WO2009015848A1

WO2009015848A1 - Dispensing device

Info

Publication number: WO2009015848A1
Application number: PCT/EP2008/006192
Authority: WO
Inventors: Brian Parry Slade
Original assignee: Brian Parry Slade
Priority date: 2007-08-01
Filing date: 2008-07-28
Publication date: 2009-02-05
Also published as: GB0714946D0

Abstract

A dispensing device (10) for suspension from a rim of a lavatory bowl (26) to dispense a dose of a liquid additive into a flow of water when the lavatory is flushed, the device comprising a reservoir (12) for the liquid additive; a resilient, flexible member (14) connected to the reservoir (12) and capable of conducting the liquid, additive from the reservoir (12),- a spacer (20) attached to the member (14); and a hanger (22) engageable with the rim to suspend the device in the bowl, the member (14) and the spacer (22) being arranged such that when the device (10) is suspended in the bowl,, the spacer (20) is urged into engagement with a wall of the bowl by the member (14), the spacer (20) preventing the member (14) from touching the wall while enabling a flow of water over the wall to flow over at least a portion of the member (14) so as to dispense the dose of the liquid additive into the flow of water.

Description

DISPENSING DEVICE

Field of the Invention

This invention relates to a dispensing device for suspension from a rim of a bowl of a lavatory to dispense a dose of a liquid additive into a flow of water when the lavatory is flushed.

Background to the Invention

A common design of lavatory, when flushed, produces a flow of water in the form of a thin layer over a wall of its bowl. In order for a dispensing device for suspension from a rim of a bowl of a lavatory to dispense a dose of an additive into the flow of water in such a lavatory, at least part of the device must be exposed to the thin layer of water, which means that at least part of the device must be brought into at least close proximity with the wall of the lavatory bowl.

However, lavatory bowls can vary considerably in the widths of their rims, so that the distance from such a dispensing device suspended from the rim of a lavatory bowl to the wall over which the thin layer of water flows can also vary considerably. This has made it difficult to design such a dispensing device that can be used with lavatories with a wide range of widths of rims of their bowls.

GB 2 426 981 shows such a dispensing device that can adjust itself for use with lavatories with a range of widths of rims of their bowls, the device including a slidable guide member operable to direct a flow of water in the form of a thin layer over a wall of a bowl of a lavatory onto dispensing means of the device to dispense the dose of the additive, and biasing means arranged to urge the guide member into engagement with the wall of the bowl of the lavatory.

It is an object of the invention to provide such a dispensing device that can adjust itself for use with lavatories with a wide range of widths of their bowls and is of simpler construction than that shown in GB 2 426 981. Summary of the Invention

According to the invention there is provided a dispensing device for suspension from a rim of a lavatory bowl to dispense a dose of a liquid additive into a flow of water when the lavatory is flushed, the device comprising a reservoir for the liquid additive, a resilient, flexible member connected to the reservoir and capable of conducting the liquid additive from the reservoir, a spacer attached to the member and a hanger engageable with the rim to suspend the device in the bowl, the member and the spacer being arranged such that when the device is suspended in the bowl, the spacer is urged into engagement with a wall of the bowl by the member, the spacer preventing the member from touching the wall while enabling a flow of water over the wall to flow over at least a portion of the member so as to dispense the dose of the liquid additive into the flow of water.

The invention can provide a dispensing device that has a resilient, flexible member that adjusts itself for use with lavatories with a wide range of widths of their bowls. The invention can also provide a dispensing device that is of simpler construction than that of GB 2 426 981. The spacer prevents the member from touching the wall because siphoning of the liquid additive from the reservoir through the member might otherwise occur.

The reservoir may advantageously comprise a chamber for holding the liquid additive, a liquid additive outlet to which the member is connected and a wick, the chamber being for orientation in use with an upper end and a lower end, the liquid additive outlet being provided in the lower end of the chamber and the wick being capable of conducting the liquid additive from the liquid additive outlet to the upper end of the chamber, the member being connected to the liquid additive outlet by the wick.

