GB2385603A

GB2385603A - Iron with retractable sole plate

Info

Publication number: GB2385603A
Application number: GB0204379A
Authority: GB
Inventors: Simon Saba; Paul Hardon; David Etherington
Original assignee: Salton Europe Ltd
Current assignee: Russell Hobbs Ltd
Priority date: 2002-02-23
Filing date: 2002-02-23
Publication date: 2003-08-27
Also published as: GB0204379D0

Abstract

The iron 10 has a trigger 16 in a handle portion 14 that controls movement of a sole plate 18. The sole plate may be connected to the trigger by a mechanical or electro-mechanical linkage. The sole plate is in a retracted or raised position B if the trigger is not held. The sole plate is lowered to a use position D as the trigger is moved in direction C. The sole plate may then contact a material 32 to be ironed via a surface such as on an ironing board 30. A protective wall 20 extends around the periphery of the sole plate to support the body 12 of the iron. A second aspect of the iron is a heating means to heat the sole plate only when the handle is held.

Description

IMPROVEMENTS IN AND RELATING TO IRONS Field of the Invention The present invention relates to irons.

Background to the Invention Irons are common implements incorporating a flat base which is heated to smooth clothes or other materials. The flat base of the iron is commonly referred to as the sole plate, and in modern irons is normally heated electrically. The electrical power can be supplied continuously via a permanently attached power lead connected to the iron. Alternatively, cordless irons exist, in which the sole plate is heated either via a battery located in the iron or by the iron being located in a holder, the holder in turn being electrically connected to the mains power supply.

By design, the sole plate of the iron reaches a relatively high temperature such that the material being ironed can be smoothed more effectively. However, this also results in the iron being a safety hazard. A person touching the surface of the sole plate might easily burn themselves. Equally, if the iron were to be left with the heated sole plate in contact with a surface, damage to the surface might easily occur, possibly even resulting in a fire.

US 6,307, 182 describes an electric iron having a microprocessor-controlled relay which automatically connects an iron to and disconnects an iron from a source

of electrical power based upon whether a user is grasping the handle of the iron and the orientation of the iron.

In use, when the hand of the user is in proximity to the handle of the iron and the iron is in the horizontal position, the switching circuit automatically connects the heating element to the source of electrical power. When the users hand is not in proximity to the handle of the iron and the iron is in a horizontal position, the switching circuit automatically disconnects the heating element from the source of electrical power. When the iron is in a vertical position, the switching circuit automatically disconnects the heating element from the source of electrical power after a pre-determined amount of time.

The present inventors have realised that whilst the iron described in US 6,307, 182 represents an improvement over the prior art, it can still be hazardous. For instance, if the iron is left in the horizontal position immediately after use, even though power has been removed from heating the iron, the sole plate will still remain hot for quite some time. Consequently, even though the sole plate is not being heated, it may still be hot enough to damage a surface with which the iron is in contact or burn someone touching the sole plate.

For instance, a conventional iron sole plate will, depending upon the setting, typically reach operating temperatures of between 750C and 200oC, and normally take from around fifteen seconds to over one minute to reach the set operating temperature. However, cooling of such an iron at room temperature will normally take a lot

longer. For instance an iron heated to an operating temperature range of between 75'and 95'C will typically take in excess of twenty minutes to cool down to 50. C, and will take over two hours to cool to room temperature (approximately 21'C). Obviously the cooling down time from higher temperatures is even longer.

It is an aim of a preferred embodiment to the present invention to provide an iron that alleviates at least one of the problems of the prior art.

Statement of the Invention In a first aspect, the present invention provides an iron comprising a handle and a sole plate, wherein the iron further comprises movement means arranged to move said sole plate between at least two positions, a first position in which the sole plate is arranged suitable for ironing a surface, and a second position in which at least a portion of the sole plate is positioned such that a surface could not be ironed.

Preferably, the sole plate is automatically positioned away from the surface if said handle is not held.

Preferably, said movement means comprises a protective wall extending at least partially around the circumference of the sole plate.

