Claims (7)

<B> CLAIMS </ B> 1. Steam iron whose sole is composed on the one hand of an aluminum molded heating body (1) comprising the sole heating element (3) of the iron, a temperature control thermostat, and a vaporization chamber ( 4) coated on its wet surfaces with a layer of a coating (6) of low thermal conductivity, and secondly with a cap (1 in thermal and mechanical relation with the molded body (1 characterized in that the structure of the body (1), the cap (18) and / or their contact face are established such that the average temperature of the body is at least 7 C higher than that of the cap, when the thermostat is set for a mean cap temperature of less than 120 C. 2. Iron according to claim 1 characterized in that the body is in contact with the cap (18) on an area between 8 and 30% projected area of the body on the cap. 3. Iron according to claim 2 characterized in that the contact area between the body (1) and the cap (18) is distributed between a wall contact (14 15, 20) of distribution channels and one or more contacts pads (21 22) of predetermined heat transfer. 4. Iron according to claim 3 characterized in that the contact area between the body (1) and the cap (18) is formed in a proportion of 80 to 95% by the contact of the channel walls. 5. Iron according to claim 3 characterized in that the or pads (21,22) predetermined heat transfer are arranged on or around the center line of the cap (18). 6. Iron according to claim 1 characterized in that the temperature drop between the body (1) and the cap (18) is obtained by the interposition between the body (1) and the cap (18) of a sheet material (30) low heat conductor and rigid in thickness. 7. Iron according to claim 6 characterized in that the material (30) weakly conductive comprises a film or a fabric that a polyamide film or a glass sheet or a glass fabric whose conductivity is such that the power transmitted by this material attached to the surface the cap is less than 230W / m2 for a degree of separation between the body and cap.