EP2035618B1 - Ironing appliance comprising a safety device and method for making an iron appliance safe - Google Patents

Abstract

Ironing appliance comprising a heating element (1) controlled by means of a thermostat (2), the appliance having a safety device comprising motion detection means (5) and a safety relay (3) connected in series with the heating element (1) to interrupt the supply to said heating element (1) when the appliance is left stationary for too long, said appliance being characterized in that said safety device comprises means (2a) for determining the state of opening of the thermostat (2) and in that the safety device opens said safety relay (3) when, simultaneously, the determining means (2a) indicate that the thermostat (2) is open and the motion detection means (5) detect that the appliance has not been moved for a time t greater than a warning threshold t1.

Description

The present invention relates to an ironing apparatus comprising a heating element regulated by means of a thermostat and more particularly to an apparatus provided with a safety device comprising motion detection means and a relay connected in series with the heating element so as to interrupt the supply of the heating element when the apparatus remains too immobile for a long time.

It is known, from the patent US 4,661,685 , an iron comprising a heating element and a safety device controlling the opening of a relay connected in series with the heating element to interrupt the supply of the latter when the iron remains too immobile on its sole. This safety device also helps to limit the power consumption of the iron by interrupting the power supply when the iron remains too long motionless on its heel.

Such a safety device controls the opening of the relay only as a function of the time of immobilization of the iron so that the opening of the relay is made most often when the relay is crossed by the supply current of the element. heating. The relay must therefore be sized to support a large number of openings while it is energized, which leads to choosing an expensive relay to manufacture.

The following invention aims to provide an ironing apparatus comprising a safety device that is more economical to implement. The invention aims in particular to provide a method of securing an iron that allows to use a less expensive safety relay to manufacture.

The object of the invention is achieved by an ironing apparatus comprising a heating element regulated by means of a thermostat, the apparatus being provided with a safety device comprising motion detection means and a safety relay mounted in series with the heating element to interrupt the power supply of the heating element when the appliance remains too a long time immobile, characterized in that the safety device comprises means for determining the opening state of the thermostat and in that the safety device controls the opening of the safety relay when, simultaneously, the determination means indicate that the thermostat is open and the motion detection means detect immobilization of the apparatus for a time t greater than a warning threshold t ₁

Such a characteristic makes it possible to control the opening of the safety relay when the latter is not traversed by a current so that the wear of the safety relay is greatly reduced.

According to another characteristic of the invention, the safety device controls, at the latest, the opening of the safety relay when the apparatus is stationary for a time t greater than a critical threshold t ₂ , the critical threshold t ₂ being greater than the alert threshold t ₁ .

Such a characteristic makes it possible to ensure maximum safety by ensuring that the power supply to the heating element is cut off when the time of immobilization of the apparatus exceeds the critical threshold t ₂ .

According to another characteristic of the invention, the safety device monitors the state of the thermostat when the time of immobilization of the apparatus is between the alert threshold t ₁ and the critical threshold t ₂ and controls the opening of the safety relay as soon as the thermostat is detected in an open state by the means for determining the open state.

According to yet another characteristic of the invention, the apparatus comprises a heel on which it can rest during the inactive ironing phases and an ironing plate, in thermal relation with the heating element, on which it can rest for the phases. active ironing apparatus, the apparatus comprising position detecting means for determining whether or not the apparatus rests on its heel and the values of the warning threshold t ₁ and the critical threshold t ₂ are a function of the position of the detected iron by the position detecting means.

According to another characteristic of the invention, the values of the alert threshold t _1r and critical threshold t _2r when the iron rests on its heel are respectively more higher than the threshold values t _1s and critical threshold t _2s when the device rests on its sole.

The invention also relates to a method of securing an ironing appliance provided with a regulated heating element by means of a thermostat in which a safety relay, arranged in series with the heating element, is open when the appliance remains for a long time immobile, characterized in that the safety relay is open when the thermostat is in an open state and the device is immobile for a time t greater than a warning threshold t ₁ .

