GB2143012A - Dish drying apparatus - Google Patents

Abstract

A dish drying apparatus comprising a rack portion (12) in which plates, cutlery etc., can be stacked and an electrically driven, hot air blower (16) disposed so as to direct hot air over such plates, cutlery etc., in the rack portion. The rack portion and the hot air blower are combined to form a free-standing, self-contained unit. <IMAGE>

Description

SPECIFICATION Improvements in dish drying apparatus The present invention is concerned with an apparatus for drying dishes and the like.

In the description which follows, the term "dish drying" is intended to cover not lust the drying of plates but also all other domestic cutlery, plates, cups, saucers, glasses and the like.

The conventional form of dish drying apparatus comprises merely an open rack in which plates, cutlery etc. are stacked, or otherwise arranged, so that they dry gradually under atmospheric conditions. This means, of course, that they can take quite a long time to dry. The alternative is to dry each article individually with a cloth. This practice has, however, become less popular due to its inherently lower hygienic standards, relying as it does on the standard of cleanliness of the cloth used. Furthermore, the articles - glasses in particular - tend to smear when dried naturally or with a cloth.

It is of course also known for dishes to be dried within an automatic dishwasher by convected heat provided by electrical heating elements after the termination of the washing cycles. Such machines are still relatively expensive, however. They are also expensive to run so that they are usually only run with a full load.

It is an object of the present invention to provide an apparatus in which washed dishes can be forcibly dried but which is relatively simple and much cheaper in comparison with an automatic dishwasher.

In accordance with the present invention, there is provided a dish drying apparatus comprising a rack portion in which plates, cutlery etc. can be stacked and one or more electrically driven, hot air blowers disposed so as to direct hot air over such plates, cutlery etc. in the rack portion, the rack portion and hot air blower(s) being combined to form a freestanding, self-contained structure.

Steps must be taken to ensure that the or each hot air blower is fully protected against the ingress of the free water which is inevitably present in the environment in which dish washing and drying equipment is likely to be used. To this end, the blower(s) is preferably contained within a housing of electrically insulating material with a suitably tortuous air path between the blower heating element and the blower outlet communication with the rack portion, whereby any free water entering the hot air supply outlet is reliably prevented from reaching the blower heating element(s). Sloping paths, which slope away from the blower inlet, can also be included for this purpose.

The hot air blower(s) can be disposed at any suitable angle so as to direct the hot air over the articles to be dried but, advantageously, is mounted above the level of the rack so as to direct hot air generally downwardly. Suitable ducting can, if necessary be included to assist in leading the hot air from the or each blower to the rack portion.

The invention is described further hereinafter, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic perspective view of one embodiment of a dish drying apparatus in accordance with the present invention; Figure 2 is a diagrammatic sectional view through the apparatus of Figure 1; and Figure 3 is a diagrammatic perspective view of a second embodiment in accordance with the invention.

The apparatus 10 of Figures 1 and 2 has a rack portion 12 of similar construction to that used in conventional dish racks where the dishes are to be dried under atmospheric conditions. As shown in the drawings, the rack portion 12 enables a plurality of articles such as plates, cutlery etc. to be stacked in an upright condition so that there is at least a small gap between each article to enable air to circulate freely around same. Holes 14 are provided in the base of the rack portion 12 to enable free water draining from the articles to pass through to the draining board on which the apparatus would normally be positioned. The holes 14 are preferably placed at the front of the rack to enable the rack to be used on a work top.

The apparatus 10 also includes an electrical heater 16 which incorporates a blower adapted to direct hot air, in the direction of a rrows A, over the articles stacked in the rack portion 12.

The heater can take many forms. In the embodiment of Figures 1 and 2, it comprises one or more mains-driven hot air blowers 18 mounted within a housing 20 having an air inlet grill 22 in its upper surface, preferably at the back to avoid water access, and an air outlet grill 24 in its side surface facing the rack portion 12. Hot air is directed generally horizontally towards the rack portion 12 so as to pass over and around the stacked articles 23.

Particular attention must be given to the electrical isolation of the blower or blowers 18 and for this purpose it or they are mounted well clear of the base 26 on insulated pillars 28. Further drain holes 30 are provided in the base 26.

In other embodiments, the housing 20 may include special ducting (not shown) for leading the hot air from the or each blower to the grill 24. Such ducting may, for example, include a water trap to ensure that the possibility of water getting to the blowers is fully eliminated.

In the embodiment of Figure 3, the housing 32 for the hot air blower, or blowers, is mounted above the level of the plate rack portion 34 whereby the or each hot air blower (not shown) can be directed generally downwardly. This arrangement has the advantage of being intrinsically safer from the electrical insulation point of view in that it is much easier to arrange for the blower to be fully isolated from contact with free water.

It is to be understood that many other configurations of rack and heater are possible and the invention is not limited to those illustrated.

Advantageously, the rack portion and heater housing are formed from moulded plastics components although other materials can conceivably be used.

The rack portion can be embraced by a surround (not shown) which can be integral with the rack or removable therefrom for easy cleaning.

Various steps may be taken to improve the electrical safety of the device. The problem is that it has to work in an environment wherein the presence of free water, even if only in the form of occasional water droplets, is inherent. As explained above, the blower(s) can be mechanically isolated from the ingress of water by the use of shrouds, covers, pillars and tortuous ducting paths. In the course of normal usage, these measures would be quite sufficient to enable safe operation by the user.

