| 摘要 |
<p>A pump assembly (1) for an atomising piston pump comprising a piston (16) slidably located in a cylinder (4), a variable volume fluid storage chamber (5) in communication with the cylinder on one side of the piston, means (18) for varying the volume of the chamber, resilient means (17) urging the varying means into a position corresponding to the minimum volume of the chamber, a fluid flow passageway (30, 31) through the piston, a resilient valve member (25) normally closing the passageway and deforming means (23) for deforming the valve member so as to open the passageway only after the piston has moved relative to the cylinder by a predetermined amount greater than zero. The pump assembly has application to dispensing metered doses of medicinal products and ensures that the dispensed dose is independent of finger pressure applied to the actuator.</p> |