Where the reservoir is so constructed, the member and spacer may advantageously be arranged such that when the device is suspended in the bowl, the member extends downwards from the upper end of the chamber between the reservoir and the wall of the bowl. In this way, in use of the device a first column of the liquid additive is established in the wick and a second column of the liquid additive is established in the member, the first and second columns being connected to, and acting against, one another so as to reduce any tendency of the liquid additive to siphon from the chamber through the member.

Preferably the reservoir comprises a chamber for holding the liquid additive, an air inlet duct and a liquid additive outlet to which the member is connected, the chamber being for orientation in use with an upper end and a lower end, the air inlet duct having an upper end at an upper end of the chamber and extending through the chamber to a lower end of the duct through which air can enter a lower end of the chamber, the upper end of the chamber being closed so as to be capable of forming an air pocket between the upper end of the chamber and the surface of the liquid additive in the chamber, and the liquid additive outlet being provided at substantially the same vertical level as the lower end of the air inlet duct.

This construction of the reservoir ensures that the pressure acting at the liquid additive outlet is substantially equal to that acting in the air inlet duct, i.e. atmospheric pressure, and that the pressure acting at the liquid additive outlet is therefore substantially invariant with the quantity of the liquid additive in the chamber. The rate at which the liquid additive is dispensed from the device therefore does not change significantly as the device is emptied of the liquid additive.

This construction of the reservoir also allows a relatively fluid liquid additive to be used, as opposed to a liquid additive in the form of a gel, as is used in known dispensing devices.

The use of a relatively fluid liquid additive has several advantages.

First, a given volume of a relatively fluid liquid additive will produce more foam than the same volume of a liquid additive in the form of a gel, when exposed to a flow of water. This means that the same amount of foam can be produced by a smaller dose of a relatively fluid liquid additive than would be produced by a larger dose of a liquid additive in the form of a gel. Thus the invention can provide a dispensing device for dispensing a relatively fluid liquid additive, the dispensing device having a smaller reservoir than known dispensing devices but being able to dispense the same number of doses of the relatively fluid liquid additive as known dispensing devices with larger reservoirs are able to dispense, with each dose of the relatively fluid liquid additive producing the same quantity of foam as a dose of a liquid additive in the form of a gel.

Thus the invention can also provide a dispensing device of which the reservoir is sufficiently small to be accommodated beneath the rim of a lavatory bowl, as opposed to beside the rim of the lavatory bowl as with known dispensing devices, which makes the appearance of the dispensing device of the invention more discrete in use than known dispensing devices.

Second, a greater proportion of fragrance can be added to a relatively fluid liquid additive than can be added to a liquid additive in the form of a gel. Such gels are used because a minimum viscosity of the liquid additive is required to ensure correct operation of a dispensing device. Adding a fragrance to a gel reduces the viscosity of the gel, so that the amount of fragrance that can be added to the gel is determined by the minimum viscosity required of the gel. Adding a fragrance to a relatively fluid liquid additive has little effect, if any, on the viscosity of the liquid additive so a much greater proportion of the fragrance can be added to the relatively fluid liquid additive. Thus the invention can also provide a dispensing device that produces a much stronger fragrancing effect for a given dose of a liquid additive than known dispensing devices.

Third, many dispensing devices, including the device of the invention, operate by charging an absorbent material with a dose of a liquid additive, the dose of the liquid additive being rinsed from the absorbent material by a flow of water when a lavatory is flushed. The absorbent material must then be recharged with another dose of the liquid additive. This can take some time with a liquid additive in the form of a gel, as the gel must flow from the reservoir to the absorbent material. A relatively fluid liquid additive can flow from the reservoir to the absorbent material much more quickly than a liquid additive in the form of a gel. Thus the invention can also provide a dispensing device that is operable to dispense a second dose of a liquid additive within a shorter time of dispensing a first dose of the liquid additive than known devices.

