Dose counters for inhalers, inhalers and methods of assembly thereof

A method of manufacturing a series of incremental dose counters for metered dose inhalers, each metered dose inhaler comprising a medicament-containing canister, wherein each incremental dose counter in the series comprises:

• a ratchet wheel having a plurality of circumferentially spaced teeth and a central axis which is above a datum plane,
• an actuator pawl comprising a lower side edge arranged to engage with and rotate the ratchet wheel,
• a count pawl arranged to repeatedly engage the ratchet wheel in a series of anti-back drive interlock configurations, and
• a dosage indicator coupled to the ratchet wheel,
• which method comprises:
• positioning the ratchet wheel, the actuator pawl and the count pawl relative to the datum plane in each dose counter in the series so that, in a canister fire process, the actuator pawl is arranged to define a first reset position in which the lower side edge of the actuator pawl is brought into engagement with a first tooth of the ratchet wheel above the datum plane;
• and a nominal canister fire position, after the first reset position, in which the lower side edge of the actuator pawl and ratchet wheel have moved to a second position at which the canister fires medicament and which is a first distance below the datum plane;
• and a nominal dose count position in which the lower side edge of the actuator pawl is a second distance below the datum plane that is greater than the first distance, and the count pawl has just resiliently jumped over a second tooth of the ratchet wheel from a first anti-back drive interlock configuration to a second anti-back drive interlock configuration and an incremental count is displayed by the dosage indicator,
• wherein an average dose count position in the series is, in the canister fire process, at or after an average canister fire position in the series.