Dose release firing systems and medicinal inhalers comprising same
A dose release firing system ( 101 ) for use in a medicinal inhaler ( 100 ). The firing system can include a plunger ( 103 ), and a stored energy device ( 109 ) configured to drive the plunger from a first position to a second position. The firing system can further include a guideway ( 121 ) and a projection ( 114 ) dimensioned to be received in the guideway, the guideway or the projection being fixedly coupled to the plunger. At least a portion of the guideway can have a helical shape, including a first portion with a first helix angle, and a second portion with a second helix angle, the second helix angle being less than the first helix angle. The projection and the guideway can be movable with respect to one another to cause the projection to be cammed along the guideway when the stored energy device drives the plunger to move from the first position to the second position.
1. A firing system for use in a medicinal inhaler, the firing system comprising:
an axis that defines an axial direction that extends along or parallel to the axis;
a plunger movable in the axial direction between a first position and a second position;
a stored energy device configured to drive the plunger from the first position to the second position when stored energy in the stored energy device is released, wherein the firing system is in a primed state when the stored energy is not released, and wherein the firing system is in a fired state when the stored energy is released;
a guideway, wherein at least a portion of the guideway has a helical shape, the guideway having a first portion having a first helix angle with respect to the axis that is greater than zero, and a second portion having a second helix angle with respect to the axis, wherein the second helix angle is less than the first helix angle; and
a projection dimensioned to be received in the guideway, the projection being movable in the guideway, such that the projection and the guideway are movable with respect to one another between a first position corresponding to the first position of the plunger and a second position corresponding to the second position of the plunger, such that the projection is configured to be cammed along the guideway when the stored energy device drives the plunger to move from the first position to the second position;
wherein the guideway or the projection is fixedly coupled to the plunger.
2. The firing system of claim 1 , wherein the stored energy device, the guideway and the projection are positioned such that the guideway and the projection move relative to one another in response to stored energy being released from the stored energy device.
3. The firing system of claim 1 , wherein the first helix angle is at least 45 degrees.
4. The firing system of claim 1 , wherein the second helix angle is less than 20 degrees.
5. The firing system of claim 1 , wherein the first portion of the guideway is helical with respect to the axis and the second portion of the guideway is aligned with or parallel to the axis.
6. The firing system of claim 1 , wherein the stored energy device is configured to provide at least 40 N of force when the stored energy is released.
7. The firing system of claim 1 , wherein:
the medicinal inhaler includes a medicament canister,
the axis is a longitudinal axis configured to be parallel to a longitudinal axis of the medicament canister,
the plunger is configured to be operatively coupled to the medicament canister, and
the plunger is configured to move between the first position and the second position to actuate a dose release valve of the medicament canister.
8. The firing system of claim 1 , wherein the plunger is with respect to the axis.
9. The firing system of claim 1 , wherein the guideway and the projection are rotatable with respect to one another about the axis.
10. The firing system of claim 1 , wherein the guideway is rotatable about the axis with respect to the projection, wherein the projection is fixedly coupled to the plunger, and wherein the projection and the plunger are rotationally fixed with respect to the axis.
11. The firing system of claim 1 , wherein the guideway is provided by a shaft having a shaft axis oriented along or parallel to the axis and comprising a wall, and wherein the guideway is formed in the wall of the shaft.
12. The firing system of claim 1 , wherein the guideway is provided by a rotary arm module, the rotary arm module comprising:
a shaft having a shaft axis oriented in the axial direction and comprising a wall, wherein the guideway is formed in the wall, the shaft including a flanged end, and
an arm extending radially outwardly from the flanged end of the shaft.
13. The firing system of claim 1 , further comprising a latch movable between (i) a first position in which the latch is coupled to at least one of the guideway and the projection to inhibit the guideway and the projection from moving relative to one another, and (ii) a second position in which the latch is decoupled from the guideway and the projection, such that the guideway and the projection are free to move relative to one another.
14. A medicinal inhaler comprising the dose release firing system of claim 1 , wherein the medicinal inhaler is a pressurized metered dose inhaler (pMDI).