Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
153 words
In an air handling apparatus having an enclosed duct through which air at a negative pressure is moved, an entry for gaining access to said duct that includes a door frame mounted in an opening in said duct, said frame including a first outer seal for providing a moisture barrier that surrounds the frame, said outer seal having an aperture therein to permit ambient air to pass therethrough, and a second inner seal for providing an air barrier that surrounds said frame, said seals having an air gap therebetween; and a door hingedly supported in said frame, said door having a first surface means for closing in sealing contact against said outer seal and a second surface means for closing in sealing contact against said inner seal when the door is closed against the frame whereby the air gap between the seals is maintained at ambient pressure when the door is at closure.
Claim 2
Dependent Claim
153 words
In an air handling apparatus having an enclosed duct through which air at a negative pressure is moved, an entry for gaining access to said duct that includes a door frame mounted in an opening in said duct, said frame including a first outer seal for providing a moisture barrier that surrounds the frame, said outer seal having an aperture therein to permit ambient air to pass therethrough, and a second inner seal for providing an air barrier that surrounds said frame, said seals having an air gap therebetween; and a door hingedly supported in said frame, said door having a first surface means for closing in sealing contact against said outer seal and a second surface means for closing in sealing contact against said inner seal when the door is closed against the frame whereby the air gap between the seals is maintained at ambient pressure when the door is at closure.
Claim 3
Dependent Claim
16 words
The apparatus of claim 1 wherein said frame is formed of a single piece of material.
Claim 4
Dependent Claim
28 words
The apparatus of claim 2 wherein said frame has a first recessed housing for containing the outer seal and a second recessed housing for containing the second seal.
Claim 5
Dependent Claim
25 words
The apparatus of claim 3 wherein said seals are bulb seals having internal air chambers whereby the seals deform against the door surfaces at closure.
Claim 6
Dependent Claim
23 words
The apparatus of claim 1 that further includes a latch means that is operable to secure the door against the frame at closure.
Claim 7
Dependent Claim
38 words
The apparatus of claim 5 wherein said latch means is a hand operated lever that is rotatably mounted in the door, said lever containing an arm that is capable of being rotated into locking engagement with the frame.
Claim 8
Dependent Claim
28 words
The apparatus of claim 1 wherein the frame is rectangular in form and the aperture in the outer seal is located along the bottom section of the frame.
Claim 9
Dependent Claim
44 words
The apparatus of claim 7 wherein the door further includes an outer panel containing said first surface means for closing in sealing contact with said outer seal, said panel having an inwardly turned lip along its peripheral edge that closes around the other seal.