GB2345840A

GB2345840A - Method and apparatus for removing water stains from tableware

Info

Publication number: GB2345840A
Application number: GB0001196A
Authority: GB
Inventors: Omar Osman
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-01-20
Filing date: 2000-01-19
Publication date: 2000-07-26
Also published as: GB0001196D0; GB9901239D0

Abstract

Apparatus for removing water stains from otherwise clean items of tableware, e.g. cutlery, comprises a tray (22) for receiving the items (20); a bath (36) containing a cleansing liquid (e.g. acidifide water) into which the tray (22) and cutlery (20) may be immersed; means (40) for agitating the cleansing liquid, e.g. by means of air bubbles, and air blast equipment (30) for blasting cleaning liquid from the cutlery after it has been removed from the bath (36). The apparatus may be embodied into a format similar to that of a batch dishwasher and obviates the task commonly performed in high class restaurants and hotels of hand polishing cutlery and tableware items to remove water stain. The cleanser is preferably a weakly acidic aq. solution e.g. of acetic acid or it may simply be softened water.

Description

METHOD AND APPARATUS FOR REMOVING WATER STAINS FROM TABLEWARE The present invention relates to a method and apparatus for removing water stains from tableware.

Tableware, including crockery, cutlery and glassware, which is washed and dried following use in a restaurant or hospitality concern, for example, is often water-stained. One reason for this is that the tableware is not dried, for example, with a tea-towel, while it is still damp. Instead, it is typically the practice to let water evaporate from the tableware following washing.

In larger restaurants, washing of tableware is done using an industrial-type dishwasher, whereas in smaller establishments, tableware may be washed by hand. In both instances, the washed tableware is probably hygienically clean. However, the presence of water stains, particularly on cutlery and glassware where it is most noticeable, is unsightly to diners and may create a poor impression of the restaurant and reduce dining pleasure.

It is not known exactly what causes the water stains, but it is thought to be soluble or insoluble solids derived from hard water solutes or detergent residues.

In practice, the water stains on tableware are typically removed by hand. This involves dipping the water-stained item into hot water and polishing it with a clean cloth to remove the water stain. In a restaurant seating seventy diners, a kitchen assistant may spend routinely two-to-three hours each day polishing water stains from cutlery. This leads to an uneconomic use of the kitchen assistant's time, which may run to many thousands of pounds a year.

I have investigated industrial dishwashers presently available on the market, and I have not found any machine that is designed to remove water stains from tableware. I have now found a readily automatable way of removing water stains by dislodging them with a liquid cleanser and then removing the cleanser from the tableware, whereby the problem of water-stained tableware is solved or reduced.

According to one aspect of the present invention, there is provided an apparatus in use for removing a water stain from an item of tableware, which apparatus includes a support for the tableware, a means for applying a liquid cleanser to the tableware, and a means for removing the cleanser from the tableware, wherein the tableware is free of water stains following removal of the cleanser.

The support may be a continuous web such as a conveyor belt for transporting tableware from a first position at which liquid cleanser is applied to a tableware surface to a second position at which the cleanser is removed from the tableware surface, or may be a tray onto which the tableware can be loaded for treatment. The tray may be moved to a first position at which liquid cleanser is applied to the tableware and thereafter to a second position at which the cleaner is removed from the tableware surface. Alternatively, the tray may remain at a single location and sequentially be treated to apply liquid cleanser to the tableware and remove cleanser from the tableware.

Preferably, the support vibrates or shakes such that, when cutlery, for example, is placed on it, the cutlery moves under influence of the shaking motion thereby exposing more of the cutlery to a cleanser application means or a cleanser removal means.

The continuous web may include holes, for example, it may be a flexible mesh-like material. In this embodiment, cleanser may be applied to the tableware from below the web i. e. through the web, and/or from above the web i. e. directly onto the tableware supported by the web. Equally cleanser removal means may be directed at the tableware supported by the web from above and/or below, i. e. through, the web.

The support may be a mesh-like structure made from, for example, plastics material. The support may be designed to receive the tableware arrange vertically or horizontally relative to the horizontal. The tableware may be adapted to be received in individual wells or stations arrayed in the support, or adapted to be supported in groups throughout the support. I prefer that when the tableware is cutlery a user does not have to separate each cutlery item into an individual well or station as this increases the loading time.

