GB2348677A - Measuring pressurised container contents by floating - Google Patents

Abstract

Dispensing apparatus comprises: housing 11 having mouthpiece 13 and valve block 2; a receptacle for receiving a quantity of fluid and a pressurised dispensing container 1 to be floated in said fluid; indicator means indicates the product quantity in the container according to a receptacle fluid level or the level at which the container floats. Embodiments include: (Figs 1a-c, 2a, b) a transparent or windowed removable cap 15, (21) with graduated scale 16 for water level comparison; a transparent graduated cylindrical sleeve (Figs. 2c,d) into which the container is placed, the contents indicated by the depth at which the container floats; graduations (Fig. 3c) on the container compared with the top of the receptacle; a ball (51 Figs. 4) floating in a receptacle wall channel and; the housing has a mouthpiece sealing cap (Figs 5) and doubles as a receptacle.

Description

IMPROVEMENTS IN OR RELATING TO DISPENSING APPARATUS The present invention relates to improvements in dispensing apparatus and, in particular, to improvements in apparatus providing means for measuring the quantity of product remaining in a pressurised dispensing container.

Pressurised dispensing containers are widely used in the pharmaceutical industry for storing medications and other products to be dispensed in aerosol form.

Such containers usually contain a propellant, such as HFC 134a, in which the product is suspended or dissolved. Solvents, such as ethanol, may also be present in the formulation. It is known to provide pressurised dispensing apparatus capable of dispensing metered doses of product from the containers upon each actuation of the container valve, for example, metered dose inhalers. The reliability and consistency of the metered dose is especially important where the product comprises or includes a medication. Inconsistent or unreliable dispensation could result in a user of the dispensing apparatus receiving too great or too little medication.

A problem found by many users of such apparatus is the inability to determine the quantity of product remaining in the container. Many types of apparatus continue to allow the dispensing of quantities of propellant and/or solvent when the container is near empty, even though the dose of product contained in the propellant is below the required level, thereby exacerbating the problem. Thus, users are often unaware that the dispensing apparatus is operating inadequately. This has potentially dangerous consequences where the product or medication dispensed is required urgently and no time is available to locate a replacement dispenser, such as in the treatment of asthmatic conditions. Sufferers of asthma often carry dispensers with them for extended periods of time, which may only be used on an occasional basis. Therefore, there is a danger that, where the user is unable to determine the contents of the pressurised dispensing container and the device is required in an emergency situation, the contents of the container may be inadequate.

It is an object of the present invention to provide apparatus for quickly and easily determining the quantity of product remaining in a pressurised dispensing container without the need for special testing equipment. Also, to provide apparatus suitable for use with conventional pressurised dispensing containers.

Accordingly, the present invention provides dispensing apparatus comprising a housing for receiving a pressurised dispensing container containing a product, a receptacle having one end which is closed and another end which is open for receiving a quantity of fluid and a pressurised dispensing container to be floated in said fluid, and indicator means for providing an indication of the quantity of product in a pressurised dispensing container according to a level at which a container floats.

In one embodiment the receptacle is removably located on the housing in a storage position.

In another embodiment the receptacle comprises an external housing which, in its storage condition, forms a dust cover for the housing.

Preferably the indicator means comprise markings.

In one embodiment the apparatus further comprises a sleeve for receiving a pressurised dispensing container, on which sleeve are provided said markings.

In another embodiment the housing is provided with said indicator means.

In a further embodiment the receptacle is at least partially transparent and the indicator means comprise graduated markings on the receptacle.

In one embodiment the indicator means comprise a channel in fluid communication with the receptacle and a floatable device located in said channel. Preferably the channel comprises a transparent portion for viewing the floatable device. Optionally the channel is formed in the receptacle. Alternatively the channel is formed in an indicator unit which is assembled with the receptacle. Optionally the transparent portion comprises graduated markings.

