EP0916150B1 - Thermostat control device - Google Patents

Description

TECHNICAL AREA

The present invention relates to the field of household electrical appliances and applies more particularly (but not exclusively) to irons.

It relates more specifically to a control device for a thermostat, including an iron thermostat, and allows, for a run data of the control means, to obtain a more precise setting in temperature and especially in the area of the most stressed temperatures.

The device according to the invention is more particularly intended to ensure a precise temperature adjustment function. As such, the device for Thermostat control according to the invention more specifically relates to but not exclusively, ironing appliances, such as irons for example.

The temperature control of the irons is done by a thermostat to bimetallic whose drive is done directly by a rotary knob or indirectly by a rack-and-pinion device described in EP-A-0 086 759 and which corresponds to the preamble of the claim independent 1 and a linear cursor. In both cases, the temperature selection range includes a part intended for warming up and another intended for adjustment for the different types of fabrics used.

The rack and pinion system allows to have a gear ratio between the slider and thermostat increasing the accuracy of the setting. Iron must have a temperature selection range from maximum (220 °) at power failure at room temperature. As part of a iron using a rack and pinion type device to ensure the thermostat control, the stroke corresponding to the selection phase of the temperatures constitute only about half of the range of thermostat. The rest of the stroke of the control means corresponds to the warm-up phase, ie from the power failure to the first temperature of iron use.

The disadvantage of such a device is that about half of the average stroke command is unusable for selecting which temperatures to use during ironing. This leaves less usable space to perform a precise adjustment in the temperature range of iron use.

SUMMARY OF THE INVENTION

The purpose of the invention is precisely to remedy this drawback, and proposes a thermostat control device, in particular an iron thermostat to ironing, which allows, for a given stroke of the control means, to obtain a more precise temperature setting and a larger stroke in the area of the most stressed temperatures.

In order to achieve this goal a thermostat control device is provided, in particular an iron thermostat, comprising a support, a opening in said support for receiving a mobile control means, a first rack means cooperating with said control means, guide means for said rack means, a pinion cooperating with the first rack means, characterized in that comprises a second rack means disposed in the extending said first rack means and said pinion has two toothed areas whose rays of the respective primitive circles are different, the first tooth zone co-operating with the first means forming rack and the second toothed zone cooperating with the second means forming a rack, said pinion being able to lead to rotating the rod of said thermostat.

The thermostat control device according to the invention makes it possible, for a same stroke of the movable control means, to have a control stroke important to the detriment of the approach run that becomes very weak. it allows precise adjustment for a more adjustable temperature range wide. In addition, it is no longer necessary to move the cursor over a long before reaching the first temperature of use.

Another advantage related to the use of a control device for thermostat according to the invention is a better selection of a temperature precise corresponding to a given type of tissue.

Moreover, given the fact that the temperature setting range is more vast, the selection is made for a larger number of temperatures and we thus obtain a greater number of corresponding tissue possibilities to choose. This allows the iron to cover a greater diversity of types of tissue.

According to an advantageous variant of the invention, the constituent parts of the control device for thermostat are integral with the support fixed on the carcass of the iron. This allows for universal support that can fit on several types of already existing iron. Construction described makes it possible to use the part comprising the adjustment members, by example the existing board, without further modifications. Otherwise, we get a compact control device set and that occupies very little space in the iron carcass. It should also be mentioned that This variant implies significant constructive and assembly facilities and, therefore, a reduction in production costs.

SUMMARY DESCRIPTION OF THE DRAWINGS

La figure 1 représente une coupe en élévation d'un fer à repasser comprenant un dispositif de commande du thermostat selon l'invention;

La figure 2 représente une vue de dessous du dispositif de commande du thermostat selon l'invention;

Les figures 3a et 3b représentent des vues de dessus et de côté de la platine d'un fer à repasser comprenant un dispositif de commande du thermostat selon l'invention;

La figure 4 représente une vue schématique en coupe d'un dispositif de commande du thermostat selon un autre mode de réalisation de l'invention;

La figure 5 représente une vue de dessus du dispositif selon l'invention montrant un exemple d'échelle d'indication du type de tissu correspondant à une température donnée.