The liquid additive outlet may advantageously be constituted by the lower end of the air inlet duct, air entering the chamber and the liquid additive leaving the chamber through the lower end of the air inlet duct.

Where the liquid additive outlet is constituted by the lower end of the air inlet duct, the member may advantageously be connected to the liquid additive outlet by means of a wick capable of conducting the liquid additive from the lower end of the air inlet duct to the upper end of the air inlet duct.

As explained above, with this construction, in use of the device a first column of the liquid additive is established in the wick and a second column of the liquid additive is established in the member, the first and second columns being connected to, and acting against, one another so as to reduce any tendency of the liquid additive to siphon from the chamber through the member.

The wick may advantageously have substantially the same cross section at its upper end as the upper end of the air inlet duct and an air inlet hole be formed in the wall of the upper end of the air inlet duct above the upper end of the chamber.

With this construction, once a column of the liquid additive is established in the wick, the upper end of the wick forms a seal in the upper end of the air inlet duct. The seal reduces evaporation and/or drying of the liquid additive in the chamber, but prevents air entering the air inlet, necessitating the air inlet hole in the wall of the upper end of the air inlet duct. The lower end of the air inlet duct may advantageously be provided with a removable plug or a frangible seal to separate the air inlet duct from the chamber, and the wick be slidable relative to the air inlet duct so as to remove the removable plug or fracture the frangible seal.

In this way the device can be supplied in a sealed state, the lower end of the air inlet duct being sealed by the plug or seal, so as to avoid leakage of the liquid additive, and unsealed only once the device is required for use.

The upper end of the wick may advantageously be flanged, the flange being engageable with the upper end of the air inlet duct so as to limit the travel of the wick in the air inlet duct in the direction of the lower end from the upper end of the air inlet duct.

The upper end of the wick may advantageously be provided with a cap that covers the upper end of the wick.

The cap reduces evaporation and/or drying of the liquid additive contained in the upper end of the wick and prevents users of the device who might touch the top of the device from coming into contact with the liquid additive. The cap also prevents water from entering the wick or the reservoir.

The reservoir may advantageously be formed such that a portion of the reservoir that is nearest to the wall of the bowl of a lavatory when the device is suspended from the rim of the lavatory has a profile complementary to that of the wall of the bowl.

In this way when the device is suspended from a rim of a lavatory bowl, at least a portion of the reservoir can be located beneath the rim of the bowl, to reduce the intrusion of the device into the bowl.

The reservoir may advantageously have a capacity of from 30 to 35ml. Known dispensing devices typically have a capacity of from 55 to 60ml. The smaller capacity of reservoir of the device of the invention enables a larger proportion of the reservoir to be located beneath the rim of the bowl than is possible with known devices.

The member may advantageously comprise a porous sheet.

The member may advantageously further comprise a coating that encloses the member except for a first portion of the member that receives the liquid additive from the reservoir and a second portion of the member over which the flow of water flows so as to dispense the dose of the liquid additive.

The coating reduces evaporation and/or drying of the liquid additive contained in the member between the first and second portions of the member, and limits the amount of water absorbed by the member when the flow of water flows over the member, whilst still permitting emanation of any fragrance included in the liquid additive.

Where the reservoir includes the air inlet duct and the member comprises the porous sheet, the first portion of the sheet may advantageously be annular so as to enable the first portion of the sheet to be placed over the upper end of the air inlet duct.

Where the first portion of the sheet is annular and the upper end of the wick is flanged, an annular protrusion may advantageously extend axially from the side of the flange nearer to the lower end of the wick towards the lower end of the wick, the internal and external diameters of the protrusion corresponding to those of the first portion of the sheet.

This construction of the sheet and wick provides a connection between the sheet and the wick that reduces evaporation and/or drying of the liquid additive.

The member may advantageously be arranged such that when the device is suspended from the rim of a lavatory bowl, the second portion of the member extends to substantially the same vertical level as the lower end of the air inlet duct. Together with the spacer, which prevents the member from touching the wall of the bowl, this prevents siphoning of the liquid additive from the chamber.