Preferably, said movement means comprises protrusion means arranged to extend from the iron such that, in a normal horizontal resting position, the iron including the sole plate would be elevated away from said surface.

Preferably, said protrusion means is resiliently biased such that a pressure exerted by a user of the iron will result in the sole plate moving from said second position to said first position.

Preferably, the iron further comprises a body, with the sole plate being withdrawn into said body when in said second position.

In a further aspect, the present invention provides an iron comprising a handle and a sole plate of low thermal mass arranged to be heated to an operating temperature suitable for ironing, wherein the iron further comprises heating means arranged to heat said sole plate to the operating temperature only when said handle is being held.

Preferably, the sole plate has a thermal mass of less than 150 Joules/ C.

Preferably, when the handle is not being held, the heating means is arranged to heat said sole plate to a standby temperature, the standby temperature being less than the operating temperature.

Alternatively, the heating means is arranged to not heat said sole plate when said handle is not being held.

Preferably, said heating means can be switched between two modes, a first mode in which the heating means is arranged to heat the sole plate to the operating temperature only when said handle is being held, and a second mode in which the heating means is arranged to continuously heat the sole plate.

Preferably, the iron further comprises detection means arranged to detect when said handle is being held.

Preferably, the detection means comprises a button.

Preferably, the detection means is arranged to detect a change in one or more electrical characteristics caused by the handle being held. Preferably, said electrical characteristics include inductance, resistivity or capacitance.

Preferably, said detection means comprises a pressure sensor arranged to detect pressure exerted by a user on said handle.

Preferably, the heating means comprises imprinted tracks of conductive ink.

Preferably, said tracks are on at least one of the sole plate or on a plate in direct thermal contact with the sole plate.

Preferably, at least one of said plates comprises a metal.

Brief Description of the Drawings For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings in which:

Figure 1 shows a 3-dimensional representation of an iron according to a preferred embodiment of the present invention, the iron being orientated in what is normally understood to be an upside down position ; Figure 2A shows the iron of Figure 1 in a rest position upon an ironing board ; Figure 2B shows a close up of the left hand side of Figure 2A ; Figure 3 shows the iron of Figure 1 in a working position ; and Figure 4 is a graph illustrating the relationship of fingertip contact with a metal causing pain with time and temperature.

Detailed Description of Preferred Embodiment As shown in Figure 1, the iron 10 comprises a body 12, which includes a handle 14 for holding the iron during use.

The handle 14 incorporates a button in the form of a trigger 16. This trigger 16 when pressed in towards the handle 14 indicates the iron is being held.

The iron 10 also includes a sole plate 18 partially surrounded by a protective wall 20, extending beneath the body 12 of the iron. The protective wall 20 extends around most of the circumference of the sole plate 18, apart from a small area 20a near the end of the iron, which is normally taken to be the front end.

In this particular embodiment, the sole plate 18 is formed of a flat piece of a metal such as stainless steel,

with imprinted tracks of conductive ink. Preferably, the sole plate is formed using the OPTECTM technology as incorporated within Russell Hobbs@ appliances such as kettles. OPTECTM uses a thick film printing technology to produce a heating element that is comparatively lightweight, with a low thermal mass and increased power density compared with conventional sole plates. Such conventional sole plates are normally formed of cast aluminium, or steel clad cast aluminium.

The OPTECTM design is relatively thin and lightweight, with the necessary rigidity for a sole plate being gained by sandwiching together sheets of compounds e. g. glass, steel and aluminium. Typically, the steel sheet forming the sole plate has a thickness of 0. 7mm or less. Such a design allows the sole plate to be heated rapidly to the desired temperature, utilises relatively little power to maintain the desired temperature, and cools rapidly after being heated.

In this particular embodiment, the iron shown is a steam iron, and hence the sole plate 18 incorporates steam outlets 19.

Figure 2A shows the iron in a typical horizontal rest position, being supported by the protective wall 20 resting on an ironing board 30. Figure 2B shows a close up of the circled area at the left hand side of figure 2A.