According to another characteristic of the invention, the safety relay is open, at the latest, when the apparatus is stationary for a time t greater than a critical threshold t ₂ , the critical threshold t ₂ being greater than the alert threshold. t ₁ .

According to another characteristic of the invention, the state of opening of the thermostat is monitored in a range of immobilization of the apparatus between the alert threshold t ₁ and the critical threshold t ₂ and the safety relay is open as soon as the thermostat is detected in an open state in the shutdown range.

• La figure 1 est une représentation schématique du circuit d'alimentation de l'élément chauffant d'un fer à repasser selon un mode de réalisation particulier de l'invention ;
• La figure 2 représente un exemple d'algorithme de fonctionnement du procédé de sécurisation selon l'invention.

The aims, aspects and advantages of the present invention will be better understood from the description given below of a particular embodiment of the invention, given by way of non-limiting example, with reference to the appended drawings. wherein :

• The figure 1 is a schematic representation of the supply circuit of the heating element of an iron according to a particular embodiment of the invention;
• The figure 2 represents an exemplary operating algorithm of the security method according to the invention.

Only the elements necessary for the understanding of the invention have been represented.

The figure 1 schematically represents the feed circuit of a heating resistor 1 of an iron having a sole in thermal relation with the heating resistor 1 and a heel on which the iron can rest substantially vertically.

The heating resistor 1 is connected in series with a thermostat 2 whose set temperature is controlled by the user and the supply circuit comprises two terminals L, N which are subjected to a supply voltage when the iron is connected to the electrical network.

In order to limit the risk of fire, the iron is provided with a safety device comprising a safety relay 3 controlled by a control module 4, the safety relay 3 being connected in series with the heating resistor 1 so that the opening of the safety relay 3 interrupts the power supply of the heating resistor 1.

The control module 4 receives, in a manner known per se, information from a motion detector 5 and a position sensor 6 for determining whether or not the iron rests on its heel. The position sensor 6 is preferably arranged to detect that the iron rests on its heel when the sole of the iron is inclined more than 20 ° relative to the horizontal. Thus, the iron is considered to be placed on its heel when it is placed on an independent iron rest, such as an iron rest built into an ironing board, these iron rests generally having an inclination of about 45 ° . Advantageously, the control module 4 consists of an ASIC or an electronic circuit carried by a printed circuit also supporting all the other elements 3, 5, 6 of the safety device.

More particularly according to the invention, the control module 4 controlling the opening of the safety relay 3 integrates or is connected to means 2a for determining the state of opening or closing of the thermostat 2. As an example these means 2a determine the opening state of the thermostat 2 by measuring the voltage across a voltage divider disposed between the heating element 1 and the thermostat 2 or by measuring the current load through the safety relay 3 using a shunt.

The safety device can thus control the opening of the safety relay 3 by taking into account the opening state of the thermostat 2 so that the opening of the safety relay 3 can be performed preferably when the thermostat 2 is open. This avoids the accelerated wear of the safety relay 3 generated in particular by the appearance of arcing when the relay of security 3 is open while it is powered on.

A particular embodiment of the method of securing the iron according to the invention will now be described in connection with the figure 2 .

According to this figure, in a first step 101 of the method, the control module 4 determines whether the iron is stationary with the aid of the information coming from the motion detector 5.

When iron is considered as stationary, the control module 4 executes step 102 of the method in which the control module 4 determines, with the aid of the position sensor 6, whether the iron is immobilized on its heel or on its sole .

• si le temps t écoulé est inférieur au seuil d'alerte t_1r, le procédé est renvoyé à l'étape 101. Le module de commande 4 continue donc de surveiller le temps t d'immobilisation du fer et de le comparer au seuil t_1r.
• si le temps t d'immobilisation du fer dépasse le seuil d'alerte t_1r, alors le procédé passe à l'étape 104A.

