GB2221385A - Dishwasher - Google Patents

Abstract

There is disclosed a dishwasher (10) which comprises an open-topped tank (11) which takes the form of a sink, but with a larger bowl than normal, and a cover (12) which is removable in order to allow dirty articles to be loaded into the tank and cleaned articles to be removed from the tank. Air nozzles (13) are arranged in a lower portion of the tank, and an air pump is connected nozzle and is operable, when the tank contains washing liquid, to pump air via the nozzles and through the liquid thereby to promote the washing action applied to the articles. <IMAGE>

Description

DISHWASHER This invention relates to a dishwasher which comprises an open-topped tank, and a cover which is removable in order to allow dirty articles e.g. dishes to be loaded into the tank prior to a washing operation and for the cleaned articles to be unloaded after completion of the washing operation.

In this specification, reference to "dishes" is intended to include plates, cups and other crockery and glass ware, as well as saucepans and cutlery i.e. all of the types of articles which are commonly cleaned in automatic dishwashers.

Automatic dishwashers are now widely used in the home, and do provide for very reliable dishwashing. However, dishwashers are expensive to purchase, and also quite expensive to operate, in that the heat energy input and the normal length of washing cycles are generally based on the worst case assumption of very heavily soiled articles requiring washing. Also, most dishwashers only operate from the domestic cold water supply, and therefore substantial electrical energy is consumed in order to heatup the water during the washing and rinsing cycles, and also during the final drying cycle.

The present invention has therefore been developed primarily with a view to provide a simplified and also more economical design of dishwasher, and yet which is capable of operating at a level of performance which is satisfactory to many users.

According to the invention there is provided a dishwasher which comprises an open-topped tank, a cover which is removable in order to allow dirty articles to be loaded into the tank and cleaned articles to be removed from the tank, air nozzles arranged in a lower portion of the tank. and an air pump connected to the nozzles and operable, when the tank contains washing liquid, to pump air via the nozzles and through the liquid and thereby to promote the washing action applied to the articles.

Preferably, the nozzles are arranged in the bottom wall of the tank so as to bubble air upwardly through the liquid in the tank-, and this agitates the liquid which promotes the washing action applied to the soiled surfaces of the articles.

Advantageously, the tank of the dishwasher generally takes the form of a kitchen sink, and is therefore provided with a drainage outlet which can be operated in order to discharge the dirty liquid after a desired washing operation has been completed. The sink therefore can be plumbed-in by generally conventional means, and indeed can be operated as a normal kitchen sink when required, with the cover removed. However, when automatic or semiautomatic operation is required, the air pump can be operated in order to bubble air through the liquid to promote the washing action and without the necessity for the articles e.g. dishes to be individually handled and cleaned manually.

Therefore, in the application of the invention to the modification of a kitchen sink, there is provided a dual purpose dishwasher which can be manufactured at an economical price and which can be operated under the control o-f the operative for only as long as is necessary to complete a cleaning operation. It will be familiar to owners of automatic dishwashers that washing and rinsing cycles of more than 30 minutes are commonplace, whereas a us## of a dishwasher according to the invention can achieve a satisfactory level of c.1C#### cleaning frz a much shorter time.

Also, by plumbing the dishwasher in-the manner of a sink, a hot-water supply. can fillthe-tank-with water at a temperature which would-be too hot-for comfortable handling of dishes in convention hand washing, and with the addition of a suitable detergent or soap and'the agitation by the introduction of air through the nozzles, a rapid and reliable washing operation can take place.

Preferably, each nozzles has a one-way or non-return valve, so that water in the tank cannot pass down through the nozzles when the air supply is terminated.

The operation of the pump may be under manual control, or under the control of a timer which may be set to operate for required lengths of time.

Conveniently, the cover is made of transparent material, so that the washing operation can be watched, and ended when the dishes appear to be clean. The dirty water can then be discharged from the drainage outlet and to the normal domestic outlet pipe.

To hold articles requiring cleaning in a suitable position within the tank, preferably a mesh rack is provided which can be supported in the lower region of the tank, and may be spaced a small distance above the bottom wall. This rack may be arranged to be removable, in the event that it is required to operate the tank of the dishwasher in the manner of a conventional kitchen sink for hand washing of articles.

One embodiment of dishwasher according to the invention will now be described in detail, by way of example only, with reference to the accompanying drawing, in which: Figure 1 is a side view of the dishwasher; and, Figure 2 is a plan view of the dishwasher.

