Aerosol dispensing device

This application is a Continuation of, and hereby claims priority under 35 U.S.C. §120 to, U.S. patent application Ser. No. 12/991,392, filed Jan. 26, 2011, now U.S. Pat. No. 8,770,187, issued Jul. 8, 2014, and entitled “Aerosol Dispensing Device,” which is the National Stage of International Application No. PCT/EP2009/053635, filed Mar. 26, 2009, which in turn claims priority to British Patent Application Number GB0808154.9, filed May 6, 2008. The entire contents of the aforementioned applications are herein expressly incorporated by reference.

This invention relates to an aerosol dispensing device for dispensing an aerosol to a user for inhalation, for example a nicotine-containing aerosol.

Hitherto, proposals have been made for a device reminiscent of a conventional tobacco-containing cigarette, for inhaling nicotine-containing products. For example U.S. Pat. No. 4,393,884 discloses an inhaler having a generally cylindrical body that receives a canister or pressurized fluid that contains nicotine, which is dispensed for inhalation when a user draws on the device in a manner similar to drawing smoke from a conventional cigarette. U.S. Pat. No. 4,945,929 discloses a generally cylindrical body containing a supply of nicotine and pressurised gas which is mixed in a valve to create an aerosol directed to a mouthpiece for a user. The body of the device includes a baffle arrangement to block the passage of relatively large droplets created in the aerosol and allow only smaller size droplets to pass to the mouthpiece for inhalation. However, a problem with this device is that the larger droplets may undesirably drain from the device in a liquid stream. Also, the mere use of a nicotine aerosol may not find acceptance by smokers as a substitute for conventional cigarettes that provide tobacco smoke for inhalation due to the lack of smoke flavour in the nicotine aerosol.

According to the invention, there is provided an aerosol dispensing device comprising a body that provides a plenum, a mouthpiece, a valve for dispensing a fluid as an aerosol with relatively large and small droplet sizes into the plenum for supply to a user through the mouthpiece, and a baffle arrangement that provides first and second passageways each coupled at one end to the plenum and so configured to receive relatively small and large droplets in the aerosol respectively, the other end of the first passageway extending to an outlet in the mouthpiece to supply the small size droplets to the user, and the other end of the second passageway being closed to inhibit passage of the large size droplets to the mouthpiece.

A member may be provided to capture the large size droplets within the second passageway, for example an absorbent pad may be located at the other end of the second passageway to capture the large size droplets. The pad may be pre-loaded with a tobacco flavourant in order to improve the acceptability of the nicotine aerosol provided to the user through the mouthpiece.

The body may be generally tubular and thereby reminiscent of a cigarette, with the mouthpiece at one end thereof.

The body arrangement may comprise an elongate baffle member within the tubular body extending from the plenum towards the mouthpiece in order to provide the first and second passageways. The baffle member may be generally cylindrical and configured so that the first passageway is between the body and the baffle member and the second passageway is within the baffle member. The tubular member and baffle member may be coaxially arranged.

The baffle member may include side apertures to permit aerosol to flow from the second passageway to the first passageway.

At least one air vent may be provided through the body member to allow external air to be drawn into the aerosol supplied to the mouthpiece.

The valve may be operable to open and supply the aerosol into the plenum in response to a user puffing on the mouthpiece. The valve may include a valve seat in the body, an orifice extending through the valve seat and configured to be supplied with pressurised fluid for forming the aerosol, and a moveable valve member resiliently biased against the valve seat to obturate the orifice and so configured that a pressure reduction caused by a user puffing on the mouthpiece causes the valve member to move away from the valve seat to release pressurised fluid through the orifice.

The valve member may include a flexible diaphragm which may include apertures to allow the passage of aerosol, biased by a compression spring towards the valve seat.

The body may include a chamber to receive the pressurised fluid, which may be held in a replaceable canister.

The pressurised fluid may include nicotine and/or other suitable flavours such as for example a tobacco extract, and the overall dress of the device may generally correspond to that of a conventional tobacco-containing filter cigarette.

In order that the invention may be more fully understood, an embodiment thereof will now be described by way of illustrative example with reference to the accompanying drawings in which:

FIG. 1 is a schematic perspective view of an aerosol device;

FIG. 2 is an exploded view of the component parts of the device shown in FIG. 1 ;

FIG. 3 is a longitudinal sectional view of the device shown in FIG. 1 ;

FIG. 4 is an enlarged view of a valve arrangement shown in FIG. 3 ;

FIG. 5 is a perspective view of the removal mouthpiece of the device from one end;

FIG. 6 is a perspective view of a mouthpiece from the other end illustrating the mouthpiece outlet; and

FIG. 7 is a sectional view of the mouthpiece shown in FIG. 5 .

