WO2008090318A1

WO2008090318A1 - Metering valve

Info

Publication number: WO2008090318A1
Application number: PCT/GB2008/000197
Authority: WO
Inventors: Richard John Warby; Paul Allsop; Colin Dickens; David Jonathan Glenton; Michael Cameron Bainton; Shane Alistair Day; Robert Perkins; Stuart George David Kelly
Original assignee: Consort Medical Ltd
Current assignee: Consort Medical Ltd
Priority date: 2007-01-22
Filing date: 2008-01-21
Publication date: 2008-07-31
Anticipated expiration: 2009-07-22
Also published as: GB2457630A; GB2457630B; GB0911454D0; GB0701183D0

Abstract

A metering valve for a pressurised dispensing container comprising a metering chamber (5); an inlet (9) to the metering chamber; an outlet (10) to the metering chamber; one or more inlet sealing members (7) for sealing the inlet (9) to the metering chamber (5), and one or more outlet sealing members (8) for sealing the outlet (10) to themetering chamber (5). The metering chamber (5) is static and the one or more inlet sealing members (7) are rotatable between a first position, in which the inlet (9) to the metering chamber is open, and a second position, in which the inlet (9) to the metering chamber is closed, and the one or more outlet sealing members (8) are rotatable between a first position, in which the outlet (10) to the metering chamber is closed, and a second position, in which the outlet (10) to the metering chamber is open.

Description

METERING VALVE

The present invention relates to improvements in or relating to metering valves. In particular, the invention relates to rotary valves in which the valve is operated by rotation of one or more parts of the valve. Preferably, the invention relates to rotary valves of the type comprising a metering chamber, to provide metered doses from pressurised dispensing containers.

In accordance with the present invention, there is provided a metering valve for a pressurised dispensing container comprising: a metering chamber; an inlet to the metering chamber; an outlet to the metering chamber; one or more inlet sealing members for sealing the inlet to the metering chamber, and one or more outlet sealing members for sealing the outlet to the metering chamber; wherein the metering chamber is static and the one or more inlet sealing members are rotatable between a first position, in which the inlet to the metering chamber is open, and a second position, in which the inlet to the metering chamber is closed, and the one or more outlet sealing members are rotatable between a first position, in which the outlet to the metering chamber is closed, and a second position, in which the outlet to the metering chamber is open.

Advantageously, rotary valves of the present invention provide simplicity of metering chamber geometry over prior art valves. In particular, the present invention of rotary valves removes the requirement for a central valve stem in _ p _

the metering chamber. Further advantageously, rotary valves of the present invention reduce the number of dimensions which determine the metered volume of product dispensed which, in turn, improves the accuracy of dispensed metered doses.

Preferably, the inlet and outlet to the metering chamber are separate and may be non-unitary.

Alternatively, the inlet and outlet to the metering chamber may be unitary, and may be a common inlet/outlet. The metering chamber may be arranged to provide uniflow of a fluid through the metering chamber or the metering valve. Preferably, uniflow of fluid is from the inlet to the outlet of the metering chamber. The term uniflow is used to mean a flow of fluid in one direction only. Therefore, a fluid expelled from a metering valve travelling in uniflow travels in, approximately, one direction through the metering valve or the metering chamber. Naturally, slight changes in direction would not substantially alter the main direction of the flow or nature of the flow of fluid, and the term encompasses small variations in direction. The one or more inlet sealing members may be rotatable on an axis parallel with the uniflow of a fluid. Further, the one or more outlet sealing members may be rotatable on an axis parallel with the uniflow of a fluid. Preferably, the inlet and outlet to the metering chamber are located at respective ends of the metering chamber. Most preferably, the inlet and outlet to the metering chamber are provided diametrically. As a consequence, the inlet and outlet are, preferably, provided directly opposite each other. The inlet and outlet of the metering chamber may be provided at side walls, or on upper or lower end walls of the metering chamber. The one or more inlet sealing members may be disc-like. Further the one or more outlet sealing members may be disc- like. The one or more inlet sealing members may be planar and provide a planar sealing surface. The one or more outlet sealing members may be planar and provide a planar sealing surface.

The metering chamber may be radially-offset from the centre of rotation of the one or more inlet sealing members and/or the one or more outlet sealing members. In this manner, when radially-offset, the metering chamber may be positioned at a radial distance from the centre of rotation of the one or more inlet seals and/or the one or more outlet seals. Additionally, the inlet and outlet to the metering chamber may be radially-offset. In this manner, the inlet and outlet may be positioned at different radial distances from the centre of rotation of the inlet or outlet sealing members .

The inlet to the metering chamber may be shaped to seal with the planar sealing surface, and the outlet to the metering chamber may be shaped to seal with the planar sealing surface.

Preferably, the one or more inlet sealing members are angularly offset from the one or more outlet sealing members. Further, the inlet and outlet may be angularly separated.

The one or more inlet sealing members may be manually rotated and, alternatively, the one or more inlet sealing members may be electro-mechanically rotated. Rotation may be provided by a piezo electric device, such as, a piezo drive or rotation may be provided by an electric motor.

Preferably, the inlet and/or outlet sealing members are each arranged to be rotatable by 180 degrees between first and second positions. The inlet and/or outlet sealing members may be arranged to be rotatable in one direction only.

Alternatively, the inlet and/or outlet sealing members are arranged to be reciprocally rotatable.

Most preferably, the metering valve comprises a dose counter, for indicating each time the metering valve is operated. The dose counter may be mechanical or may be electro-mechanical. Advantageously, rotary valves provide an increased displacement of inner and/or outer seals between a chamber filling / isolation position and a chamber dispensing position, which aids the design and tolerancing of dose counters, in particular, mechanical dose counters. Ideally, walls of the metering chamber are rigid, to aid accuracy of dispensed metered doses. The metering chamber may be provided in two parts. The metering valve may be provided as part of a pressurised dispensing container.

Advantageously, end stops may be provided on the metering chamber, the ferrule and/or the sealing members, to prevent over-rotation of the inlet or outlet sealing members. Further, a ratchet may be provided to provide rotation of the sealing members in one direction only.