Other features and advantages of the invention will appear more clearly in the light of the description and the drawings which follow, illustrating, by way of non-limiting examples, embodiments of the invention. Thus, reference is made to FIGS. 1 to 5, where:

Figure 1 shows an elevational section of an iron comprising a thermostat control device according to the invention;

Figure 2 shows a bottom view of the thermostat control device according to the invention;

Figures 3a and 3b show top and side views of the plate of an iron comprising a thermostat control device according to the invention;

Figure 4 shows a schematic sectional view of a thermostat control device according to another embodiment of the invention;

FIG. 5 represents a view from above of the device according to the invention showing an exemplary indication scale of the type of fabric corresponding to a given temperature.

BEST MODE OF REALIZING THE INVENTION

FIG. 1 illustrates an iron 1 comprising, in a manner known per se, a sole 2 heated by means of a heating body 3, a chamber of spray located above the sole, a device for supplying water the vaporization chamber and means for adjusting said device. The iron also includes a thermostat 7, for example bimetallic type, to regulate heating temperature of soleplate 2 and electrical connections connecting the sector to the heating body of the sole. The various elements of adjustment are advantageously provided on a plate 6 disposed above the vaporization chamber. These different elements are arranged in a carcass 9 forming at its upper part a gripping means 4 facilitating the manipulation of iron.

The iron according to the invention comprises a device for controlling the thermostat 10 to act optimally on the thermostat 7. A rod 8 of thermostat, arranged between the latter and said control device of the thermostat, serves as a mechanical connection between these elements.

The different elements of the thermostat control device are better visible in Figure 2. This figure illustrates a preferred example of realization of the thermostat control device according to the invention.

A support 11 has two openings 12 allowing the connection between a mobile control means 13 disposed on the outer side of the support 11 and a rack assembly disposed on the inner side of said support. Said set rack is provided to mesh with a pinion 16 which acts on the rod 8 of the thermostat 7. This rack assembly comprises a first means of rack 14 and a second rack means 15 in the extension from the first. The pinion 16 comprises a first toothed zone 17 on a first sector of its circumference. It also includes a second toothed zone 18 on a second sector of its circumference juxtaposed with first.

The radius R1 of the pitch circle of the first tooth zone 17 is less than radius R2 of the original circle of the second tooth zone 18. The first rack 14 is provided to cooperate with the first toothed zone 17 and the second rack means 15 is provided to cooperate with the second toothed zone 18 of the pinion 16.

In a rack-and-pinion system the relationship between the rack-and-pinion race and the angle of rotation of the pinion is governed by the equation A = C * 180 / (Π * R) where A is the angle of rotation of the pinion, C is the race of the rack and R the radius of the primitive circle. It is therefore observed that the angle of rotation of the pinion is inversely proportional to the radius of the primitive circle. On this idea is based the operation of the thermostat control device according to the invention. As part of the adjustment of a thermostat for iron there are two temperature ranges: a temperature range corresponding to a so-called approach run of the control means and a second run, so-called selection of temperatures to use during ironing. In summing the two races corresponding to the two beaches mentioned, gets the total stroke of the control medium. The control device of the thermostat according to the invention proposes to reduce the approach stroke in the purpose of using more effectively the rest of the race of the means of command corresponding to the selection or adjustment zone in temperature. For this, in the approach phase, the first means forming rack 14 drives in rotation the first toothed zone 17 of the pinion. The radius of the pitch circle R1 is low so the rotation, due to the equation previous, is important. We thus obtain a weak approach run for starting and warming up the iron (low stroke for a significant variation in temperature).

In the adjustment phase, the second rack means 15 leads to its turn in rotation the second toothed zone 18 of the pinion. The radius of the circle Primitive R2 is important so the angle of rotation of the pinion is low. We gets this time a big race and a big range of selection temperatures to be used during ironing (important stroke for a restricted temperature increase).

The pinion 16 is mounted on the rod 8 of the thermostat 7 and thus, the movement in rotation of said pinion rotates the rod of said thermostat which acts to its turn on the bimetal to change the temperature of contact opening between the heating element and the power source.

In the embodiment shown in FIG. 2, it can be seen that the rack assembly is guided in its movement relative to the support 11 by a guiding means 19. Said guide means is integral with the support 11 and is in the form of a rail to allow sliding of the means forming the rack assembly.
In an advantageous embodiment of the invention, the support 11 and related elements are molded plastic to facilitate manufacturing, reduce weight and reduce manufacturing costs.

