GB2320489A — Inhaler dose counter

USPTO 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 (Figure 6), the control surface 371 is omitted and the means for preventing reverse rotation comprise a stepless restraint 664.