In a second aspect the invention provides the following. Preferably the one or more inlet sealing members comprise a sleeve enveloping at least a portion of the metering chamber and wherein the inlet sleeve may comprise an inlet hole arranged to interact with the inlet to the metering chamber. Further, the inlet sealing member may comprise an inner sleeve and an outer sleeve. Preferably, the one or more outlet sealing members may comprise a sleeve enveloping at least a portion of the metering chamber and the outlet sleeve may comprise an outlet hole arranged to interact with the outlet to the metering chamber. Further, the outlet sealing member may comprise an inner sleeve and an outer sleeve.

The inlet and outlet may be angularly and/or axially separated around an axis of rotation of the inlet or outlet sealing members and/or along a length of the metering chamber body.

Advantageously, the inner sleeve aids sealing between the outer sleeve and the metering chamber. Most preferred is that the inner sleeve is made of a material comprising an elastomeric material. Alternatively, the inlet sleeve and the outlet sleeve are a unitary sleeve.

In a third aspect the invention provides the following. Preferably the one or more inlet sealing members comprise a rotatable sealing disc and the one or more outlet sealing members comprise a rotatable sealing disc. The inlet or outlet sealing disc may be rotatable by 180 degrees between first and second positions.

The two sealing discs may be independently rotatable with respect to the metering chamber. Preferably the inlet or outlet rotatable sealing disc comprises an aperture for interacting with the inlet or outlet to the metering chamber. Most preferably, the apertures of the first and second sealing discs are angulary offset. The sealing discs may be driven to rotate, for example, by a piezo electric device, such as one or more piezo elements or a piezo drive. The sealing discs may be provided with teeth to interact with a cog driven to rotate the discs. The teeth are, preferably, provided on peripheries of the sealing disc. Alternatively, the sealing discs may be rotated by means of a gearbox from a single motor or piezo electric device .

In a fourth aspect the invention provides the following. Preferably, the one or more inlet sealing members are provided by two separate inlet plates, and the one or more outlet sealing members are provided by two separate outlet plates. Each of the two sets of separate plates may comprise apertures, which when the plates are put together, are alignable. The plates are, ideally, rotatable relative to each other to provide alignment.

A bimetallic spring may provide a motion force for alignment of the inlet and/or outlet plates. Preferably, a bimetallic spring is provided for each of the sets of the inlet plates and the outlet plates.

Most preferably, the inlet and/or outlet plates are ceramic or ceramic coated.

In a fifth aspect the invention provides the following. Preferably the one or more inlet sealing members comprise a rotary valve, and the one or more outlet sealing members comprise a rotary valve. A rotary valve may be provided at each end of the metering chamber to seal the metering chamber. The rotary valves may be independently rotatable or may be geared together to provide corresponding opening of one valve and closure of the other valve. Each rotary valve may comprise a rotatable valve core located within a correspondingly-shaped valve body. The valve core includes an aperture through the valve core and is spherical, in preferred embodiments.

Rotation of the valve core may be provided by a piezo ring motor which, preferably, drives the gearing.

The sealing members provide a fluid-tight seal at the inlet and outlet of the metering chamber. The invention is described in relation to movable sealing members - inlet and/or outlet sealing members - with respect to a static metering chamber. In order to provide a seal between two parts of a valve, both a valve seal and a valve seat are provided, one on each part. The valve seal interacts with the valve seat and, when in touching engagement, they can act to close the valve. At least part of the sealing member is arranged to communicate directly or otherwise with at least part of the metering chamber body to seal the metering chamber. Therefore, it will be understood that either the sealing member or the metering chamber body may act as a valve seal-type part, and the other part a valve seat-type part, and vice-versa. Additionally, the part acting as a valve seal-type part will preferably comprise at least a portion made from a suitable sealing material. Further additionally, the part acting as the valve seat-type part may also comprise at least a portion made from a suitable sealing material.

The metering valve may be for use in a pharmaceutical dispensing device, such as, for example, a pulmonary, nasal, or sub-lingual delivery device. A preferred use of the valve is in a pharmaceutical metered dose aerosol inhaler device. The term pharmaceutical as used herein is intended to encompass any pharmaceutical, compound, composition, medicament, agent or product which can be delivered or administered to a human being or animal, for example pharmaceuticals, drugs, biological and medicinal products. Examples include antiallergics, analgesics, antibodies, vaccines, bronchodilators, antihistamines, therapeutic proteins and peptides, antitussives, anginal preparations, antibiotics, anti-inflammatory preparations, hormones, or sulfonamides, such as, for example, a vasoconstrictive amine, an enzyme, an alkaloid, or a steroid, including combinations of two or more thereof. In particular, examples include isoproterenol [alpha- (isopropylaminomethyl) protocatechuyl alcohol] , phenylephrine, phenylpropanolamine, glucagon, insulin, DNAse, adrenochrome, trypsin, epinephrine, ephedrine, narcotine, codeine, atropine, heparin, morphine, dihydromorphinone, ergotamine, scopolamine, methapyrilene, cyanocobalamin, terbutaline, rimiterol, salbutamol, flunisolide, colchicine, pirbuterol, beclomethasone, orciprenaline, fentanyl, and diamorphine, streptomycin, penicillin, procaine penicillin, tetracycline, chlorotetracycline and hydroxytetracycline, adrenocorticotropic hormone and adrenocortical hormones, such as cortisone, hydrocortisone, hydrocortisone acetate and prednisolone, insulin, cromolyn sodium, and mometasone, including combinations of two or more thereof.

