Pressure differential filtering apparatus and method

Claim 2

A pressure differential filtering apparatus comprising: an elongated sampling member defining a central passageway a portion of which collects liquid, said central passageway being open at both ends and extending through the entire length of said sampling member with one end portion of said sampling member having a resilient lip projecting radially to form a piston, said lip being capable of formIng a seal with the walls of a container which contains a liquid to be filtered when said piston is inserted into the container, said central passageway at the end portion of said sampling member having said lip being a cylindrical bore which is smaller in diameter than the diameter of the portion of said central passageway above said bore which collects filtered liquid, one end of said bore providing the opening through which a liquid to be filtered enters said filtering apparatus with the other end of said bore communicating with the portion of said central passageway which collects filtered liquid, and a porous filter member fitted within said bore to enable the filtration of a liquid as the liquid flows through said bore into the portion of the central passageway which collects filtered liquid.

Claim 3

The apparatus as set forth in claim 1 wherein said filter member has a plurality of interconnected voids, said interconnected voids defining a number of passageways in said filter member, said passageways communicating directly with the open ends of said bore.

Claim 4

The apparatus as set forth in claim 1 wherein said lip is formed on the bottom surface of said sampling member.

Claim 5

The apparatus as set forth in claim 3 wherein said bottom surface has a frusto-conical configuration.

Claim 6

The apparatus as set forth in claim 4 wherein said lip is a rounded rim on said bottom surface.

Claim 7

A pressure differential filtering apparatus for separating a liquid contained in an open mouth container comprising: an elongated sampling member defining a central passageway a portion of which collects filtered liquid, said central passageway being open at both ends and extending through the entire length of said sampling member; a piston member, having a cylindrical bore, mounted on one end of said sampling member, said bore being open at both ends, one end of said bore providing the opening through which a liquid to be separated enters the filtering apparatus with the other end of said bore communicating with the portion of said central passageway which collects filtered liquid, said bore being smaller in diameter than the diameter of the portion of said passageway above said bore which collects filtered liquid, said piston member having a resilient lip projecting outwardly from said sampling member, said lip being capable of forming a seal with the open mouth container when said piston member is inserted into the container, and a porous filter member fitted within said bore to enable the filtration of a liquid as the liquid flows through said bore into the portion of said central passageway which collects filtered liquid, said porous filter member having a plurality of interconnected voids, said interconnected voids defining a number of passageways in said filter member, said passageways communicating directly with the open ends of said bore.

Claim 8

A pressure differential filtering apparatus for separating a liquid contained in an open mouth container comprising: an elongated sampling member defining a central passageway a portion of which collects filtered liquid, said central passageway being open at both ends and extending through the entire length of said sampling member; a piston member, having a cylindrical bore, mounted on one end of said sampling member, said bore being open at both ends, one end of said bore providing the opening through which a liquid to be separated enters the filtering apparatus with the other end of said bore communicating with the portion of said central passageway which collects filtered liquid, said bore being smaller in diameter than the diameter of the portion of said passageway above said bore which collects filtered liquid, said piston member having a resilient lip projecting outwardly from said sampling member, said lip being capable of forming a seal with the open mouth container when said piston member is inserted into the container, and a porous filter member fitted within said bore to enable the filtration of a liquid as the liquid flows through said bore into the portion of said central passageway which collects filtered liquid, said porous filter member having a plurality of interconnected voids, said interconnected voids defining a number of passageways in said filter member, said passageways communicating directly with the open ends of said bore.

Claim 9

The apparatus as set forth in claim 6 wherein said piston has a frusto-conical bottom surface and said lip is a rounded rim on said bottom surface.

Claim 10

A pressure differential filtering apparatus for separating a liquid comprising: a hollow cylindrical walled container having a closed bottom and an open top for containing a liquid to be filtered and separated; an elongated sampling member defining a central passageway a portion of which collects filtered liquid, said central passageway being open at both ends and extending through the entire length of said sampling member; a piston member, having a cylindrical bore, mounted on one end of said sampling member, said bore being open at both ends, one end of said bore providing the opening through which a liquid to be separated enters the filtering apparatus with the other end of said bore communicating with the portion of said central passageway which collects filtered liquid, said bore being smaller in diameter than the diameter of the portion of said passageway above said bore which collects filtered liquid, said piston member having a resilient lip projecting outWardly from said sampling member, said lip being capable of forming a seal with the walls of said container when said piston is inserted into said container, and a porous filter member fitted within said bore to enable the filtration of a liquid as the liquid flows through said bore into the portion of said central passageway which collects filtered liquid, said porous filter member having a plurality of interconnected voids, said interconnected voids defining a number of passageways in said filter, said passageways communicating directly with the open ends of said bore.

Claim 11

A pressure differential filtering apparatus for separating a liquid comprising: a hollow cylindrical walled container having a closed bottom and an open top for containing a liquid to be filtered and separated; an elongated sampling member defining a central passageway a portion of which collects filtered liquid, said central passageway being open at both ends and extending through the entire length of said sampling member; a piston member, having a cylindrical bore, mounted on one end of said sampling member, said bore being open at both ends, one end of said bore providing the opening through which a liquid to be separated enters the filtering apparatus with the other end of said bore communicating with the portion of said central passageway which collects filtered liquid, said bore being smaller in diameter than the diameter of the portion of said passageway above said bore which collects filtered liquid, said piston member having a resilient lip projecting outWardly from said sampling member, said lip being capable of forming a seal with the walls of said container when said piston is inserted into said container, and a porous filter member fitted within said bore to enable the filtration of a liquid as the liquid flows through said bore into the portion of said central passageway which collects filtered liquid, said porous filter member having a plurality of interconnected voids, said interconnected voids defining a number of passageways in said filter, said passageways communicating directly with the open ends of said bore.

Claim 12

The apparatus as set forth in claim 8 wherein said lip of said piston member has a sufficient resiliency so that it may be urged sideways for compressing a portion of said lip against the inside wall surface of said cylindrical container and space the opposite portion of said lip from the opposite inside wall surface of said cylindrical container to form a gap so that said piston member can be moved axially within said container without creating appreciable pressure differential between the fluids on opposite sides of said lip.