The trigger 16 is connected to the sole plate 18 with movement of the trigger 16 resulting in movement of the sole plate 18. In the preferred embodiment, the trigger 16 is mechanically connected to the sole plate 18 so as to

achieve this movement, but equally it will be appreciated that it could otherwise be connected (e. g. an electrical connection, with for instance the sole plate 18 being moved by an electro-mechanical actuator or an electric motor).

In the rest position shown, the trigger 16 is not depressed i. e. it is released, and hence projects outwardly from the handle 14 in the direction shown in the figure by the arrow A. This results in the sole plate 18 being in the raised position, elevated in the direction B in towards the body 12 of the iron, and consequently away from the surface of the ironing board on which the iron 10 is resting.

As the protective wall 20 extends around the majority of the sole plate 18, and extends away from the iron body 12 the iron rests in a stable position supported by the wall (or skirt) 20. Consequently, even if the sole plate is heated or still hot, it is unlikely to damage the surface of the ironing board.

The trigger 16 in this preferred embodiment has three nominal positions: a first position as shown in figure 2A in which the trigger is fully released; a second position as shown in figure 3 in which the trigger is fully pressed in towards the handle 14; and a third, intermediate position midway between the first and second positions, which corresponds to the trigger being partially depressed.

Figure 3 shows the iron in the working position, in which the trigger C is fully depressed (i. e. pressed in towards the handle 14 in the direction shown by arrow C). This results in the sole plate 18 being removed away from the body 12 of the iron in the direction shown by arrow D, such that the sole plate 18 extends beyond the ends of the surface of the wall 20 furthest away from the iron body 12.

This movement of the sole plate 18 allows the sole plate to used to smooth (i. e. iron) the material 32 into which it comes into contact, and which in this case is resting on the ironing board 30.

In this particular embodiment, the trigger 16 not only controls the movement of the sole plate, but also controls the power applied to heat the sole plate.

When the trigger is in the first position shown in figure 2A (i. e. fully released) the sole plate is in the raised position, retracted in close to the body 12 of the iron, and no power is applied to heat the sole plate 18.

When in the fully depressed position shown in figure 3, the trigger acts to move the sole plate 18 away from the iron, and also to result in power being applied to the sole plate so as to heat up the sole plate. When the trigger 16 is in the intermediate position (not shown) in which it is only partially depressed, the sole plate 18 is in the position shown in figure 2A, but power is applied to heat the iron.

As shown in close up in figure 2B, a portion of the sole plate 18a is not surrounded by the wall 20 when the

sole plate is in the retracted position. By heating the sole plate 18 (or preferably simply the portion of the sole plate 18a which extends beyond the area of the sole plate 18 surrounded by the wall 20), the portion of the sole plate 18a can be utilised at the edge of an ironing surface to iron small pieces of the material 32 e. g. the collars or cuffs on a shirt.

By controlling the heating of the sole plate as described above, power consumption of the iron is minimised. Further, the likelihood of the iron being a safety risk and burning articles and/or people is minimised, as due to the sole plate having a low thermal mass, the iron will only remain hot for a relatively small amount of time after use.

Thermal mass is the mass (weight) of the material multiplied by the specific heat capacity for that material. A conventional aluminium sole plate weighs 389

grams, and has a specific heat capacity of 9l3J/kgOCt and consequently has a thermal mass of approximately 355J/oC.

In contrast, a typical OPTECTM sole plate is mainly formed from steel, and only weighs approximately 117 grams, with a specific heat capacity of 450J/kg. Ct and so has low thermal mass of approximately 53J/ C. Preferably, a low thermal mass is of 150J/ C or less, and may be of 125J/ C or less, or 100J/ C, or even 75J/ C or less. Equally, a low thermal mass could be any range of thermal masses between 150J/ C and 1J/ C.

Further, as the majority of sole plate is only positioned to be in contact with the surface to be ironed if the handle is held by a user (and hence the trigger

fully depressed), then the risk of the sole plate causing damage is further minimised. Additionally, this allows the iron to be maintained in the more stable, horizontal position when not in use, rather than placed in the less stable position of resting on one end.

