GB2128647A - Dispensing device for flushing cistern - Google Patents

Abstract

A dispensing device for suspension in a cistern to dispense a quantity of a solution of treatment material at each flushing operation comprises a plastics container 10 defining a chamber 12 having upper and lower conduits 14 and 16 extending to openings 30, 32 which are the sole means of communication between chamber 12 and the exterior. The conduits 14, 16 have bends 36, 42 intermediate their ends adapted to form air-locks. In use, when the cistern is full and the container fully immersed, chamber 12 is filled with water which forms, with a dissolved portion of a body 44 of treatment material therein, a body of treatment solution isolated from the water in the cistern by air locks in the bends 36, 42. When the cistern is emptied the water level falls past the conduit 14 and a portion of the solution in the chamber 12 is dispensed, through conduit 16, into the cistern. <IMAGE>

Description

SPECIFICATION Dispensing device for flushing cistern This invention relates to a dispensing device for use in a flushing cistern, e.g. in a water closet, for dispensing intermittently, into the water in the cistern, a water-soluble treatment material, such as a disinfectant.

Dispensing devices for this purpose are already known which incorporate a perforate container, within which a block of sparingly soluble treatment material is disposed and which devices are suspended within the associated cistern and arranged so that when the cistern is temporarily drained in a flushing operation, the water within the container, containing a relatively high concentration of the treatment material in solution, drains from the container into the cistern, to be replaced by fresh water when the cistern is re-filled.In known devices of this kind, the container serves principally to inhibit, at times when the cistern remains filled, the migration of the treatment material, i.e. the exchange of the more highly concentrated solution within the container, around the block of treatment material, with the water outside the container, containing a relatively low concentration of the treatment material. Nevertheless, because the container is perforated, such migration does take place, albeit slowly, so that if the cistern remains filled for a protracted time, e.g. overnight, or over a holiday, substantial dissolution of the treatment material may take place, and the concentration of dissolved treatment material within the cistern may become relatively high.As a resuit, there is unnecessary wastage of the treatment material, and the high concentration of dissolved treatment material may lead to corrosion problems over an extended period.

Co-pending Patent Application No. 8138140 discloses a dispensing device including an upper chamber and a lower chamber, a conduit connecting the lower end of the upper chamber with an upper part of the lower chamber having a bend therein in which an air lock can form, and a further conduit, forming an outlet from the lower chamber in said upper part likewise having a bend therein in which an air lock can form. The upper chamber has inlet holes adjacent its upper end. In use of the device disclosed in Patent Application No. 8138140, the lower chamber is occupied by a block of sparingly soluble treatment material, and the block and liquid in the lower chamber are isolated, when the device is fully immersed in water, from the surrounding water and from the upper chamber by air locks in the bends in said conduits.When the water level is lowered past the device, water from the upper chamber runs by gravity, past the respective air-lock, into the lower chamber, whilst solution from the lower chamber flows from said outlet, past the respective air lock.

It is an object of the present invention to provide a dispensing device for flushing cisterns, by means of which the above-noted migration of treatment material can be avoided and which is of simpler configuration then the device disclosed in Application No. 8138140.

According to the present invention, there is provided a dispensing device for use in a flushing cistern, comprising a unitary chamber and at upper and lower levels of said chamber, respectively, an upper conduit and a lower conduit, each incorporating respective sections crJable of trapping air to form air locks in the respective conduits when the device is immersed in water, said chamber being sealed, apart from said conduits, said upper conduit having at one end a port in said chamber, said lower conduit having at one end, a port in said chamber at a lower level than said port of the upper conduit, said upper conduit having at its opposite end, a further port, and said lower conduit having, at its opposite end, a further port below the level of said further port of the upper conduit, the arrangement being such that, in use, with a water soluble treatment material disposed in said chamber, and 'the device immersed in water, the water in said chamber can be isolated by such air locks from the water in which the device is immersed, to prevent migration of dissolved treatment material to the water in which the device is immersed, while when the level of the surrounding water is lowered past the device water can flow from said chamber via the lower conduit and air can flow into said chamber via the upper conduit, and, conversely, when the level of water is raised past the device, water can flow into said chamber via the lower conduit whilst air flows from the chamber via said upper conduit.

An embodiment of the invention is described below by way of example with reference to the accompanying drawings in which: FIGURE 1 is a side elevation view of a dispensing device embodying the invention, and FIGURE 2 is a view in section aiong the line Il-Il of Figure 1.

Referring to the drawings, a dispensing device 10 embodying the invention comprises a unitary chamber 12 having a conduit 14 extending from its upper end and a conduit 16 extending -therefrom intermediate its upper and lower ends.

The device is preferably formed from two superimposed, generally rectangular plastics sheets, one of which, indicated at 1 8 in Figure 2, is generally planar and the other of which, indicated at 20 in Figure 2, is deformed, for example by a vacuum forming process, to afford a recess, of substantially uniform depth, and the periphery of which is indicated at 22 in Figure 1, which recess is surrounded by a generally planar fiange or margin, constituting the undeformed portion of the sheet and which is bonded to the marginal portions of the sheet 18 on which it is superimposed, the bonding being, for example, by welding, adhesive, or the like.As shown in Figure 1, the conduits 14 and 16 are partly defined by a strip-like portions 22, 24, 26 of the sheet 20 which remain in the plane of the undeformed sheet and are likewise bonded to the opposing sheet 1 8. Openings 30, 32, at the ends of conduits 14 and 15 respectively provide ports allowing communication between the interior of chamber 12 and the exterior. Openings 30, 32 may be formed in the material of the sheet 20, at the locations indicated, or may, alternatively, be formed in the planar sheet 1 8. Apart from the openings 30,32, the chamber 12 is completely sealed with respect to the exterior.

