Canister   

Abstract: In one embodiment, a canister has a housing closed by a crimped cap and includes a metered valve for dispensing a metered dose of aerosol. A seal is provided between the canister and the body of the metered valve to prevent leakage of the pressurised fluid from within a canister around the valve. The seal is also configured to deform resiliently and admit pressurised fluid continuously into the canister when pressurised fluid is applied to the valve exteriorly of the canister. In this way, the canister can be pressurised with a continuous flow of pressurised fluid from its exterior notwithstanding the metering action of the valve. A liner is disposed around the valve to seal the crimped joint between the housing and the cap, and the fluid that enters the canister can pass unobstructed along passageways past the liner into the housing to fill the canister with pressurised fluid, without substantially deforming the liner, so that the liner maintains a seal between the housing and the cap.

The present inventions are directed generally to apparatuses, methods and systems for controlled delivery, and more particularly, to apparatuses, methods, systems and canisters for dispensing a metered dose of pressurised fluid (“invention”), for example for producing an aerosol spray.

It is known to provide a canister filled with fluid including a pressurised propellant that can provide an aerosol through a push-operated outlet valve. Some canisters may be filled with propellant by back-filling through a push-operated valve, for example as described in U.S. Pat. No. 3,827,608.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be more fully understood, a non-limiting embodiment thereof will now be described by way of illustrative example with reference to the accompanying drawings.

FIG. 1a is view of a canister from one side having a metered valve in a datum position in which the valve is unopened;

FIG. 1b is a view of the canister shown in FIG. 1 when the valve is in an operative position to release a metered dose of aerosol;

FIG. 2 is a longitudinal sectional view of the canister shown in FIG. 1a;

FIG. 3 is an exploded, perspective view of the canister shown in FIGS. 1 and 2;

FIG. 4 is an enlarged, perspective view of the body of the metered valve shown in FIGS. 2 and 3;

FIG. 5a is an enlarged, sectional view of the metered valve in the canister in the datum position;

FIG. 5b is an enlarged, sectional view of the metered valve in the canister in the operative position to release a metered dose of aerosol;

FIG. 5c is a sectional view of the metered valve corresponding to FIG. 5b when the canister is being filled with pressurised fluid through the stem of the metered valve;

FIG. 6 is a partially broken away view in perspective of the passage of fluid through passageways on the exterior of the valve body during filling of the canister; and

FIG. 7 is partial sectional view in perspective of the metered valve in the canister during the filling process.

DETAILED DESCRIPTION

Some aerosol canisters may be provided with a metered valve that, upon actuation, releases only a metered dose with aerosol, after which the valve needs to be released and operated a multiple times in order to release multiple metered doses. Previously, refilling such a canister has been difficult, as the metering action of such a valve has prevented back-feeding pressurised fluid through the valve.

Small canisters, such as those used in handheld aerosol delivery devices, may comprise a housing closed by a cap, with an interior metered valve for delivering aerosol from pressurised liquid within the housing. In such canisters, an interior liner may be provided around the body of the valve to seal the join between the cap and the housing. Previously, refilling or back-filling such a canister has been difficult, as back-filling with pressurised fluid by forcing the fluid into the valve such that it passes around the exterior of the body of the valve within the canister, in order to enter the housing, can dislodge the liner and degrade the functionality of the canister.

An embodiment of the invention provides a canister for dispensing a metered dose of pressurised fluid which comprises a housing for containing fluid and a metered valve within the container operable to release a metered dose of the fluid. A seal is provided between the canister and the metered valve to prevent leakage of the pressurised fluid from within a canister around the valve. The seal is also configured to deform resiliently and admit pressurised fluid continuously into the canister when pressurised fluid is applied to the valve exteriorly of the canister. In this way, the canister can be pressurised with a continuous flow of pressurised fluid from its exterior notwithstanding the metering action of the valve.

In some embodiments, the metered valve may include a valve body including a plenum, a valve body inlet to admit pressurised fluid from the housing into the plenum, a moveable valve member in the body and a valve member outlet in the valve member for discharging the fluid from the plenum, for example to form an aerosol spray. The valve member may be moveable back and forth between a datum position in which the valve body inlet is open to the interior of the housing so that the dose of pressurised fluid is admitted into the plenum without discharge through the valve member outlet, and a discharge position in which the dose of fluid in the plenum is discharged through the valve member outlet, at which time the valve body inlet is closed by the valve member so that the metered dose can be discharged through the valve member outlet.

In some embodiments, a canister may comprise a main body and a cap overlying an opening in the main body, with the seal being in the form of gasket disposed between the valve body and the cap to prevent leakage of the pressurised fluid from within the housing. A liner may be disposed around the valve and configured to block leakage of the pressurised fluid from within the housing between the housing and the cap.

In some implementations, at least one unobstructed passageway may extend past the liner so that on filling, the pressurised fluid that deforms the seal passes into the housing through the passageway past the liner. This can avoid deformation of the liner thereby avoiding any compromise of the pressure tight seal between the cap and the housing.

As illustrated in FIGS. 1, 2 and 3, in some embodiments, a canister 1 has a housing that includes a generally cylindrical main body 2 e.g. made of metal such as aluminium, having a closed, distal end 3 and a circular opening 4 closed by a cap 5. In use, the main body 2 contains pressurised fluid that is dispensed as an aerosol in metered doses by means of a metered valve 6. The valve 6 comprises a generally cylindrical valve body 7 that includes an interior plenum 8 that receives compression spring 9 that surrounds a longitudinally slidable valve member 10. The valve member 10 has a tubular valve member outlet comprising valve stem 11 which protrudes through cap opening 12 disposed on the longitudinal axis of the cylindrical main body 2. A transverse outlet passageway 13 extends through the tubular body of the valve stem 11 adjacent a peripheral, circular flange 14 on the valve member to provide a path for pressurised fluid in the plenum 8 to discharge through the valve stem 11 when the valve is operated. Central region 15 of the valve member comprises an axial, solid rod of circular cross section that terminates in a tapered end region 16 formed with a longitudinally extending inlet groove 17.