Referring now to the drawing, the embodiment of dishwasher according to the invention is designated generally by reference 10 and comprises an open-topped tank 11 which takes the form of a sink with a much larger bowl than normal, and made of specialised plastics material. A removable cover 12 is provided which is made of transparent material capable of withstanding the operating temperatures when very hot water is introduced into the tank 11, and the cover 12 can be removed in order to allow dirty articles to be loaded into the tank 11, and the cleaned articles to be removed subsequently from the tank. Also, the cover 12 can be removed when it is required to operate the dishwasher in the manner of a conventional kitchen sink for hand washing of articles.

Air nozzles 13 are arranged in a lower portion of the tank, and as can be seen in Figure 1, are actually arranged in the bottom wall 14 of the tank 11.

An air pump (not shown) is connected by a manifold 15 and flexible hoses 16 to the nozzle 13 and is operable, when the tank 11 has been filled with washing liquid, to pump air through the nozzles 13 and upwardly through the liquid in the tank, thereby to promote the washing action applied to the articles e.g. cups and crockery.

A wire mesh rack 17 is detachably mounted in the lower portion of the tank 11, and serves to have the articles to be cleaned placed thereon, with suitable spacing to allow free circulation of liquid therearound, and the upward movement of bubbles from the nozzles 13 through the liquid agitates the liquid. thereby promoting the washing action applied to the soiled surfaces of the article.

The tank 11 takes the general form of a kitchen sink, and will normally be plumbed-in so as to receive hot and cold water supplies, and also has a drainage or waste outlet 18 which can be operated to discharge dirty water after a desired washing operation has been completed, the outlet 18 being plumbed-in to a domestic outlet pipe.

An on / off button 19 is provided, which is connected to a pressure switch controlling the operation of the pump unit, and .his can be operated for fOn 2= lons as is r-#%#i#red by the operative, who wh# 6 are to- inspect S p he progress of the washing operation through the transparent cover 12.

A timer control unit may be provided which is preprogrammed with set intervals of operation, or which can be set to operate for required short intervals e.g. 5 or 10 minutes.

The nozzles 13 are provided with non-return valves so that there is no risk of water from the tank 11 entering the air pressure system when the pump unit is stopped.

Following completion of a desired washing operation, and discharge of the dirty liquid, the pumped air supply to the tank 11 may be resumed, if it is desired to achieve at least a certain level of drying action, and this of course may be promoted if an electrical heater unit is arranged to heat the air supplied to the tank.

The embodiment of dishwasher according to the invention therefore provides an economical modification of a kitchen sink, which can then be used as a conventional kitchen sink, or operated as a dishwasher which can be operated much more quickly, uses less water, and much less energy input than existing more expensive and complicated designs of automatic dishwashers. The dishwasher unit is fitted with a fractional horse power motor to operate the pump unit, and is therefore very economical to operate.

Claims (9)

1. A dishwasher which comprises an open-topped tank, a cover which is removable in order to allow dirty articles to be loaded into the tank and cleaned articles to be removed from the tank, air nozzles arranged in a lower portion of the tank, and an air pump connected to the nozzles and operable, when the tank contains washing liquid, to pump air via the nozzles and through the liquid and thereby to promote the washing action applied to the articles.

2. A dishwasher according to Claim 1, in which the nozzles are arranged in the bottom wall of the tank so as to bubble air upwardly through the liquid in the tank.

3. A dishwasher according to Claim 1 or 2, in which the tank generally takes the form of a kitchen sink, and is provided with a drainage outlet which can be operated in order to discharge the dirty liquid after a desired washing operation has been completed.

4. A dishwasher according to any one of Claims 1 to 3, in which each nozzle has a one way or non-return valve, so that water in the tank cannot pass down through the nozzles when the air supply is terminated.

5. A dishwasher according to any one of Claims 1 to 4, in which the operation of the pump is arranged to be under manual control, or under the control of a timer.

6. A d.shwask,er according'to any one of the preceding claim#, in which the cover then cover is r#rte of tr#ns#arent material, so that the washing operation can be watched, and ended when the dishes appear to be clean.

7. A dishwasher according to any one of the preceding claims, including a mesh rack supported in the lower region of the tank, and spaced a small distance above the bottom wall, to hold articles requiring cleaning in a suitable position within the tank.

8. A dishwasher according to Claim 7, in which the rack is removable.

9. A dishwasher according to Claim I and substantially as hereinbefore described with reference to, and as shown in the accompanying drawing.