Preferably, however, the member is arranged such that when the device is suspended from the rim of a lavatory bowl, the second portion of the member extends a sufficient distance below the lower end of the air inlet duct to ensure that the hydrostatic pressure of the liquid additive contained in the member acting at the second portion of the member displaces any water absorbed by the second portion of the member following flushing of the lavatory.

In this way following flushing of the lavatory and dispensing of the dose of the liquid additive from the second portion of the member, any water absorbed by the member can be displaced by the liquid additive remaining in the member, while more of the liquid additive is drawn into the wick and member from the chamber to replace the dispensed dose of the liquid additive.

This has been found to improve the fragrancing effect of liquid additives that include a fragrance, because the fragrance can emanate directly from the second portion of the member, without having to first pass through a layer of water absorbed by the second portion of the member.

Brief Description of the Drawing Figures

The invention will now be described by way of example and with reference to the attached drawings, in which:

Figure 1 is a side view of a dispensing device according to the invention suspended from a relatively wide rim of a lavatory bowl; Figure 2 is a side view of the device of Figure 1 suspended from a relatively narrow rim of a lavatory bowl;

Figure 3 is a sectional side view of a reservoir and collar forming parts of the device of Figures 1 and 2;

Figure 4 is a partial sectional side view of the device of Figures 1 and 2 in a sealed condition;

Figure 5 is a partial sectional side view of the device of Figures 1 and 2 in an unsealed condition;

Figure 6 is a plan view of a flexible, resilient member forming part of the device of Figures 1 and 2;

Figure 7 is a plan view of the reservoir of Figure 3;

Figure 8 is a plan view of the reservoir of Figure 7 with the flexible, resilient member of Figure 6 fitted;

Figure 9 is a plan view of the reservoir and flexible, resilient member of Figure 8 with a cap fitted;

Figure 10 is a front view of the reservoir of Figure 3 with a hanger forming part of the device of Figures 1 and 2 fitted;

Figure 11 is a schematic sectional side view of the reservoir of Figure 3 and a wick forming part of the device of Figures 1 and 2, showing the operation of the reservoir and wick; and Figure 12 is a partial schematic side view of the device of Figures 1 and 2 showing the movement of the flexible, resilient member of the device.

Detailed Description of an Embodiment

The dispensing device 10 of Figure 1 comprises a reservoir 12 for a liquid additive, a resilient, flexible member 14 in the form of a porous sheet 16 of high density polyethylene (HDPE) with a non-porous HDPE coating 18 covering a middle portion of the sheet 16, an upper portion of the member 14 being connected to the reservoir 12, a spacer 20 attached to a lower portion of the member 14 and a hanger 22 engageable with a rim 24 of a lavatory bowl 26 to suspend the device in the bowl.

The porous HDPE sheet 16 has a thickness of 1.5 mm and a pore size of from 100 to 150 microns. The upper portion of the sheet 16 is attached to an upper end of the reservoir 12 such that when the device is suspended from the rim 24 of the lavatory bowl 26 the sheet 16 extends downwards and away from the upper end of the reservoir towards the wall of the bowl 26, and the spacer 20, which is attached to the middle of the lower edge of the lower portion of the sheet 16, engages the wall of the bowl.

In Figure 1 the device is shown suspended from a relatively wide rim 24 of a lavatory bowl 26. In Figure 2 the device is shown suspended from a relatively narrow rim 28 of a different lavatory bowl 30. The spacer 20 is urged into engagement with the wall of a bowl of a lavatory in which it is suspended whether the rim of the bowl is relatively wide, as shown in Figure 1, or relatively narrow, as shown in Figure 2. The engagement of the spacer 20 with the wall of the bowl bends the member 14 towards the reservoir 12 of the device, the member 14 being bent by a relatively small amount when the device is suspended from the relatively wide run 24 and being bent by a relatively large amount when the device is suspended from the relatively narrow rim 28.