The valve body 7 is generally cylindrical and includes a cylindrical main wall 18 that has a rebated front end 19 and a rear end wall 20 that couples to an inlet tube 21 which opens into the plenum 8. The compression spring 9 is received on the central region 15 of the valve member so as to be received between the flange 14 and the rear end wall 20 of the valve member within the plenum 8.

Passageways in the form of axially extending grooves 22 are formed in the outer surface of the valve body 7, extending from the front end 19 to the rear end wall 20 of the valve body 7 to facilitate continuous back filling of the container with propellant, as will be explained in more detail hereinafter.

A dip tube 23 is coupled to the inlet tube 21 of the valve body 7, the tube 23 extending towards the end 3 of the main body 2 in order to supply pressurised fluid into the plenum 8 through inlet tube 21 under the control of the moveable valve member 10.

An annular gasket seal 24 is arranged between the inner end surface of the cap 5 and the rebated front end 19 of the valve body 7. The seal 24 may be formed of rubber or similar resiliently deformable material so as to prevent pressurised fluid leaking from within the container around the valve body 7 and out of the canister

To assemble the canister, the cap 5 is crimped onto the valve body 7 and also onto the opening 4 of the main body 2. A resiliently deformable, annular liner 25, for example of rubber or like material is disposed around the valve body 7 between the opening 4 and the cap 5 so as to provide a seal and prevent leaks between the cap 5 and the main body 2.

In normal operation, when the canister is charged with a liquid to be aerosolised and pressurised propellant, the valve can be moved from a closed, datum position shown in FIG. 5a, to an operative position shown in FIG. 5b in which a metered dose of aerosol is discharged. In the datum position shown in FIG. 5a, pressurised fluid from within the main body 2 passes through the dip tube 23 into the inlet tube 21 of valve body 7, so as to flow in the direction of arrows A into the plenum 8, in region 26 that also contains the spring 9. Pressurised fluid enters through the inlet groove 17 in the tapered region 16 of the valve member 10.

In the datum position, the compression spring 9 presses against the end wall 20 of the valve body 7 and the flange 14 of the valve member 10 so as to drive the flange 14 against the gasket seal 24, so that in combination with the pressure exerted by the liquid in the canister, the valve body is pushed against the seal 24 so as to prevent pressurised liquid from leaking out of the canister. The region 26 thus fills with pressurised liquid in preparation for the dispensation of a metered dose.

When the valve stem 11 is pushed inwardly as shown in FIG. 5b, the rod shaped central region of valve member 10 slides rearwardly within the inlet tube 21 so as to seal off the passage of liquid into the plenum 8 from the dip tube 23. Concurrently, the transverse opening 13 in the valve stem 11 moves inwardly of the plenum 8 so as to provide a discharge path for the pressurised fluid within the plenum into the valve stem 11, so as to be discharged as an aerosol. The discharge of the liquid to form the aerosol spray is shown by arrows B in FIG. 5b, creating spray 27.

Once the metered dose has been discharged, the user releases pressure on the valve stem 11 to allow spring 9 to return the valve member 10 to the position shown in FIG. 5a. In this way, the plenum 8 is replenished with fluid ready for the next metered dose discharge.

The process can continue until the pressure within the main body 2 is insufficient to form further metered dose aerosol discharges.

In some embodiments, the canister 1 can be filled with pressurised fluid by backfilling through the valve stem 11. This is illustrated in FIG. 5c in which an external source of pressurised fluid, for example from a larger reservoir, is fed into the valve stem 11 in the direction of arrows C. As shown schematically in FIG. 5c, the source of pressurised fluid has a coupling 28 which in use is pressed against the valve stem 11 so as to move the valve member 10 to the operative position previously described with reference to FIG. 5b. The pressurised fluid from the reservoir passes axially down the valve stem 11 and through the transverse passageway 13 into the plenum 8. Since the valve 6 is in the operative position, the central region 15 of the valve member 10 is inserted into the inlet tube 21 so as to provide a seal as previously described in relation to the metering action of the valve. Thus, the pressurised fluid from refill device 28 cannot pass into the dip tube 23 in order to refill the canister. However, the configuration of the gasket seal 24 and the rebated front end 19 of the valve body allows the pressurised fluid travelling through the passageway 13 into the plenum to deform the gasket 24 so that fluid passes in the direction of arrow C towards the outer cylindrical surface of the valve body 7 into the longitudinal passageways 22. This permits the fluid to pass along the passageways 22 into the main body 2 so as to fill the canister 1. The configuration of the passageways 22 allows the fluid to pass unobstructed past the liner 25 without causing substantial deformation of the liner. Thus, the seal provided by the liner 25 between the main housing 2 and the cap 5 is not compromised during the filling process by deformation of the liner 25.

It will be appreciated that the back-filling process described with reference to FIG. 5c may be used to pressurise the canister 1 prior to its initial use or for refilling it after its initial contents have been used up.

Depending on the embodiment, the canister 1 may be relatively small, for example of dimensions similar to those of conventional cigarette. For example, the canister may be used to dispense a nicotine-containing aerosol spray as described in U.S. Ser. Nos. 12/787,271; 12/787,257; 12/787,258 and 12/787,259 all assigned to the assignee of the present application, the contents whereof are incorporated herein by reference.

Many modifications and variations falling within the scope of the invention as claimed hereinafter will be evident to those skilled in the art in the light of the foregoing description.