A steam iron

FIELD OF THE INVENTION

The present invention relates to a steam iron having a chamber to receive calcified deposits.

BACKGROUND OF THE INVENTION

A steam iron has a housing incorporating a handle, a heel on which the iron rests when not in use, and a heated soleplate to remove creases from clothes. A steam iron also has a reservoir to contain water which is supplied to a steam generator to generate steam which is ejected through steam distribution openings in the soleplate onto the clothes as they are ironed to assist with crease removal.

Conventional steam irons can be provided with a chamber, within or attached to the soleplate, positioned to receive calcified deposits, commonly called 'scale', which is formed in the steam generator as a result of the steam generation process, especially when the water being used to generate steam is hard. Usually, the chamber is positioned towards the rear of the iron so that, whenever the iron is placed on its heel, the calcified deposits fall under gravity from the steam generator and into the chamber where they are retained. The chamber may be periodically opened for emptying after a number of ironing cycles have been performed. A typical steam iron having a calcified deposit collection chamber is known from EP2584089.

When an iron is placed on its heel, it is known for a small quantity of water to flow into the calcified deposit collection chamber together with any calcified deposits. When the iron is subsequently used again, the water flows out of the chamber and back into the steam generator. This can result in an undesirable shot of steam being generated which can be unnerving or cause surprise to the user. SUMMARY OF THE INVENTION

It is an object of the invention to provide a steam iron which substantially alleviates or overcomes the problems mentioned above.

The invention is defined by the independent claims; the dependent claims define advantageous embodiments.

It is known from US-A-5345704 to provide a steam iron comprising a steam generator and a chamber having an inlet positioned so that residual water and calcified deposits formed in the steam generator fall under the influence of gravity through said inlet and into the chamber when the iron is moved from an ironing position into a non-ironing position, wherein the chamber includes an inlet conduit and a collection reservoir, the inlet conduit extending from said inlet into the collection reservoir which is otherwise sealed.

A steam iron according to the present invention is characterised in that the chamber is configured so that said residual water collected in the chamber fills the inlet conduit when the iron is returned to its ironing position creating a drop in pressure in the collection chamber which, together with atmospheric pressure acting on the water in the inlet conduit over the inlet, becomes balanced against a gravitational force acting to draw water out of the inlet conduit, thereby holding water in the inlet conduit.

By configuring the chamber so that the inlet conduit fills with water that has entered the chamber and thereby prevents the flow of air back into the chamber via the inlet and along the inlet conduit, water is prevented from flowing back out of the chamber when the iron is returned to its ironing position. Therefore, a sudden shot of steam no longer occurs.

A small drop in pressure occurs in the collection reservoir when the iron is returned to its ironing position and the water fills and blocks the inlet conduit. This suction effect serves to hold the water in the collection reservoir. Atmospheric pressure acting over the inlet also adds to the suction force which together overcomes the force of gravity which would otherwise cause the water to drop out of the chamber via the inlet.

Preferably, the collection reservoir extends away from the inlet conduit at an angle relative to a plane in which the soleplate lies. By arranging the collection reservoir so that it extends away from the inlet conduit, the level of the water in the collection chamber will be above the inlet conduit, thereby reducing the possibility that air will flow through the inlet and via the inlet conduit into the collection reservoir.

The collection reservoir may extend from the inlet conduit at an angle in the range of 5 and 60 degrees. Most preferably, the collection reservoir extends from the inlet conduit at an angle of approximately 27 degrees.

The inlet conduit defines a first volume and the collection reservoir defines a second volume. The second volume may be larger than the first volume.

In some embodiments, the inlet conduit has a rectangular cross-section having a height, a width and a length and the height of the inlet conduit is preferably between 3 and 8mm. Most preferably, the height of the inlet conduit is approximately 6mm, the width of the inlet conduit is approximately 24mm and the length of the inlet conduit is approximately 8mm. The length of the collection reservoir may also be approximately 52mm.

The collection reservoir may taper outwardly in a direction away from the inlet conduit.

In another embodiment, the collection reservoir extends laterally from the inlet conduit, the inlet conduit and the collection reservoir being separated by a step.

Preferably, the chamber is integrally formed.