The reservoir 12 is shown in greater detail in Figure 3 and comprises a chamber 32 made of transparent polyethylene for holding the liquid additive 34, an air inlet duct 36 extending from an upper end 38 through an upper end 40 of the chamber 32 through the chamber to a lower end 42 inside a lower end 44 of the chamber 32. An air inlet hole 46 is formed in the wall of the upper end 38 of the air inlet duct 36 above the upper end 40 of the chamber 32. A collar 48 with a partial circular wall 50 and a circular hole in its base is attached to the reservoir 12 by inserting the upper end 38 of the air inlet duct 36 into the hole in the base of the collar so as to form an annular channel between the wall of the upper end 38 of the air inlet duct 36 and the partial circular wall 50 of the collar 48, the partial circular wall 50 being open for approximately one quarter of its length. The open portion of the wall 50 enables an annular upper portion of the member 14 to be placed over the upper end 38 of the air inlet duct so as to occupy the annular channel, the remainder of the member 14 extending through the open portion of the wall 50.

Figure 3 shows an upper interface 52 between the air 54 in the upper end 40 of the chamber and the liquid additive 34, and a lower interface 56 between the air in the air inlet duct 36 and the liquid additive 34. The pressure of the air 54 in the upper end 40 of the chamber is arranged to be less than atmospheric pressure, such that the sum of the pressure of the air 54 and the hydrostatic pressure of the liquid additive 34 acting at the lower interface 56 is equal to atmospheric pressure, so that an equilibrium exists between the liquid additive 34 and the air in the air inlet duct. If any of the liquid additive 34 is removed from the chamber 32, atmospheric pressure forces air from the air inlet duct to enter the chamber 32, where it bubbles up through the liquid additive 34 into the air 54 in the upper end 40 of the chamber, increasing the pressure of the air 54 until the equilibrium is re-established.

Turning to Figure 4, this shows the device with the member 14 attached to the collar 48 and a wick 58 inserted into the upper end of the air inlet duct 36. The wick 58 comprises a polyvinyl chloride (PVC) sheath containing polyester fibres. The wick has a lower, relatively narrow portion 60 with an external diameter approximately equal to two thirds of an internal diameter of the air inlet duct 36, and an upper, relatively wide portion 62 with an external diameter approximately equal to the internal diameter of the air inlet duct. The upper portion 62 has a flange 64 approximately halfway along its length. An annular collar 66 extends from the periphery of the side of the flange 64 nearer to the lower portion 60 of the wick towards the lower portion 60 of the wick. The flange 64, collar 66 and that portion of the upper portion 62 of the wick above the flange 64 are covered by a cap 68 formed from polyethylene.

In Figure 4 the device is shown in a sealed condition, with a removable plug 70 located in the lower end 42 of the air inlet duct 36. It will be appreciated that a frangible seal could be used instead of the removable plug 70. The device would be provided to a user of the device in the sealed condition, which prevents the liquid additive 34 from entering the air inlet duct 36. The wick 58 is slidable inside the air inlet duct 36. The PVC sheath of the wick gives the wick sufficient rigidity to enable the wick to be pushed downwards so that the lower end of the lower portion 60 of the wick engages the plug 70, until the plug is pushed out of the lower end 42 of the air inlet duct 36, so as to place the device in an unsealed condition in which the liquid additive can be dispensed from the device.