It will be appreciated that the above preferred embodiment is by way of example only, and various other alternatives within the scope of the present invention will be apparent to the skilled person.

For instance, whilst the above embodiment has described an iron as having a single detection means (i. e. trigger) arranged to detect when the handle is being held, and for this trigger to both control the heating of the sole plate and the new position of the sole plate, it will be appreciated that two separate detection means could be used to separately control these two functions. Equally, an iron could be provided that simply has either a low thermal mass sole plate, the heating of which is controlled by a detection means, or alternatively a sole plate of any thermal mass, the position of the sole plate controlled by a detection means.

In an alternative embodiment, the temperature of the sole plate of the iron is controlled by a detection means such as a button. When it is detected that the button is depressed (i. e. the iron is being held), then the sole plate is arranged to be heated to the operating temperature suitable for the desired ironing application.

However, when the button is not depressed, the iron is arranged to only heat the sole plate to a standby temperature. In other words, if a garment is being

ironed, with the button depressed, and then the button released then the sole plate will cool from the operating temperature to the standby temperature. This standby temperature could be a pre-determined temperature set by the iron manufacturer, or alternatively a temperature set by the user. The standby temperature can be arranged to be, for instance, 50 C.

Figure 4 shows the relationship of fingertip contact causing pain with time and temperature for a fingertip coming into contact with a metal. Such information can, for instance be found within BSI (British Standards Institute) publication PD6504: 1983,"Medical Information on Human Reaction to Skin Contact with Hot Surfaces". As can be seen, a metal at 50. C will not cause pain to a person touching the metal, even if a person touches the metal for ten seconds. Thus, the standby temperature is selected according to pre-determined criteria so as to minimise pain to people coming into contact with the iron, or alternatively could be selected to minimise damage to articles with which the sole plate is in contact. An iron having a low thermal mass sole plate and such a standby temperature thus has the same advantages of an iron with a low thermal mass sole plate to which heat is not applied when the iron is not being held. In other words, the sole plate will similarly cool rapidly to a temperature which will not damage a surface with which the iron is in contact and/or a person coming into contact with the sole plate. However, the iron having the standby temperature has the added advantage that when a user wishes to subsequently operate the iron again, the iron can be more rapidly heated to the operating temperature from the standby temperature (compared to an iron that would have

to be heated from room temperature i. e. 21. C to the operating temperature). Thus the heating of the iron to operating temperature can be achieved more rapidly, minimising inconvenience for the user.

It will be appreciated that the standby temperature can be selected depending upon the desired use of the

iron, and may, for instance, be 60. C or less, SO. C or indeed any temperature down to 30. C, and indeed any range of temperatures between 60. C and 30. C.

Whilst the detection means in this embodiment takes the form of a button, it could equally use other types or combinations of types of sensor e. g. a pressure sensor, or a sensor embedded within the handled arranged to detect a change in the resistivity or capacitance or inductance when the handle is being held. Equally, a light or other electro magnetic radiation detector (preferably coupled to a light or similar source) could be used to detect a change in the reflectivity or transmission when the handle is held.

In the first embodiment a skirt or wall 20 surrounds the majority of the sole plate 18, with the sole plate 18 retracting inwardly towards the body of the iron 12. Equally, however, the sole plate 18 could be fixably located with respect to the body of the iron 12, with a skirt or apron (or similar movement means such as legs or pegs) being moveable so as to extend out and retract back in towards the iron. Such a skirt or similar movement means could be resiliently biased, such that a pressure exerted by a user is required for the skirt to retract into the body (or even simply moved to a collapsed

position), so as to allow the sole plate to be moved to the preferred ironing position.

Further, an alternative embodiment of the iron comprises a protective wall (e. g. skirt or apron) extending completely around the circumference of the sole plate. In a steam iron, this would be advantageous as it would act to entrap the steam released by the iron (particularly when the iron is resting on a surface to be ironed), and hence help to improve ironing efficiency.

