Patent ID: 12220521

DETAILED DESCRIPTION

In the following, a tensioning arrangement for an aerosol dispenser and an aerosol dispenser comprising the tensioning arrangement, will be described. The same reference numerals will be used to denote the same or similar structural features.

FIG.1represents a side view of one example of an aerosol dispenser10comprising a tensioning arrangement12. The aerosol dispenser10comprises a housing14and a rotatable member16rotatable relative to the housing14to make a tensioning rotation18. InFIG.1, the rotatable member16is constituted by an outer base of the aerosol dispenser10. However, the rotatable member16may alternatively be constituted by, for example, an intermediate exterior portion of the aerosol dispenser10.

The aerosol dispenser10inFIG.1further comprises an openable lid20, connected to the housing14via a hinge22, and a button24for triggering a dose shot. The aerosol dispenser10of this example further comprises a dose indicator26that indicates the number of doses left in the aerosol dispenser10and a state indicator28that indicates a loading state of the aerosol dispenser10(e.g. unloaded or loaded with a container).

InFIG.1, a needle or conveying tube (not shown) within the aerosol dispenser10is in an initial position30.FIG.1further denotes an axial tensioning movement32and an axial priming movement34for the conveying tube. The tensioning movement32is made in a tensioning direction36along a longitudinal axis38of the aerosol dispenser10. The tensioning direction36may be said to be in a distal direction, i.e. towards the rotatable member16.FIG.1further shows a Cartesian coordinate system for referencing purposes. The aerosol dispenser10may however be oriented arbitrarily in space.

FIG.2represents a top view of the aerosol dispenser10. As can be seen inFIGS.1and2, the aerosol dispenser10of this example has a generally cylindrical shape.

FIG.3represents a perspective partially cut-out view of the aerosol dispenser10. In the cut-out section ofFIG.3, it can be seen that the tensioning arrangement12comprises a transmission mechanism40. The transmission mechanism40is configured to transmit the tensioning rotation18of the rotatable member16to the tensioning movement32of the conveying tube (not shown) along the longitudinal axis38of the aerosol dispenser10.

The tensioning arrangement12of this example comprises two cam profiles42(only one is visible inFIG.3) and two cam followers44(only one is visible inFIG.3), each arranged to follow a respective cam profile42. Each cam profile42of this example is a helical surface concentric with the longitudinal axis38of the aerosol dispenser10. The tensioning arrangement12may alternatively comprise only one pair of a cam profile42and a cam follower44, or more than two pairs. As a further alternative, the tensioning arrangement12may comprise only one cam profile42and two or more cam followers44. As a further alternative, the tensioning arrangement12may comprise two or more cam profiles42and only one cam follower44.

A plurality of priming structures46are provided on each cam profile42. Each priming structure46is arranged to prevent the rotatable member16from rotating in a direction opposite to the tensioning rotation18. This is useful if for example the patient loses the grip of the rotatable member16when making the tensioning rotation18. In the example ofFIG.3, each priming structure46is constituted by a protrusion.

In the cut-out section ofFIG.3, a piston or holding member48of the tensioning arrangement12can also be seen. The holding member48holds the conveying tube (not shown). In the example inFIG.3, the two cam followers44are fixed relative to the holding member48. More specifically, each cam follower44is integrally formed with the holding member48and projects in parallel with the longitudinal axis38towards the cam profile42, i.e. in a proximal direction.

Furthermore, in the cut-out section ofFIG.3, an actuator member50of the aerosol dispenser10, here implemented as an actuator ring, can be seen. The actuator member50is movable between a blocking position, in which the actuator member50blocks the holding member48and the conveying tube52from being released, and an unblocking position. InFIG.3, the actuator member50is in the unblocking position. The actuator member50can be moved from the unblocking position to the blocking position by means of the tensioning rotation18of the rotatable member16. The button24is operatively coupled to the actuator member50. By pushing the button24, the actuator member50can be moved from the blocking position to the unblocking position, i.e. the actuator member50can be released to expel an aerosol.