The pharmaceutical may be used as either the free base or as one or more salts conventional in the art, such as, for example, acetate, benzenesulphonate, benzoate, bircarbonate, bitartrate, bromide, calcium edetate, camsylate, carbonate, chloride, citrate, dihydrochloride, edetate, edisylate, estolate, esylate, fumarate, fluceptate, gluconate, glutamate, glycollylarsanilate, hexylresorcinate, hydrobromide, hydrochloride, hydroxynaphthoate, iodide, isethionate, lactate, lactobionate, malate, maleate, mandelate, mesylate, methylbromide, methylnitrate, methylsulphate, mucate, napsylate, nitrate, pamoate, (embonate) , pantothenate, phosphate, diphosphate, polygalacturonate, salicylate, stearate, subacetate, succinate, sulphate, tannate, tartrate, and triethiodide, including combinations of two or more thereof. Cationic salts may also be used, for example the alkali metals, e.g. Na and K, and ammonium salts and salts of amines known in the art to be pharmaceutically acceptable, for example glycine, ethylene diamine, choline, diethanolamine, triethanolamine, octadecylamine, diethylamine, triethylamine, l-amino-2-propanol-amino-2- (hydroxymethyl) propane-1, 3-diol, and l-(3,4- dihydroxyphenyl) -2 isopropylaminoethanol .

The pharmaceutical will typically be one which is suitable for inhalation and may be provided in any suitable form for this purpose, for example as a solution or powder suspension in a solvent or carrier liquid, for example ethanol, or isopropyl alcohol. Typical propellants are HFA134a, HFA227 and di-methyl ether.

The pharmaceutical may, for example, be one which is suitable for the treatment of asthma. Examples include salbutamol, beclomethasone, salmeterol, fluticasone, formoterol, terbutaline, sodium chromoglycate, budesonide and flunisolide, and physiologically acceptable salts (for example salbutamol sulphate, salmeterol xinafoate, fluticasone propionate, beclomethasone dipropionate, and terbutaline sulphate) , solvates and esters, including combinations of two or more thereof. Individual isomers such as, for example, R-salbutamol, may also be used. As will be appreciated, the pharmaceutical may comprise of one or more active ingredients, an example of which is flutiform, and may optionally be provided together with a suitable carrier, for example a liquid carrier. One or more surfactants may be included if desired.

The valve seals and gaskets of the valve may be formed from any suitable material having acceptable performance characteristics. Preferred examples include nitrile, EPDM and other thermoplastic elastomers, butyl and neoprene. Other rigid components of the valve, such as the valve body, chamber body and valve stem may be formed, for example, from polyester, nylon, acetal or similar. Alternative materials for the rigid components of the valve include stainless steel, ceramics and glass. These rigid components can be termed as 'non-sealing components', although it will be understood that the inner seal, outer seal or gasket may form a seal when abutting the so-called non-sealing components.

One or more components of the metering valve may have a layer of one or more polymerised monomers bonded to at least a portion thereof. Preferably the one or more monomers are selected from the group of materials comprising perfluoro- cyclohexane, perfluoro-hexane, tetrafluoroethylene, trifluoroethylene, vinylidene fluoride, vinylfluoride, fluoroethylene, fluoropropylene, a siloxane, a silazane, and a parylene .

In order that the invention may be fully disclosed, embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a cross-sectional view of a first embodiment of metering valve according to the present invention;

Figure 2 is an exploded view of part of the metering valve of Figure 1;

Figure 3 is a partial-cross-sectional view of a second embodiment of metering valve according to the present invention;

Figure 4 is a view of a gearing arrangement utilised in the metering valve according to Figure 3;

Figure 5 is a cross-sectional view of a third embodiment of metering valve according to the present invention;

Figure 6 is a view showing internal components of the metering valve of Figure 5;

Figure 7 is a view showing an alternative arrangement of some internal components to those of Figure 6;

Figure 8 is a cross-sectional view of a fourth embodiment of metering valve according to the present invention;

Figure 9 is a part-perspective view of the rotary valve arrangement of Figure 8;

Figure 10 is a cross-sectional view of a fifth embodiment of metering valve according to the present invention.

Figure 1 shows a first embodiment of metering valve according to the present invention, the metering valve being indicated, in general, by reference 1. The metering valve 1 is intended for use in a pressurised dispensing container and is arranged to be located in a neck of a container (not shown) . A ferrule 3 is provided to hold the metering valve 1 in the correct position in the neck of the container 2 to provide a pressurised dispensing container which is capable of providing metered doses. A nozzle 37 is also provided as part of the ferrule 3, to guide a dispensed pressurised fluid to a target area. The metering valve 1 is provided by a metering chamber 5, inlet valve seal 7, and outlet valve seal 8.

According to the present invention, the metering valve 1 is provided with a static metering chamber body 5, one or more rotatable inlet sealing members 7 and one or more rotatable outlet sealing members 8.

The metering chamber 5 is cylindrical and is provided as part of a disc-like member 30, which provides the metering chamber body 5, and defines a metering chamber volume 5C. The disc 30 is static. The metering chamber body 5 has an inlet 9 and an outlet 10 of the metering chamber volume 5C, located at respective ends of the cylinder. In this embodiment, the inlet 9 and outlet 10 are provided diametrically. Rotatable inlet and outlet sealing members 7,8 are provided in the form of sealing discs 33 and 34, respectively, which interact with part of the disc 30 The inlet sealing member 7 is provided by an upper surface of the sealing disc 33, which contacts a lower surface of the static disc 30. In particular, the sealing disc 33 contacts parts of the metering chamber body 5 outside of the metering chamber volume 5C - to provide the required fluid-tight seal. The sealing disc 33 has a circular or arcuate sealing path 7A which allows it to seal the metering chamber volume 5C at the inlet 9, whilst the sealing disc 33 rotates. The outlet sealing member 8 is provided by a lower surface of the sealing disc 34, which contacts an upper surface of the static disc 30. In particular, the sealing disc 34 contacts parts of the metering chamber body 5 outside of the metering chamber volume 5C - to provide the required fluid-tight seal. The sealing disc 34 has a circular or arcuate sealing path 8A which allows it to seal the metering chamber volume 5C at the outlet, whilst the sealing disc 34 rotates. The sealing discs 33,34 are held in contact with the disc 30 and metering chamber body 5 by a valve body 6. The sealing disc 33 is provided with an aperture 35, which is positioned to interact with the inlet 9 for filling the metering chamber volume 5C, and the sealing disc 34 is provided with an aperture 36, for interacting with the outlet 10, for emptying the metering chamber volume 5C. The apertures 35 and 36 are angularly offset about the axis of rotation of the sealing discs 33,34, such that, the metering chamber volume 5C is arranged to only interact with one of apertures 35 or 36 at a time. As it can be seen from Figure 1, the metering chamber body 5 is static and inlet sealing member 7 is rotatable between a first position, in which the inlet 9 to the metering chamber volume 5C is open, and a second position, in which the inlet 9 to the metering chamber volume 5C is closed, and the outlet sealing member 8 is rotatable between a first position, in which the outlet 10 to the metering chamber volume 5C is closed, and a second position, in which the outlet 10 to the metering chamber volume 5C is open. Further, rotation between the first and second positions of the inlet and outlet sealing member is shown as 180 degrees; however, other angles may be used.

