The present invention relates to a liquid atomiser. In particular, the present invention relates to a liquid atomiser which is integrally formed with a gas cylinder.

A device for atomising liquids is known from EP 2 229 204, the contents of which is incorporated herein by reference in its entirety. In this device, a liquid to be atomised is forced through a small opening under pressure causing the liquid to be dispensed from the device as an atomised mist. The pressure is applied to the liquid by a piston which may be directly mechanically driven, or which may be hydraulically or pneumatically driven.

Atomised liquids produced by devices such as those described above can be used for many purposes. One such use is for therapy, for example, by application to the skin or by inhalation. One example is the atomisation of sodium chloride solution for inhalation to assist with the removal of mucus and debris from the lungs. Another example is the atomisation of hyaluronic acid for skin beauty purposes.

The present invention provides a liquid atomiser comprising a gas cylinder, wherein an outlet of the gas cylinder is closed by a pierceable diaphragm, the atomiser further comprising a flexible bladder located inside the cylinder and containing a liquid to be atomised, wherein the space between the cylinder and the bladder contains pressurised gas, and wherein a mouth of the flexible bladder is in fluidic communication with the outlet of the cylinder.

In one example, the cylinder and the mouth of the flexible bladder are closed by the pierceable diaphragm which may be sealed at a common peripheral crimp surrounding the outlet of the cylinder. Preferably, the cylinder further comprises an access valve for inserting the pressurised gas into the space between the cylinder and the bladder, which preferably comprises a valve stem which is biased closed onto a seat by a biasing member and is openable by being displaced against the biasing member. The access valve therefore provides a convenient mechanism for filling the cylinder with pressurised gas.

Preferably, the cylinder has an inturned portion defining a recess surrounding the valve stem such that the valve stem never projects outwardly beyond the recess. In this way, the valve stem is protected by the cylinder from knocks, accidental actuation, and/or damage.

Preferably, the valve stem seats directly onto the part of the cylinder which surrounds the access valve. By seating the access valve directly on the cylinder, rather than on an intermediary component located on the cylinder, this reduces the number of components needed in the valve, making the atomiser easier to manufacture.

The biasing member may be a compression spring, which may be cylindrical but is preferably conical.

Preferably, the access valve is at least partially formed as a deep drawn component, as this makes the atomiser cheaper to manufacture. Preferably, the cylinder contains a gas at a pressure of up to 300 bar.

The cylinder may have a water capacity less than or equal to 500ml, or more preferably less than or equal to 200ml, or even more preferably less than or equal to 100ml.

In another aspect, the present invention provides a method of atomising a liquid comprising providing a flexible bladder containing the liquid to be atomised inside a pierceable gas cylinder, wherein the space between the cylinder and the bladder contains pressurised gas, and wherein a mouth of the flexible bladder is in fluidic communication with an outlet of the cylinder, the method further comprising piercing a sealing diaphragm of the gas cylinder and dispensing the liquid as a atomised mist.

Examples of the present invention will now be described with reference to the following figures in which:

Figure 1 shows a schematic diagram of a prior art atomiser;

Figure 2 shows an atomiser according to the present invention; and

Figure 3 shows a portion of the atomiser from Figure 2.

Referring to Figure 1 , a schematic diagram of a prior art atomiser 10 is shown. The atomiser 10 comprises a piston chamber 12 and a piston 1 1 . A liquid to be atomised 15 is located in the piston chamber 12. In use, the piston 1 1 is forced towards a small orifice 13 by a piston rod 16, or

alternatively, by gas pressure. As the liquid 15 is forced through the orifice 13, the liquid atomises into an atomised mist. Referring now to Figure 2, an atomiser 20 is shown comprising a gas cylinder 21 inside which is located a flexible bladder 22. The liquid to be atomised 25 is located in the flexible bladder 22. The atomiser 20 also preferably comprises an access valve 100. The flexible bladder 22 has a mouth 26 which is in fluidic