The device is shown in the unsealed condition in Figure 5, in which it can be seen that the lower end of the lower portion 60 of the wick 58 has pushed the plug 70 out of the lower end 42 of the air inlet duct 36. In the unsealed condition the lower portion 60 of the wick comes into contact with the liquid additive 34 in the chamber. The annular end surface of the lower end of the collar 66 of the wick is brought into contact with the annular portion of the porous sheet 16 which lies inside the annular channel formed between the partial circular wall 50 of the collar 48 and the upper end of the air inlet duct 36. With the plug 70 pushed out of the lower end 42 of the air inlet duct, the liquid additive is absorbed by the lower end 60 of the wick 58 and is conducted by capillary action from the lower end 60 to the upper end 62 of the wick, including the flange 64 and collar 66 of the wick. As the end surface of the lower end of the collar 66 is in contact with the porous sheet 16 of the member 14, the liquid additive is absorbed by the sheet 16 from the lower end of the collar 66 and conducted by capillary action to the lower portion of the sheet 16 to which the spacer 20 is attached.

The cap 68 and sheath 18 prevent evaporation and/or drying of the liquid additive as it flows from the upper end 62 of the wick, through the flange 64 and collar 66 and through the porous sheet 16. The cap and sheath also prevent any water that flows over the device when the lavatory is flushed from being absorbed by the upper ends of the wick 58 and the porous sheet 16. This is important because if water were to be absorbed into the upper end of the wick or the porous sheet, the presence of the water would prevent the liquid additive from being conducted by capillary action from the reservoir to the lower end of the porous sheet because the capillary channels of the wick and/or porous sheet would be saturated by the water. Of course, some evaporation and/or drying of the liquid additive can occur once the liquid additive has reached the lower portion of the sheet to which the spacer 20 is attached and before the dose of the liquid additive is dispensed from the device by a flow of water over the lower portion of the sheet. This, however can be advantageous. The liquid additive can be formulated so as to contain a fragrance, in which case evaporation of the fragrance from the liquid additive is desirable. The liquid additive can also be formulated such that drying of the liquid additive results in an increase in the viscosity of the liquid additive, this helping to reduce any tendency of the liquid additive to siphon from the dispenser.

It will be observed from Figures 4 and 5 that the lower end of the lower portion of the member 14, to which the spacer 20 is attached, is slightly lower than the lower end 42 of the air inlet tube. It has been found that with this arrangement of the member and air inlet tube, when the lower end of the member 14 is exposed to water when the lavatory is flushed, any water absorbed by the lower end of the member is rapidly displaced by the liquid additive that flows into the lower end of the member to replace the dose of the liquid additive rinsed from the lower portion of the member by the flush water, because the hydrostatic pressure due to the column of the liquid additive contained in the member 14 acting at the lower portion of the member 14 is slightly greater than the hydrostatic pressure due to the column of the liquid additive contained in the wick 58 acting at the lower end of the air inlet duct 36. However, in spite of this slight difference in hydrostatic pressure, siphoning of the liquid additive from the reservoir does not take place.

This is believed to be because the liquid additive has a stronger affinity for the porous HDPE sheet than the water, because polyethylene is hydrophobic, or because the viscosity of the liquid additive is greater than that of water, so that a difference in hydrostatic pressure that is sufficient to cause a flow of water from the member is insufficient to cause a flow of the liquid additive, or because the liquid additive, having been prevented from drying out between the chamber 32 and lower portion of the member 14 by the cap 68 and the sheath 18, dries out slightly when it is exposed to the air upon reaching the lower portion of the member and thickens, such that the difference in hydrostatic pressure is insufficient to cause a flow of the thickened liquid additive from the member. It may be that a combination of these factors is responsible for this advantageous feature of the device.

Whatever the mechanism that allows the rapid removal of water from the lower portion of the member 14, without siphoning of the liquid additive, it is advantageous because it allows a relatively fluid liquid additive rather than a liquid additive in the form of a gel to be used. A gel would be more difficult to conduct from the reservoir to the lower portion of the member and, where the liquid additive includes a foaming agent, the relatively fluid liquid additive produces more foam than would a liquid additive in the form of a gel.