In one embodiment the receptacle is formed by the housing. Preferably the housing comprises a pressurised dispensing container receiving section, a mouthpiece, and a mouthpiece cover which is locatable on the mouthpiece and forms a water-tight seal therewith. Preferably an inner surface of the mouthpiece cover is provided with sealing means.

Optionally the sealing means comprise a rubber O-ring.

Alternatively the sealing means comprises a rubber gasket.

The present invention also provides dispensing apparatus as previously claimed assembled with a pressurised dispensing container.

In one embodiment depression of the receptacle in a storage condition actuates the pressurised dispensing container in the housing.

Optionally markings are provided on the pressurised dispensing container.

Preferably the apparatus further comprises a sealing means for closing a valve stem of the pressurised dispensing container prior to flotation of the pressurised dispensing container in the flotation container.

The present invention thus provides apparatus for quickly and easily determining the quantity of product remaining in a pressurised dispensing container. No separate testing equipment is required. Also, the apparatus is suitable for use with conventional pressurised dispensing containers. Embodiments of the present invention will now be described, by way of example only, with reference to the following drawings, in which : Figure la is a sectional side elevation of a first embodiment of dispensing apparatus according to the present invention; Figure lb is a perspective view of the apparatus of Figure la; Figure lc is a perspective view of a receptacle of the apparatus of Figure la being used in the determination of the quantity of contents of a pressurised dispensing container; Figure 2a is a sectional side elevation of a second embodiment of dispensing apparatus according to the present invention; Figure 2b is a perspective view of a receptacle of the apparatus of Figure 2a; Figure 2c is a perspective view of a sleeve of the apparatus of Figure 2a with and without a pressurised dispensing container; Figure 2d is a perspective view of a sleeve of the apparatus of Figure 2a without a pressurised dispensing container; Figure 3a is a side elevation of a third embodiment of dispensing apparatus according to the present invention; Figure 3b is a perspective view of the apparatus of Figure 3a; Figure 3c is a side elevation of an upper part of a modified version of the third embodiment of dispensing apparatus according to the present invention being used in the determination of the quantity of contents of a pressurised dispensing container; Figure 3d is a side elevation of the apparatus of Figure 3c; Figure 4a is a side elevation of a fourth embodiment of dispensing apparatus according to the present invention; Figure 4b is a perspective view of an indicator means of the apparatus of Figure 4a; Figure 4c is a plan view of the apparatus of Figure 4a; Figure 5a is a side elevation of a fifth embodiment of dispensing apparatus according to the present invention; Figure 5b is a perspective view of an indicator means of the apparatus of Figure 5a; Figure 5c is a plan view of the indicator means of Figure 5b ; Figure 5d is a perspective view of a modified version of indicator means of the apparatus of Figure 5a; Figure 5e is an end view of a mouthpiece cover of the apparatus of Figure 5a.

The following embodiments of the present invention are described for use in combination with a pressurised dispensing container 1 of known design. A typical pressurised dispensing container 1 has a metering valve secured to a can, for storing the product for dispensing, by means of a crimped ferrule.

The valve has a valve stem 3 projecting therefrom.

Depression of the valve stem 3 relative to the container actuates the valve mechanism to dispense a metered dose of product through an outlet of the valve stem.

Figures la to lc show a first embodiment of dispensing apparatus 10 according to the present invention. The dispensing apparatus 10 comprises a housing 11, having a substantially cylindrical portion 12 open at one end for receiving in use the pressurised dispensing container 1 and a mouthpiece 13 extending laterally from one end of cylindrical portion 12. Preferably, the mouthpiece 13 extends at a slight downward angle from cylindrical portion 12 as viewed in the orientation shown in Figure la.

The cylindrical portion 12 is provided with a valve stem block 2 for receiving an end of the valve stem 3 of the pressurised dispensing container 1. The valve stem block 2 defines a duct and orifice orientated towards mouthpiece 13 such that product dispensed from the container 1 through the valve stem 3 is directed into the mouthpiece 13 for inhalation by the user.