In an alternative embodiment, the support includes a drum, the drum being made up of individual stations for receiving tableware such as cutlery, the stations being arrayed around the drum. In this embodiment the drum is pivotably mounted within a chamber. A cleanser application means is directed into the chamber so as to contact the tableware inserted in the stations. Cleanser applied to the tableware in the chamber is removed by spinning the drum. The drum may be perforated, for example, as a mesh made of e. g. plastics material. Cleanser removed from the tableware by centripetal forces applied during spinning of the drum may drain through the mesh, and be collected in a sump in the chamber. It is important in this embodiment that the drum is balanced so that the weight of tableware placed around the drum does not cause vibration and wear on bearings when it is spun.

In a particularly preferred embodiment, the means for removing cleanser from the tableware surface is an air blast, for example from an air knife i. e. a highly directional blast of air which blows the cleanser from the tableware surface and substantially does not evaporate cleanser from the surface of the tableware.

The means for applying the cleanser may take several forms. For example, the cleanser may be held in a bath into which the support and tableware are dipped. In this embodiment, the apparatus may include the feature of vibrating the support following dipping, so that cleanser is shaken from the surface of the tableware supported thereon. The cleanser may also be agitated by blowing compressed gas, e. g. air through it to aid in dislodging the water stain.

Alternatively, the cleanser may be applied to the tableware as a finemist spray or as a jet of cleanser or as hot vapour.

The cleanser may be treated to remove water hardness which may be a cause of water stains. For example, the cleanser may be mains water which has been softened with a suitable de-ionising or water softening treatment. Of course, if the cleanser is to be physically removed from the surface of the tableware, e. g. by an air blast or by or spinning, treatment of the cleanser is less important and the cleanser may be untreated mains water, whether hard or soft.

Preferably the cleanser is a solvent i. e. a liquid capable of solubilising the water-stain. Suitable solvents include a weakly acidic aqueous solution capable of neutralising basic salts which are the cause of hard water and possibly water stains. This acidic aqueous solution may be acetic acid for example and preferably the solvent is in the pH range of from 2 to 5 and most preferably 3 to 4. The acidic component of the acidic aqueous solution may be made by introducing a concentrate such as a tablet or solution to mains water for example.

The cleanser may be circulated in the apparatus so that it is reused for several water stain removal cycles. This cuts down on cleanser wastage.

However, it is important to monitor cleanser quality so that, for example, for softened mains water or aqueous acidic solution cleanser the recycled cleanser remains within predetermined tolerances for effective stain removal e. g. pH and ionic content. If the properties of the cleanser detected fall outside the predetermined working ranges, fresh cleanser can be made up. Alternatively, the original cleanser can be further treated, for example, by passing the used cleanser through the water softening cycle, or by addition of further acidic concentrate.

It is possible for the cleanser to be an aqueous acidic solution made up with de-ionised or softened water. If this cleanser is treated following use, it is important that the acid and pH chosen do not react with the water softening treatment filters.

The means for removing the cleanser from the tableware may be by air blower, preferably by hot air blower, for example. This method is particularly preferred if the cleanser includes softened water or is the weakly acidic aqueous solution, since we have found that when the cleanser is either of these two, cleanser evaporated from the surface of the tableware leaves no or minimal water stains.

Alternatively, the cleanser may be applied to the tableware at elevated temperatures for example 75-80 C or as a vapour such that when the tableware is exposed to a reduced temperature, but non-saturated atmosphere, the inherent temperature of the tableware evaporates the cleanser from the surface of the tableware. Once again, this means of removing the cleanser is preferably used in conjunction with softened water cleanser, or an acidic aqueous solution solvent.

The skilled person will note that the use of high temperatures will also prevent bacterial growth and that of certain other pathogens.

Alternatively, the means for removing the cleanser may include a buffing wheel, which may be deep-pile for extra absorbency, although this is less preferred than the air-knife embodiment.

In a further aspect, the invention provides a method of removing water stains from tableware, which method comprises dislodging the water stain with a liquid cleanser (as herein defined), and removing the cleanser from the tableware, wherein the method is fully automated.

The steps of the method are preferably controlled electronically in much the same way as a dishwasher or clothes washing machine may be programmed with washing cycles suitable for different items.

The apparatus and method of the present invention are preferably for removing water stains from glassware, and most preferably cutlery.

In a further aspect, the invention provides for the use of an apparatus in a method according to the present invention. The apparatus in this aspect of the invention may comprise a known dishwasher, for example. In another aspect, there is provided a dishwasher when used in a method according to the present invention.

In order that the invention may be more fully understood, an embodiment thereof will now be described with reference to the accompanying drawing, in which: Figure 1 is a part cut away schematic side elevation of an apparatus according to the present invention.

Apparatus 10 is a tableware water stain remover. In terms of size and shape it resembles a dishwasher and is suitable for insertion below work-top level although certain smaller embodiments may be for use on a work-top. The tableware water stain remover apparatus unit 10 requires a water supply for example from mains supply 12 and has a drain 14 for removal of used cleanser.