The inlet and outlet sealing discs 33,34 are driven to rotate by a piezo electric device 31, in the form of one or more piezo elements. Each of the sealing discs 33,34 are provided with teeth 32 on their peripheries for interacting, directly or otherwise through a gearing arrangement, with the piezo electric device 31. Sealing disc 33 is rotatable between a first position, in which the inlet 9 to the metering chamber volume 5C is open and a second position, in which the inlet 9 is closed. Further, sealing disc 34 is rotatable between a first position, in which the outlet 10 to the metering chamber volume 5C is closed and a second position, in which the outlet 10 is open.

In use with a pressurised dispensing container (not shown) , and as can be seen from Figure 1, aperture 35 is adjacent the inlet 9 and pressurised fluid enters the metering chamber volume 5C, through the aperture 35 and inlet 9, until an equilibrium is reached between the container and the metering chamber volume 5C. Typically, refilling of the metering chamber volume 5C is caused by the internal pressure of fluid in the pressurised dispensing container outweighing the atmospheric pressure of any remaining fluid in the metering chamber volume 5C. The sealing disc 33 is rotated - from a first position - which closes the open inlet 9 to a second position where the inlet 9 is closed. In this example, the sealing disc 33 rotates 180 degrees. As regards sealing disc 34, it is rotated from a first position - in which the outlet 10 is closed - to a second position - in which the outlet 10 is open. When the outlet 10 is open, the pressurised fluid exits the metering chamber volume 5C through the outlet 10, aperture 36 and nozzle 37. Pressurised fluid leaves the metering chamber volume 5C owing to volatisation of the product within the metering chamber volume 5C, i.e. the fluid is expelled from the metering chamber volume 5C by the vapour pressure of the propellant, as the propellant comes into contact with atmospheric pressure when the outlet 10 is opened. Therefore, a metered dose of product is dispensed from the pressurised dispensing container. In order to refill the metering chamber volume 5C, the outlet sealing disc 34 is rotated in return towards its first position from its second position by a further 180 degrees. This rotation can occur in either direction from the second position back towards the first position. Subsequently, the inlet sealing disc 33 is also rotated by 180 degrees in either direction towards the first position of the inlet sealing disc 33. In the first position of the inlet sealing disc 33, pressurised fluid from the pressurised dispensing container flows into the metering chamber volume 5C until an equilibrium is reached again, and the whole process can be repeated for subsequent metered doses. In an alternative, either one of the sealing discs may be rotated by an electric motor or solenoid arrangement, or by a piezo drive.

The inlet sealing disc 33 and outlet sealing disc 34 are arranged to rotate at the same time, but are also arranged such that only the inlet 9 or outlet 10 is open at any one time. As an alternative, the sealing discs 33,34 may be independently rotated.

As it will be seen from Figure 1, the aperture 35 of the inlet sealing disc 33 and the aperture 36 of the outlet sealing disc 34 are angularly offset by 180 degrees. In particular, this provides the advantage that only one of the inlet 9 or outlet 10 can be open at any one time.

In order to aid sealing of the metering chamber 5, the disc 30 may be provided with additional seals which are provided to interact with inner surfaces of sealing discs 33,34. Alternatively, or additionally, the sealing discs 33,34 may be provided with additional seals which interact with the disc 30. These additional seals may be a layer of an appropriate sealing material covering parts of the respective discs 30,33,34 or 0-ring seals surrounding the metering chamber 5 or apertures 35,36.

A second embodiment of the present invention is shown in Figures 3 and 4. The second embodiment is similar to the first embodiment discussed above and only the main differences will be discussed in detail. A pressurised dispensing container is shown by reference 2.

This embodiment also includes a metering chamber body 5 defining a metering chamber volume 5C. An inlet sealing disc 33 is provided to open and close the inlet 9. Further, an outlet sealing disc 34 is provided to open and close the outlet 10. In this embodiment, the metering chamber volume 5C is provided as part of the valve body 6 - which includes the metering chamber body 5. Therefore, as compared to the first embodiment, the valve body 6 encloses all of the parts of the metering valve 1 and defines the metering chamber volume 5C. In addition, the valve body 6 may form part of the ferrule 3 for connecting the metering valve 1 to a pressurised dispensing container 2. Alternatively, a separate ferrule 3 may be provided.

As discussed in relation to the first embodiment, sealing discs 33 and 34 are rotatable to provide an open inlet 9 and a closed outlet 10, and following rotation of those sealing discs 33,34, a closed inlet 9 and an open outlet 10. However, in this embodiment, appropriate gearing is provided such that both sealing discs 33,34 are driven to rotate by a single piezo electric device 31. The piezo electric device 31 is provided with gears to rotate both sealing discs 33,34 at the same time, which arrangement can be seen more clearly in Figure 4. In Figure 4, the piezo electric device 31 drives sealing disc 34 using an upper gear wheel 13A which meshes with the teeth 32 of the sealing disc 34. Further, and in a similar manner, a lower gear 13B is provided for rotation of the inlet sealing disc 33.