The internal workings of the pressurised dispensing container 1 and valve stem block 2 are of known design and do not form part of the present invention.

A cap 15 is provided which can be positioned over the cylindrical portion 12 of housing 11 and is slidable thereto. The cap 15 is open at one end and closed at the other end, and is made from a transparent material, preferably a plastic. An inner surface of the cap 15 is provided with inwardly directed projections 17 to ensure that an annular air gap 18 is maintained between the cap 15 and housing 11 which allows a flow of air from an exterior of the dispensing apparatus 10 into the interior.

The apparatus 10 may be used to dispense a metered dose of product from the dispensing container without first removing cap 15. A user of the apparatus inserts the mouthpiece 13 into his/her mouth and depresses the closed end of cap 15. This moves pressurised dispensing container 1 downwardly, as shown in Figure la, relative to the housing 11. Valve stem 3 is thus depressed relative to the pressurised dispensing container 1 to cause a dose of product to be dispensed in a known fashion.

In order to determine the quantity of product remaining in the pressurised dispensing container 1, the cap 15 is removed from the housing 11 by sliding the cap 15 off the cylindrical portion 12. The cap 15 is then placed on a flat, stable surface with its closed end lowermost and partially filled with water to a given mark.

The cap 15 has embossed on its outer surface a series of markings 16 forming a graduated scale which is used to indicate the quantity of product in the pressurised dispensing container 1, as described below.

The pressurised dispensing container 1 is removed from the housing 11 and placed in the cap 15 with the valve stem 3 uppermost. The pressurised dispensing container 1 floats in the water, thus causing a quantity of water to be displaced. The quantity of water displaced directly correlates to the mass of the pressurised dispensing container 1, and the mass of the container 1 is directly proportional to the contents contained therein. Therefore, the rise in water level in the cap 15 is a direct measure of the quantity of contents contained in the pressurised dispensing container 1 and hence may be used to determine the quantity of product in the dispensing container. A user may read off the quantity in the container by viewing which of the markings 16 on the cap 15 coincides with the level of the water.

A moulded cap may be provided to cover the valve stem 3 when the pressurised dispensing container 1 is inserted in the cap 15 to ensure that water does not become entrapped in the valve stem 3, which may result in the valve stem 3 becoming clogged.

Figures 2a to 2d show a second embodiment of dispensing apparatus according to the present invention. As in the first embodiment, the dispensing apparatus 10 comprises a housing 11 having a cylindrical portion 12 and mouthpiece 13 which receives, in use, a pressurised dispensing container 1 as previously described.

The apparatus 10 further comprises an outer housing 20, having a generally cylindrical portion 21 shaped to pass over the inner housing cylindrical portion 12, and a laterally extending portion 22, shaped to pass over the mouthpiece 13 as shown in Figure 2a. As shown in Figure 2b, the laterally extending end of the outer housing 20 is open to enable the inner housing 11 and pressurised dispensing container 1 to be inserted into the outer housing 20.

The cylindrical end of the outer housing 20 is closed.

The outer housing 20 is made either from a transparent material or has a transparent region defined therein.

The pressurised dispensing container 1 preferably has graduated markings 16 on its exterior surface.

Alternatively, a tight fitting transparent cylindrical sleeve 23, shown in Figure 2d, closed at one end may be provided in which the pressurised dispensing container may be inserted as shown in Figure 2c. An outer surface of the cylindrical sleeve bears graduated markings 16.

In order to determine the quantity of product in the pressurised dispensing container 1, the outer housing 20 is removed from the inner housing 11, the closed cylindrical end is placed on a flat stable surface and is partially filled with water. The pressurised dispensing container 1 is then removed from inner housing 11 and inserted either directly in the water-filled outer housing 20 with the valve stem 3 uppermost. Alternatively, the container is first placed in the cylindrical sleeve 23 and then placed in the water-filled outer housing 20 with the valve stem 3 uppermost. The outer housing 20 must be filled with enough water so that the container 1 is able to float.

