GB2058147A - Improvements in steam ions - Google Patents

Abstract

An electrically heated steam iron comprises a heated base plate 1 having an evaporation chamber 2 formed therein. A drip feed valve supplies water dropwise to the chamber. A bimetallic element 9, arranged, as the chamber 2 is heated and cooled, to deform substantially at right angles to the valve body axis removes and prevents build-up of lime scale on the valve and on the chamber bottom. <IMAGE>

Description

SPECIFICATION Improvements in steam irons The invention relates to an electrically heated steam iron with an evaporation chamber arranged in the steam-iron baseplate and with a drip-feed valve arranged to supply water dropwise into said chamber.

With such steam irons the quantity of water required for the steam action is conveyed dropwise out of a water tank into the electrically heated evaporation chamber. The dosing is effected via the drip-feed valve. Known steam irons have the disadvantage that the walls of the evaporation chamber and the drip-feed valve tend to fur up with limescale. In the case of drip-feed valves with a metal body especially, the stalactitelike lime deposits assume on their outer faces reaching into the evaporation chamber such magnitudes that the through-flow opening becomes encrusted in a dripping manner and the iron is therefore no longer workable as a steam iron. Valve bodies made of silicone rubber are also known.These valve bodies are less inclined to encrustation on their outer faces, but they have the disadvantage that lime deposits on the valve stem enlarge the hole cross-section in course of time during actuation of the drop-feed valve and a dropwise supply of water into the evaporation chamber is no longer possible.

The object of this invention is to provide an electrically heated steam iron which does not have the above-mentioned disadvantage and with which lime deposits are largely prevented in the region of the evaporation chamber.

According to the invention there is provided an electrically heated steam iron comprising a base plate, an evaporation chamber formed in the base plate, a drip feed valve for supplying water to the chamber and a bimetallic element mounted in the chamber said element being deformable substantially at right angles to the valve body axis and being arranged on such deformation to remove and prevent the build-up of lime scale on the valve. In a preferred embodiment of the invention the element is adapted also to remove and prevent the build-up of lime scale on the bottom of the chamber. For example, one edge of the bimetal may stand in touch contact with the evaporation chamber bottom. Preferably, one face of the bimetal stands in touch contact with the evaporation chamber wall.

It is thus ensured that no lime deposits can form either on the drip-feed valve or on the walls of the evaporation chamber. When the evaporation chamber is heated and cooled, the non-fastened region of the bimetallic element bends back and forth in the chamber. In so doing, the bimetal scrapes over the valve body and over the chamber bottom. An incrustation of the through-flow opening of the valve is no longer possible, since upon the heating and cooling of the bimetal any lime deposits on the valve body and on the evaporation chamber wall are scraped off.

The flow rate therefore remains constant.

Furthermore, the life of a steam iron is substantially lengthened due to the invention and no especial scale-repelling materials have to be used for the drip-feed valve.

In order that the invention may be readily understood an embodiment thereof will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a longitudinal section through a steam iron according to the invention, Figure 2 is a cross section through the steam iron shown in Fig 1, and Figure 3 is a perspective view of the base plate.

The valve region, shown by way of example, of a steam iron illustrates the part region of the baseplate 1, the evaporation chamber 2 and the heating element 3. The evaporation chamber 2 is closed upwardly by a cover 4, as is conventional.

Arranged over the evaporation chamber 2 is a water supply tank 5 which is connected to the evaporation chamber via a drip-feed valve 6 which has a through-flow opening 8 which is opened and closed by a valve stem 7. A bimetallic element 9 is fastened at one end in the vaporation chamber 2.

The element 9 can be fastened in various known ways, but it is especially advantageous if the element 9 is mortised at one end in the vicinity of the heating element 3. The faces 16 and 12 of the element 9 stand in touch contact with the evaporation chamber bottom 1 1 and the face 13 of the drip-feed valve 6. When the baseplate 1 is heated, the element 9 bends in the direction of the arrow at right angles to the axis of the-drip-feed valve 6 and, upon cooling, it bends back into its normal position. Due to this deforming movement of the element 9 any lime deposits on the dripfeed valve 6 and on the evaporation chamber bottom 11 are scraped off.

1. An electrically heated steam iron comprising a base plate, an evaporation chamber formed in the base plate, a drip feed valve for supplying water to the chamber and a bimetallic element mounted in the chamber said element being deformable substantially at right angles to the valve body axis and being arranged on such deformation to remove and prevent the build-up of lime scale on the valve.

