Filter

Claim 2

A filter comprising: an inlet duct section; an outlet duct section; a filter enclosure disposed between and attached to said outlet and inlet duct sections and having four rectangularly disposed side walls, said enclosure defining a flow passageway section in flow communication with said inlet and outlet duct sections, and a filter withdrawal chamber comprising an outward extension of said flow passageway section, said chamber having a bottom wall and a detachably mounted top plate; filter box means slidably disposed within said filter enclosure for sliding movement between said flow passageway section and said filter withdrawal chamber; an expendable filter media contained within said filter box means; and handle means attached to said filter box means and extending to the exterior of said filter enclosure for causing said filter box means to move between said flow passageway section and said filter withdrawal chamber.

Claim 3

A filter as defined in claim 1 and further including parallel track means attached to the inner faces of opposing walls of said filter enclosure, and extending the full length of said flow passageway section and at least partway into said filter withdrawal chamber said track means sealingly receiving opposing parallel sides of said filter box means, for guiding said filter box means in its sliding movement between said filter withdrawal chamber and said flow passageway section and for preventing leakage past said filter box means.

Claim 4

A filter as defined in claim 1 wherein said handle means comprises: at least one elongated rod attached to said filter box means and extending through a mating opening in the wall of said filter enclosure spaced farthest frOm said flow passageway section; a handle portion attached to the end of said rod exterior of said filter enclosure and having a flat surface facing the exterior of said wall containing said opening, said rod being of such a length that when said filter box means is fully inserted into said flow passageway said flat surface engages the exterior of said wall thereby preventing leakage through said opening.

Claim 5

A filter as described in claim 3 further including a sealing gasket attached to said exterior of said wall and surrounding said opening through which said rod extends, and means for removably fastening said handle to said exterior of said wall thereby compressing said gasket to further insure that leakage does not occur through said opening.

Claim 6

A filter comprising: an inlet duct section; an outlet duct section; a filter enclosure disposed between and attached to said outlet and inlet duct sections and having four rectangularly disposed side walls, said enclosure defining a flow passageway section in flow communication with said inlet and outlet duct sections, a first filter withdrawal chamber comprising a first lateral extension of said flow passageway section, and a second filter withdrawal chamber comprising a second lateral extension of said flow passageway, said first and second chambers each having bottom walls and detachably mounted top plates, said first chamber and said second chamber further being positioned on opposite sides of said flow passageway section and being in longitudinal alignment with each other and with said flow passageway section; filter box means slidably disposed within said filter enclosure for sliding movement between a first position wherein a portion of said filter box means extends across said flow passageway section and is moveable to said first chamber and a second position wherein a portion of said filter box means extends across said flow passageway section and is moveable to said second chamber; two expendable filter media of equal size contained within said filter box means in side-by-side relation; and handle means attached to said filter box means and extending to the exterior of said filter enclosure for causing said filter box means to move between said first and second positions.

Claim 7

A filter comprising: an inlet duct section; an outlet duct section; a filter enclosure disposed between and attached to said outlet and inlet duct sections and having four rectangularly disposed side walls, said enclosure defining a flow passageway section in flow communication with said inlet and outlet duct sections, a first filter withdrawal chamber comprising a first lateral extension of said flow passageway section, and a second filter withdrawal chamber comprising a second lateral extension of said flow passageway, said first and second chambers each having bottom walls and detachably mounted top plates, said first chamber and said second chamber further being positioned on opposite sides of said flow passageway section and being in longitudinal alignment with each other and with said flow passageway section; filter box means slidably disposed within said filter enclosure for sliding movement between a first position wherein a portion of said filter box means extends across said flow passageway section and is moveable to said first chamber and a second position wherein a portion of said filter box means extends across said flow passageway section and is moveable to said second chamber; two expendable filter media of equal size contained within said filter box means in side-by-side relation; and handle means attached to said filter box means and extending to the exterior of said filter enclosure for causing said filter box means to move between said first and second positions.

Claim 8

A filter as defined in claim 5 further including parallel track means attached to the inner faces of opposing side walls of said filter enclosure and extending substantially the full length of said flow passageway section and said second filter removal section and at least partially into said first filter removal section, said track means sealingly receiving opposing parallel sides of said filter box means, for guiding said filter box means in its sliding movement between said first and second positions and for preventing leakage past said filter box means.

Claim 9

A filter as defined in claim 6 wherein said handle means comprises: at least one elongated rod attached to said filter box means and extending through mating opening in the wall of said first filter removal section of said filter enclosure which is spaced farthest from said flow passageway section; a handle portion attached to the end of said rod exterior of said filter enclosure and having a flat surface facing the exterior of said wall containing said opening, said rod being of such a length that when said filter box means is fully inserted into said flow passageway said flat surface engages the exterior of said wall thereby preventing leakage through said opening.

Claim 10

A filter as described in claim 7 further including a sealing gasket attached to said exterior of said wall and surrounding said opening through which said rod extends, and means for removably fastening said handle to said exterior of said wall thereby compressing said gasket to further insure that leakage does not occur through said opening.

Claim 11

A filter as described in claim 8 further including a second sealing gasket attached to the interior of said wall and surrounding said opening through which said rod extends.