In either case, the quantity of product in the pressurised dispensing container 1 is determined by the level at which the pressurised dispensing container 1 floats in the water-filled outer housing 20, as indicated by the level of water on the graduated scale of markings 16.

The outer housing 20 advantageously acts as a dust cover when located over the inner housing 11, as well as providing the measuring means.

Figures 3a to 3d show a third embodiment of dispensing apparatus according to the present invention. In this embodiment, a separate flotation vessel 30 is provided for determining the quantity of product in the pressurised dispensing container 1. As shown in Figures 3a and 3b, a first version of the third embodiment comprises a flotation vessel 30 with a scale of markings 16 marked on an exterior surface.

The flotation vessel 30 is made either wholly of a transparent material or has a transparent portion.

Preferably, the flotation vessel 30 has a generally cylindrical portion 31 and a laterally extending portion 32 shaped so as to fit over the housing 11 for storage purposes as shown in Figure 3d. However, the flotation vessel 30 may be any shape suitable for holding the pressurised dispensing container 1. In order to determine the quantity of product remaining in the pressurised dispensing container 1, the flotation vessel 30 is removed from housing 11, placed on a flat stable surface and filled with water to a predetermined level. The pressurised dispensing container 1 is then removed from housing 11 and inserted into the flotation vessel 30 with the valve stem 3 uppermost. The flotation of the pressurised dispensing container 1 results in a rise in the level of water in the flotation vessel 30. The rise of water level is directly related to the mass of the pressurised dispensing container and hence the quantity of product within the pressurised dispensing container 1. A user reads off the quantity of product by determining which of markings 16 coincides with the water level.

Figure 3c shows a second version of the third embodiment in which the markings 16 are indicated on a label 34 affixed to the pressurised dispensing container 1. The markings may relate to the number of doses remaining, and the number is determined by which mark on label 34 aligns with the top of flotation vessel 30.

Figures 4a to 4c show a fourth embodiment of dispensing apparatus according to the present invention. As in the third embodiment, a separate flotation vessel 30 is provided in which the pressurised dispensing container 1 is floated.

However, in this embodiment, an indicator gauge 50 is provided, which comprises an indicator ball 51 held within a channel 52 in fluid communication with the remainder of the flotation vessel 30. The exterior portion of the channel 52 is transparent such that the flotation indicator ball 51 may be seen by a user.

Markings 16 are provided either on the exterior portion of the guide channel 52 or on the flotation vessel 30 itself adjacent the guide channel 52.

Preferably, detent means 36 are provided at the top of the channel to prevent the indicator ball 51 from coming out of the channel 52, e. g. when the flotation vessel 30 is inverted.

The method of determining the quantity of product in the pressurised dispensing container is the same as in the third embodiment. However, the water level is more easily readable by viewing the position of the indicator ball against markings 16.

Figures 5a to Se show a fifth embodiment of the present invention. In this embodiment, a flotation vessel 50 is formed from the housing 11 itself. The housing 11 comprises a generally cylindrical portion 12 and mouthpiece 13 as in the previous embodiments.

However, a mouthpiece cover 14 is also provided which has an inner rubber seal 60 located on an inner surface thereof to provide a watertight seal between the mouthpiece cover 14 and the mouthpiece 13 when the mouthpiece cover 14 is positioned over the mouthpiece 13. The seal 60 may be an O-ring, gasket or other suitable seal and may be manufactured from suitable materials other than rubber.

An upper end of the housing cylindrical portion 12 is provided with a cut-out slot 61 in which an indicator window 62 is positioned. As shown in Figure 5b, the indicator window 62 may include a hollow channel 71 and indicator ball 72 similar to that described above in connection with the fourth embodiment. Alternatively, as shown in Figure 5d, the indicator window 92 may simply comprise a section of transparent material 73 provided with markings 16.

