| abstract |
A dose counter for a metered dose inhaler comprises actuator means ( 341 ), drive means ( 350 ) for driving a rotary gear ( 360 ) in step-wise fashion in response to displacement of said actuator means ( 341 ), said rotary gear ( 360 ) comprising a wheel having a plurality of ratchet teeth (not shown) around its periphery. Means ( 364 ) are provided to prevent reverse rotation of the rotary gear ( 360 ). A flexible tape ( 368 ) is provided with a visible array of incrementing integers on its surface indicating the number of medicament doses remaining in the inhaler. The tape ( 368 ) indexes by a single integer in response to each step of the step-wise rotary motion of the rotary gear ( 360 ). A control surface ( 371 ) regulates the position of engagement and disengagement between the drive means ( 350 ) and the rotary gear ( 360 ). In an alternative embodiment (FIG. 6), the control surface ( 371 ) is omitted and the means for preventing reverse rotation comprise a stepless restraint ( 664 ). |