| 摘要 |
A finger actuated pump dispenser employs a first upper hollow vertical cylinder with a first diameter and open upper and lower ends and a second lower hollow vertical cylinder with a second and smaller diameter and a closed lower end with a central opening. The lower end of the first cylinder is joined to an open upper end of the second cylinder. The inner wall of the second cylinder has a horizontal annular recess. A first vertical hollow piston has openings in top and bottom ends and extendings slidably above and within first cylinder. The first piston has an enlargement intermediate its ends peripherally engaging and defining a first unbroken seal with the inner surface of the first cylinder. A second vertical piston has a central vertical bore extending therethrough and is disposed slidably within the second cylinder. The second piston peripherally engages and defines a second seal with the inner surface of the second cylinder. The second seal is unbroken except when the second piston is aligned with and spaced from the annular recess. A vertical stem is disposed slidably within the first piston with an outwardly extending central horizontal flange secured thereto intermediate its ends. The bottom opening of the first piston engages and defines a third seal with the flange. The third seal is broken when the bottom opening of the first piston is separated from the flange. A portion of the stem below the flange extends vertically and slidably downwards through the central bore of the second piston. The portion engages and defines a fourth unbroken seal with said bore. A spring extends within the second cylinder between its lower end and the lower end of the second piston.
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