This invention concerns a dispensing apparatus, and particularly apparatus for repeatedly dispensing a required volume of liquid from a container.

It may be required to repeatedly dispense a required volume of a liquid from a container. An example of such a requirement may be for dispensing detergents, cleaning liquids or other cleaning or disinfectant products, in for instance a domestic situation.

According to a first aspect of the invention there is provided a dispensing apparatus, the apparatus including a mounting arrangement to permit mounting onto an opening in a container to permit doses of liquid to be dispensed from the container through the opening, an outlet, a chamber member with a proximal end in connection with and surrounding the outlet, with the chamber member extending away from the outlet, one or more filling openings being provided in walls of the chamber member towards the proximal end, a closure member slidably moveable in the chamber from a closed position closing the outlet to an open position spaced from the outlet, an inlet being provided in the chamber member at a distal end thereof, a valve member being moveably mounted to the chamber member, and moveable between a closed position closing the chamber inlet, and an open position permitting liquid to pass through the inlet, one or more timing openings being provided in the valve member to permit liquid to flow into the chamber member at least when the valve member is in the closed position, the dispensing apparatus being configured such that as liquid flows through the or each timing opening into the chamber member, this will urge the closure member to a closed position.

The or each timing opening may have a profiled entrance converging thereinto, and walls of the entrance may be curved. The or each timing opening may have a profiled exit diverging therefrom, and the walls of the exit may be curved.

A profiled guide may be provided on the valve member adjacent to the or reach timing opening to guide liquid theretowards.

In one embodiment three timing openings are provided in the valve member, which timing openings may be equispaced and may be circumferentially spaced around a central axis.

The ratio of the total minimum cross sectional area of the or each filling opening to the total minimum cross sectional area of the or reach timing openings, may be greater than 12, may be at least 14, and may be at least 18.

The valve member may be slidably moveable towards or away from the chamber member, and retaining means may be provided to limit the extent of movement of the valve member away from the chamber member. The retaining means may comprise a plurality of spaced fingers with profiled distal ends to engage with a rim or other formation on the chamber member.

The chamber member may be substantially cylindrical. A rim may be provided at the distal end of the chamber member surrounding the inlet, which inlet may be coaxial with the chamber member.

A cylindrical sleeve may be provided surrounding the outlet and extending part way along the length of the chamber member. The closure member may be sealingly engageable with the cylindrical sleeve to close the outlet. The or each filling opening may extend from adjacent the proximal end of the chamber member, and may be in the form of a slot or slots in the chamber member walls. A plurality of filling openings may be provided in the chamber member walls, and the filling openings may be equispaced around the chamber member.

The apparatus may include a body which provides the mounting arrangement, and the mounting arrangement may comprise a screw thread. The chamber member may be selectively mountable on the body.

The closure member may comprise a disc coaxially eatable in the chamber member, and a plurality of legs may extend longitudinally from the circumferential edge of the disc to guide same.

According to a second aspect of the invention there is provided a container assembly for liquid, the assembly including a container and a dispensing apparatus according to any of the preceding twelve paragraphs.

The container may have flexible side walls such that the container may be squeezed to dispense liquid therefrom.

According to a third aspect of the invention there is provided a method of dispensing a required amount of liquid from a container, the method including using a dispensing apparatus according to any of said preceding twelve paragraphs, and choosing a chamber member with a required filling opening or openings to provide a required amount of liquid to be dispensed. A plurality of chamber members may be provided, with different openings to provide dispensing of different amounts of liquid, and a plurality of chamber members with substantially the same area of filling openings may be provided, but each with a different number of filling openings.

An embodiment of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which:-

Fig. 1 is a diagrammatic perspective view of a dispensing apparatus according to the invention; Figs 2-5 are respectively diagrammatic cross sectional perspective views in different conditions of the apparatus of Fig. 1 ;

Fig. 6 is a diagrammatic perspective cross sectional view of a component of the apparatus of Fig. 1 ;

Fig. 7 is a further diagrammatic perspective view of the component of Fig. 6; and

Fig. 8 is a diagrammatic perspective view of a number of alternative components of the apparatus of Fig. 1 .

Figs. 1 to 7 of the drawings show a dispensing apparatus 10 mountable for instance on a squeezable plastic bottle for holding liquids such as cleaning fluids or other cleaning disinfecting products. The apparatus 10 comprises a body in the form of a cap 12 with a screw thread 14 mountable on a corresponding thread on the bottle surrounding an opening in the bottle. A central outlet 16 is provided in the cap 12 with a short cylindrical surround 18 on the outside of the cap 12 and a longer cylindrical surround 20 on the inside of the cap 12.