However, where one has to take account of worstcase situations, then further steps are preferable.

Most such problems can be overcome if the apparatus is arranged to be electrically deactivated in the event that the apparatus is displaced from its operational position, whether by being lifted or simply by it sliding or being knocked.

A first solution to this problem is to include a simple switch, for example in the form of an conventional microswitch, in or on the body of the apparatus, the arrangement being that the switch is activated by engagement with the surface on which the apparatus is to operate so as to supply mains voltage to the blower(s). However, in the event that the apparatus is lifted by whatever means, such that the switch is deactivated, then the mains supply is cut off from the blower(s). The arrangement can be that once deactivated by this switch, the electrical circuit has to be re-set by a suitable reset button before it can be re-used. The switch body can be disposed at a position remote from the base of the apparatus if, for example, the switch operating button has a suitable extension.

A problem with this solution is that, even though the blower has been deactivated, the mains is still present in the body of the apparatus so that in the worst-case situation that the apparatus should become wholly immersed in water, an extremely dangereous situation could arise.

In order to avoid this, it is necessary to arrange for the mains supply itself to be isolated from the body of the apparatus in the event that an undesirable operating situation is detected by the switch.

One possibility for overcoming this problem is shown diagrammatically in Figure 4. In Figure 4, the body of the apparatus is denoted by the reference numeral 36, the blower(s) by the numeral 38 and the switch by the numeral 40. The switch 40 can be a simple mechanical switch responsive to the position of the apparatus or could be a moisture detector, or a tilt detector (mercury operated switch) or indeed any other form of detector adapted to respond to a predetermined undesired operating condition of the apparatus. The common characteristic of all such sensing devices is, however, that they should be arranged for low voltage working, preferably about 3 to 9 volts D.C. The D.C. supply for the sensing device is established in a control unit 42 disposed remote from the body 36 of the apparatus.Preferably, although not essentially, the control unit is formed integrally with the mains plug so that it is plugged directly into the mains supply socket, for example a wall-mounted socket 44.

Contained within the control unit 42 is a simple means of deriving a low voltage (preferably stabilized) D.C. supply. This D.C. supply is carried to the main body of the apparatus by the provision of further wires 46 in addition to the mains wires 48 leading to the blower(s) 38. The wires 48 and 46 are preferably in a single cable but could be in a double cable if desired. The arrangement in the control unit 42 is such that mains voltage is only supplied to the wires 48 when a predetermined low voltage signal is supplied back to the control unit by the sensor device 40. In the event that the sensor detects an undesirable condition, the mains supply can therefore be isolated altogether from the main body of the apparatus.

Simple switching circuits, for example using silicon controlled rectifiers (5CRs),forthecontrol of A.C. mains by the presence or absence of low level D.C. are well known and need not be described in detail herein.

Using such an arrangement, the electrical safety of the apparatus is increased considerably since, in the event of an undesirable condition occuring, the main body of the apparatus is completely isolated from the main supply. Suitable fuses can also be incorporated to increase the ability of the apparatus to become isolated in the event of malfunction or mishap.

Claims (10)

1. A dish drying apparatus comprising a rack portion in which plates, cutlery and the like can be stacked, and one or more electrically driven, hot air blowers disposed so as to direct hot air over such plates, cutlery and the like in the rack portion, the rack portion and hot air blower or blowers being combined to form a free-standing unit which is self-contained other than for the supply of suitable electrical power.

2. A dish drying apparatus as claimed in claim 1 wherein the or each blower is contained within a housing of electrically insulating material, hot air being discharged towards the rack portion by way of a blower outlet.

3. A dish drying apparatus as claimed in claim 2 wherein the air drawn over the heating element of the blower(s) is arranged to follow a tortuous path before being discharged towards the rack portion via said blower outlet, such that any free water entering said blower outlet is prevented from reaching said heating element.

4. A dish drying apparatus as claimed in claim 1 including ductwork for leading the hot air from the blower(s) to said rack portion.

5. A dish drying apparatus as claimed in claim 1 where the hot air blower(s) is disposed above the level of said rack portion and is angled so as to direct the hot air generally downwardly over items in the rack portion to be dried.

6. A dish drying apparatus as claimed in claim 1 wherein the or each blower is contained within a housing of electrically insulating material, said housing and rack portion comprising an integrally moulded unit.

7. A dish drying apparatus as claimed in any of claims 1 to 6 including a switching means in or on the apparatus which is adapted to connect the electrical supply to the blower or blowers only in the event that the apparatus is in its operational position and/or orientation.

8. A dish drying apparatus as claimed in claim 7 in which the switching means is a mechanical switch whose switching member is adapted to engage or be coupled to the surface on which the apparatus is to operate, such that if the switch is deactivated by movement of the apparatus relative to said surface then the electrical supply to the blower(s) is cut off.

9. A dish drying apparatus as claimed in any of claims 1 to 6 including a detecting means in or on the apparatus and adapted to be responsive to a predetermined operating or positional condition of the apparatus, the detecting means being powered by a low voltage supply established in a control unit disposed remotely from said free-standing unit, and the blower(s) being arranged to receive mains driving voltage via said control unit only in the event that said predetermined operating or positioned condition, as detected by said detecting means, is present, whereby the free-standing unit is completely isolated from the mains supply when said predetermined operating or positional condition is absent.

10. A dish drying apparatus substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.