A third embodiment of the present invention is shown in Figures 5, 6 and 7. Common references to the first two embodiments have been utilised where appropriate. Figure 5 shows a metering valve 1 for location in the end of a pressurised dispensing container (not shown) . A gasket seal 4 is provided to seal between the metering valve 1 and the container. A metering chamber volume 5C is defined within a metering chamber body 5 and inlet and outlet sealing members 7, 8. The valve body 6 surrounds the metering valve 1 and provides a nozzle 37. Additionally, the valve body 6 comprises a ferrule for connecting the metering valve to a container (not shown) .

The metering chamber volume 5C is cylindrical and is static. The inlet sealing members 7 are provided by two separate inlet plates HA and HB, and the outlet sealing members 8 are provided by two separate outlet plates 12A and 12B. The plates HA, HB are provided with apertures 14,15, respectively - which apertures 14,15 are alignable to open the inlet 9 and may be non-aligned to close the inlet 9.

The outlet plates 12A, 12B are provided with apertures 16,17, respectively - which apertures 16,17 are alignable to open the outlet 10 and may be non-aligned to close the outlet 10. The inlet plates HA, HB are rotatable with respect to each other. In particular, the plates HA, HB, 12A, 12B are ceramic or ceramic coated. In this manner, one of plates HA or HB may remain stationary or both plates HA, HB may be rotated. Rotation of either one or both of plates HA, HB is provided by a bimetallic spring arrangement, which provides a motion force for alignment of the apertures 14,15. In addition, outlet plates 12A, 12B work in a similar manner to inlet plates HA, HB, such that apertures 15,16 may be aligned by a motion force provided a bimetallic spring arrangement. A separate helical bimetallic spring 18 is provided to align apertures 14,15, to open the inlet to the metering chamber volume 5C. In addition, a further separate helical bimetallic spring 19 is provided to align apertures 15,16, to open the outlet 10 of the metering chamber volume 5C. In accordance with the present invention, the bimetallic springs 18,19 provide either the inlet 9 or outlet 10 open at any one time. Figure 6 shows, in particular, the arrangement of the bimetallic spring 18 and inlet plates HA and HB. A portion 18A of the bimetallic spring 18 is located in an aperture 2OA of the plate HA. A corresponding portion 18B of the bimetallic spring 18 is locatable in an aperture 2OB of the plate HB. Once plates HA and HB have been contacted together, they easily slide relative to one another. In a first position of the plates HA, HB, the apertures- 14, 15 are provided in alignment. However, following a rotation of the plates HA, HB, the apertures 14,15 are provided in non-alignment. Therefore, it will be understood that rotation of plates HA, HB provides an opening and closure of the inlet sealing members 7 to the metering chamber volume 5C. The bimetallic spring 18 is sensitive to changes in temperature and can react to relatively small temperature differentials to exert a force, through portions 18A, 18B to the plates HA, HB, which rotates the plates HA, HB relative to each other. As such, a small temperature differential can provide opening and closing of the inlet 9 of the metering chamber volume 5C. It will, of course, be understood that the arrangement of bimetallic spring 19 and plates 12A, 12B which make up the outlet sealing members 8 (and outlet 10) of the metering chamber volume 5C are arranged to operate in the same manner as the inlet sealing members 7 (and inlet 9) .

In particular, and as shown in Figure 5, it will be understood that the metering chamber body 5 is static and the inlet plates HA, HB are rotatable between a first position, in which the inlet apertures 14,15 are aligned, and a second position, in which the inlet apertures 14,15 are non-aligned, and the outlet plates 12A, 12B are rotatable between a first position, in which the outlet apertures 16,17 are non-aligned, and a second position in which the outlet apertures 16,17 are aligned. This arrangement provides for either filling of the metering chamber volume 5C or emptying thereof. Therefore, in the first position of inlet plates HA, HB, 12A, 12B, a pressurised fluid enters the metering chamber volume 5C and, following relative rotation of the plates HA, HB, 12A, 12B to their second positions, the pressurised fluid exits the metering chamber volume 5C and travels through the nozzle 37.

Preferably, heat energy is supplied to the bimetallic springs 18,19 for them to expand or contract to open and close the inlet 9 and/or outlet 10 of the metering chamber volume 5C. A small electrical charge may be used, for example, supplied from a battery.

Most preferably, a dispensing apparatus will be provided by a hand-held device, having a retained electronic unit and disposable reservoir unit for medicament. Figure 7 shows an alternative arrangement of bimetallic spring 18,19, in which a spiral bimetallic spring may be used instead of the helical spring shown in Figures 5 and 6.

The fourth embodiment of the present invention is shown in Figures 8 and 9. Common references to the first three embodiments have been utilised where appropriate. Figures 8 and 9 show an arrangement of rotary valves (metering valve 1) for providing metered doses from a pressurised dispensing container (not shown) . In this embodiment, the inlet sealing members 7 comprises a rotary valve 7 and the outlet sealing members 8 also comprises a rotary valve 8. Each sealing member 7,8 comprises a spherical, rotary valve core located within a correspondingly-shaped body. The valve cores form barriers that are used to seal the inlet 9 and outlet 10 of the metering chamber. A metering chamber body 5 is provided between the inlet sealing member 7 and outlet sealing member 8 and the metering chamber body 5 defines therewithin a metering chamber volume 5C. A nozzle 37 extends from the outlet sealing member 8 to direct a dispensed dose to a target area. Further, a ferrule 3 is provided to connect the metering valve 1 to a pressurised dispensing container (not shown) . In particular, the inlet rotary valve 7 is provided at an inlet 9 of the metering chamber volume 5C and the outlet valve 8 is provided at the outlet 10 of the metering chamber volume 5C. Each rotary valve 7,8 is provided by a rotatable valve core 2OA, 2OB, within a correspondingly-shaped valve body 21. The inlet rotary valve 7 includes an aperture 22 through the valve core 2OA, creating a passageway for fluid through the valve 7. Further, the outlet valve 8 includes an aperture 23 through the valve core 2OB, creating a passageway for fluid through the valve 8. Each rotary valve 7,8 is rotatable from an open position to a closed position. In accordance with the present invention, the valve core of the inlet rotary valve 7 is rotatable between a first position in which the inlet 9 to the metering chamber volume 5C is open, and a second position, in which the inlet 9 to the metering chamber volume 5C is closed, and the valve core of the outlet rotary valve 8 is rotatable between a first position, in which the outlet 10 to the metering chamber volume 5C is closed, and a second position, in which the outlet 10 to the metering chamber volume 5C is open. In particular, the metering valve 1 is arranged such that, the inlet rotary valve 7 is arranged to provide an open inlet 9 whilst the outlet rotary valve is arranged to provide a closed outlet 10 and vice versa. Therefore, in this manner, it will be understood that only the inlet rotary valve 7 or the outlet rotary valve 8 is open at any one time.

