GB2035788A - Dispensing detergents into washing machines - Google Patents

Abstract

A washing machine such as dishwashing machine 10 includes a dispenser 20 for introducing detergent into the machine. The dispenser consists of a sealable container 38 which is in communication with a water passage 42 by means of an aperture 46 formed through its wall. A liquid detergent is placed in the container. The viscosity of the detergent is such that it does not flow freely through the aperture into the water passage. However when water flows through the passage the detergent is entrained in the water and is thereby carried with the water into the wash chamber of the machine. <IMAGE>

Description

SPECIFICATION Washing aid dispenser This invention relates to a dispenser for introducing a washing aid into a washing machine such as a dishwashing machine.

It is an object of the invention to provide a washing machine with a simple yet effective dispenser for introducing a washing aid such as a liquid detergent into the washing machine.

The invention provides a washing machine which comprises a housing defining a volume in which washing action takes place and a dispenser for introducing a washing aid into the volume, the dispenser comprising a sealable container for the washing aid, means forming a water passage adjacent the container, means for connecting the water passage to a water supply, and conduit means extending from the passage into the volume, the container being formed with at least one aperture in its wall so that water flowing through the passage carries washing aid from the aperture through the conduit means into the volume.

The conduit means may have fixed to it a nozzle for directing the water and washing aid into the washing volume but preferably the conduit means is perforated so that the water and washing aid are sprayed into the volume.

To ensure an acceptable distribution of the washing aid inside the washing volume the conduit means extends inside the volume horizontally near a lower side of the housing, vertically near a side wall of the housing, and horizontally near an upper side of the housing.

In a preferred form of the invention the container is located above the water passage and the aperture is in the base of the container. Consequently if a liquid detergent is used as a washing aid the detergent tends to flow through the aperture under gravity action. However according to the invention the viscosity of the detergent and the cross-sectional area of the aperture are such that in the absence of water flow in the passage the detergent does not flow freely through the aperture. However when water flows through the water passage the detergent at the mouth of the aperture is entrained and carried with the water into the washing volume. The effectiveness of the entrainment action may be increased by forming the water passage so that it directs the flow of water onto the aperture with the result that the water tends to flow through the aperture.This enhances the mixing action of the water with the liquid detergent.

The invention also extends to a method of introducing a washing aid into a washing volume of a washing machine, the method including the steps of placing the washing aid in a container which is in communication with a water passage through at least one aperture which is formed in the wall of the container, causing water to flow through the passage so that washing aid at the aperture is entrained in the water, and directing the water and the entrained washing aid into the washing volume.

The invention is further described by way of example with reference to the accompanying drawings in which: Figure 1 is a cross-sectional side view of a washing machine and dispenser according to the invention, Figure 2 is a plan view of the washing machine of Fig. 1, and Figure 3 is an enlarged cross-sectional view of the dispenser used in the washing machine of Fig. 1.

The drawings illustrate a dishwashing machine according to the invention which includes a housing 10 which defines a washing volume 12 in which washing takes place.

An axle 14 extends vertically through the centre of the volume and carries a dish rack 16. The axle and the rack are rotatable by means of an electrically driven motor 18 which is mounted on top of the housing 10.

A dispenser 20 is secured to a base plate 22 of the housing. A conduit 24 extends from the dispenser into the washing volume. The conduit has a horizontal run 26 adjacent the base plate 22, a vertical run 28 adjacent a side wall 30 of the housing 10, a second horizontal run 32 adjacent an upper side 34 of the housing and a downwardly extending vertical run 36 adjacent the axle 14. Along its length the conduit is formed with spaced holes 38 which face inwardly into the volume 12.

The construction of the dispenser 20 is shown in detail in Fig. 3. The dispenser includes a container 38 to which is fitted a screw cap 40. A water passage 42 is formed below the container which is secured to the base plate 22 by means of a screw on connection 44. This connection is used to connect the dispenser 20 to a hot water mains supply 46. The conduit 24 is connected to the water passage at a position which is above the base plate 22. An aperture 48 is formed in the base of the container 38. In use of the washing machine dishes which are to be washed are stacked on the rack 16. Liquid detergent 50 is then placed in the container 38 and the screw cap 40 is turned down. A valve controlling the flow of the hot water from the mains 46 is then opened so that water flows through the passage 42 and the conduit 24 from where it is sprayed through the holes 38 into the washing volume.The positioning of the conduit and the holes are such that water is directed from all sides onto the dishes on the rack. This rack is rotated by means of the motor 18 so that all dishes are subjected to the water spray.

The detergent which is placed in the container is a liquid detergent and because of its viscosity and the relatively small cross sectional area of the aperture 48 does not flow freely through the aperture. However under the action of gravity the detergent flows into the aperture 48 but it does not flow through the aperture because of surface tension effects. The flowing water in the passage 42 mixes with the detergent at the mouth of the aperture and effectively reduces its viscosity and the water with the entrained detergent then flows through the conduit into the washing volume.

The process is one in which the detergent is gradually drawn from the container and entrained in the water. The container is relatively small in volume and after a period of two or three minutes, depending on the water pressure, the viscosity of the detergent and the size of the aperture, the detergent in the container 38 is depleted. By this time all the dishes on the rack 16 have been subjected to a spray of detergent and the matter on them has been loosened.

Once the detergent is exhausted the water which flows through the conduit is clean and acts to wash off the matter on the plates and rinse the plates. After a rinsing period of two or three minutes the valve which controls the flow of hot water through the dispenser is closed and the dishes may be withdrawn from the washing machine.

The advantage of the dispenser is that it permits detergent to be diluted to a fairly constant degree and then to be sprayed onto the plates which are to be washed over an extended interval. In addition once the supply of detergent is exhausted the water which is continuously being directed onto the plates automatically becomes pure and is ideal for rinsing the plates so that they are free of dirt and of detergent.

Claims (9)

1. A washing machine which comprises a housing defining a volume in which washing action takes place and a dispenser for introducing a washing aid into the volume, the dispenser comprising a sealable container for the washing aid means forming a water passage adjacent the container, means for connecting the water passage to a water supply, and conduit means extending from the passage into the volume, the container being formed with at least one aperture in its wall so that water flowing through the passage carries washing aid from the aperture through the conduit means into the volume.

2. A washing machine according to claim 1 in which the conduit means is perforated so that the water and washing aid are sprayed into the volume.

3. A washing machine according to claim 2 in which the conduit means extends inside the volume horizontally near a lower side of the housing, vertically near a side wall of the housing, and horizontally near an upper side of the housing.

4. A washing machine according to any one of claims 1 to 3 in which the container is located above the water passage.

5. A washing machine according to any one of claims 1 to 4 in which the water passage directs the flow of water onto the aperture so that the water tends to flow through the aperture.

6. A method of introducing a washing aid into a washing volume of a washing machine, the method including the steps of placing the washing aid in a container which is in communication with a water passage through at least one aperture which is formed in the wall of the container, causing water to flow through the passage so that washing aid at the aperture is entrained in the water, and directing the water and the entrained washing aid into the washing volume.

7. A method according to claim 6 in which the washing aid is liquid and is of a viscosity which prevents the washing aid from flowing freely through the aperture.

8. A washing machine which includes a detergent dispenser substantially as herein described with reference to the accompanying drawings.

9. A method of introducing a washing aid into a washing machine substantially as herein described with reference to the accompanying drawings.