Instead of being manufactured by vacuum forming, as described, the device 10 may be formed of plastics material by injection moulding.

As shown in Figure 1, the chamber 12 has an upper wall 34 inclined with respect to the horizontal, a continuation of the upper wall 34 forming an initial part of an upper side of an upwardly inclined portion of conduit 14, from which a downwardly inclined portion of the conduit 14 extends to the outlet 30. There is thus defined an uppermost bend 36 in which an air lock may form.

At an intermediate level, below that of the conduit 14, the conduit 1 6 has, within and immediately adjoining the chamber 12, an inclined upper wall 38 bounded by the strip-like portion 24 and extending upwardly to a downwardly inclined portion of the conduit 16 extending to the outlet 32. There is thus defined a further bend 42 in which an air lock can form. A block of sparingly soluble treatment material, indicated at 44, is disposed within the chamber 1 2. An aperture 50 is provided in the marginal flange of the device adjacent the upper edge of the device, whereby the device may be suspended from its upper edge in a flushing cistern.

Operation of the device is as follows. The device is normally suspended within a flushing cistern in the orientation illustrated in Fig. 1, with the plane of the sheet 1 8 substantially vertical, the device being at such a level that when the cistern is full, it is completely immersed in the water in the cistern, and that immediately after a flushing operation the water level within the cistern is below the outlet 32. As a result, when the cistern fills after a flushing operation, a body of air is trapped in the bend 42, but is displaced slightly, as the cistern fills, by water passing into the chamber 12 through the conduit 1 6 via the outlet 22, whilst air vents from the chamber 12 through the conduit 14.When the water level within the cistern reaches the level of the outlet 30, further air is prevented from venting from the chamber 1 2 and an air lock is formed in the bend 36. The cessation of flow of water into the chamber 12 at this time allows the body of air trapped in bend 42 to form an air lock at that location, so that the body of water within the chamber 1 2 is cut-off from the surrounding water in the cistern.

When the cistern is subsequently flushed, as the water level in the cistern falls past the device, solution from the chamber 12 flows out through the outlet 32, displacing slightly the body of air in the bend 42, whilst air passes into the chamber 12 through the conduit 14. When the outlet 32 is exposed by the falling water level within the cistern, or the lower edge of the wall 38 is exposed by the failing solution level within chamber 12 (whichever occurs first) dispensing of solution into the cistern from the chamber 12 is terminated.

Thus a fairly precisely metered, small quantity of liquid containing dissolved treatment material is discharged into the cistern each time it is flushed.

It will be appreciated that because, during an interval between flushing operations, the material 44 is in contact with only the very small quantity of liquid in chamber 12, and because the material is generally only sparingly soluble in water, over a period, the solution in chamber 12 becomes saturated with the treatment material so that dissolution of the latter is arrested, before substantial dissolution of the material takes place, so that even if the interval between successive flushing operations is protracted, for example where the premises are unoccupied over a holiday period, dissolution of the treatment material is limited and there is no rise in theconcentration of dissolved treatment material within the cistern, and thus the risk of undue corrosion due to such a rise in concentration is avoided.

Claims (8)

1. A dispensing device for use in a flushing cistern, comprising a unitary chamber and, at upper and lower levels of said chamber, respectively, an upper conduit and a lower conduit, each incorporating respective sections capable of trapping air to form air locks in the respective conduits when the device is immersed in water, said chamber being sealed, apart from said conduits, said upper conduit having at one end a port in said chamber, said lower conduit having at one end, a port in said chamber at a lower level than said port of the upper conduit, said upper conduit having at its opposite end, a further port, and said lower conduit having, at its opposite end, a further port below the level of said further port of the upper conduit, the arrangement being such that, in use, with a water soluble treatment material disposed in said chamber, and the device immersed in water, the water in said chamber can be isolated by such air locks from the water in which the device is immersed, to prevent migration of dissolved treatment material to the water in which the device is immersed, while when the level of the surrounding water is lowered past the device water can flow from said chamber via the lower conduit and air can flow into said chamber via the upper conduit, and, conversely, when the level of water is raised past the device, water can flow into said chamber via the lower conduit whilst air flows from the chamber via said upper conduit.

2. A dispensing device according to claim 1 wherein said lower conduit has said port thereof in said chamber disposed at a level above the bottom of said chamber, whereby when, in use, the level of the surrounding water is lowered past the device and predetermined a residual quantity of water is left in the bottom of said chamber.

3. A dispensing device according to claim 1 or claim 2 which is formed of plastics material by injection moulding.

4. A dispensing device according to claim 1 or claim 2 which comprises two plastics sheets bonded together face-to-face, said sheets having edge portions lying in respective substantially coincident planes and at least one of said sheets having portions deformed out of the plane of the respective said edge portions to define recesses which define, together with the other sheet, said chamber and said conduits.

5. A device according to claim 4 wherein at least one of said sheets is vacuum formed to define said recesses.

6. A device according to any preceding claim, including, disposed in said lower chamber, a block of water soluble treatment material.

7. A dispensing device for use in a flushing cistern, substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

8. Any novel feature on combination of features described herein.