As shown in Figures 8 and 9, the inlet rotary valve 7 is open as the aperture 22 is in-line with the inlet 9 of the metering chamber volume 5C. In this position, filling of the metering chamber volume 5C can occur. The outlet rotary valve 8 is shown as closed because aperture 23 is not in-line with the outlet 10 of metering chamber volume 5C.

As can be seen in Figure 8, the valve cores 2OA, 2OB of the inlet rotary valve 7 and outlet rotary valve 8 are geared together, using gears 24,25, respectively, so that both valve cores 2OA, 2OB rotate at the same time. Rotation of the valve cores 2OA, 2OB is provided by a piezo ring motor (not shown) . In particular, the piezo ring motor drives the gear 24, which subseguently drives the gear 25. It will be seen from Figures 8 and 9 that a rotation by 90 degrees of both valve cores 2OA, 2OB is required to close the inlet aperture 22 and open the outlet aperture 23. Of course, other angles of rotation may be chosen.

In use, and as shown in Figure 8 in particular, a pressurised fluid enters the metering chamber volume 5C via the open inlet rotary valve 7, through the aperture 22, until an equilibrium is reached. Operation of the piezo ring motor drives the gear 24 to rotate the gear 25, such that, the valve core 20 of the inlet rotary valve is rotated by 90 degrees and the valve core 2OB of the outlet rotary valve 8 is also rotated by 90 degrees. During this rotation from a first position of each valve to a second position of that valve, the inlet valve 7 is closed by the rotation and the outlet valve 8 is subsequently opened. In the second position of the inlet rotary valve 7, the inlet 9 is closed. However, in the second position of the outlet rotary valve 8, the outlet 10 is open such that a pressurised fluid within the metering chamber volume 5C is dispensed to the atmosphere, in a similar manner to that described in relation to embodiment 1. Further, refilling of the metering chamber volume 5C occurs by an opposite rotation of gears 24,25 to, at first, close the open outlet 10 and, subsequently, open the closed inlet 9. In this first position, a pressurised fluid may again enter the metering chamber volume 5C.

Figure 10 shows a fifth embodiment of metering valve according to the present invention. Common references to the first four embodiments have been utilised where appropriate.

This fifth embodiment comprises a static metering chamber body 5 located partially, within a rotatable sleeve 28 and, partially, within a rotatable sleeve 29. The sleeve 28 envelops at least a portion of the metering chamber body 5 and contact between the two parts provides an inlet sealing member. The inlet sleeve 28 is provided with an inlet hole 26, that is arranged to interact with the inlet 9 of the metering chamber volume 5C. Additionally, an outlet sealing member is provided by contact between a sleeve 29 enveloping at least a portion of the metering chamber body 5. The outlet sleeve 29 is provided with an outlet hole 27, that is arranged to interact with the outlet 10 to the metering chamber volume 5C. The sleeve 28 and sleeve 29 cover at least part of the metering chamber body 5, and in particular, the sleeve 28 surrounds the inlet 9 to the metering chamber volume 5C and the sleeve 29 surrounds the outlet 10 from the metering chamber volume 5C, providing fluid-tight seals.

An inner surface 38 of the sleeve 28 provides a fluid-tight seal between the sleeve 28 and an outside surface 39 of the metering chamber body 5 adjacent the inlet 9. In a similar manner, an inner surface 40 of the sleeve 29 forms a fluid-tight seal with an outer surface 41 of the metering chamber body 5 adjacent the outlet 10. Alternatively, a valve seal such as an 0-ring or fine seal may be located between the inlet sleeve 28 and metering chamber body 5 and/or the outlet sleeve 29 and the metering chamber body 5. The inlet hole 26 is provided in the sleeve 28 to interact with the inlet 9, when the inlet 9 is adjacent the inlet hole 26, and provide a passage for fluid to enter the metering chamber volume 5C. The outlet hole 24 is provided in the outlet sleeve 29 to interact with the outlet 10, when the outlet 10 is adjacent the outlet hole 27, and provide a passage for fluid to exit from the metering chamber volume 5C, as shown by arrow 42 in Figure 10. The metering chamber body 5 is static and the sleeves 28,29 are rotatable. In particular, the inlet sleeve 28 is rotatable between a first position, in which the inlet 9 to the metering chamber volume 5C is open, and a second position, in which the inlet 9 to the metering chamber volume 5C is closed, and the outlet sleeve 29 is rotatable between a first position in which the outlet 10 to the metering chamber volume 5C is closed, and a second position, in which the outlet 10 to the metering chamber volume 5C is open. Advantageously, the arrangement as described provides an opening at one of the inlet 9 or outlet 10, and a closure at the other.

The inlet 9 and outlet 10 are provided at respective ends of the metering chamber body 5, such that, they are axially offset along the longitudinal axis of the metering chamber body 5. The inlet and outlet holes 26,27 are provided on the sleeves 28,29 and are oriented to face in the same direction. Consequently, for the inlet hole 26 to interact with the inlet 9 and the outlet hole 27 to interact with the outlet 10 independently, the inlet 9 and outlet 10 are also angularly offset by 90 degrees, about the axis of rotation of the metering chamber body 5. Thus, the sleeve 28 and sleeve 29, and therefore the inlet hole 26 and outlet hole 27, rotate around the metering chamber body 5 by 90 degrees between first and second positions. Of course, it will be understood that other angular separation between the inlet and outlet 9,10 can be chosen. As shown in Figure 10, electro-mechanical rotation of the inlet hole 26 and outlet hole 27 around the metering chamber body 5 is provided by a rotary solenoid 43 surrounding the metering chamber body 5. In this manner, the rotary solenoid 43 connects with the sleeves 28,29 and causes them to rotate, to provide opening and closing of the inlet 9 and outlet 10. In a further alternative, rotation of the inlet hole 26 and outlet hole 27 around the metering chamber body 5 may be provided by. an electric motor connected to the sleeves 28,29.It will be understood that, in relation to this embodiment, the location of the inlet 9, outlet 10, inlet hole 26 and outlet hole 27 can be altered to suit needs without departure from the invention.