FIG.4represents a cross-sectional view of the aerosol dispenser10along line A-A inFIG.2. InFIG.4, the conveying tube52of the tensioning arrangement12can be seen. The aerosol dispenser10is loaded with a container54containing liquid, such as a drug, to be dispensed as an aerosol.

The conveying tube52has pierced a closure56of the container54and is thereby brought into communication with the liquid in the container54. The conveying tube52comprises an optional conveying tube check valve58at a proximal end of the conveying tube52, i.e. at an opposite end with respect to the container54. In this example, the neck of the container54is held by a locking structure60on the holding member48. The locking structure60is here exemplified as a plurality of resilient arms projecting from the holding member48towards the rotatable member16. The container54comprises a stopper62that closes the bottom of the container54.

The aerosol dispenser10of this example comprises a stationary pump cylinder64, i.e. stationary with respect to the housing14. A dose chamber66is provided in the pump cylinder64. The conveying tube52is movable back and forth to expand and compress the volume of the dose chamber66. A sealing68, here exemplified as an X-ring, is provided to seal between the conveying tube52and the pump cylinder64. The sealing68may alternatively be constituted by an O-ring, or other types of sealings known in the art.

The aerosol dispenser10further comprises a spray nozzle unit70having a spray nozzle71at a proximal side of the dose chamber66. The spray nozzle unit70may for example comprise a spray nozzle check valve72and a membrane or filter74. The aerosol dispenser10further comprises a mouthpiece76which is exposed to a user by opening the lid20.

As can be seen inFIG.4, the transmission mechanism40of this example also comprises an inner sleeve78. The inner sleeve78is fixedly connected to the rotatable member16. The inner sleeve78and the holding member48are rotationally coupled. However, the holding member48is allowed to move axially relative to the inner sleeve78and the rotatable member16. This type of coupling between the inner sleeve78and the holding member48may for example be realized by means of a pin or rib engaged in a slot parallel with the longitudinal axis38. The rotatable member16of this example comprises a proximally protruding collar80for contacting the stopper62of the container54.

In the example inFIG.4, the cam profiles42are provided on a stationary part82, here constituted by a central part of the housing14. The cam profiles42are integrally formed with the stationary part82and faces in the distal direction, i.e. towards the rotatable member16.

The arrangement of the cam profiles42and the cam followers44may alternatively be reversed. That is, the cam profiles42may be provided on the holding member48and the cam followers44may be provided on the stationary part82.

The tensioning arrangement12further comprises an elastic member84, here constituted by a compression coil spring enclosing the container54. The elastic member84is arranged to store mechanical energy from the tensioning movement32of the holding member48and the conveying tube52from the initial position30inFIG.3to a tensioning position86according toFIG.4.

FIG.4further shows a housing stop88projecting distally from the housing14and a holding member stop90projecting proximally from the holding member48. Expansion of the elastic member84is limited when the holding member stop90contacts the housing stop88.

When the rotatable member16is manually rotated, the optional inner sleeve78rotates together with the rotatable member16. The tensioning rotation18of the rotatable member16and the inner sleeve78is transmitted to a rotation of the holding member48. The rotation of the holding member48causes the cam followers44to travel along the associated cam profiles42. Due to the cooperation between the cam followers44and the cam profiles42, the tensioning rotation18of the rotatable member16is transmitted to the tensioning movement32of the conveying tube52and the holding member48in the distal tensioning direction36against the force of the elastic member84until the conveying tube52has moved from the initial position30to the tensioning position86according toFIG.4.

InFIG.4, the actuator member50is in the blocking position and holds the holding member48and the conveying tube52in the tensioning position86. In this state, the tensioning arrangement12is tensioned. In the blocking position of the actuator member50, the force from the elastic member84pushes the holding member48and the actuator member50against the housing14. The actuator member50is thereby clamped between the holding member48and the housing14.

As the conveying tube52moves in the tensioning direction36, the volume of the dose chamber66expands and an underpressure is established in the dose chamber66.

