GB2159125A - A liquid dispenser - Google Patents

Abstract

A liquid dispenser, suitable for dispensing liquid detergent in a washing machine, includes a sealed, substantially non-deformable reservoir (1) connected to a chamber (2), including a venting tube (4), by a generally vertical pipe (3), which pipe extends into the chamber (2) to a predetermined height (h) above the base of the chamber. The chamber (2) is provided with a valve-controlled inlet(5) and an outlet (7) connected to a receptacle (9) via a syphoning arrangement (8) and a conduit (10). In operation, a liquid (12) flows from the reservoir (1), under gravity, into the chamber (2) until it fills the chamber (2) to height (h), which defines a predetermined charge (14) of the liquid. Flushing fluid is then introduced into chamber (2) via inlet (5) to flush the liquid charge (14) into the receptacle (9), through syphoning arrangement (8). <IMAGE>

Description

SPECIFICATION A liquid dispenser This invention relates to a liquid dispenser for feeding a predetermined liquid charge from a reser voirofthe liquid to a receptacle.

A liquid dispenser of this type is disclosed in UK Patent Application No. 2111 021A, wherein a first liquid flows, under gravity, from a reservoir of the first liquid into a dispensing chamber, via a connecting pipe, and a second liquid is fed into the chamber, under pressure, to mix with the first liquid and force it into the receptacle.

However, utilisation of such an arrangement may necessitate the inclusion of a valve mechanism, such as that shown in the above-mentioned application, wherein the force of the second liquid entering the chamber causes a valve member to rise and block the inlet of the first liquid into the chamber, so that the flow of the first liquid into the chamber is inhibited whilst the liquid already contained therein is being forced out into the receptacle.

It is therefore an object of the present invention to provide a liquid dispenser which removes the necessity of including a valve mechanism for the abovementioned purpose.

According to the invention there is provided a liquid dispenserforfeeding a liquid charge from a substantially constant volume to a receptacle, said dispenser including a chamber vented to atmosphere and provided with an inlet, into which a first end of a generally vertical pipe member is connected, the other end of said pipe member being capable of connection to a reservoir outlet provided at or adjacent the lowest point of said reservoir, said pipe member being connected into said chamber, so that said first end is located at a predetermined height above the base of said chamber, said height defining a predetermined charge of liquid which, in use, flows from said reservoir into said chamber via said pipe member, said chamber further including a valve-controlled inlet for introducing a flushing fluid into said chamber, and an outlet to said receptacle, through which, in use, said liquid charge is flushed from said chamber into said receptacle by said flushing fluid.

A syphoning arrangement is preferably provided to retain the liquid charge within the chamber until it is flushed out by the flushing fluid and to syphon out flushing fluid remaining in the bottom of the chamber after the flushing procedure.

A cover member is preferably provided surrounding the first end of the pipe member connected into the chamber, so that, if a layer of flushing fluid settle above the liquid charge during standing periods, only a minor proportion of that flushing fluid is permitted to migrate up the pipe member into the reservoir, thereby preventing a large volume of flushing fluid accumulating in the reservoir upon repeated operation of the dispenser.

Preferably, the dispenser is employed to dispense liquid detergent into a washing machine, the charge of liquid detergent being flushed into the drum of the machine at predetermined times during the wash programme, with water being used as the flushing fluid.

The invention will now be further described by way of example only with reference to the accompanying drawings, wherein: Figure 1 shows schematically a first embodiment of the present invention, Figure 2 shows schematically a magnified view of one part of the embodiment, Figure 3 shows a plan view of that shown in Figure 2, Figure 4 and 5 illustrate schematically the function of the part shown in Figures 2 and 3, Figure 6shows schematically a second embodiment of the invention, Figure 7shows schematically a simplified side view of part of the second embodiment, Figure 8 shows a simplified plan view of that shown in Figure 7, Figure 9 shows a plan view of the embodiment shown in Figure 6, and Figure 10 shows a plan view of an alternative arrangement of the second embodiment.

Figure 1 shows a sealed reservoir 1, which is formed from a substantially non-deformable material, so that it maintains a substantially constant volume. The reservoir 1 is preferably connected at its lowest point to an upper inlet of a chamber 2 by a generally vertical reservoir pipe 3, which extends downwardly into the chamber 2 to a predetermined height h above the base of the chamber.

The chamber 2 is also provided with a venting tube 4 to vent the chamber to atmospheric pressure.

The chamber 2 is further provided with an inlet 5, near the top of the chamber, opening and closing of which is controlled by a solenoid valve 6, and an outlet 7, preferably situated at the lowest point of the chamber 2. The outlet 7 extends into a syphoning arrangement 8, which is connected to an inlet of a receptacle 9 via a conduit 10.

The lower end of the reservoir pipe 3 is surrounded by a tubular cover 11, the function of which will be explained hereinafter.

In operation, a liquid 12 contained in the reservoir 1 flows, under gravity, into the chamber 2, until an equilibrium level is reached at height h within the chamber 2, the liquid also flowing out through outlet 7 and rising up the syphoning arrangement 8 to a corresponding level.

