RELEASE DEVICE

Abstract: A release device for a lavatory or the like comprises a perforated container (20) filled with a gel (24) that is suspended in the lavatory pan. As water flows over the container (20) some of the gel (24) is dissolved, through the perforations (23).

Description: Release Device The present invention relates to release devices, and more particularly to devices for releasing a substance into a body of liquid. A known release device for releasing a disinfectant or the like into a lavatory bowl comprises a plastics cage containing a block of solid disinfectant which is suspended against the side of the bowl. When the lavatory is flushed, water passes through the cage and dissolves some of the disinfectant. However, the amount of disinfectant dissolved with every flush decreases with the age of the block, as its surface area decreases. Also, specialised equipment is required to manufacture devices of this type. The present invention seeks to provide a release device that releases a substance into a body of liquid at a substantially constant rate throughout its life. The invention further seeks to provide a release device which is simple to manufacture using standard machinery. According to a first aspect of the invention there is provided a release device comprising a container at least partially filled with a fluent substance, wherein the container allows contact between the fluent substance and a liquid outside the container through at least a portion of the walls of the container, and in use the fluent substance leaves the container by dissolving into the liquid. In a preferred arrangement, the fluent substance is a gel and the walls of the container include one or more perforations, through which the gel does not by itself flow under normal conditions of use. Alternatively, at least a part of the walls of the container is made from a porous material. Preferably, the container substantially comprises an elongate cylinder. The cylinder may be elliptical in cross section. The container may be divided by two partitions extending longitudinally through the container. The longitudinal axis of the cylinder may be curved. Preferably, the device further comprises suspension means to suspend the device from an object. The perforations may be arranged opposite the suspension means. Preferably, the perforations are arranged in a substantially rectangular wall forming a part of the container, formed in the lower part of said elongate cylinder. The perforations can be formed in a cap which closes an opening in said wall. Preferably, detachable closure means are provided to close the perforations. The closure means may comprise a tear-off or snap-off strip. Preferably, the device is formed to hang from the rim of a lavatory pan and rest against the bowl thereof. The device may contain one or more of the following substances: a detergent, a colouring agent, a perfume, a biocide, bleach, or an insecticide. According to a second aspect of the invention there is provided a method of releasing a fluent substance into a body of liquid, the method comprising the steps of: filling a perforated container with the fluent substance, the properties of the fluent substance being such that the substance does not flow by itself through the perforations, and suspending the container in said body of liquid. According to a third aspect of the invention there is provided an apparatus comprising a flowing stream of a liquid contained by containment means, and a container at least partially submerged in said stream, wherein the container is at least partially filled with a fluent substance and allows contact between the substance and the liquid through at least a portion of the wall of the container, and in use the fluent substance leaves the container by dissolving into the liquid. In a preferred arrangement the containment means is a lavatory bowl and the liquid is water. In order that the invention and its various other features may be understood more easily, embodiments thereof will now be described by way of example only, with reference to the drawings, wherein:- Fig. 1 is a sectional view along 1-1 in Fig. 2 of a release device according to a first embodiment of the invention Fig. 2 is a plan view of the device shown in Fig.l; Fig. 3 is a side view of a release device according to a second embodiment of the invention; Fig. 4 is a detail underneath plan view of the cap member of the device shown in Fig. 3; Figs. 5 and 6 are perspective views of a third and fourth embodiment of the invention; Fig. 7 is a side elevation of a fifth embodiment of the invention; Fig. 8 is a view in direction 8 in Fig. 7; Fig. 9 is a section on 9-9 in Fig. 7; and Fig. 10 is an underneath plan view of a cap comprising a part of the embodiment shown in Fig. 7. The release device shown in Fig. 1 comprises a hook member 10 and a container 20. The container 20 comprises a cylindrical portion 21 and a trapezoid portion 22. In the floor of the trapezoid portion there are a plurality of perforations 23. The diameter of the perforations lies between 1mm and 2.4mm. The container contains a gel 24. The gel may comprise a detergent, a colouring agent, a perfume, a biocide, bleach and/or an insecticide in a suitable carrier substance. Suitable carrier substances are composed of natural gums and a cellulosic gel. The properties of the gel are such that it cannot flow