In either case, the quantity of product in the pressurised dispensing container 1 is determined by removing the pressurised dispensing container 1 from its dispensing position and then, after ensuring that mouthpiece cover 14 is securely fitted to mouthpiece 13, partially filling the housing 11 to a predetermined level. The pressurised dispensing container 1 is placed in the water with valve stem 3 uppermost. The water level can be determined by viewing the position of the indicator ball 72 or water level in the transparent portion 73.

Advantageously, in the fifth embodiment of the present invention the housing 11 and flotation vessel are formed from the same components. This reduces the number of components to be manufactured and also the number of parts to be carried by a user of the apparatus. Additionally the risk of the user losing the flotation vessel is removed.

The components of the above embodiments are preferably manufactured from plastic. Advantageously the components may be easily washed and cleaned.

Claims (22)

1. Claims: 1. Dispensing apparatus comprising a housing for receiving a pressurised dispensing container containing a product, a receptacle having one end which is closed and another end which is open for receiving a quantity of fluid and a pressurised dispensing container to be floated in said fluid, and indicator means for providing an indication of the quantity of product in a pressurised dispensing container according to a level at which a container floats.
2. 2. Apparatus as claimed in claim 1 wherein the receptacle is removably located on the housing in a storage position.
3. 3. Apparatus as claimed in claim 2 wherein the receptacle comprises an external housing which, in its storage condition, forms a dust cover for the housing.
4. 4. Apparatus as claimed in any preceding claim in which the indicator means comprise markings.
5. 5. Apparatus as claimed in claim 4 further comprising a sleeve for receiving a pressurised dispensing container, on which sleeve are provided said markings.
6. 6. Apparatus as claimed in any one of claims 1 to 3 wherein the housing is provided with said indicator means.
7. 7. Apparatus as claimed in claim 6 wherein the receptacle is at least partially transparent and the indicator means comprise graduated markings on the receptacle.
8. 8. Apparatus as claimed in claim 6 wherein the indicator means comprise a channel in fluid communication with the receptacle and a floatable device located in said channel.
9. 9. Apparatus as claimed in claim 8 wherein the channel comprises a transparent portion for viewing the floatable device.
10. 10. Apparatus as claimed in claim 8 or claim 9 wherein the channel is formed in the receptacle.
11. 11. Apparatus as claimed in claim 8 or claim 9 wherein the channel is formed in an indicator unit which is assembled with the receptacle.
12. 12. Apparatus as claimed in any one of claims 9 to 11 wherein the transparent portion comprises graduated markings.
13. 13. Apparatus as claimed in any one of claims 4 to 12 wherein the receptacle is formed by the housing.
14. 14. Apparatus as claimed in claim 13 wherein the housing comprises a pressurised dispensing container receiving section, a mouthpiece, and a mouthpiece cover which is locatable on the mouthpiece and forms a water-tight seal therewith.
15. 15. Apparatus as claimed in claim 14 wherein an inner surface of the mouthpiece cover is provided with sealing means.
16. 16. Apparatus as claimed in claim 15 wherein the sealing means comprise a rubber O-ring.
17. 17. Apparatus as claimed in claim 15 wherein the sealing means comprises a rubber gasket.
18. 18. Dispensing apparatus as claimed in any preceding claim assembled with a pressurised dispensing container.
19. 19. Apparatus as claimed in claim 18 wherein depression of the receptacle in a storage condition actuates the pressurised dispensing container in the housing.
20. 20. Apparatus as claimed in claim 18 or claim 19 wherein markings are provided on the pressurised dispensing container.
21. 21. Apparatus as claimed in any one of claims 18 to 20 further comprising a sealing means for closing a valve stem of the pressurised dispensing container prior to flotation of the pressurised dispensing container in the flotation container.
22. 22. Apparatus substantially as hereinbefore described with reference to and as shown in the accompanying drawings.