| 摘要 |
A metering valve ( 1 ) is provided for a pressurised container ( 14 ) containing a pharmaceutical formulation. The valve has a stem ( 2 ) with a central flange ( 11 ) and a hollow open end ( 19 ) with a side port ( 20 ). The stem slides in a body ( 3 ) having larger and smaller diameter portions, and being closed off by a seal ( 4 ) against which the flange ( 11 ) rests in an inoperative position. A second seal is located around the stem on the opposite side of the flange and trapped by a spring ( 6 ) which urges the stem into its inoperative position. When the stem is depressed, the inner seal ( 5 ) forms a sliding seal with the smaller diameter portion of the body to define a metering chamber ( 13 ) filled with the pharmaceutical. Continued depression opens the side hole ( 20 ) to allow the contents of the metering chamber to be dispensed.
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