Referring to FIG. 1 , the aerosol device has a generally cylindrical, tubular body of a size and dress generally corresponding to a conventional tobacco-containing cigarette. The device has a mouthpiece member 1 , a proximal tubular body member 2 coupled to a distal tubular body member 3 having an end cap 4 .

As shown in FIGS. 2 & 3 , the distal tube 3 of the body member 3 acts as a chamber that receives a canister 5 charged with a pressurised fluid containing a substance to be inhaled by the user e.g. nicotine or a nicotine containing substance or mixture. The canister may be pressurised with a gas such as nitrogen or carbon dioxide or may contain a propellant such as hydrofluoroalkane. The canister 5 has an internal valve 6 operated by depression of an inwardly slidable outlet tube 7 to release pressurised fluid from within the canister. The structure of the valve 6 can be conventional, of the type commonly used in pressurised aerosol sprays to provide a continuous rather than a metered flow, and so will not be described in further detail herein. In order to fit the canister into the device, the end cap 4 is removed from a threaded fitment 8 on the far end of the distal tube 3 and the canister 5 is slid into the distal tube so as to abut a canister valve coupling 9 located between the proximal distal body tubes 2 , 3 .

The canister valve coupling 9 includes an inlet part 10 and an outlet part 11 shown in more detail in FIG. 4 . The inlet part 10 includes an axial, tubular opening 12 which is formed with an annular flange 13 that captures an O-ring 14 . In use, the outlet tube 7 of the canister 5 is inserted into the opening 12 to abut the outlet part 11 . As the canister 5 is moved into position and the end cap 4 is closed, the canister valve tube 7 is forced inwardly of the canister 5 to open the valve 6 . A pressure seal is formed by the O-ring 14 and also by a gasket 15 within the opening 12 . The outlet part 11 includes an axial orifice 16 for supplying pressurised fluid from the canister 5 in the direction of the mouthpiece 1 .

Flow of the fluid from the canister is controlled by a valve 17 that comprises a valve seat 18 formed in the outlet part 11 of the valve coupling 9 , and an axially moveable valve member 19 that comprises a generally cup-shaped diaphragm which abuts at its periphery a transverse bulkhead 20 that contains an outlet nozzle 21 . The valve member 19 also includes a central valve block 22 which is biased by a compression spring 23 against the valve seat 18 so as normally to close the orifice 16 .

The valve 17 is configured to open and release pressurised fluid from the canister 5 in response to a user drawing on the mouthpiece, in a manner corresponding to drawing smoke from a conventional tobacco-containing cigarette. The puffing action reduces pressure in the proximal tube 2 of the body and the reduced pressure is communicated through the outlet nozzle 21 such that the pressure of fluid in the canister 5 can act against the force of the compression spring 23 to move the valve block 22 towards mouthpiece, thereby opening the orifice 16 so that fluid from the canister 5 can flow towards the mouthpiece 1 through the orifice 16 . The diaphragm 19 includes a plurality of small apertures 21 to allow the fluid to flow through the diaphragm and then pass through the outlet nozzle 21 into the proximal tube part 2 . The diameter of the outlet nozzle 21 is configured to produce an aerosol spray of fluid into the proximal tube part 2 of the body.

For example, assuming a pressure of 125 psi in the canister 5 and an orifice diameter of 0.2 mm, the force of the pressurized fluid acting to open the diaphragm 19 is approximately 3 grams. The domed, cup shape of the diaphragm 19 will move to open the valve 17 in response to a user applying negative pressure during inhalation that exceeds the closure force. In this example, if a safety factor of 2 is assumed to keep the outlet closed by means of the spring 23 i.e. approx 6 grams, and with a diaphragm diameter of approximately 8 mm, the negative pressure needed to open the valve 17 is approximately 0.16 psi. This also provides the benefit of a “built-in” natural resistance for the inhalation that approximates to the resistance of a conventional cigarette.

The bulkhead 20 includes a diametric groove 25 aligned with the outlet nozzle 21 so that if the valve block 22 abuts bulkhead 20 whilst the valve is opened, it does not block the outlet nozzle 21 since fluid that passes through the diaphragm apertures 24 can pass along the groove 25 into the nozzle 21 .

