| 摘要 |
<p>An arrangement is disclosed for, in connection to an inhalation operation, opening and closing and air inlet of a dry powder inhaler device (DPI) provided with a dose member (4). The arrangement requires a minimum pressure differential between a surrounding atmosphere and the airways of the inhaling person in order to open the inlet for outside air to enter into the DPI. The arrangement controlling the air inlet presents a biased flap connected to biased catch mechanism. The biased flap (16) closes the air inlet (23) of the DPI to the atmosphere by the force exerted by a compression spring (13), which acts oh the flap through a mechanism of levers. In order to open the flap a force FP bigger than the closing force FC of the spring and lever mechanism must be applied. The necessary force results from a pressure differential resulting when sucking the mouthpiece of the DPI. The catch is through the mechanism of levers released by the flap (16) when the flap opens, and triggers a sequence of events constituting the irreversible process of administering a dose to the user of the inhaler. The mechanism of levers uses rounded shapes (14) where moving parts are in contact with each other to minimize contact areas and rubbing effects to thereby achieve near zero friction losses. The flap is further by a counterweight (15) statically balanced, which almost completely eliminates the risk of external forces, e.g., gravitation or blows of the DPI to accidentally trigger the process of administering a dose.</p> |
