GB2419081A

GB2419081A - Food steamer with water treatment device

Info

Publication number: GB2419081A
Application number: GB0422690A
Authority: GB
Inventors: Christina Goodrick-Meech; Suzie Patel
Original assignee: Kenwood Marks Ltd
Current assignee: Kenwood Marks Ltd
Priority date: 2004-10-13
Filing date: 2004-10-13
Publication date: 2006-04-19
Also published as: GB0422690D0

Abstract

A food steamer 1 has a water reservoir 6 in communication with a heater 8 to produce steam. The steamer comprises water treatment means disposed to treat water to be heated in the heater to reduce the content of scale-producing or flavour-tainting materials therein. This water treatment device preferably comprises a filter medium contained within a cartridge device 10 which the water is constrained to flow through on its passage to a water reservoir 6. The cartridge 10 may be removed for cleaning or replacing. A mechanical or electrical indicator means may indicate the expiry of the useful life of the filter medium.

Description

1 2419081

FOOD STEAMER

This invention relates to food steamers and it relates especially, though not exclusively, to tiered steamer systems, wherein a plurality of food s support trays is stacked within an enclosure supported on a base containing a water heater, and arranged such that food on each tray can be subjected to steam issuing from the heater.

It is well accepted that steaming is a healthy and tasty way of preparing 0 certain foods, and current interest in healthy eating has promoted significant interest in domestic appliances of this kind. There are several such appliances available on the market, and most operate efficiently and are user-friendly. However, certain difficulties can arise in operation of such appliances, including tendencies for the heater efficiency to reduce over time, due at least in part to scale formation, and for water-borne chemicals, such as chlorine, to taint the flavour of food steamed therein.

It is an object of this invention to address such difficulties and, in accordance with one example of the invention there is provided a food steamer comprising at least one tray member for food to be steamed, a water reservoir in communication with an electrically operated heater arranged to generate steam; the heater having a steam outlet, support means for supporting the tray member so that food placed thereon can be exposed to the steam, and an enclosure enclosing the tray member and 2s the steam outlet, the steamer further comprising water treatment means disposed to treat water to be heated in the heater, such as to reduce the content of scale-producing and/or flavour-tainting materials therein.

Preferably, the water-treatment means comprises a filter medium contained within a cartridge device, and the steamer is configured to house said device in fluid communication with water added to said reservoir. Ideally, the water is constrained to flow through the filter medium in the device on its passage to said reservoir.

It is further preferred that the cartridge device is mounted so as to be readily removable from the steamer for replacement or recharging.

In particularly preferred embodiments of the invention, indicator means are provided for indicating expiry of the useful life of the filter medium, as a result of usage and/or effluxion of time. By this means, a user of the steamer is made aware of the need to refill or replace spent cartridges, to thereby ensure that an effective filter medium is at all times exposed to the water.

The indicator means may take any convenient form, such as a colour change associated with the medium itself, or an additive thereto; such an arrangement requiring part at least of a readily visible portion of the cartridge to be sufficiently transparent or translucent to permit a user to observe the colour change.

An alternative, or additional, indicator means may respond to motion of a part of the steamer that is opened, or otherwise moved, when water is to be added to the reservoir, or the steamer otherwise readied for operation. l

Some preferred embodiments of the invention, may comprise a ratchet mechanism linking the motion of said steamer part to a progressively mobile mechanical indicator; for example, one of the same general kind as that disclosed in EP-0756583-B1 and EP-0861809-B1. s

It is further preferred, however, that electrical signals indicative of motion of the said part are generated, and supplied to an electronic indicating device, such as a liquid crystal display (LCD) device, and/or one or more light-emitting diodes (LEDs). Microprocessor devices may be employed in known manner to drive such electronic indicating devices.

A particularly preferred embodiment of the invention detects the switching on of power to the steamer as a primary indication of usage, whereby electrical signals indicative of such switching operations are generated and an electronic display indicative of usage of the steamer is derived therefrom.

In all embodiments of the invention utilising electrical or electronic indicator means, such electrical power as may be required to drive components such as sensors, displays and microprocessors may be derived from the mains electricity supply (suitably processed as necessary), or any or all such components may be battery powered.

Preferably, the power is primarily derived from the mains supply, but is 2s backed up by battery in case of mains failure, or to allow for prolonged periods of non-use. l

In all embodiments, the water reservoir may be supplied with water either directly through a filler orifice or indirectly by way of a removable tank, which may be carried to a water tap for filling. If a removable tank is used, it is preferably provided with means whereby the water level s therein is rendered readily visible to a user. Such means may comprise the use of a transparent or translucent medium for part of the tank itself, or the incorporation of one or more windows through which the water level can be discerned. The tank and/or the window may advantageously bear capacity markings to enable a user to readily decide when the tank lo should be filled or topped up with water.

In any of the foregoing embodiments of the invention, it is advantageous, though not essential, to trap and recycle condensed steam.