Such a completely enclosing protective wall would be particularly advantageous if resiliently biased, such that the pressure exerted by the user is sufficient so as to cause the wall to retract and/or collapse. This would allow the user to easily control how the steam is trapped/to what extent the steam is trapped by altering the pressure exerted downwards upon the iron and/or lifting the iron from the surface.

In yet another alternative embodiment, the base of the iron comprises a rotational surface to facilitate the movement of the iron over a surface on which the iron is resting. For instance, the movement means (e. g. the protrusion means) could comprise rollers or bearings.

Such rollers or bearings could be mounted around the circumference of the sole plate, or could be mounted within the skirt, pegs or protective wall extending around the sole plate. The use of such rotatable surfaces is particularly advantageous in cases where the protrusion means (i. e. the wall, skirt, pegs, rollers or bearings) is resiliently biased, as it permits the iron to rest on the surface to be ironed, and easily moved over the surface,

the sole plate only being moved into contact with the surface when pressure is exerted by the user.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment (s). The invention extend to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

Claims 1. An iron (10) comprising a handle (14) and a sole plate (18), wherein the iron (10) further comprises movement means (16,20) arranged to move said sole plate between at least two positions, a first position in which the sole plate (18) is arranged suitable for ironing a surface (32), and a second position in which at least a portion of the sole plate (18) is positioned such that a surface could not be ironed.
2. An iron as claimed in claim 1, wherein the sole plate is automatically positioned away from the surface if said handle is not held.
3. An iron as claimed in claim 1 or claim 2, wherein said movement means comprises a protective wall (20) extending at least partially around the circumference of the sole plate.
4. An iron as claimed in any one of the above claims, wherein said movement means comprises protrusion means arranged to extend from the iron such that, in a normal horizontal resting position, the iron including the sole plate would be elevated away from said surface.
5. An iron as claimed in any one of the above claims, wherein said protrusion means (20) is resiliently biased such that a pressure exerted by a user of the iron will result in the sole plate moving from said second position to said first position.

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6. An iron as claimed in any one of the above claims, wherein the iron further comprises a body, with the sole plate (18) being withdrawn into said body when in said second position.
7. An iron (10) comprising a handle (14) and a sole plate (18) of low thermal mass arranged to be heated to an operating temperature suitable for ironing, wherein the iron further comprises heating means arranged to heat said sole plate (18) to the operating temperature only when said handle is being held.
8. An iron as claimed in claim 7, wherein the sole plate has a thermal mass of less than 150 Joules/'C.
9. An iron as claimed in claim 7 or claim 8, wherein when the handle is not being held, the heating means is arranged to heat said sole plate to a standby temperature, the standby temperature being less than the operating temperature.
10. An iron as claimed in claim 7 or claim 8, wherein the heating means is be arranged to not heat said sole plate when said handle is not being held.
11. An iron as claimed in any one of claims 7 to 10, wherein said heating means can be switched between two modes, a first mode in which the heating means is arranged to heat the sole plate to the operating temperature only when said handle is being held, and a second mode in which the heating means is arranged to continuously heat the sole plate.

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12. An iron as claimed in any one of claims 7 to 11, wherein the iron further comprises detection means arranged to detect when said handle is being held.
13. An iron as claimed in claim 12, wherein the detection means comprises a button (16).
14. An iron as claimed in claim 12 or claim 13, wherein the detection means is arranged to detect a change in one or more electrical characteristics caused by the handle being held.
15. An iron as claimed in claim 14, wherein said electrical characteristics include inductance, resistivity or capacitance.
16. An iron as claimed in any one of claims 12 to 15, wherein said detection means comprises a pressure sensor arranged to detect pressure exerted by a user on said handle.
17. An iron as claimed in any one of claims 7 to 16, wherein the heating means comprises imprinted tracks of conductive ink.
18. An iron as claimed in claim 17, wherein said tracks are on at least one of the sole plate or on a plate in direct thermal contact with the sole plate.
19. An iron as claimed in claim 18, wherein at least one of said plates comprises a metal.