Consequently, liquid in the container54is sucked by the conveying tube52into the dose chamber66. The holding member48and the conveying tube52is then held in the tensioning position86by means of the actuator member50. When the conveying tube52is in the tensioning position86, the volume of the dose chamber66corresponds to one dose.

When the user pushes the button24, the actuator member50is moved to its unblocking position such that the actuator member50no longer blocks the holding member48. As a consequence, the entire force from the elastic member84acts on the liquid in the dose chamber66via the holding member48, the conveying tube52and the conveying tube check valve58. The force in the elastic member84may for example be 5-50 N. The high pressure in the dose chamber66presses the liquid through the spray nozzle check valve72and the filter74of the spray nozzle unit70. The liquid is thereby expelled as an aerosol. The pressure in the dose chamber66may be approximately 15-75 bar. In view of prior art, this enables the use of a relatively weak spring as elastic member84.

FIG.5represents a partial perspective view of a housing14of the aerosol dispenser10. InFIG.5, it can be seen that the cam profile42comprises a cam profile length92. The cam profile length92of this example extends over an angular distance of approximately 150° around the longitudinal axis38.

The leftmost proximal position on the front cam profile42corresponds to the initial position30of the conveying tube52. The rightmost distal position on the front cam profile42corresponds to the tensioning position86of the conveying tube52.

The priming structures46are evenly distributed over the cam profile length92from the position corresponding to the initial position30(in this example the leftmost proximal position) to the position corresponding to the tensioning position86(in this example the rightmost distal position). InFIG.5, the cam profile42comprises six priming structures46. The first priming structure46, i.e. the leftmost priming structure46of the front cam profile42inFIG.5, is positioned less than 20% (approximately 14%) of the cam profile length92from the position corresponding to the initial position30of the conveying tube52(in this example the leftmost proximal position). The above also applies for the rear cam profile42which is not fully visible inFIG.5.

FIG.6represents an enlarged view of section B inFIG.5. InFIG.6, it can be seen that each priming structure46is wedge-shaped. More specifically, each priming structure46comprises a priming structure surface94at an angle of approximately 10° to its adjacent surface96of the cam profile42.

When the rotatable member16is manually rotated to make the tensioning rotation18and the cam followers44travel along the associated cam profiles42, the conveying tube52generally makes the tensioning movement32in the tensioning direction36from the initial position30to the tensioning position86. However, when the cam followers44travel over a priming structure46on an associated cam profile42, the conveying tube52makes a temporary priming movement34towards the initial position30, i.e. in the proximal direction of the aerosol dispenser10. Each priming movement34is shorter than the tensioning movement32. When the conveying tube52makes a priming movement34, the dose chamber66is compressed and a small volume of liquid (corresponding to the length of the priming movement34) is expelled that fills out dry cavities in the aerosol dispenser10(e.g. in the spray nozzle unit70) and pushes out foreign particles, such as bacteria and/or residue, from the spray nozzle unit70. The small volumes of liquid may be referred to as priming doses.

FIG.7shows a diagram of an example movement of the conveying tube52of the aerosol dispenser10. More specifically,FIG.7shows the tensioning movement32and the priming movements34of the conveying tube52as a function of the tensioning rotation18of the rotatable member16.

FIG.7further shows a tensioning distance98, which is the axial length of the tensioning movement32of the conveying tube52. InFIG.7, the tensioning distance98is approximately 9.2 mm.

FIG.7further shows a priming distance100for one of the priming movements34. The priming distance100may be the same for all priming movements34, or different. InFIG.7, all priming distances100have the same length of approximately 0.4 mm. A sum of a distance of all priming movements34of the conveying tube52is approximately 24% of the tensioning distance98.

The horizontal line C inFIG.7indicates the most tensioned position of the conveying tube52. During the last tensioning rotation18of the rotatable member16, e.g. from approximately 150° to 180°, the actuator member50is pushed laterally from the unblocking position to the blocking position to thereby block the holding member48.

While the present disclosure has been described with reference to exemplary embodiments, it will be appreciated that the present disclosure is not limited to what has been described above. For example, it will be appreciated that the dimensions of the parts may be varied as needed.