In order that the invention may be clearly understood and readily carried into effect, certain embodiments thereof will now be described with reference to the accompanying drawings, of which: Figure I shows, in side elevation and in part cross-sectional view, a steamer in accordance with one example of the invention; and Figure 2 shows, in similar view to Figure 1, the base part of a steamer in accordance with another example of the invention.

2s Referring now to Figure 1, there is shown a steamer in accordance with one example of the invention. It will be appreciated that, since many components of the steamer illustrated are conventional, such components s will either not be referenced at all or, if mentioned, will not be described in detail.

The steamer is shown generally at 1, and comprises at least one tray s member, or basket, such as 2 for food to be steamed, supported within a casing 3 with a lid 4; the casing 3 being mounted on a base 5. Mounted within the base 5 are primary and secondary water reservoirs 6, 7 respectively, and an electrically operated heater 8 comprising a tubular, through-flow water heater of known kind. The heater 8 is plumbed into 0 fluid communication with the reservoir 7 and arranged to heat water supplied to it from the reservoir in order to generate steam, which issues into the enclosure formed by the ridded casing 3 by way of a steam outlet 9.

In this example, three baskets such as 2 are provided for presenting food to be steamed, and these are supported in any convenient manner so that food placed thereon can be exposed to the steam. If desired, as is known, the steam outlet 9 may be coupled to a centrally located tube, or chimney, (not shown) extending upwardly within the casing 3 and configured to promote the supply of steam to the locations occupied by the baskets 3; the baskets being centrally apertured to accommodate the chimney.

In any event, the steamer of Figure 1 further comprises a water treatment means disposed to treat water to be heated in the heater.

The water treatment means in this example comprises a cartridge 10 containing a water treatment medium intended to reduce the content of scale-producing and/or flavour-tainting materials therein. In this example, the filter cartridge 10 is positioned such that its lid lea which, s in known manner, is configured to comprise a water inlet to the cartridge, is disposed at a low point of the primary water reservoir 6. Water filtered through the water treatment medium within the cartridge 10 fills the secondary reservoir 7, which is connected by a water outlet tube 11 to the inlet of the heater 8.

It will be observed that the water outlet tube 11 is plumbed to an upper region of the reservoir 7. This configuration is used particularly for cartridges whose water-filtration media are intended to be kept constantly wet. For alternative media, the plumbing of the tube l l may differ.

A user of the steamer 1 can add water to the primary reservoir 6 by way of a fill aperture 12 provided in the base 5, and it is also preferable for the steamer to be configured such that condensate from the steaming operation is caught in a perforated tray member 13 and channelled therefrom into the primary reservoir 6 for re-cycling.

It will be appreciated that the cartridge 10 is mounted so as to be readily removable from the steamer for replacement or for recharging of the water-treatment medium therein. 2s

In this respect, it is of importance for a user to know when to replace or recharge a filter cartridge, in order to ensure that an effective filter medium is at all times exposed to the water, and thus an indication of actual or forthcoming expiry of the useful life of the filter medium, as a result of usage and/or effluxion of time, is preferably provided.

s Such an indication may take any convenient fount, such as a colour change associated with the medium itself, or an additive thereto; such an arrangement requiring part at least of a readily visible portion of the cartridge to be sufficiently transparent or translucent to permit a user to observe the colour change.

Alternatively or additionally, the indication may be provided by a specific indicator means located on the base 5 of the steamer. Such an indicator means may respond, for example, to motion of a part of the steamer (such as a flap or lid (not shown) covering the water inlet 12) that is opened, or otherwise moved, when water is to be added to the reservoir, or when the steamer is otherwise readied for operation. In such circumstances, the indicator means may comprise a ratchet mechanism linking the motion of said steamer part to a progressively mobile mechanical indicator; for example, one of the same general kind as that disclosed in EP-0756583-B1 and EP-0861809-B1.

In the embodiment of the invention shown in Figure 1, however, electrical signals indicative of motion of the said part are generated by any convenient means, such as one or more magnetic reed switches which are not shown, but are well known in the art, and supplied to en electronic indicating device, such as a liquid crystal display (LCD) device 14, and/or one or more light-emitting diodes (LEDs).

Microprocessor devices may be employed in known manner to process the electrical signals and to drive such electronic indicating devices.

Instead of generating electrical signals in response to the motion of said part of the steamer, it is preferable in some respects to detect the switching on of electrical power to the steamer as a primary indication of usage, whereby electrical signals indicative of such switching operations are generated and the indication provided by the electronic display 14, indicative of usage of the steamer, and thus the likely condition of the lo water treatment medium, is derived therefrom.

However the signals are generated, a preferred configuration is for the display 14 to show an accumulating count representing the actual number of uses of the steamer, or a decrementing count, indicating how many uses can be tolerated before replacement of the cartridge is advisable. In addition, a day-by-day background count, purely indicative of elapsed time since the previous installation of a cartridge, is preferably performed by the microprocessor, and used to display, either by means of the LCD itself, or by illumination of an adjacent LED, when the cartridge fill has time-expired. In some embodiments, it may be preferred to show the elapsed time count as the principal display and to use a usage- related count as a back-up.