through the perforations under normal conditions of use. The container is divided by two longitudinal partitions 25,26. The partitions extend adjacent to one another along the length of the container, dividing it into two compartments 27,28. The partitions are thinner than the walls of the container. There is a vent (not shown in Figures) in eac compartment 27,28 to equalise the pressure inside an outside the container. The hook member 10, the containe 20, and the partitions 24,26 are made in a plastic material. The device is made in two parts. Two mouldings ar formed which each correspond to one half of the devic when it is bisected by a vertical plane extending alon the longitudinal axis. Each moulding is partially filled with gel 24 and seale using a layer of thin plastics sealing material. Th two halves are then welded together to form the device. The layers of sealing material form the partitions 25,26 within the container 20. The release device is configured for use in a lavator bowl. The device is hung on the rim of the bowl by the hook member 10, above the surface of the water in the bowl. When the lavatory is flushed, water runs down the sides of the bowl and over the device. Some of the water enters the perforations 23 and contacts the gel 2 . This dissolves some of the gel and carries it into the lower part of the bowl, where it mixes with the body of water therein. As gel that is adjacent to the perforations is dissolved, more gel flows down the container to replace it. The gel is prevented from flowing through the perforations by surface tension forces and other properties of the fluid such as density and viscosity. The release device is configured so that the size of the perforations creates a surface tension force that is sufficient to prevent the gel in the container flowing through the perforations under the effect of gravity. Example A prototype of the device having 2.4 mm diameter perforations and containing a proprietary brand of shower gel, was found to distribute the gel into flowing water at a steady rate over an extended period. The device has the advantage that it discharges substantially the same amount of gel 24 into the water with every flush until the gel is exhausted. The device is simple and cheap to produce with standard machinery. The two part construction of the device makes it easier to fill the container with the viscous gel, as it is difficult to fill the container through small apertures. The shape of the device ensures that it does not protrude excessively into the bowl. In a modification of the first embodiment of the invention each compartment 27,28 contains a different gel. In another modification, the partitions extend transversely of the device. In a further modification the container is formed as a single compartment. The container is filled with gel through the perforations. The container is filled under pressure to enable gel to enter the container. Also, the gel may be warmed to reduce its viscosity. The device can be refilled when it is empty. Fig. 3 shows a second embodiment of the invention. The container is formed as a single compartment. The lower part of the container 30 has a single opening therein. A removable cap 31 fits over the opening to contain the liquid. The cap contains perforations 32 through which water can contact the gel. The cap 31 allows the container to be easily filled. A range of caps with different sized perforations can be provided for use with a single container. A further cap can be provided that fits over the perforated cap 31 to seal the container when it is not in use. Fig. 5 shows a further embodiment of the invention. The container wholly comprises a cylinder with an elliptical cross-section. Rows of perforations (designated 40 but not shown in Fig. 5) are arranged along the lower part of container. The shape of the container ensures a relatively streamlined flow over the container. This reduces the incidence of dead spots adjacent to the perforations, and enhances mass transfer. A number of modifications can be made to all of the embodiments of the invention. The container can be curved along its longitudinal axis so that the curvature of the container matches the shape of the lavatory pan. A closable opening can be provided in the upper part of the container to allow the container to be filled or refilled more easily. The device can be suspended in the cistern of the lavatory. In addition to, or instead of, the above-described perforations, one or more perforations can be provided in the sides of the container. The shape of the container can be varied to suit the application for the device. Fig 6. shows an alternative configuration of device. Alternatively, the container can comprise a cylinder which is suspended vertically. Further, a conventional bottle shape may be employed. Figs. 7 to 10 show a fifth embodiment of the invention. The container 50 comprises a tank 51 having flanges 52, 53 at its top and bottom. A hole 54 allows the device to be suspended in a lavatory. Decorative markings 55 are applied to the outside of the tank. The device is closed by a threaded cap 60. The roof of the cap contains three perforations 61. Each perforation is formed in the floor of a tapered circular inset 62 in the roof of the cap. The thickness of the cap at the perforation 61 (i.e. the length of perforation) is preselected to match the properties of the