EP0966309A2 — 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 (FIG. 6), the control surface (371) is omitted and the means for preventing reverse rotation comprise a stepless restraint (664).