Filter system

Claim 2

Clean air apparatus suitable for clean benches, clean rooms, and the like comprising a housing having an outlet, a high efficiency air filter having at least a 75 percent efficiency for the removal of 0.3 micron particles as determined by the standard D.O.P. Test of the Army Chemical Corps. and having an air inlet surface and an air discharge surface, first means for mounting the high efficiency filter on the housing in the housing outlet with the filter inlet surface within the housing, a conduit within the housing and having an inlet end portion and a discharge end portion sealed to the filter to provide air under pressure at the filter inlet surface, said filter having a filter frame and said first means comprising a filter cradle of somewhat flexible material that surrounds the filter frame in abutting relationship thereto, said cradle being secured to the housing and being made of metal that is resilient, a grill mounted by the cradle exterior of the housing to protect the discharge surface of the filter, and second means for providing a source of air under pressure and a vacuum within the housing in the space between said housing and the conduit and the portion of the filter extending within the housing, said second means having a discharge end portion fluidly connected to the conduit inlet end portion for discharging air under pressure into the conduit, and said conduit and the filter portion within the housing being spaced from the housing to provide a surrounding air space.

Claim 3

Clean air apparatus suitable for clean benches, clean rooms, and the like comprising a housing having front, top, bottom and side walls joined together, said front wall having a discharge outlet substantially spaced from the other walls, a high efficiency air filter having at least a 75 percent efficiency for the removal of 0.3 micron particles as determined by the standard D.O.P. Test of the Army Chemical Corps. and having a filter frame, an air inlet surface and an air discharge surface, first means for mounting the high efficiency filter on the housing in the housing outlet with the filter inlet surface within the housing, a conduit within the housing and having an inlet end portion and a discharge end portion sealed to the filter to provide air under pressure at the filter inlet surface, said first means comprising a filter cradle of somewhat flexible material that surrounds the filter frame and is secured thereto and secured to the housing, said cradle extending Through the discharge outlet into the housing interior in surrounding relationship to the filter frame, and second means for providing a source of air under pressure and a vacuum within the housing in the space between said housing and the conduit and the portion of the filter extending within the housing, said second means having a discharge end portion fluidly connected to the conduit inlet end portion for discharging air under pressure into the conduit, said conduit and the filter portion within the housing being spaced from the housing to provide a surrounding air space, said second means comprising a powered blower that has an air inlet within the housing and has said second means discharge end portion, said blower inlet being in direct air flow communication with the cradle to draw any leakage air adjacent the cradle into the second means.

Claim 4

Clean air apparatus suitable for clean benches, clean rooms, and the like comprising a housing having front, top, bottom and side walls joined together, said front wall having a discharge outlet substantially spaced from the other walls, a high efficiency air filter having at least a 75 percent efficiency for the removal of 0.3 micron particles as determined by the standard D.O.P. Test of the Army Chemical Corps. and having a filter frame, an air inlet surface and an air discharge surface, first means for mounting the high efficiency filter on the housing in the housing outlet with the filter inlet surface within the housing, a conduit within the housing and having an inlet end portion and a discharge end portion sealed to the filter to provide air under pressure at the filter inlet surface, said first means comprising a filter cradle of somewhat flexible material that surrounds the filter frame and is secured thereto and secured to the housing, said cradle extending Through the discharge outlet into the housing interior in surrounding relationship to the filter frame, and second means for providing a source of air under pressure and a vacuum within the housing in the space between said housing and the conduit and the portion of the filter extending within the housing, said second means having a discharge end portion fluidly connected to the conduit inlet end portion for discharging air under pressure into the conduit, said conduit and the filter portion within the housing being spaced from the housing to provide a surrounding air space, said second means comprising a powered blower that has an air inlet within the housing and has said second means discharge end portion, said blower inlet being in direct air flow communication with the cradle to draw any leakage air adjacent the cradle into the second means.

Claim 5

Clean air apparatus suitable for clean benches, clean rooms, and the like comprising a housing having front, top, bottom and side walls joined together, said front wall having a discharge outlet substantially spaced from the other walls, a high efficiency air filter having at least a 75 percent efficiency for the removal of 0.3 micron particles as determined by the standard D.O.P. Test of the Army Chemical Corps. and having a filter frame that has a front edge, an air inlet surface and an air discharge surface, first means for mounting the high efficiency filter on the housing in the housing outlet with the filter inlet surface within the housing, a conduit within the housing and having an inlet end portion and a discharge end portion sealed to the filter to provide air under pressure at the filter inlet surface, said first means comprising a filter cradle of somewhat flexible material that surrounds the filter frame and is secured to the housing, said cradle overlapping the front edge of the filter frame, third means for releasably retaining the filter frame closely adjacent the cradle, second means for providing a source of air under pressure and a vacuum within the housing in the space between said housing and the conduit and the portion of the filter extending within the housing, said third means having a discharge end portion fluidly connected to the conduit inlet end portion for discharging air under pressure into the conduit, said conduit and the filter portion within the housing being spaced from the housing to provide a surrounding air space, and a resilient pad surrounding at least a part of the filter frame, abutting against the duct and housing, spaced from the front wall to provide a second air space between the filter frame and side and bottom walls and having a bore fluidly connecting the second air space to the air space rearwardly of the pad whereby any air leakage into the second space is drawn into the third means.