Figure 6 shows the structure of the member 14, including the upper, annular portion 16a, that fits over the upper end 38 of the air inlet tube 36 so as to attach the member to the reservoir 12, a middle portion, which is covered by the sheath 18, and a lower portion 16b to which the spacer 20 is attached, to the middle of the lower edge of the lower portion 16b. The spacer 20 has the form of a short cylinder, the cylindrical side wall of the spacer being provided with a slot for receiving a portion of the bottom edge of the lower portion of the sheet 16 so as to attach the spacer to the sheet. The middle portion of the sheet has a cut-out 72, which causes the sheet, when suspended from the reservoir, to bend with a relatively small radius of curvature in the region of the cut-out, so that the sheet can follow the profile of the side of the reservoir that faces the wall of the bowl closely, which allows more of the device to be accommodated below the rim of a lavatory bowl from which the device is suspended. Figure 7 shows more clearly the collar 48 attached to the reservoir 12 by placing the upper end 38 of the air inlet duct in the circular hole of the collar 48 so as to form an annular channel 74 between the partial circular wall 50 and the wall of the upper end 38 of the air inlet duct. Figure 8 shows the attachment of the member 14 to the reservoir by placing the annular portion 16a of the member over the upper end 38 of the air inlet duct so that the annular portion 16a lies in the annular channel 74.

In Figure 9 wick 58 has been inserted into the air inlet duct and the cap 68 has been placed over the upper end 62 of the wick 58, so as to reduce evaporation and/or drying of the liquid additive contained in the upper end 62 of the wick, and to prevent flush water from being absorbed by the upper end 62 of the wick 58 and the annular portion 16a of the sheet 16.

Turning to Figure 10, the structure of the hanger 22 can be seen, the hanger having a lower portion 76 in the form of an inverted U-shape and a flexible upper portion 78 shaped to engage with a rim of a lavatory bowl in which the device is to be suspended. The upper end of the reservoir is provided with a pair of lugs 80 and 82, the lugs being provided with holes (not shown) for receiving protrusions (not shown) at the ends of the arms of the U- shaped lower portion 76 of the hanger 22.

Figure 11 shows the movement of air and the liquid additive 34 through the air inlet duct 36 in use of the device. As can be seen more clearly in Figures 4 and 5, the upper portion 62 of the wick 58 has an external diameter equal to the internal diameter of the air inlet duct 36. When the wick contains the liquid additive, the upper portion 62 of the wick forms a substantially airtight seal in the upper end 38 of the air inlet duct 36. The air inlet hole 46 (not shown in Figure 11) is therefore provided in the upper end of the air inlet duct above the upper end of the chamber 32. The lower portion 60 of the wick 58 has a smaller external diameter than the internal diameter of the air inlet duct 36, such that an annular passage 84 is formed between the external surface of the lower portion 60 of the wick and the internal surface of the air inlet duct 36 and connects the air inlet hole 46 and the lower end 42 of the air inlet duct. Thus, as the liquid additive 34 is drawn by the wick 58 out of the chamber 32, as shown by the arrows denoted by reference numeral 86, air is forced by atmospheric pressure from the air inlet hole 46 to the lower end 42 of the air inlet duct to replace the liquid additive 34, as shown by the arrows denoted by reference number 88. The air entering the chamber 32 forms air bubbles, one of which is denoted by reference numeral 90, which rise through the liquid additive 34 to expand the air pocket 54 in the upper end 40 of the chamber.

Turning finally to Figure 12, this shows three possible positions of the member 14 relative to the reservoir 12. The first position 92 is that taken up by the member before the device is suspended from a rim of a lavatory bowl, in which the member extends downwards and away from the upper end of the reservoir. The second position 94 is that taken up by the member when the device is suspended from a relatively wide rim of a lavatory bowl, as shown in Figure 1 , in which the lower end of the member is bent slightly back towards the reservoir. The third position 96 is that taken up by the member when the device is suspended from a relatively narrow rim of a lavatory bowl, as shown in Figure 2, in which the lower end of the member is bent considerably back towards the reservoir and follows the profile of the portion of the reservoir that faces the wall with which the spacer is engaged.