A major proportion of the air displaced from within the chamber 2 vents to atmosphere via tube 4, so that a partial vacuum forms in ullage 13 within the substantially non-deformable reservoir 1.

The dispenser is thus charged with a predetermined charge 14 being defined substantially by the horizontal cross-sectional surface area of the chamber 2 and the height h, and it remains in a quiescent state until the liquid charge 14 is required to be dispensed into the receptacle 9.

When dispensing of the liquid charge 14 is required, solenoid valve 6 is activated for a predetermined time and a flushing fluid (not shown) is introduced into the chamber 2 through inlet 5, so as to flush the liquid charge 14 out through the outlet 7, the syphoning arrangement 8 and the conduit 10 into the receptacle 9.

During the flushing procedure, no further liquid 12 will flow out of the open end of the reservoir pipe 3, unless the pressure at that end is reduced or the height of liquid and flushing fluid in the chamber 2 falls below the open end of the pipe 3.

After the liquid charge 14 has been flushed into the receptacle 9, the solenoid valve 6 is de-activated and the charged syphoning arrangement 8 syphons any flushing fluid remaining in the chamber 2 out therefrom and into the receptacle 9, the venting tube 4 supplying air to displace the flushing fluid.

As soon as the flushing fluid level within the chamber 2 falls below the open end of the pipe 3, the liquid 12 will begin to flow into the chamber 2.

However, as long as the flow out of the chamber 2 is greater than that of the liquid from the reservoir 1, the flushing fluid will syphon out of the chamber 2 and break the syphoning effect before the slowermoving liquid 12 can meet it.

The chamber 2 thus replenishes with the predetermined liquid charge 14from the remaining liquid 12 in the reservoir 1 ready for the next required flushing procedure.

Figures 2 to 5 show views of the tubular cover 11 surrounding the open end of the reservoir pipe 3, as shown in Figure 1. Figure 3 shows that the cover 11 is connected to the outer wall of the pipe 3, adjacent the open end thereof, by supporting members 15 and 16.

The function of the cover 11 will now be explained with reference to Figures 4 and 5. Once the liquid charge 14 has flushed out of the chamber 2 and syphoning arrangement 8 has syphoned out flushing fluid, which is preferably water, some of the fluid will flow back into the chamber 2 when the syphoning effect breaks.

Once replenishment of the liquid charge 14 in chamber 2 has occurred, the small quantity of flushing fluid remaining, which is generally less dense than the liquid 12, separates out to form a layer 17 upon the surface of the charge 14.

Without the cover 11, substantially all of the layer 17 of flushing fluid would gradually migrate up the pipe 3 and separate out to form a corresponding layer upon the surface of the liquid 12 in the reservoir 1. Upon repeated flushing procedures, the thickness of the layer of flushing fluid in the reservoir 1 would increase so that, when substantially all of the liquid 12 in the reservoir 1 has been consumed, the reservoir 1 would only contain flushing fluid, and the subsequent replenishment of the liquid charge 14 will consist substantially only of flushing fluid.

However, to alleviate this problem, the cover 11 extends below the surface of the liquid charge 14 (and thus below the open end of the pipe 3), so as to segment a portion 18 of the layer 17, as shown in Figure 4. This results in substantially only the flushing fluid enclosed within the portion 18 migrating up the pipe 3 to separate out upon the liquid 12 in the reservoir 1, thereby substantially reducing the build-up of the layer of flushing fluid in the reservoir.

For efficient operation of the liquid dispenser, the syphoning arrangement 8 should rise at least above the height h of the liquid charge 14 and preferably also above the top of the chamber 2, as shown in Figure 1, and should also connect the receptacle 9, via conduit 10, at a point which is substantially lower than the chamber 2.

The sealed reservoir 1 of substantially constant volume enables a partial vacuum to form in the ullage 13, so that the pressure head of liquid 12 in the reservoir 1 is maintained.

A preferred application of the liquid dispenser in accordance with the present invention is as a liquid detergent dispenser employed in a washing machine, the dispensed liquid being the liquid detergent, the flushing fluid being water, and the receptacle being a drum of the washing machine, within which clothing articles are washed.

Preferably the solenoid valve is activated at a specific time in the washing cycle, such as immediately after the pre-fill stage and before the wash stage of the washing programme, so that the charge of liquid detergent is flushed out into the drum. If more than one charge of liquid detergent is required, for, for example, heavily soiled laundry, then the flushing procedure can be repeated, once the liquid detergent charge has been replenished, as many times as is required. A repeated flushing procedure may be implemented by a suitable control arrangement.

Preferably, the reservoir 1 is detachable from the chamber 2 so that it can be replaced, when the reservoir 1 is empty of liquid detergent, with a full reservoir. In this way, the dispenser will be cleaned whenever the disposable reservoir is replaced, which may be via a suitable opening in a front panel of the washing machine.

Alternatively, a refillable, sealed reservoir permanently fitted into the machine may be utilised.

Figure 6 shows a second embodiment wherein a reservoir 20, containing liquid to be dispensed, and a dispensing chamber 21 are housed in a housing 22 by insertion through opening 23 in the housing 22.