Claim 6

Clean air apparatus suitable for clean benches, clean rooms, and the like comprising a housing having front, top, bottom and side walls joined together, said front wall having a discharge outlet substantially spaced from the other walls, a high efficiency air filter having at least a 75 percent efficiency for the removal of 0.3 micron particles as determined by the standard D.O.P. Test of the Army Chemical Corps. and having a filter frame that has a front edge, an air inlet surface and an air discharge surface, first means for mounting the high efficiency filter on the housing in the housing outlet with the filter inlet surface within the housing, a conduit within the housing and having an inlet end portion and a discharge end portion sealed to the filter to provide air under pressure at the filter inlet surface, said first means comprising a filter cradle of somewhat flexible material that surrounds the filter frame and is secured to the housing, said cradle overlapping the front edge of the filter frame, third means for releasably retaining the filter frame closely adjacent the cradle, second means for providing a source of air under pressure and a vacuum within the housing in the space between said housing and the conduit and the portion of the filter extending within the housing, said third means having a discharge end portion fluidly connected to the conduit inlet end portion for discharging air under pressure into the conduit, said conduit and the filter portion within the housing being spaced from the housing to provide a surrounding air space, and a resilient pad surrounding at least a part of the filter frame, abutting against the duct and housing, spaced from the front wall to provide a second air space between the filter frame and side and bottom walls and having a bore fluidly connecting the second air space to the air space rearwardly of the pad whereby any air leakage into the second space is drawn into the third means.

Claim 7

Clean air apparatus suitable for clean benches, clean rooms, and the like comprising a housing having front, top, bottom and side walls joined together, said front wall having a discharge outlet substantially spaced from the other walls, a high efficiency air filter having at least a 75 percent efficiency for the removal of 0.3 micron particles as determined by the standard D.O.P. Test of the Army Chemical Corps. and having a filter frame, an air inlet surface and an air discharge surface, first means for mounting the high efficiency filter on the housing in the housing outlet with the filter inlet surface within the housing, a conduit within the housing and having an inlet end portion and a discharge end portion sealed to the filter to provide air under pressure at the filter inlet surface, said first means comprising a filter cradle that surrounds the filter frame, second means for removably securing the cradle to the housing with the cradle closely adjacent the discharge outlet, third means for providing a source of air under pressure and a vacuum within the housing in the space between said housing and the conduit and the portion of the filter extenDing within the housing, said third means having a discharge end portion fluidly connected to the conduit inlet end portion for discharging air under pressure into the conduit, said conduit and the filter portion within the housing being spaced from the housing to provide a surrounding air space, said third means comprising a powered blower that has an inlet within the housing and has said third means discharge end portion, said blower inlet being in direct air flow communication with the cradle to draw any leakage air adjacent the cradle into the second means, and fourth means for releasably retaining the filter frame closely adjacent the cradle.

Claim 8

Clean air apparatus suitable for clean benches, clean rooms, and the like comprising a housing having front, top, bottom and side walls joined together, said front wall having a discharge outlet substantially spaced from the other walls, a high efficiency air filter having at least a 75 percent efficiency for the removal of 0.3 micron particles as determined by the standard D.O.P. Test of the Army Chemical Corps. and having a filter frame, an air inlet surface and an air discharge surface, first means for mounting the high efficiency filter on the housing in the housing outlet with the filter inlet surface within the housing, a conduit within the housing and having an inlet end portion and a discharge end portion sealed to the filter to provide air under pressure at the filter inlet surface, said first means comprising a filter cradle that surrounds the filter frame, second means for removably securing the cradle to the housing with the cradle closely adjacent the discharge outlet, third means for providing a source of air under pressure and a vacuum within the housing in the space between said housing and the conduit and the portion of the filter extenDing within the housing, said third means having a discharge end portion fluidly connected to the conduit inlet end portion for discharging air under pressure into the conduit, said conduit and the filter portion within the housing being spaced from the housing to provide a surrounding air space, said third means comprising a powered blower that has an inlet within the housing and has said third means discharge end portion, said blower inlet being in direct air flow communication with the cradle to draw any leakage air adjacent the cradle into the second means, and fourth means for releasably retaining the filter frame closely adjacent the cradle.

Claim 9

The apparatus of claim 4 further characterized in that said conduit is of an increasing cross-sectional area from the blower to the filter.

