US3853510A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two stage high efficiency air filter
Assignee: SYST DISCIPLINE Inc
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Filing: 1974-03-04
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Granted: 1974-12-10
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Expires: 1994-03-04
Abstract
Abstract A two-stage filter in which the first stage, when clean, initially filters both large and small particles from an air stream containing particulate matter, but as loading of the first stage increases, thereby increasing the resistance of the filter, a progressively greater portion of the smaller particles passes through perforations in the first stage into a cavity defined by the walls of the first and second stage filter media to be filtered by the second stage.
Inventors
- 👤 P Burnstein
- 👤 R Meyer
- 👤 J Kearney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:26
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/02; B01D46/023
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
170 words
An apparatus for filtering particulate matter containing relatively fine and relatively coarse particles from an air stream, said apparatus comprising: at least one wedge-shaped filter unit having a first wedgeshaped filter comprising filter walls disposed inside a second wedge-shaped filter, the outside surface of said first wedgeshaped filter and the inside surface of said second wedgeshaped filter defining a cavity therebetween; said first wedge-shaped filter and said second wedge-shaped filter having a common open upstream end; a plurality of perforations in said filter walls near the upstream end of said first wedge-shaped filter the size of said perforations being greater than the porosity of said filter walls; so that said perforations direct a substantial portion of said relatively fine particles to said cavity while at the same time permitting said relatively coarse particles to be filtered by the filter walls of said first wedge-shaped filter when the first wedge-shaped filter is less than completely occluded with particulate matter; and, means for maintaining said common upstream end in an open position.
Claim 2
Independent Claim
170 words
An apparatus for filtering particulate matter containing relatively fine and relatively coarse particles from an air stream, said apparatus comprising: at least one wedge-shaped filter unit having a first wedgeshaped filter comprising filter walls disposed inside a second wedge-shaped filter, the outside surface of said first wedgeshaped filter and the inside surface of said second wedgeshaped filter defining a cavity therebetween; said first wedge-shaped filter and said second wedge-shaped filter having a common open upstream end; a plurality of perforations in said filter walls near the upstream end of said first wedge-shaped filter the size of said perforations being greater than the porosity of said filter walls; so that said perforations direct a substantial portion of said relatively fine particles to said cavity while at the same time permitting said relatively coarse particles to be filtered by the filter walls of said first wedge-shaped filter when the first wedge-shaped filter is less than completely occluded with particulate matter; and, means for maintaining said common upstream end in an open position.
References Cited (Backward Citations)
US3396517A
Cited
US3443366A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |