Dose counter with lockout mechanism

Abstract

A medicament dispenser, in particular a metered dose inhaler, which is able to count the number of time the dispenser is activated and then disable the device, which then prevents any additional medicament from being dispensed. Additional embodiments include a medicament dispenser which are adapted to display either the number of activations that have occurred or the number of activations remaining.

What is claimed is: 
     
         1 . A metered dose inhaler comprising:
 (a) a pressurized canister [ 167 ] containing a medicament formulation, said canister further comprising a metering valve having a spring loaded valve stem [ 168 ];   (b) an inhaler body;   (c) a mouthpiece [ 130 ];   (d) a cocking lever [ 110 ];   (e) a cradle [ 140 ] which fixedly holds said canister, and which is slideably engaged with said inhaler body; said cradle comprising a cradle latch assembly [ 156 ],
 said cradle latch assembly [ 156 ] comprising a cradle latch  155 ] optionally engaged with a trigger shelf [ 190 ], wherein:
 (i) when said cradle latch [ 155 ] is engaged with said trigger shelf [ 190 ], said cradle [ 140 ] adopts a first position, wherein its movement is restricted along said inhaler body; and 
 (ii) when said cradle latch [ 155 ] is disengaged from said trigger shelf [ 190 ], said cradle [ 140 ] adopts a second position, wherein its movement is not restricted along said inhaler body; 
 
 wherein said cradle further comprises a reset arm [ 152 ″] and an actuation arm [ 150 ]; 
   (d) a compression assembly [ 240 ] comprising one or more springs [ 250 ] and a compression assembly latch [ 158 ] that detachably affixes said compression assembly to said cradle; said compression assembly latch [ 158 ] having:
   (i) an engaged configuration in which said compression assembly [ 240 ] is fixedly attached to said cradle [ 140 ]; and   (ii) a disengaged configuration in which said compression assembly [ 240 ] is slideably engaged with said cradle [ 140 ];   
   (e) a dose counter wheel [ 217 ] adapted to be detentably rotatable in one direction;
 wherein said dose counter wheel comprises a dropout cam [ 220 ]; and 
   (f) a lobed cam [ 270 ] positioned between said reset arm [ 152 ] and said compression assembly [ 240 ]; such that:
   (i) when said lobed cam [ 270 ] is oriented in a first position, the cam lobe is biased against said reset arm [ 152 ] and urges said cradle [ 140 ] into said first position; and   (ii) when said lobed cam [ 270 ] is oriented in a second position, said cam lobe is biased against said compression assembly [ 240 ], which causes mechanical energy to be stored in said compression assembly [ 240 ] when said cradle latch [ 155 ] is engaged with said trigger shelf [ 190 ], and said compression assembly latch [ 158 ] is in the engaged position;   
 wherein said inhaler is configured such that said actuation arm [ 150 ] engages with said dose counter wheel [ 217 ] and causes said dose counter wheel [ 217 ] to incrementally rotate each time said cradle [ 140 ] moves from said second position to said first position; said dose counter wheel [ 217 ] is adapted to display a different dose indicia each time said dose counter wheel [ 217 ] is incrementally rotated; and 
 said dropout cam [ 220 ] is adapted to cause said compression assembly latch [ 158 ] to disengage after a predetermined number of incremental rotations; and 
 whereby after the predetermined number of incremental rotations have passed, there is no physical blocking or interference of any of the foregoing moving parts of the inhaler, such that said compression assembly [ 240 ] can no longer be compressed, thereby disabling the metered dose inhaler and preventing further discharge of said medicament formulation. 
   
     
     
         2 . The metered dose inhaler of  claim 1 , wherein said cocking lever [ 110 ] is manually rotatable within said inhaler body. 
     
     
         3 . The metered dose inhaler of  claim 2 , wherein said cocking lever [ 110 ] is manually rotatable to adopt an open position away from said mouthpiece [ 130 ], enabling said mouthpiece to be inserted into a patient's mouth; and a closed position, wherein said mouthpiece [ 130 ] is covered by said cocking lever [ 110 ]. 
     
     
         4 . The metered dose inhaler of  claim 3 , wherein the rotating of said cocking lever [ 110 ] into said open position, away from said mouthpiece [ 130 ], results in rotation of lobed cam [ 270 ] and compression of the one or more springs [ 250 ]. 
     
     
         5 . The metered dose inhaler of  claim 1  wherein disengagement of said cradle latch [ 155 ] from said trigger shelf [ 190 ] is breath-actuated. 
     
     
         6 . The metered dose inhaler of  claim 1 , wherein said compression assembly latch [ 158 ] comprises a first latching member [ 257 ] and second latching member [ 157 ], said first latching member [ 257 ] fixedly attached to said compression assembly [ 240 ], and said second latching member [ 157 ] fixedly attached to said cradle [ 140 ], wherein at least one said latching members can be directly or indirectly physically displaced by said dropout cam [ 220 ] so that said compression assembly and said cradle are not fixedly attached to each other. 
     
     
         7 . The metered dose inhaler of  claim 1 , wherein said dose counter wheel [ 217 ] has numbers on the periphery of said dose counter wheel; said inhaler adapted to indicate a specific number as the number of interest. 
     
     
         8 . The metered dose inhaler of  claim 7 , wherein said inhaler is adapted to display either the number of activations that have occurred or the number of activations remaining.