Claims

Claims:

1. A dispensing device for suspension from a rim of a lavatory bowl to dispense a dose of a liquid additive into a flow of water when the lavatory is flushed, the device comprising a reservoir for the liquid additive, a resilient, flexible member connected to the reservoir and capable of conducting the liquid additive from the reservoir, a spacer attached to the member and a hanger engageable with the rim to suspend the device in the bowl, the member and the spacer being arranged such that when the device is suspended in the bowl, the spacer is urged into engagement with a wall of the bowl by the member, the spacer preventing the member from touching the wall while enabling a flow of water over the wall to flow over at least a portion of the member so as to dispense the dose of the liquid additive into the flow of water.

2. A device according to claim 1 wherein the reservoir comprises a chamber for holding the liquid additive, a liquid additive outlet to which the member is connected and a wick, the chamber being for orientation in use with an upper end and a lower end, the liquid additive outlet being provided in the lower end of the chamber and the wick being capable of conducting the liquid additive from the liquid additive outlet to the upper end of the chamber, the member being connected to the liquid additive outlet by the wick

3. A device according to any of the preceding claims wherein the member and spacer are arranged such that when the device is suspended in the bowl, the member extends downwards from the upper end of the chamber between the reservoir and the wall of the bowl.

4. A device according to any of the preceding claims wherein the reservoir comprises a chamber for holding the liquid additive, an air inlet duct and a liquid additive outlet to which the member is connected, the chamber being for orientation in use with an upper end and a lower end, the air inlet duct having an upper end at an upper end of the chamber and extending through the chamber to a lower end of the air inlet duct through which air can enter a lower end of the chamber, the upper end of the chamber being closed so as to be capable of forming an air pocket between the upper end of the chamber and the surface of the liquid additive in the chamber, and the liquid additive outlet being provided at substantially the same vertical level as the lower end of the air inlet duct.

5. A device according to claim 4 wherein the liquid additive outlet is constituted by the lower end of the air inlet duct such that air entering the chamber and liquid additive leaving the chamber do so through the lower end of the air inlet duct.

6. A device according to claim 5 wherein the member is connected to the liquid additive outlet by means of a wick capable of conducting the liquid additive from the lower end of the air inlet duct to the upper end of the air inlet duct.

7. A device according to any of the claims 2 to 6 wherein the wick is substantially of the same cross-section at its upper end as the upper end of the air inlet duct.

8. A device according to any of the claims 4 to 7 wherein an air inlet hole is formed in the wall of the upper end of the air inlet duct above the upper end of the chamber.

9. A device according to any of the claims 4 to 8 wherein the lower end of the air inlet duct is provided with a removeable plug or a frangible seal to separate the air inlet duct from the chamber and the wick is slidable relative to the air inlet duct so as to remove the removeable plug or fracture the frangible seal.

10. A device according to any of the claims 4 to 9 wherein the upper end of the wick is flanged, the flange being engageable with the upper end of the air inlet duct so as to limit the travel of the wick in the air inlet duct in the direction of the lower end from the upper end of the air inlet duct.

11. A device according to any of the claims 2 to 10 wherein the upper end of the wick is provided with a cap that covers the upper end of the wick.

12. A device according to any of the preceding claims wherein the member comprises a porous sheet.

13. A device according to any of the preceding claims wherein the member additionally comprises a coating that encloses the member but for a first portion of the member that receives the liquid additive from the reservoir and a second portion of the member over which flush water is designed to flow in order to dispense a dose of liquid additive.

14. A device according to claim 13 wherein the first portion of the member is adapated to be placed over and around the upper end of the air inlet duct.

15. A device according to claim 14 wherein the first portion of the member is annular in construction.

16. A device according to any of the claims 13 to 15 wherein the member is arranged such that when the device is suspended from the rim of a lavatory bowl the second portion of the member extends a sufficient distance below the lower end of the air inlet duct to ensure that the hydrostatic pressure of the liquid additive contained in the member at the second portion of the member displaces any water absorbed by the second portion of the member following flushing of the lavatory.