Further, for any of the disclosed embodiments, end stops may be provided on the metering chamber body, the ferrule or the sealing members to prevent over rotation of the one or more inlet or outlet sealing members. .

Claims

CLAIMS :

1.) A metering valve for a pressurised dispensing container comprising: a metering chamber; an inlet to the metering chamber; an outlet to the metering chamber; one or more inlet sealing members for sealing the inlet to the metering chamber, and one or more outlet sealing members for sealing the outlet to the metering chamber; wherein the metering chamber is static and the one or more inlet sealing members are rotatable between a first position, in which the inlet to the metering chamber is open, and a second position, in which the inlet to the metering chamber is closed, and the one or more outlet sealing members are rotatable between a first position, in which the outlet to the metering chamber is closed, and a second position, in which the outlet to the metering chamber is open.

2.) A metering valve as claimed in claim 1, wherein the inlet and outlet to the metering chamber are separate.

3.) A metering valve as claimed in claim 1 or claim 2, wherein the inlet and outlet to the metering chamber are non-unitary.

4.) A metering valve as claimed in claim 1, wherein the inlet and outlet to the metering chamber are unitary.

5.) A metering valve as claimed in claim 4, wherein the inlet and outlet to the metering chamber are a common inlet/outlet.

6.) A metering valve as claimed in any preceding claim, wherein the metering chamber is arranged to provide uniflow of a fluid through the metering chamber or the metering valve.

7.) A metering valve as claimed in claim 6, wherein uniflow of fluid is from the inlet to the outlet of the metering chamber.

8.) A metering valve as claimed in claim 6 or claim 7, wherein the one or more inlet sealing members are rotatable on an axis parallel with the uniflow of a fluid.

9.) A metering valve as claimed in claim 6, 7 or 8, wherein the one or more outlet sealing members are rotatable on an axis parallel with the uniflow of a fluid.

10.) A metering valve as claimed in any preceding claim, wherein the inlet and outlet to the metering chamber are located at respective ends of the metering chamber.

11.) A metering valve as claimed in any preceding claim, wherein the inlet and outlet to the metering chamber are provided diametrically.

12.) A metering valve as claimed in any preceding claim, wherein the inlet and outlet to the metering chamber are provided at side walls, or on upper or lower end walls of the metering chamber.

13.) A metering valve as claimed in any preceding claim, wherein the one or more inlet sealing members are disc-like.

14.) A metering valve as claimed in any preceding claim, wherein the one or more outlet sealing members are disc- like.

15.) A metering valve as claimed in any preceding claim, wherein the metering chamber is radially-offset from the centre of rotation of the one or more inlet sealing members.

16.) A metering valve as claimed in any preceding claim, wherein the metering chamber is radially-offset from the centre of rotation of the one or more outlet sealing members .

17.) A metering valve as claimed in claim 15 and claim 16, wherein the inlet and outlet to the metering chamber are radially-offset with respect to each other.

18.) A metering valve as claimed in any preceding claim, wherein the one or more inlet sealing members are planar and provide a planar sealing surface.

19.) A metering valve as claimed in any preceding claim, wherein the one. or more outlet sealing members are planar and provide a planar sealing surface.

20.) A metering valve as claimed in any preceding claim, wherein the inlet to the metering chamber is shaped to seal with the planar sealing surface.

21.) A metering valve as claimed in any preceding claim, wherein the outlet to the metering chamber is shaped to seal with the planar sealing surface.

22.) A metering valve as claimed in any preceding claim, wherein the one or more inlet sealing members are angularly offset from the one or more outlet sealing members.

23.) A metering valve as claimed in any preceding claim, wherein the one or more inlet sealing members are manually rotated.

24.) A metering valve as claimed in any one of claims 1 to 22, wherein the one or more inlet sealing members are electro-mechanically rotated.

25.) A metering valve as claimed in any preceding claim, wherein the- one or more outlet sealing members are manually rotated.

26.) A metering valve as claimed in any one of claims 1 to 24, wherein the one or more outlet sealing members are electro-mechanically rotated.

27.) A metering valve as claimed in claim 24 or claim 26, wherein rotation is provided by a piezo electric device.

28.) A metering valve as claimed in claim 24 or claim 26, wherein the piezo electric device is a piezo drive.

29.) A metering valve as claimed in claim 24 or claim 26, wherein rotation is provided by an electric motor.

30.) A metering valve as claimed in any preceding claim, wherein the inlet and/or outlet sealing members are each arranged to be rotatable by 180 degrees between first and second positions.

31.) A metering valve as claimed in any preceding claim, wherein the inlet and/or outlet sealing members are arranged to be rotatable in one direction only.

32.) A metering valve as claimed in any one of claims 1 to 30, wherein the inlet and/or outlet sealing members are arranged to be reciprocally rotatable.

33.) A metering valve as claimed in any preceding claim, wherein the metering valve comprises a dose counter, for indicating each time the metering valve is operated.

34.) A metering valve as claimed in claim 33, wherein the dose counter is mechanical.

35.) A metering valve as claimed in claim 33, wherein the dose counter is electro-mechanical.

36.) A metering valve as claimed in any preceding claim, wherein walls of the metering chamber are rigid.

37). A metering valve as claimed in any preceding claim, wherein the metering chamber is provided in two parts.

38.) A metering valve as claimed in any preceding claim, wherein the metering valve is provided as part of a pressurised dispensing container.