It is also known to provide a calcified deposit collection accessory removably mountable within a steam iron to collect residual water and calcified deposits that fall under gravity when said steam iron is moved from an ironing position into a non-ironing position, the calcified deposit collection accessory comprising a chamber having an inlet, an inlet conduit extending from the inlet and a collection reservoir which is sealed other than by the inlet conduit, wherein said chamber is configured so that said residual water collected in the chamber fills the inlet conduit when the iron is returned to its ironing position creating a drop in pressure in the collection chamber which, together with atmospheric pressure acting on the water in the inlet conduit over the inlet, becomes balanced against a gravitational force acting to draw water out of the inlet conduit, thereby holding water in the inlet conduit. These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Fig. 1 is a cross-sectional side view of a steam iron according to an embodiment of the invention;

Fig. 2 is a perspective view of a calcified deposit collection chamber that is received within the iron of Fig. 1 ;

Fig. 3 is a cross-sectional side view of the calcified deposit collection chamber shown in Fig. 2;

Fig. 4 is a perspective view of another embodiment of a calcified deposit collection chamber; and Fig. 5 is a cross-sectional side view of the calcified deposit collection chamber shown in Fig. 4.

DETAILED DESCRIPTION OF THE EMBODIMENTS

A steam iron 1 according to an embodiment of the present invention is illustrated in Fig. 1 and includes a housing 2 having an integral handle 3. A soleplate 4 is mounted to the housing 2 and is electrically heated to remove creases from clothes when they are laid on a flat surface such as an ironing board la and the soleplate 4 is pressed against and moved across them. The steam iron 1 is also provided with a reservoir (not shown) within the housing 2 to contain water for supply to a steam generator 5 located within the soleplate 4 that generates steam for delivery through steam distribution openings 4a in the soleplate 4 to assist in crease removal. Alternatively, the reservoir may be placed external to the housing, for instance in a separate base, and water transferred to the steam generator via a hose.

Fig. 1 shows the steam iron in a typical in-use or ironing position, with the soleplate 4 facing downwardly so that the weight of the iron 1 will rest on the clothes being ironed. The housing 2 also has a heel 6. When not in use, the iron may be placed in a stable, non- ironing, upright position resting on its heel 6 so that the soleplate 4 is out of contact with any surfaces.

The steam iron 1 includes a calcified deposit collection chamber 7 having an inlet 8, and an inlet conduit 9 that leads into a collection reservoir 10. The collection reservoir 10 is sealed in an air and fluid tight manner by a removable plug or cap 11 that is accessible by the user. A rubber seal o-ring 14 (shown in Fig. 3), acting as a sealing element, is disposed between the collection reservoir 10 and the removable plug or cap to form an air and fluid seal. The inlet conduit 9 and the collection reservoir 10 both define a volume. The volume of the collection reservoir 10 is substantially greater than the volume of the inlet conduit 9. The chamber 7 may be integrally formed as a single unit, although it may be formed from multiple parts which are manufactured or molded separately and then joined to each other in a subsequent step. The joining of parts may be necessary if the chamber has a more irregular shape which is difficult to mold as one piece.

The inlet 8 is positioned adjacent to a rear face 4b of the soleplate 4 so that calcified deposits that are formed in the steam generator 5 adjacent to the rear face 4b of the soleplate 4 will fall downwardly under their own weight through the inlet 8, along the inlet conduit 9 and into the collection reservoir 10 when the steam iron 1 is placed on its heel 6. A scoop 12 or other element extends from the plug 11 into the collection reservoir that collects or holds the calcified deposits and prevents them from passing back out of the collection reservoir 10 via the inlet conduit 9 and the inlet 8 when the iron is moved back into its ironing position orientation, as shown in Fig. 1.

It will be appreciated that residual water in the steam generator 5 will also flow downwardly and into the calcified deposit collection chamber 7 together with any calcified deposits when the steam iron is placed on its heel 6. However, the chamber 7 is configured so that this water is prevented from flowing back out of the chamber 7 when the steam iron 1 is returned to its operational or ironing position, as shown in Fig. 1.

The inlet conduit 9 is sized and shaped so that when the steam iron 1 is returned from the heel position to its ironing position, water in the collection reservoir 10 flows into, and fills, the inlet conduit 9. As the collection reservoir 10 is sealed, other than by the inlet 8 and inlet conduit 9, the water which fills the volume of the inlet conduit 9 effectively prevents the passage of air through the inlet 8 and along the inlet conduit 9 into the collection reservoir 10. As air is unable to pass along the inlet conduit 9 and into the collection reservoir 10, which would be necessary in order to equalise a drop in pressure in the collection reservoir 10 that would occur as a result of water flowing out of the collection reservoir 10 via the inlet conduit 9, water is held in the collection reservoir 10 and in the inlet conduit 9. The absence of a flow of air into the collection reservoir 10 causes a suction or pressure drop to form in the collection reservoir 10 which, together with atmospheric pressure acting on the water over the inlet 8, is balanced against the force of gravity which would otherwise allow the water to fall out of the inlet 8 when the steam iron 1 is held in its ironing position. The water is therefore retained in the chamber 7.