The mouthpiece 1 comprises a generally tubular member that may be integrally moulded in a plastics material and is configured to be removably fitted into the proximal tube part 2 for interchange. In this example, the mouthpiece 1 is push-fitted into the proximal tube part 2 to assume a configuration shown in FIG. 3 .

Referring to FIGS. 5, 6 and 7 , the mouthpiece 1 includes a cylindrical outer part 26 and a coaxial generally cylindrical inner part 27 . At the proximal end of the mouthpiece, the inner part 27 defines a continuous tube which is closed at the proximal end of the mouthpiece by an end plate 28 . Towards the distal end, the inner part 27 includes side apertures 29 disposed between wings 30 that in this example comprise cylindrical extensions of the inner part 27 . The inner part 27 thus acts as a baffle member as explained in more detail hereinafter.

A pad 31 of absorbent material is included within the inner part 27 at its closed end 28 . The pad 31 may be formed of cellulose acetate material of the kind conventionally used in filters for tobacco-containing cigarettes and may be impregnated with a tobacco flavourant e.g. menthol and/or a flavourant which simulates the aroma of tobacco smoke e.g. by pre-exposing the pad 31 to tobacco smoke. However, it will be appreciated that the pad 31 can be made of other absorbent materials.

As shown in FIG. 3 , when the mouthpiece 1 is inserted into the tube 2 , a plenum 32 is provided in the tube 2 adjacent to the outlet nozzle 21 for the aerosol produced from fluid in the canister 5 . The inner and outer parts 26 , 27 of the mouthpiece 1 define first and second passageways extending from the plenum 32 towards the proximal end of the mouthpiece 1 . The first passageway 33 is generally cylindrical and provided between the inner and outer parts 26 , 27 of the mouthpiece. The first passageway 33 has an inlet that communicates with the plenum 32 and an outlet coupled to outlet apertures 34 in the mouthpiece 1 , for supplying aerosol from the plenum 32 to the user in response to the user drawing on the mouthpiece.

Referring to FIG. 3 , the proximal tube 2 includes air vents 35 adjacent the bulkhead 20 that allow external air to be drawn into the plenum 32 in response to the user drawing on the mouthpiece 1 . The air mixes with the aerosol in the plenum 32 to dilute the aerosol supplied to the user through the passageway 33 .

The aerosol emitted by the nozzle 21 will have a range of droplet sizes and the mouthpiece and baffle arrangement is configured so that only relatively small size aerosol droplets reach the user. For example, the nozzle configuration may produce droplets with a size range of 2 μm to 200 μm, although for effective delivery, a relatively small droplet size range of less than 50 μm may desirable, for example in the range of 2.5 μm to 4 μm for long delivery or 20 μm to 50 μm for buccal delivery. The relatively large sized droplets due to their large mass tend to be projected more longitudinally of the axis of the mouthpiece as compared with the smaller size droplets. The inner part 27 acts as a second passageway 36 that is closed by end plate 28 and captures the relatively large size droplets, which can be absorbed by the pad 31 to prevent a leakage of liquid from the canister passing to the mouthpiece and through openings 34 . Furthermore, the dampening of the pad 31 by the aerosol may facilitate release of the flavourant from the pad which will become mixed into the aerosol flow supplied to the user through the first passageway 33 . The mouthpiece 1 can be easily removed to allow the mouthpiece to be changed, in particular to allow the pad 31 to be changed when its flavourant becomes expired.

Referring again to FIG. 1 , it will be understood that the dress of the aerosol device may be configured to correspond to the appearance of a conventional cigarette, with the end cap 4 corresponding to the ash, the distal tube 3 corresponding to the tobacco rod and the proximal tube 2 corresponding to the filter. However, unlike a conventional cigarette, the device described herein operates without emitting tobacco smoke. The canister may include sufficient pressurised fluid to replicate the smoking of a plurality e.g. twenty conventional tobacco-containing cigarettes, after which the canister may be removed and replaced by unscrewing the end cap 4 .

Many modifications and variations of the described example of the invention will be evident to those skilled in the art, which fall within the scope of the claims hereinafter. For example, although the described device is charged with pressurised fluid in the canister 5 , the chamber within the distal tube 3 could be a sealed chamber which is directed charged with pressurised fluid through a filling valve. Also, the device need not be tubular in appearance and other body shaped could be used.