Clearly alternative or additional warnings, such as audible warnings, can 2s be provided if preferred; any audible warning preferably (once having been actuated) being operative to sound each time the steamer is switched on until the cartridge is replaced. In this respect, the audible alarm may operate for a fixed time period and/or be capable of being switched off by means of a user-operated cancellation button, effective until the next switching-on of the steamer.

s In all embodiments of the invention utilising electrical or electronic indicator means, such electrical power as may be required to drive components such as sensors, displays and microprocessors may be derived from the mains electricity supply (suitably processed as necessary to effect functions such as voltage reduction and stabilization), or any or all such components may be battery powered. Preferably, the power is primarily derived from the mains supply, but is backed up by battery in case of mains failure, or to allow for prolonged periods of non- use.

In the embodiment of the invention shown in Figure 2, wherein all components common to Figure 1 carry corresponding reference numbers, the secondary water reservoir 7 is supplied with water indirectly by way of a removable tank 15, which may be carried to a water tap for filling. If a removable tank such as 15 is used, it is preferably provided with means whereby the water level therein is rendered readily visible to a user.

Such means may comprise the use of a transparent or translucent medium for part of the tank itself, or the incorporation of one or more windows through which the water level can be discerned. The tank and/or the window may advantageously bear capacity markings to enable a user to readily decide when the tank should be filled or topped up with water.

The water outlet tube 11 is, in this instance, plumbed in near the base of the secondary reservoir 7. If it is necessary to maintain the filter medium in cartridge 10 in a permanently wet condition, a weir arrangement is provided by a wall 16. s

In general terms, it will be appreciated that the relative dimensions of the primary and secondary water reservoirs, or of the tank and the secondary reservoir in the case of Figure 2, can be adjusted as required to suit any set of operational and/or design criteria for the steamer, and no criticality is ascribed thereto. Furthermore, there are many electronic and mechanically driven displays known in the art of water- filter usage indication (for example, from the art of jug-based water filter units used in the home) and it is not intended to exclude any viable display technique from the scope of this invention.

Claims

CLAIMS: 1. A food steamer comprising at least one tray member for food to

be steamed, a water reservoir in communication with an electrically operated heater arranged to generate steam; the heater having a steam outlet, support means for supporting the tray member so that food placed thereon can be exposed to the steam, and an enclosure enclosing the tray member and the steam outlet, the steamer further comprising water treatment means disposed to treat water to be heated in the heater, such lo as to reduce the content of scale-producing and/or flavour-tainting materials therein.

2. A food steamer according to claim 1 wherein the water-treatment means comprises a filter medium contained within a cartridge device, and the steamer is configured to house said device in fluid communication with water added to said reservoir.

3. A food steamer according to claim 2 wherein water is constrained to flow through the filter medium in the device on its passage to said reservoir.

4. A food steamer according to claim 2 or claim 3, wherein the cartridge device is mounted so as to be readily removable from the steamer for replacement or recharging. 2s

S. A food steamer according to any preceding claim, wherein indicator means are provided for indicating expiry of the useful life of the filter medium, as a result of usage and/or effluxion of time.

s 6. A food steamer according to claim 5, wherein said indicator means comprises a colour change associated with the medium itself, or an additive thereto, and wherein part at least of a readily visible portion of the cartridge is sufficiently transparent or translucent to permit a user to observe the colour change.

7. A food steamer according to claim S or claim 6, wherein said indicator means is conditioned to respond to motion of a part of the steamer that is opened, or otherwise moved, when water is to be added to the reservoir, or the steamer otherwise readied for operation.

8. A food steamer according to claim 7, wherein said indicator means comprises a ratchet mechanism linking the motion of said steamer part to a progressively mobile mechanical indicator.

9. A food steamer according to any of claims S. 6 or 7, further including means for generating electrical signals indicative of motion of the said part, and for supplying said signals, or signals derived therefrom, to an electronic indicating device.

10. A food steamer according to any of claims S. 6 or 7, further including means for generating electrical signals indicative of the switching on of power to the steamer, and for supplying said signals, or signals derived therefrom, to an electronic indicating device.

11. A food steamer according to claim 9 or claim 10, wherein said electronic indicating device comprises a liquid crystal display (LCD) device, and/or one or more light-emitting diodes (LEDs).

12. A food steamer according to any of claims 9, 10 or 11, further including a microprocessor device to drive said electronic indicating lo device.

13. A food steamer according to any of claims 9 to 12, wherein electrical power required for said electronic indicating device is derived from the mains electricity supply.

14. A food steamer according to any of claims 9 to 13, wherein said electronic indicating device is battery powered.

15. A food steamer according to any preceding claim, wherein said water reservoir is supplied with water directly through a filler orifice.

16. A food steamer according to any one of claims l to 14 wherein said water reservoir is supplied with water indirectly by way of a removable tank.

17. A food steamer according to claim 16 wherein said tank is provided with means whereby the water level therein is rendered readily visible to a user.

18. A food steamer substantially as herein described with reference to and/or as shown in the accompanying drawings.