The above described principle is akin to the effect that occurs when the lower end of a drinking straw is immersed in a fluid and a finger placed on and retained over the upper end whilst the straw is removed from the fluid. It will be noted that fluid remains in the straw and does not flow back out of the lower end until the finger covering the upper end of the straw is removed. This phenomenon occurs because, in the absence of a finger placed over the end of the straw, water in the straw would drop out under gravity with air flowing into the straw through its upper open end to replace the water. However, when the upper end of the straw is blocked, air cannot flow into the straw from either end and so cannot displace the water. This creates a suction effect within the straw which holds the water within it until the upper end of the straw is unblocked and air can flow freely into the upper end of the straw to replace the water flowing out of its lower end.

The collection reservoir 10 extends upwardly away from the inlet conduit 9 with the steam iron 1 in the ironing orientation, as shown in Fig. 1. This ensures that water in the collection reservoir 10 is above the uppermost point (point 'P' in Figs. 1, 3 and 5) of the inlet conduit 9, so that the entrance to the inlet conduit 9 from the collection reservoir 10 remains fully submerged in order to prevent the passage of air into the collection reservoir 10 which would allow pressures to equalise and water to flow out.

In preferred embodiments, the inlet conduit 9 extends parallel to the soleplate 4 and the collection reservoir 10 extends away from the inlet conduit 9 at an angle relative to a plane in which the soleplate 4 lies ('a' as shown in Fig. 3) of between 5 and 60 degrees. This means that, in a normal ironing position in which the soleplate 4 is held horizontally, the collection reservoir 10 extends at an upwardly extending angle away from the horizontal soleplate 4. At angles in excess of 60 degrees, the ability of the chamber 7 to collect calcified deposits may be compromised, as it is harder for the deposits to reach the end of the collection reservoir 10 when the steam iron 1 is placed on its heel 6. In a particularly preferred embodiment, the collection reservoir 10 extends upwardly from the inlet conduit 9 at an angle of approximately 27 degrees.

The collection reservoir 10 may also taper outwardly away from the inlet conduit 9 towards the plug 11 at the opposite end of the collection reservoir 10, so the walls of the collection reservoir 10 need not be parallel to each other.

The inventors have determined that the height ('a' in Fig. 2) of the inlet 8 should be in the order of 3mm to 8mm. If the height is less than 3mm, then the inlet conduit 9 may become choked with calcified deposits relatively quickly. In a preferred embodiment, the height of the inlet 8 is approximately 6mm, the width ('b' in Fig. 2) of the inlet conduit 9 is approximately 24mm and the length ('c' in Fig. 2) of the inlet conduit 9 is approximately 8mm. The length ('d' in Fig. 2) of the collection reservoir 10 may also be in the order of 52mm.

A second embodiment is shown in Figs 4 and 5. This embodiment is identical to the embodiment described with reference to Figs. 2 and 3, except that the collection reservoir 10 does not extend upwardly away from the inlet conduit 9. On the contrary, the collection reservoir 10 is simply a lateral extension of the inlet conduit 9 and so angle a, as shown in Fig. 3, can be assumed to be zero in the embodiment of Fig. 5)), although the collection reservoir 10 has a larger volume than the inlet conduit 9. A step 13 is formed between the inlet conduit 9 and the collection reservoir 10, separating the smaller volume inlet conduit 9 from the larger volume collection reservoir 10.

It is envisaged that the calcified deposit collection chamber 7 could be provided as a replacement part or accessory for existing steam irons. Such an embodiment is generally the same as the embodiments described above and so a detailed description will be omitted herein. Although in the above described embodiments the inlet 8 and inlet conduit 9 are each shown to have a rectangular profile, it will be understood that in alternative embodiments each of the inlet 8 and inlet conduit 9 may be formed to define a different shape, for example an oval profile.

It will be appreciated that the term "comprising" does not exclude other elements or steps and that the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to an advantage. Any reference signs in the claims should not be construed as limiting the scope of the claims.

Although claims have been formulated in this application to particular combinations of features, it should be understood that the scope of the disclosure of the present invention also includes any novel features or any novel combinations of features disclosed herein either explicitly or implicitly or any generalisation thereof, whether or not it relates to the same invention as presently claimed in any claim and whether or not it mitigates any or all of the same technical problems as does the parent invention. The applicants hereby give notice that new claims may be formulated to such features and/or combinations of features during the prosecution of the present application or of any further application derived therefrom.