39.) A metering valve as claimed in any preceding claim, wherein end stops are provided on the metering chamber, the ferrule and/or the sealing members.

40.) A metering valve as claimed in any preceding claim, comprising a ratchet to provide rotation of the one or more inlet sealing members and/or one or more outlet sealing members in one direction only.

41.) A metering valve as claimed in any preceding claim, wherein the one or more inlet sealing members comprise a sleeve enveloping at least a portion of the metering chamber.

42.) A metering valve as claimed in claim 41, wherein the inlet sleeve comprises an inlet hole arranged to interact with the inlet to the metering chamber.

43.) A metering valve as claimed in claim 41 or claim 42, wherein the inlet sealing members comprise an inner sleeve and an outer sleeve.

44.) A metering valve as claimed in any preceding claim, wherein the one or more outlet sealing members comprise a sleeve enveloping at least a portion of the metering chamber .

45.) A metering valve as claimed in claim 44, wherein the outlet sleeve comprises an outlet hole arranged to interact with the outlet to the metering chamber.

46.) A metering valve as claimed in claim 44, or claim 45, wherein the outlet sealing members comprise an inner sleeve and an outer sleeve.

47.) A metering valve as claimed in claim 43 or claim 46, wherein the inner sleeve aids sealing between the outer sleeve and the metering chamber.

48.) A metering valve as claimed in claim 47, wherein the inner sleeve is made of a material comprising an elastomeric material .

49.) A metering valve as claimed claim 47 or claim 48, wherein the inlet sleeve and the outlet sleeve are a unitary sleeve.

50.) A metering valve as claimed in any one of claims 41 to 49, wherein electro-mechanical rotation of the one or more inlet sealing members and/or one or more outlet sealing members is/are provided by a rotary solenoid.

51.) A metering valve as claimed in any one of claims 41 to 50, wherein electro-mechanical rotation of the one or more inlet sealing members and/or one or more outlet sealing members is provided by an electric motor.

52.) A metering valve as^' claimed in any one of claims 41 to 51, wherein rotation of the one or more inlet sealing members and/or one or more outlet sealing members is/are provided by an externally-mounted gear.

53.) A metering valve as claimed in any one of claims 1 to 40, wherein the one or more inlet sealing members comprise a rotatable sealing disc.

54.) A metering valve as claimed in any one of claims 1 to 40, or claim 53 wherein the one or more outlet sealing members comprise a rotatable sealing disc.

55.) A metering valve as claimed in claim 53 or claim 54, wherein the inlet or outlet sealing disc is rotatable by 180 degrees between first and second positions.

56.) A metering valve as claimed in any o,ne of claims 53 to 55, wherein the two sealing discs are independently rotatable with respect to the metering chamber.

57.) A metering valve as claimed in any one of claims 53 to 55, wherein the inlet or outlet rotatable sealing disc comprises an aperture for interacting with the inlet or outlet to the metering chamber.

58.) A metering valve as claimed in claim 57, wherein the apertures of the first and second sealing discs are angularly offset.

59.) A metering valve as claimed in any one of claims 53 to 58, wherein the sealing discs are driven to rotate.

60.) A metering valve as claimed in claim 59, wherein the sealing discs are driven by a piezo electric device.

61.) A metering valve as claimed in claim 60, wherein the piezo electric device is one or more piezo elements.

62. ) A metering valve as claimed in claim 60, wherein the piezo electric device is a piezo drive.

63.) A metering valve as claimed in any one of claims 59 to 62, wherein the sealing discs are provided with teeth to interact with a cog driven to rotate the discs.

64.) A metering valve as claimed in claim 63, wherein teeth are provided on peripheries of the sealing discs.

65.) A metering valve as claimed in anyone of claims 63 to 64, wherein the sealing discs are rotated by means of a gearbox from a single motor or piezo electric device.

66.) A metering valve as claimed in anyone of claims 1 to 40, wherein the one or more inlet sealing members are provided by two separate inlet plates.

67.) A metering valve as claimed in any one of claims 1 to 40, or claim 66, wherein the one or more outlet sealing members are provided by two separate outlet plates.

68.) A metering valve as claimed in claim 66 or claim 67, wherein each of the two separate plates comprise apertures, which when the plates are put together, are alignable.

69.) A metering valve as claimed in claim 68, wherein the plates are rotatable relative to each other to provide alignment .

70.) A metering valve as claimed in claim 68 or claim 69 wherein a bimetallic spring provides a motion force for alignment of the inlet and/or outlet plates.

71.) A metering valve as claimed in claim 70, wherein a bimetallic spring is provided for each of the inlet plates and the outlet plates.

72.) A metering valve as claimed in any one of claims 66 to 71, wherein the inlet and/or outlet plates are ceramic or ceramic coated.

73.) A metering valve as claimed in any one of claims 1 to 40, wherein the one or more inlet sealing members comprise a rotary valve.

74.) A metering valve as claimed in any one of claims 1 to 40, or claim 73 wherein the one or more outlet sealing members comprise a rotary valve.

75.) A metering valve as claimed in claim 74, wherein a rotary valve is provided at each end of the metering chamber to seal the metering chamber.

76.) A metering valve as claimed in claim 74 or claim 75, wherein the rotary valves are independently rotatable.

77.) A metering valve as claimed in any one of claims 74 to 76, wherein the rotary valves are geared together to provide corresponding opening of one valve and closure of the other valve.

78.) A metering valve as claimed in any one of claims 74 to 76, wherein the rotary valve comprises a rotatable valve core located within a correspondingly-shaped valve body.

79.) A metering valve as claimed in claim 78, wherein the valve core includes an aperture through the valve core.

80.) A metering valve as claimed in claim 79, wherein the rotatable valve core is spherical.

81.) A metering valve as claimed in any one of claims 78 to 80, wherein rotation of the valve core is provided by a piezo ring motor.

82.) A metering valve as claimed in claim 81, wherein the piezo ring motor drives the gearing.

83.) A metering valve for a pressurised dispensing container substantially as herein disclosed, with reference to the accompanying drawings and description.