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(11) | EP 0 517 673 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A steam ironing machine |
| (57) The invention relates to a steam ironing machine, in particular for domestic use.
The machine comprises a boiler (1) for the production of steam internally to which
there are two resistors (R1) and (R2) supplied with electricity independently one
from the other, as well as an iron (2) which has a resistor (R3) that absorbs the
same electric power as the boiler second resistor (R2); an electric commutator (C1)
is envisaged, which, on command, connects to the electricity supply either the second
resistor (R2) of the boiler (1) or the resistor (R3) of the iron (2). |
[0002] The prior art teaches steam ironing machines, also for domestic use, which comprises a boiler, for the production of the steam, from which the steam produced is sent, on command, to the iron; in this type of machine the boiler and the iron are two separate elements.
[0003] Both the boiler and the iron use resistors respectively for the hating of the water and the production of the steam as well as for the heating of the ironing plate of the iron.
[0004] In particular, in ironing machines for domestic use, it is important to maintain the total electric power below a certain value inasmuch as the domestic power supply is not sufficient to bear request for electrical power above a predetermined level (in Italy in general this level is 3 KW). The total power requested by domestic irons is therefore in general kept below 2 KW.
[0005] For this reason ironing machines of the type in question, in which the iron requires electrical power which is usually comprised between 0.7 and 0.9 KW, have available a rather limited amount of electrical power for the production of steam. This brings about quite long waiting times while the steam pressure is building up to the desired level, as well as a considerable reduction in steam pressure during use, in particular during lengthy use.
[0006] One aim of the present invention is that of eliminating the above-mentioned drawback by providing a steam ironing machine wherein the waiting time for the reaching of a desired steam pressure is reduced and in which there are no notable reductions in the steam pressure during use.
[0007] One advantage of the steam ironing machine object of the invention, which derives from its constructional particulars, is represented by its simplicity of assembly as well as by the reduction of the problem connected with the presence of parasitic currents internally to the boiler.
[0008] These aims and others besides are all attained by the the ironing machine object of the present invention, as it is characterised in the claims which follow, which comprises a boiler for the production of steam in which there are two resistors which are separately supplied with electric power, as well a an iron having two resistors which absorb the same electric power as one of the resistors in the boiler; an electric commutator is also envisaged, which on command connects either the resistor of the iron or the equally absorbent resistor of the boiler to the electricity supply. Further characteristics and advantages of the invention will better appears in the detailed description that follows, of a preferred but non-exclusive embodiment of the invention illustrated in the accompanying figures purely in the form of a non-limiting example, in which:
- Figure 1 shows an electrical diagram indicative of the connections among the various resistors of the ironing machine; in this figure the broken line indicates blocks 1 and 2 which present respectively the boiler and the iron;
- Figure 2 shows a view from above of a particular relative to the assembly of the resistors of the boiler on the boiler itself;
- Figure 3 shows a lateral view of the particular of figure 2.
[0009] The ironing machine comprises a boiler 1 for the production of steam, and an iron 2; the boiler 1 and the iron 2 are two separate elements which are connected, like in all machines of this type, by means of two cords, not indicated in the figures, one of which carries the electrical connections while the other conducts the steam from the boiler 1 to the iron 2.
[0010] For the heating of the water in the boiler and the production of steam, two resistors R1 and R2 are envisaged which are physically separated one from the other. The ends of the two resistors R1 and R2 are connected to a flange 4. The two resistors R1 and R2 are long and conformed in such a way as to be insertable into the boiler through a hole 3 made in the wall of the boiler 1 itself.
[0011] By the side of the hole 3, on the boiler 1, two threated bushes 6 are envisaged. The flange 4, once the resistors are introduced through the hole 3 is fixed to the threated bushes 6 by means of bolts 7 ; this permits an always correct positioning of the resistors internally to the boiler 1, which is not the case in several prior art machine in which the resistor heating the water in the boiler is connected to a screw that is tightened on to a threated hole in the boiler itself.
[0012] Between the flange 4 and the boiler 1 insulating elements 5 are envisaged, constituted by, for example, gaskets made of teflon, which electrically insulate the flange 4, and thus the two resistors R1 and R2 from the boiler 1. This considerably reduces the damaging effects due to parasitic currents which can cause deterioration and even perforation of the boiler 1.
[0013] The iron 2, or more specifically its hotplate, is heated electrically by means of a resistor R2; resistor R3 absorbs the same power absorbed by one of the resistors (for example, resistor R2) of the boiler 1.
[0014] The machine comprises further an electric commutator C1, which on command connects to the electricity supply either the resistor R3 of the iron 2 or the resistor R2 of the boiler 1; in other words the two resistors R2 and R3 are never both connected to the electricity supply. This means that, under any operative conditions, the power absorbed by the machine in question is always the same.
[0015] Supposing that the resistor R3 absorb 0.8 KW power, the boiler 1 can be equipped with two resistors which together absorb 2 KW and that individually 1,2 Kw and 0.8 KW.
[0016] When the machine is turned on, for example by means of the switch I1, the water begins to be heated for the production of steam; during this phase, the iron 2 is not functioning and all of the power absorbed by the machine can be used for the heating of the water in the boiler 1.
[0017] Once the steam pressure reaches the desired level, the iron 2 is connected to the electricity supply, for example by means of a switch not indicated in the figure; simultaneously the commutator C1 is activated, which cuts off the connection with the resistor R2 and effects the connection of the resistor R3. During this phase the iron 2 can function normally while the boiler 1 continues to be heated by means of the resistor R1 alone. When the iron 2 reaches the desired temperature, a thermostat, with which the iron 2 is usually equipped, cuts off the current to the resistor R3 of the iron 2; the said thermostat can activate the commutator C1 so as again to supply the resistor R2 and to use the maximum power absorbed by the machine for the heating of the water.
[0018] Substantially, differently from that happens in prior art machines, in the present machines it is possible to use, when the resistor R3 of the iron 2 is not heating the hotplate of the iron 2, the entire power absorbed by the machine for the heating of the water. This permits a much quicker initial heating of the water, in that when the machine is switched on the iron 2 is not likewise switched on; this further permits of maintaining high steam pressure internally to the boiler 1 during functioning of the machine in that, since the suspension of power to the iron 2 are very frequent due to its reaching the required temperature, the times when all of the power can be dedicated to the production of steam can be equally frequent.
1. A steam ironing machine of the type comprising: a boiler (1) for the production of
steam, wherein water is electrically heated; an iron (2) having a hotplate which is
electrically heated by means of a resistor (R3); characterised by the fact of comprising
: two resistors (R1) and (R2) for the heating of the water in the boiler (1) , which
resistors are separately supplied, the second of which resistors (R2) absorbs the
same power as the resistor (R3) used for the iron (2) hotplate; an electric commutator
(C1) to connect to the electricity supply either the second resistor (R2) of the boiler
(1) or the resistor (R3) of the iron (2).
2. A machine as in claim 1, characterised by the fact that the boiler (1) exhibits a
hole (3) by the side of which two heated bushes (6) are envisaged; the resistors of
the boiler (1) are conformed in such a way as to be insertable into the said hole
(3) and are both connected to a flange (4) connectable to the boiler (1) by means
of bolts (7) which are screwed in to the said threated bushes (6); electrically insulating
elements (5) are also envisaged, interpositioned between the said flange (4) and the
said boiler 1.