摘要 |
Disclosed herein is a dose counter (18) for counting doses of medicament dispensed by or remaining in a metered-dose inhaler. The dose counter comprises a rotatably mounted first gear wheel (30) having a circular arrangement of ratchet teeth and a display (44) coupled to the first gear wheel, the display having a visible array of dose counting indicia indexable in response to rotary motion of the first gear wheel. The dose counter further comprises an actuator mechanism (20,22,24,26) having a first ratchet drive pawl for engaging the ratchet teeth of the first gear wheel in response to the dispensation of a medicament dose, and a second ratchet drive pawl for engaging the ratchet teeth of a gear wheel coupled to the display. The actuator mechanism is configured such that, in use of the dose counter for counting a dispensed dose, a first ratchet tooth of the first gear wheel is engaged and rotatably driven by the first ratchet drive pawl and then a second ratchet tooth of the gear wheel coupled to the display is engaged and rotatably driven by the second ratchet drive pawl. The gear wheel arranged for engagement by the second ratchet drive pawl is a different gear wheel to the first gear wheel. |