The reservoir 20 is connected to the chamber 21 by connecting pipe 24, so that the reservoir 1 can be disconnected from the chamber 21, for cleaning and re-filling purposes, by unscrewing a coupling screw 25 containing a rubber seal (not shown) to prevent leakage of the liquid.

The dispensing chamber 21 accommodates a syponing arrangement 26, attached to, and having an outlet from, the base of the chamber 21. The syphoning arrangement 26 has a syphon cover 27, which is removable for cleaning purposes, and the syphoning arrangement 26 functions in the same way as the syphoning arrangement 8 in the first embodiment as shown in Figure 1.

The exit end of the connecting pipe 24 is connected into the chamber 21 so as to define a height h' above the base of the chamber 21, to which height the chamber 21 is filled with liquid to be dispensed, thereby defining the liquid charge.

A valve-controlled nozzle 28 is disposed directly above the chamber 21 and is arranged to direct flushing fluid into the chamber 21 to flush out the liquid charge through outlet 29 in the syphoning arrangement 26 and out through outlet 30 in the housing 22 into a receptacle (not shown).

The exit end of the connecting pipe 24 is surrounded by a cover 31, which has the same function as the cover 11 in the Figure 1, namely to prevent a large volume of flushing fluid from migrating up the connecting pipe 24 into the reservior 20.

Figures 7 and 8 show respectively a simplified side view and plan view of the dispensing chamber 21, illustrating the semi-circular, cylindrical shape of the cover 31 surrounding the exit end of the connecting pipe 24.

In the preferred application of the present invention, wherein the dispenser is employed to dispensed liquid detergent into the drum of a washing machine, using water as the flushing fluid, then the housing 22 is positioned within the washing machine so that a user of the machine can easily insert and removed the reservoir 20 and dispensing chamber 21 into, and out of, the housing 22.

As the liquid detergent dispenser is inserted an electro-mechanical mechanism (not shown) switches the nozzle 28 into operation, whilst additional nozzles shown at 32, used for prewash and main wash for dispensing of powder detergents, are disengaged from operation. A further nozzle 33 for dispensing of fabric softener is also engaged.

The plan view of the housing 20, as shown in Figure 7, illustrates the relative positioning of the engaged nozzles, with respect to the liquid detergent dispensing chamber 28 and a fabric softener chamber 34, and the disengaged nozzles 32 for dispensing of powder detergents. In this arrangement the washing machine is programmed to use liquid detergent and fabric softener, these two liquids being flushed out of their respective chambers at a predetermined stage of the wash cycle by water from the respective nozzles 28 and 33.

Figure 10 shows a plan view of the housing 20 when powder detergent is required to be used, instead of liquid detergent. The liquid detergent dispenser has been removed from the housing 20 and nozzle 28 is disengaged. A conventional powder detergent chamber, having compartments 35 and 36 for pre-wash and main wash respectively, is inserted into the housing 20 and nozzles 32 and 33 are engaged for dispensing of powder detergent from the compartments 35 and 36 and fabric softener from the chamber 34.

A viewing window, or some other form of liquid level indicator, may be provided on the front panel to provide an indication to a user of the machine of the amount of liquid detergent remaining in the reservoir.

It will however be appreciated that many alternative applications of the present invention, wherein a predetermined charge of a first substance is required to be mixed with a second substance, may be envisaged by a man of ordinary skill in the art. Such applications may be found, for example, in the preparation of foodstuffs, such as flavoured beverages.

Claims (8)

1. A liquid dispenserforfeeding a liquid charge from a reservoir of substantially constant volume to a receptacle, said dispenser including a vented chamber communicating with said reservoir through a generally vertical pipe member arranged so that a lower end of said pipe member is located at a predetermined height above the base of said chamber, said height defining a predetermined charge of liquid which, in use, flows from said reservoir into said chamber via said pipe member, said chamber further including a valve-controlled inlet for introducing a flushing fluid into said chamber and an outlet to said receptacle, through which in use said liquid charge is flushed from said chamber into said receptacle by said flushing fluid.

2. A liquid dispenser as claimed in claim 1 wherein said reservoir is detachable from said chamber.

3. A liquid dispenser as claimed in claim 1 or 2 and including a syphoning arrangement connected between said chamber and said receptacle, to retain the liquid charge within said chamber until flushing thereof occurs and to syphon out flushing fluid remaining in the chamber after flushing has occurred.

4. A liquid dispenser as claimed in any preceding claim wherein an open-ended cover member surrounds said lower end of said pipe member to inhibit a major proportion of any flushing fluid, which settle above the liquid charge in said chamber, from migrating up said pipe member into said reservoir.

5. A liquid dispenser substantially as herein described with reference to Figures 1 to 5 or Figures 6to 10 of the accompanying drawings.

6. A liquid dispenser as claimed in any preceding claim for use in a washing machine wherein said liquid charge is a liquid detergent, said flushing fluid is water and said receptacle is a drum for retaining articles to be washed.

7. Awashing machine including a liquid dispenser as claimed in claim 6.

8. Awashing machine as claimed in claim 7 and including means for indicating the amount of liquid detergent in said reservoir.