A chamber member 22 is coaxially mounted relative to the outlet 16 on the inside of the cap 12. The chamber member 22 has an enlarged profiled proximal head 24 engageable in a snap fit on a profiled annular projection 26 on the inside of the cap 12. The chamber member 22 has a cylindrical body 28 extending from the head 24 and turning into a distal end 30 with a central opening providing an inlet 32 into the apparatus 10, the inlet 32 being surrounded by a rim 34. A plurality of filling openings 36 are provided in the walls of the chamber member 22 in the form of slots extending distally part way along the chamber member body 28 from the head 24.

Slidably mounted within the chamber member 22 is a closure member 38. The closure member 38 is in the form of a disc 40 slidably extending across the interior of the chamber member 22, with a plurality of spaced fingers 42 extending proximally around the edge of the disc 40 to guide the closure member 38 within the chamber member 22. A valve member 44 is provided moveably mounted to the inlet 32 of the chamber member 22. The valve member 44 comprises a circular body 46 which is larger than the inlet 32 such that in a closed position of the valve member 44 as shown for example in Figs. 3 to 5, the body 46 closes the inlet 32. A plurality of equispaced fingers 48 extend proximally from the circular body 46 so as to be extendible through the inlet 32. An outward step 50 is provided at each end of the fingers 48 which is of a size such that the steps 50 cannot pass through the inlet 32, thereby restricting the valve member 44 to a limited sliding movement relative to the chamber member 22. Three equispaced timing openings 52 are provided through the circular body 46. The timing openings 52 are circular in cross section and have a profiled entrance 54 on the distal side of the circular body 46. The profiled entrance 54 comprises a curved converging surface surrounding the respective opening 52. A profiled exit 56 is also provided on the proximal side of the circular body 46, again with in this instance a diverging surface. The profiled exit 56 is significantly less pronounced than the profiled entrance 54. A guide formation 58 is provided on the distal side of the circular body 46 and comprises an upstanding member 60 with a respective part circular and gently diverging surface 62 adjacent to each respective profiled entrance 54 to guide liquid thereinto.

In use, the apparatus 10 will be mounted on a flexible plastics material container of liquid (not shown), and in a rest position the apparatus will be in the condition shown in Figs. 1 and 2. As can be seen the valve member 44 extends distally from the chamber member 22 such that liquid can pass the valve member 44 through the inlet 32 into the chamber member 22. The valve member 44 is restrained in position by the steps 50 on the fingers 48 engaging with the rim 34. The closure member 38 substantially abuts against the fingers 48. To dispense liquid from the bottle, the bottle is inverted and squeezed.

The pressure applied by this squeezing action will cause the valve member 44 to be urged to a closed position as shown in Fig. 3. Liquid will enter into the chamber member 22 through the filling openings 36 and out through the outlet 16. As liquid exits through the outlet 16, further liquid will pass into the chamber member 22 through the filling openings 36. At the same time liquid will be passing through the timing openings 52 into the distal part of the chamber member 22. This liquid will urge the closure member 38 towards the outlet 16 until it engages with the inner cylindrical surround 20 to close off the outlet 16, by which point a required dose of liquid will have been dispensed.

Once pressure is released on the bottle as it is no longer squeezed, the valve member 44 will move distally and be opened, and the closure member 38 will move distally back towards the valve member 44 by virtue of liquid flowing into the chamber member 22 through the filling openings 36. As soon as the chamber member 22 is full again of liquid on the proximal side of the closure member, a further required dose of liquid can be dispensed in a similar manner. There is thus described an apparatus for dispensing a required dose of liquid which has been found to operate consistently and can be readily and inexpensively manufactured for long term reliable operation. The profiling of the guide formations and the entrance and exits through the valve member, mean that the ratio of the minimum area of the filling openings to the timing openings can be kept relatively large and can be at least 12, maybe 16 and maybe 18. This profiling provides for a reduced frictional loss as liquid contacts the walls surrounding the timing openings, and Vena Contracta is reduced by avoiding sudden contractions of the area through which the liquid passes. Providing the timing openings in the valve member provide for a stable configuration.

Fig. 8 shows a range of different chamber members 22 with differing numbers of filling openings 36, but where the overall total area of the filling openings 36 remains substantially constant. By using chamber members 22 with different numbers of filling openings 36, it is possible to provide different dosing volumes. For instance with a greater number of opening inlets, due to fluid dynamics the flow of liquid through the filling openings 36 is reduced such that a smaller dose of liquid will be achieved as a smaller amount of liquid will pass through the filling openings 36 into the chamber member 22 prior to closure of the outlet by the closure member 38.

A wide range of other modifications may be made without departing from the scope of the invention. For instance a different number of timing openings may be provided in the valve member. Different profiling could be provided on the valve member. The apparatus could be mountable on a container by a different configuration. Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.