gel to be distributed. A downwardly directed ring 63 forms a seal between the cap and the neck of the tank. Three grooves 64 are formed in the periphery of the cap. Prior to use the device is sealed by an overcap 70. This has resiliently deformable keys 71 which engage the grooves 64 in the cap 60. Nipples 73 on the overcap seal the perforations 61. The perforations 23 can be replaced by capillary or porous wall sections. This allows the surface tension of the gel inside the container to be reduced. The porous wall sections can be made from a semipermeable membrane, a sponge material, a felt, or a suitable ceramic material. The embodiments shown have rigid walled containers, but flexible walled containers can be used. The container can comprise a flexible, perforated sachet of gel. The structure of the outside of the container adjacent to the perforations can be configured to produce an area of low pressure on the perforations. This allows some of the gel inside the container to flow out of the perforations and increases the release rate of gel into the water. After filling, but before use, the device can be sealed by a tear-off foil or plastics strip, stuck over the perforations. A snap-off strip may also be used. It is emphasised that the use of the device in a lavatory is exemplary only. The device is suitable for applications in any flowing body of liquid. The flow can be intermittent or continuous. A particular example of an alternative use is in releasing weed killer into waterways. An enlarged release device containing the weed killer in a gel formulation is partially or totally submerged in the upstream section of a canal or river. The device ensures even dosing of the water over a prolonged period. The device can also be used in an immersed position in a closed pipe or conduit. In this case, as the gel flows out of the container, liquid from the outside flows in through the vents in the upper part of the container to fill the container. This forms a pool of liquid above the gel.

Claims: CLAIMS 1. A release device comprising a container at leas partially filled with a fluent substance, wherein th container allows contact between the fluent substanc and a liquid outside the container through at least portion of the walls of the container, and in use th fluent substance leaves the container by dissolving int the liquid. 2. A release device according to claim 1, wherein th container substantially comprises an elongate cylinder. 3. A release device according to claim 2, wherein th cylinder is elliptical in cross section. 4. A release device according to claims 2 or 3, wherein the longitudinal axis of the cylinder is curved. 5. A release device according to any preceding claim, wherein the container is divided by two partition extending longitudinally therethrough. 6. A release device according to any preceding claim, further comprising suspension means to suspend the device from an object. 7. A release device according to any preceding claim, wherein the fluent substance is a gel and the walls of the container include one or more perforations, through which the gel does not by itself flow under normal conditions of use. 8. A release device according to claims 6 and 7, wherein the perforations are arranged opposite the suspension means. 9. A release device according to claims 7 or 8, wherein the perforations are arranged in a substantially rectangular wall forming part of the container, formed in the lower part of said elongate cylinder. 10. A release device according to claim 9, wherein the perforations are formed in a cap which closes an opening in said wall. ιι. A release device according to any of claims 7 to 10, wherein detachable closure means are provided to close the perforations. 12. A release device according to claim 11 wherein the closure means comprises a tear-off or ' snap-off strip. 13. A release device according to any of claims 1 to 6, wherein the fluent substance is a gel and at least a part of the walls of the container is made from a porous material. 14. A release device according to any preceding claim, wherein the device is formed to hang from the rim of a lavatory pan and rest against the bowl thereof. 15. A release device according to any preceding claim containing one or more of the following substances: a detergent, a colouring agent, a perfume, a biocide, bleach or an insecticide. 16. A method of releasing a fluent substance into a body of liquid, the method comprising the steps of: filing a perforated container with a fluent substance, the properties of the fluent substance being such that the substance does not flow by itself through the perforations, and suspending the container in said body of liquid. 17. An apparatus comprising a flowing stream of a liquid contained by containment means, and a container at least partially submerged in said stream, wherein the container is at least partially filled with a fluent substance and allows contact between the substance and the liquid through at least a portion of the wall of the container, and in use the fluent substance leaves the container by dissolving into the liquid. 18. An apparatus according to claim 17, wherein containment means is a lavatory bowl and the liquid is water.

Inventors: DAVIS RAYMOND CHRISTOPHER, DAVIS, RAYMOND, CHRISTOPHER
Applicants: BROOKLINE ALPHA LIMITED
Application year: 1992
Main classification: E03D9
IPC codes: E03D9