communication with an opening 27 located in a first end 21 A of the cylinder 21 . Both the mouth 26 of the flexible bladder 22 and the opening 27 of the cylinder 21 are closed by a pierceable diaphragm 23 which is crimped at its peripheral edge 24 around the cylinder opening 27. The mouth 26 of the flexible bladder is crimped around its peripheral edge between the diaphragm 23 and the cylinder opening 27. In this way, both the cylinder 21 and flexible bladder are sealed. In an alternative, the cylinder opening 27 and mouth 26 of the flexible bladder may be closed with a weld depending on the gas stored within the cylinder. A combination of crimping and welding may be used.

The access valve 100 is responsible for filling the cylinder 21 with pressurised gas, and is located within an opening 130 in the second end 21 B of the cylinder 21 .

Figure 3 shows in more detail a possible construction for the access valve 100. The access valve 100 is a deep drawn component formed generally of a cylindrical valve stem 1 18 which has a bulbous head 120 at its first end and a radially outwardly extending annular skirt 124 at its other end which extends back towards the head 120. The radially extending skirt contains an annular seal 126 that acts as a valve seat which is engageable against the cylinder 21 to plug the opening 130 in the cylinder 21 . The access valve 100 is biased into sealing engagement with the cylinder by a biasing member 128 in the form of a conical compression spring which acts between the bulbous head 122 of the valve 100 and the cylinder 21 . From this closed position, the valve 100 is openable by exerting an inward force on the valve stem 1 18 which overcomes the opposing biasing force from the biasing member 128.

The location of the access valve 100 on the cylinder 21 is not critical, and it will be appreciated that the access valve can be located anywhere on the cylinder 21 so long as it does not interfere with the operation of the diaphragm 23.

To prevent accidental damage or actuation of the valve 100, and to minimise the overall length of the cylinder 21 , the portion of the cylinder 21 housing the access valve 100 comprises an inturned portion 132 defining a recess within which the access valve 16 is located. Particularly, the recess is narrow enough and deep enough such that the valve stem 1 18 is only actuatable by a correspondingly narrow actuator (not shown), and such that the valve stem 1 18 never projects outwardly beyond the recess.

The atomiser 20 is constructed by initially locating the access valve through the opening in the first end 21 A of the cylinder 21 . The flexible bladder 22 is then installed at the first end 21 A, filled with liquid 25, and then crimped/welded into place together with a diaphragm 23.

A pressurised gas such as nitrogen is then pumped through the access valve 100, such that the gas is stored under pressure in the cylinder 21 . Once the gas has been pumped into the cylinder 21 , the cylinder 21 is ready to use.

In use, the diaphragm 23 is pierced to create a small orifice. In so doing, the liquid 25 is placed in communication with atmospheric pressure and the pressurised nitrogen in the cylinder squeezes the flexible bladder causing the liquid 25 to be ejected through the orifice as an atomised mist.

Once the liquid 25 has been squeezed out, the cylinder can either be disposed of, or the cylinder 21 can be sent off for refilling. To refill the cylinder 21 , the pierced diaphragm 23 is removed, the bladder 22 refilled with new liquid 25, and the bladder 22 then re-crimped/welded into place together with a new diaphragm 23. Pressurised gas is then pumped through the access valve 100 to re-pressurise the cylinder 21 . The water capacity of the cylinder 21 is typically less than 50cl and more preferably less than 20cl. In a particularly compact arrangement, the water capacity of the cylinder is 10cl or less.

The pressure of the gas in the cylinder 21 is up to 300 bar, but more preferably 200 bar. Lower pressures than 200 bar may also be used. It will be appreciated that rather than using an access valve 100 to fill the cylinder 21 with pressurised gas, the cylinder 21 could be manufactured without an access valve, and the bladder 22 inserted and located in the cylinder under pressurised conditions. In this way, the space between the cylinder and the bladder would be pressurised without the need for pumping gas into the cylinder using an access valve.