Claim 10

The apparatus of claim 4 further characterized in that the filter frame has a front edge, that the cradle overlaps the filter frame front edge, and that the conduit extends between the filter front edge and the cradle.

Claim 11

The apparatus of claim 4 further characterized in that the cradle extends through the discharge outlet into the housing interior in surrounding relationship to the filter frame and is secured to the filter frame.

Claim 12

The apparatus of claim 4 further characterized in that the first means includes a resilient pad surrounding the filter frame, abutting against the duct and housing and spaced from the front wall to provide an air space between the filter frame and side and bottom walls, the resilient pad being secured to the housing and having a bore therethrough for placing the blower inlet in direct air flow communication with the cradle.

Claim 13

The apparatus of claim 4 further characterized in that the first means includes a plurality of resilient pads abutting against the housing and the duct between the filter frame and the housing, and spaced from the front wall and cradle, said pads being secured to the housing and spaced from one another to provide openings for providing direct air flow communication between the blower inlet and the cradle.

Claim 14

The apparatus of claim 4 further characterized in that the first means includes resilient pads means abutting against the housing side walls and bottom wall between the housing and the filter frame, and that the fourth means comprises spring means for resiliently urging the filter frame toward the cradle and retaining it adjacent thereto, the filter frame being movable relative the cradle and having a front edge, the cradle overlapping the filter frame front edge.

Claim 15

Clean air apparatus suitable for clean benches, clean rooms, and the like comprising a housing having front, top, bottom and side walls joined together, said front wall having a discharge outlet substantially spaced from the other walls, a high efficiency air filter having at least a 75 percent efficiency for the removal of 0.3 micron particles as determined by the standard D.O.P. Test of the Army Chemical Corps. and having a filter frame that has a front edge, an air inlet surface and an air discharge surface, first means for mounting the high efficiency filter on the housing in the housing outlet with the filter inlet surface within the housing, a conduit within the housing and having an inlet end portion and a discharge end portion sealed to the filter to provide air under pressure at the filter inlet surface, said first means comprising a filter cradle of somewhat flexible material that surrounds the filter frame and is secured to the housing, said cradle overlapping the front edge of the filter frame, third means for releasably retaining the filter frame closely adjacent the cradle, second means for providing a source of air under pressure and a vacuum within the housing in the space between said housing and the conduit and the portion of the filter extending within the housing, said third means having a discharge end portion fluidly connected to the conduit inlet end portion for discharging air under pressure into the conduit, sAid conduit and the filter portion within the housing being spaced from the housing to provide a surrounding air space, and resilient pad means abutting against the duct and housing and spaced from the front wall to provide a second air space between the filter frame and side and bottom walls, said pad means providing an opening fluidly connecting the second air space to the air space rearwardly of the pad means whereby any air leakage into the second space is drawn into the second means.

Claim 16

Clean air apparatus suitable for clean benches, clean rooms, and the like comprising a housing having front, top, bottom and side walls joined together, said front wall having a discharge outlet substantially spaced from the other walls, a high efficiency air filter having at least a 75 percent efficiency for the removal of 0.3 micron particles as determined by the standard D.O.P. Test of the Army Chemical Corps. and having a filter frame that has a front edge, an air inlet surface and an air discharge surface, first means for mounting the high efficiency filter on the housing in the housing outlet with the filter inlet surface within the housing, a conduit within the housing and having an inlet end portion and a discharge end portion sealed to the filter to provide air under pressure at the filter inlet surface, said first means comprising a filter cradle of somewhat flexible material that surrounds the filter frame and is secured to the housing, said cradle overlapping the front edge of the filter frame, third means for releasably retaining the filter frame closely adjacent the cradle, second means for providing a source of air under pressure and a vacuum within the housing in the space between said housing and the conduit and the portion of the filter extending within the housing, said third means having a discharge end portion fluidly connected to the conduit inlet end portion for discharging air under pressure into the conduit, sAid conduit and the filter portion within the housing being spaced from the housing to provide a surrounding air space, and resilient pad means abutting against the duct and housing and spaced from the front wall to provide a second air space between the filter frame and side and bottom walls, said pad means providing an opening fluidly connecting the second air space to the air space rearwardly of the pad means whereby any air leakage into the second space is drawn into the second means.

Claim 17

The apparatus of claim 11 further characterized in that the first means includes means mounted in the housing for abutting against the duct to exert a force against the filter frame to resiliently retain the filter frame closely adjacent the cradle and urging the filter frame toward the cradle.

Claim 18

The apparatus of claim 11 further characterized in that the pad means comprises a resilient pad surrounding at least a part of the filter frame, the last mentioned opening comprising a pad bore extending through the pad.

Claim 19

The apparatus of claim 11 further characterized in that said pad means comprises a plurality of pads spaced around the periphery of the filter frame, each of the pads being spaced from the front wall, and an adjacent pair of pads being spaced to provide the last mentioned opening.