2. A steam iron according to claim 1 in which the element is adapted also to remove and prevent the build-up of lime scale on the bottom of the chamber.

3. An electrically heated steam iron substantially as herein described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (3)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in steam irons The invention relates to an electrically heated steam iron with an evaporation chamber arranged in the steam-iron baseplate and with a drip-feed valve arranged to supply water dropwise into said chamber. With such steam irons the quantity of water required for the steam action is conveyed dropwise out of a water tank into the electrically heated evaporation chamber. The dosing is effected via the drip-feed valve. Known steam irons have the disadvantage that the walls of the evaporation chamber and the drip-feed valve tend to fur up with limescale. In the case of drip-feed valves with a metal body especially, the stalactitelike lime deposits assume on their outer faces reaching into the evaporation chamber such magnitudes that the through-flow opening becomes encrusted in a dripping manner and the iron is therefore no longer workable as a steam iron. Valve bodies made of silicone rubber are also known.These valve bodies are less inclined to encrustation on their outer faces, but they have the disadvantage that lime deposits on the valve stem enlarge the hole cross-section in course of time during actuation of the drop-feed valve and a dropwise supply of water into the evaporation chamber is no longer possible. The object of this invention is to provide an electrically heated steam iron which does not have the above-mentioned disadvantage and with which lime deposits are largely prevented in the region of the evaporation chamber. According to the invention there is provided an electrically heated steam iron comprising a base plate, an evaporation chamber formed in the base plate, a drip feed valve for supplying water to the chamber and a bimetallic element mounted in the chamber said element being deformable substantially at right angles to the valve body axis and being arranged on such deformation to remove and prevent the build-up of lime scale on the valve. In a preferred embodiment of the invention the element is adapted also to remove and prevent the build-up of lime scale on the bottom of the chamber. For example, one edge of the bimetal may stand in touch contact with the evaporation chamber bottom. Preferably, one face of the bimetal stands in touch contact with the evaporation chamber wall. It is thus ensured that no lime deposits can form either on the drip-feed valve or on the walls of the evaporation chamber. When the evaporation chamber is heated and cooled, the non-fastened region of the bimetallic element bends back and forth in the chamber. In so doing, the bimetal scrapes over the valve body and over the chamber bottom. An incrustation of the through-flow opening of the valve is no longer possible, since upon the heating and cooling of the bimetal any lime deposits on the valve body and on the evaporation chamber wall are scraped off. The flow rate therefore remains constant. Furthermore, the life of a steam iron is substantially lengthened due to the invention and no especial scale-repelling materials have to be used for the drip-feed valve. In order that the invention may be readily understood an embodiment thereof will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a longitudinal section through a steam iron according to the invention, Figure 2 is a cross section through the steam iron shown in Fig 1, and Figure 3 is a perspective view of the base plate. The valve region, shown by way of example, of a steam iron illustrates the part region of the baseplate 1, the evaporation chamber 2 and the heating element 3. The evaporation chamber 2 is closed upwardly by a cover 4, as is conventional. Arranged over the evaporation chamber 2 is a water supply tank 5 which is connected to the evaporation chamber via a drip-feed valve 6 which has a through-flow opening 8 which is opened and closed by a valve stem 7. A bimetallic element 9 is fastened at one end in the vaporation chamber 2. The element 9 can be fastened in various known ways, but it is especially advantageous if the element 9 is mortised at one end in the vicinity of the heating element 3. The faces 16 and 12 of the element 9 stand in touch contact with the evaporation chamber bottom 1 1 and the face 13 of the drip-feed valve 6. When the baseplate 1 is heated, the element 9 bends in the direction of the arrow at right angles to the axis of the-drip-feed valve 6 and, upon cooling, it bends back into its normal position. Due to this deforming movement of the element 9 any lime deposits on the dripfeed valve 6 and on the evaporation chamber bottom 11 are scraped off. CLAIMS

1. An electrically heated steam iron comprising a base plate, an evaporation chamber formed in the base plate, a drip feed valve for supplying water to the chamber and a bimetallic element mounted in the chamber said element being deformable substantially at right angles to the valve body axis and being arranged on such deformation to remove and prevent the build-up of lime scale on the valve.

2. A steam iron according to claim 1 in which the element is adapted also to remove and prevent the build-up of lime scale on the bottom of the chamber.

3. An electrically heated steam iron substantially as herein described with reference to the accompanying drawings.