If the iron rests on its heel, the control module 4 then goes to step 103A of the method in which it measures the time t elapsed since the last time t ₀ where the iron was identified as immobile. This iron immobilization time t is compared with a predetermined warning threshold t _1r , for example of the order of 8 minutes, and then depending on the result, the following operations are performed:

• if the time t elapsed is below the alert threshold t _1r , the method is returned to step 101. The control module 4 therefore continues to monitor the immobilization time t of the iron and to compare it with the threshold t _1r .
• if the immobilization time of iron exceeds the alert threshold t _1r, then the process proceeds to step 104A.

• si le thermostat 2 est dans un état ouvert, le module de commande 4 exécute alors immédiatement l'étape 106 du procédé dans laquelle le module de commande 4 ordonne l'ouverture du relais de sécurité 3. Une telle ouverture du relais de sécurité 3 s'effectue alors que ce dernier n'est pas traversé par un courant de sorte que l'usure du relais de sécurité est extrêmement faible.
• à l'inverse, lorsque le thermostat 2 est dans un état fermé, le module de commande 4 exécute l'étape intermédiaire 105A du procédé.

In step 104A, the control module 4 monitors the opening or closing state of the thermostat 2 and performs the following operations:

• if the thermostat 2 is in an open state, the control module 4 then immediately performs step 106 of the method in which the control module 4 orders the opening of the safety relay 3. Such an opening of the safety relay 3 s when the latter is not traversed by a current so that the wear of the safety relay is extremely low.
• conversely, when the thermostat 2 is in a closed state, the module of control 4 executes the intermediate step 105A of the method.

During step 105A, the control module 4 checks whether the immobilization time of the iron exceeds a critical threshold t _2r , greater than the alert threshold t _1r . By way of example, the value of the critical threshold t ₂ can be chosen such that t _2r = t _1r + 20 seconds.

• si le temps t d'immobilisation du fer n'excède pas la valeur du seuil critique t_2r, le procédé de sécurité est renvoyé à l'étape 101 et le module de commande 4 effectue de nouveau les opérations associées aux étapes 101 et suivantes.
• lorsque le temps t d'immobilisation du fer dépasse le seuil critique t_2r, le module de commande 4 exécute immédiatement l'étape 106 du procédé dans laquelle le module de commande 4 ordonne l'ouverture du relais de sécurité 3. Cette ouverture du relais de sécurité 3 au delà du seuil critique t_2r d'immobilisation s'effectue alors que le relais de sécurité est sous tension.

The control module 4 then performs the following operations:

• if the iron immobilization time t does not exceed the value of the critical threshold t _2r , the security method is returned to step 101 and the control module 4 performs the operations associated with steps 101 and following again.
• when the immobilization time of the iron exceeds the critical threshold t _2r , the control module 4 immediately executes step 106 of the method in which the control module 4 orders the opening of the safety relay 3. This opening of the relay 3 safety beyond the critical threshold t _2r immobilization occurs while the safety relay is energized.

Once the safety relay 3 has been opened, the control module 4 again carries out the various operations associated with the steps 101 and following of the method.

In particular, if the detector 5 detects a movement of the iron during the step 101 of the method, the control module 4 then executes step 110 which consists in controlling the closing of the safety relay 3.

Finally, if during step 102, the position sensor 6 sends to the control module 4 the information that the iron rests on its sole, the control module 4 then executes the steps 103B and following of the method. These steps 103B, 104B and 105B of the method are in all respects similar to the steps 103A, 104A and 105A previously described but with threshold values t _1s and t _2s instead of the thresholds t _1r and t _2r .

By way of example, the alert threshold t _1s is of the order of 30 seconds and the critical threshold t _2s is of the order of 40 seconds, so that the closing of the safety relay 3 by the security method intervenes much more quickly when the iron rests on its sole than when it rests on its heel.