The unit basically comprises a chamber 16 closeable by a door 18 into which chamber 16 is placed water-stained tableware such as cutlery 20. The cutlery 20 is supported vertically in individual wells (not shown) in a plastic mesh tray 22, each well being capable of receiving a plurality of cutlery items. The tray 22 is removable so that it may be loaded with cutlery 22 prior to insertion in the unit 10. When the tray 22 is inserted into the chamber 16 inter-engaging members 24 at either end thereof engage with carriage 26. One inter-engaging member 24 is eccentrically mounted on a rotor of a motor (not shown) and the other member 24 is floating, such that turning the rotor causes the tray 22 to shake or vibrate.

Cone shaped bodies 28 project into the chamber 16 from the chamber wall. These each include air lines 30 which comprise part of air knife apparatus 32. This apparatus 32 further includes a high speed fan 34 to draw an air from the exterior of the unit 10 to the air lines 30.

A liquid cleanser bath 36 is disposed below the tray 22 and is adapted to receive it. The bath 36 is filled with a liquid cleanser 38 in use. The cleanser may be treated mains water, for example, water which has been deionised or softened by passing it through a water softening or de-ionising unit (not shown).

The floor of the bath 36 includes bubble jets 40 for creating many fine bubbles in the cleanser 38. In this particular embodiment, the cleanser is not heated above ambient temperature. Air for supply to the air jets 40 is from the high-speed fan 34 via an air line 42.

The front of the unit 10 includes buttons 44 and a dial 46 and these are linked to the units pre-programmed electronics (not shown) for controlling operation of the machine. This enables a water stain removal cycle to be chosen by a user. The dial may indicate the progress of the cycle.

In use the tray 22 is lowered into the bath 36 as the carriage 26 descends. Cleanser 38 covers the water-stained cutlery 20 and air is bubbled through the cleanser to dislodge the water stains.

The carriage 26 then rises removing the tray 22 and supported cutlery 20 from the cleanser 38 to their original starting position. The tray 22 is then shaken to remove cleanser from the tableware, and air knife apparatus 32 then blows excess cleanser from the surface of the cutlery. The cutlery 20 resulting from the treatment described is substantially free from water stains and ready to be set on a table of a restaurant, for example.

Whilst we have exemplified an embodiment of the apparatus in relation to cutlery, the skilled person will appreciate that other tableware such as glassware or crockery may be used in the apparatus.

Claims

CLAIMS: 1. Apparatus for use in removing water stain from items of tableware, the apparatus comprising a support for the tableware ; means for applying a liquid cleanser to the tableware to dissolve water stain on the tableware; and means for removing the cleanser from the tableware to leave the tableware free of water stains.
2. Apparatus according to claim 1 wherein the means for applying a liquid cleanser to the tableware comprises means for spraying the tableware with liquid cleanser.
3. Apparatus according to claim 1 wherein the means for applying a liquid cleanser comprises means for immersing the tableware in liquid cleanser.
4. Apparatus according to claim 3 including means for agitating the liquid cleanser to assist in removal of the water stains.
5. Apparatus according to claim 4 wherein the means for agitating the water comprises means for bubbling compressed gas, preferably air, through the liquid cleanser.
6. Apparatus according to any preceding claim wherein the means for removing liquid cleanser comprises means for blasting air at the tableware to blow liquid cleanser from the tableware.
7. Apparatus according to claim 6 wherein the air blast means comprises an air knife.
8. Apparatus according any preceding claim wherein the support comprises a tray for receiving tableware to be treated and comprising means for lowering the tray into a bath of cleansing liquid.
9. Apparatus according to claim 8 wherein the apparatus includes a casing defining a bath for the cleansing liquid and a carriage for receiving the tray, the carriage being lowerable to immerse the tray in cleansing liquid and raisable to remove the tray from the cleansing liquid.
10. Apparatus according to claim 8 or claim 9 including means for vibrating or shaking the tray.
11. Apparatus according to any of claims 8-10 including air blast means for blasting cleansing liquid from tableware supported in the tray.
12. A method of removing water stain from tableware comprising treating the tableware with a cleansing liquid which will dissolve the water stain and removing the cleansing liquid from the tableware.
13. A method according to claim 12 wherein the cleansing liquid is acidifide water
14. A method according to claim 12 or claim 13 wherein the cleansing liquid is removed from the tableware by means of an air blast.
15. Apparatus for removing water stains from items of tableware, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
16. A method of removing water stain from items of tableware substantially as hereinbefore described with reference to and as shown in the accompanying drawings.