US 4,792,398 A · Manual vacuum filtration device

Abstract

A manual liquid filtration device includes a housing having an open lower end providing access to an internal vacuum chamber, and defining a liquid specimen receiving chamber at its upper end adapted for flow communication with the vacuum chamber. An elastic diaphragm extends across the lower open end of the housing and upwardly along its outer peripheral surface so as to cooperate with air orifices in the housing to define valve means enabling unidirectional air flow from the vacuum chamber. A porous membrane filter element is interposed between the specimen receiving chamber and the vacuum chamber and when dry enables air to pass therethrough from the vacuum chamber upon flexing of the diaphragm into the vacuum chamber. When wetted by water, the filter element maintains vacuum in the vacuum chamber but enables liquid from a liquid specimen to be drawn through the filter element so as to retain solid particulate on the filter element for diagnosis or further reagent washing.

Claims14

Dependent claims

A liquid filtration device comprising, in combination, a housing having upper and lower ends and defining an internal chamber opening outwardly of said housing, said housing further defining a liquid specimen receiving chamber at its upper end adapted for flow communication with said internal chamber, a filter element interposed between and exposed to said specimen receiving chamber and said internal chamber, said filter element being charcterized as substantially impervious to air flow therethrough when wetted by liquid but enabling flow of specimen liquid therethrough when subjected to vacuum within said internal chamber, and elastic means mounted on said housing so as to traverse said outward opening of said internal chamber, said elastic means enabling flexing into said internal chamber so as to displace air from said internal chamber and create a vacuum therein upon wetting of said filter element and release of said elastic means.

A system for effecting vacuum filtration of a liquid specimen comprising;

a liquid filtration device including a housing having upper and lower ends and defining an internal chamber opening outwardly of said housing, said housing further defining a liquid specimen receiving chamber at its upper end adapted for flow communication with said internal chamber, a filter element interposed between and exposed to said specimen receiving chamber and said internal chamber, said filter element being characterized as substantially impervious to air flow therethrough when wetted by liquid but enabling flow of specimen liquid therethrough when subjected to vacuum within said internal chamber, elastic means mounted on said housing so as to traverse said outward opening of said internal chamber, said elastic means enabling flexing into said internal chamber so as to displace air from said internal chamber and create a vacuum therein upon wetting of said filter element and release of said elastic means, and tool means cooperative with said housing and elastic means to enable said flexing of said elastic means into said internal chamber.

Dependencies are inferred from the claim text.

Manual vacuum filtration device

Life of this patent

Manual vacuum filtration device

Life of this patent

Abstract

Claims14