Such a method of securing an iron, by controlling the opening of the safety relay when the thermostat is in an open state in a range of iron downtime between a warning threshold t _1r . t _1s and a critical threshold t _2r , t _2s , has the advantage of allowing in most cases the opening of the safety relay when the latter is not crossed by a current. In particular, when the iron rests long on its heel, the thermostat starts to cycle quickly so that the probability that the thermostat is in an open state in the time range between t _1r and t _2r is very important.

Such a method of securing thus reduces the solicitation of the safety relay, which allows to significantly increase its life and therefore reduce the size of the relays. This results in a less expensive security device.

Advantageously, the security method can also control the activation of one or more LEDs to inform the user when the immobilization time of the iron exceeds respectively the alert threshold and the critical threshold.

Of course, the invention is not limited to the embodiment described and illustrated which has been given by way of example. Modifications are possible, particularly from the point of view of the constitution of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Thus, in an alternative embodiment, the security device may have only one sensor which, by an analysis of the signals, will determine both the position of the iron and its setting in motion. For example, this sensor may be a sensor providing a signal relative to the position of the iron, the detection of movement of the iron then being performed by deriving the signal provided by this sensor.

Thus, in an alternative embodiment not shown, the invention can also be applied to a vertical steamer.

Claims (8)

1. Ironing appliance composed of a heating element (1) controlled by means of a thermostat (2), the appliance being provided with a safety device comprising means for detection of movement (5) and a safety relay (3) assembled in series with the heating element (1) allowing to interrupt the supply of power to said heating element (1) when the appliance remains motionless too long, characterized in that said safety device comprises means (2a) for determining the state of opening of the thermostat (2) and the safety device controls the opening of said safety relay (3) when, simultaneously, the means (2a) for determining indicate that the thermostat (2) is open and the means for detection of movement (5) detect an immobilization of the appliance during a time t longer than an alarm threshold t₁.
2. Ironing appliance according to claim 1, characterized in that the safety device controls, at the latest, the opening of the safety relay (3) when the appliance is motionless during a time t longer than a critical threshold t₂, the critical threshold t₂ being longer than the alarm threshold t₁.
3. Ironing appliance according to claim 2, characterized in that the safety device monitors the state of the thermostat (2) when the time during which the appliance is motionless is comprised between the alarm threshold t₁ and the critical threshold t₂ and controls the opening of the safety relay (3) as soon as the thermostat is detected to be in an open state by the means (2a) for determining the state of opening.
4. Ironing appliance according to any one of claims 1 to 3, characterized in that it is composed of a heel on which it can rest during inactive phases of ironing and an ironing soleplate in thermal communication with the heating element, on which it can rest during active phases of ironing, the appliance comprising position detecting means (6) making it possible to determine if the appliance rests or not on its heel and in that values of the alarm threshold t₁ and the critical threshold t₂ are a function of the position of the iron detected by the position detecting means (6).
5. Ironing appliance according to claim 4, characterized in that the values of the alarm threshold t_1r and critical threshold t_2r when the iron rests on its heel are respectively longer than the values of the alarm threshold t_1s and critical threshold t_2s when the appliance rests on its soleplate.
6. Safe operating method for an ironing appliance provided with a heating element (1) controlled by means of a thermostat (2) in which a safety relay (3), disposed in series with the heating element (1), is open when the appliance remains motionless too long, characterized in that the safety relay (3) is open when the thermostat (2) is in an open state and the appliance is motionless for a time t longer than an alarm threshold t₁.
7. Safe operating method according to claim 6, characterized in that the safety relay (3) is opened, at the latest, when the appliance is motionless for a time t longer than a critical threshold t₂, the critical threshold t₂ being longer than the alarm threshold t₁.
8. Safe operating method for an ironing appliance according to claim 7, characterized in that the state of opening of the thermostat (2) is monitored over a range of immobilization time of the appliance comprised between the alarm threshold t₁ and the critical threshold t₂ and the safety relay (3) is at opened as soon as the thermostat is detected in an open state in said range of immobilization time.

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