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.
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.
a is view of a canister from one side having a metered valve in a datum position in which the valve is unopened;
b is a view of the canister shown in
a is an enlarged, sectional view of the metered valve in the canister in the datum position;
b is an enlarged, sectional view of the metered valve in the canister in the operative position to release a metered dose of aerosol;
c is a sectional view of the metered valve corresponding to
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
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
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
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
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
It will be appreciated that the back-filling process described with reference to
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.