In FIG. 2, it can be seen that the mobile control means 13 comprises a holding means on the slots 12. This holding means also serves as mechanical connection means between the mobile control means 13 and the rack set.

In an advantageous variant of the invention, the support 11 and the elements therein are made of molded plastic to facilitate industrialization, reduce the weight and reduce, also, manufacturing costs.

The rack assembly may present, in a manner known per se, on the face opposite to that of the gear with the pinion and over its entire length, a notched portion. This notched portion cooperates with an elastic tongue fixed to the support 11. Such an arrangement confers on the mobile control means 13 a ratcheting effect resulting in a more accurate positioning over the entire length of the stroke of said means of ordered.

Said control means comprises graduations corresponding to the different types of fabrics used. FIG. 5 also shows that the stroke of the mobile control means 13 is virtually divided into two temperature zones: zone 1 corresponding to the approach zone and the zone 2 to the adjustment zone, the first being much smaller than the second.

In the example shown in FIG. 2, the various elements of the device of the thermostat according to the invention belong to the support 11.

According to an advantageous variant of the invention, the different elements of said control device are integral with the plate 6 of the iron to 1. Platinum is located above the spray chamber iron and substantially parallel to the sole. It forms, in a way known in itself, a support for the water supply members of the vaporization chamber, for the means for adjusting the temperature and for the electrical connections of said iron. Such a platinum can be realized separately and equipped with all the controls on a support common, which then facilitates mounting in the iron. Its location in a position substantially parallel to the sole allows movement in a horizontal direction of the rack means without increasing clutter. The plate is made of insulating plastic and it has on the opposite side to the sole of the metallized conductive tracks whose ends are intended to be connected to the power cord of the iron. Figures 3a and 3b illustrate this embodiment.

According to another advantageous variant of the invention and which is illustrated in Figure 4, the two toothed zones of the racks 14 and 15 are lie in two different parallel planes. In this case, the pinion 16 has two toothed sectors or two toothed wheels 17 and 18 also located in two different parallel planes to cooperate with both areas aforementioned toothed racks 14 and 15.

POSSIBILITIES OF INDUSTRIAL APPLICATION

The invention finds its application in the technical field of apparatus appliances.

Claims (7)

1. A thermostat control device (10) for controlling a thermostat, in particular a thermostat (7) of a smoothing iron, said control device comprising a support (11), an opening (12) in said support receiving moving control means (13), first rack-forming means (14) co-operating with said control means, guide means (19) for guiding said rack-forming means, and a pinion (16) co-operating with the first rack-forming means, said control device being characterized in that it further comprises second rack-forming means (15) disposed following on from said first rack-forming means, and in that said pinion has two toothed zones whose respective pitch circle radii are different, the first toothed zone (17) co-operating with the first rack-forming means (14) and the second toothed zone (18) co-operating with the second rack-forming means (15), said pinion being suitable for rotating the rod (8) of said thermostat (7).
2. A control device according to claim 1, characterized in that one of the two toothed zones of the pinion (17, 18) and of the racks (14, 15) corresponds to the temperature run-up zone and the other of said zones corresponds to the adjustment zone of the thermostat.
3. An iron including a control device according to claim 1 or claim 2, said iron being characterized in that the component portions of said thermostat control device (10) are secured to said support (11) which is fastened to the casing (9) of said iron.
4. An iron including a control device according to claim 1 or 2, said iron being characterized in that the component portions of said thermostat control device (10) are secured to the plate (6) carrying all of the adjustment members for adjusting said iron.
5. A device according to claim 4, characterized in that the two toothed zones of the racks (14, 15) lie in different, parallel planes, and in that the racks mesh with corresponding toothed zones (17, 18) of the pinion in the above-mentioned parallel planes.
6. An iron including a control device according to any one of claims 1 to 5, characterized in that said control means (13) of said device (10 are situated in a place that is easily accessible during iron, in particular under the handle (4) of said iron.
7. An iron including the control device according to claim 6, characterized in that said control means (13) of said device (10) have graduations corresponding to the various types of fabric ironed.

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