GB2364649A — Inhaler with Dose Counter

USPTO Abstract

A multiple-dose powder inhaler for use in the treatment of asthma, for example, comprises an inhaler body <B>3</B> defining a medicament container <B>8</B>, an air channel <B>13</B> and a mouthpiece <B>4</B>; a rotatable metering drum <B>2</B> with one or more peripheral dosing recesses <B>10</B>;<BR> ```a dose counter for indicating the number of metered doses of medicament that have been dispensed from, or remain in, the medicament container, said dose counter comprising a counter wheel <B>1</B> having a central hole <B>17</B> said counter wheel <B>1</B> being rotatably mounted about a bearing axle <B>18</B> having a longitudinal axis substantially parallel to and spaced from the rotational axis of the metering drum <B>2</B>, said bearing axle <B>18</B> extending from the inhaler body <B>3</B> and through the central hole <B>17</B>, and said counter wheel <B>1</B> having counting indicia thereon and a plurality of gear teeth (<B>25, fig. 5</B>);<BR> ```extending from the metering drum <B>2</B> a driving pin <B>31</B> adapted to engage with at least one of gear teeth (<B>25</B>) of the counter wheel <B>1</B> upon every complete revolution of the metering drum <B>2</B> so as to rotate said counter wheel <B>1</B> an incremental amount; and a flexible brake finger <B>33</B> extending from the inhaler body <B>3</B> and adapted to engage with the counter wheel <B>1</B> so as to maintain a unidirectional rotation and to prevent unintentional movement of the counter wheel <B>1</B>. Preferably, the inhaler comprises a depressible cover <B>6</B> for actuating said inhaler by the axial movement of the depressible cover <B>6</B>. The depressible cover <B>6</B> preferably comprises an elongate pawl <B>9</B> adapted to engage with the ratchet teeth <B>14</B> of the metering drum <B>2</B> upon each axial movement of the depressible cover <B>6</B>. Alternatively, said complete revolution of the metering drum <B>2</B> is accomplished by making a predetermined number of said axial movements of the depressible cover <B>6</B>.