US4559067A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Portable air filtration device
Assignee: ENVIROCOR Ltd TOWER HOUSE HIXON AIRFIELD INDUSTRIAL ESTATE STAFFORD ST18 OPF ENGLAND A BRITISH Co
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Filing: 1984-03-09
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Granted: 1985-12-17
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Expires: 2004-03-09
Abstract
Abstract A Coanda-type airmover 16 is mounted vertically on a hollow base 10 to draw air through the base from filtering means comprising a pre-filter 26 and an absolute (HEPA) filter 28. The airmover discharges the filtered air upwards. The two filters are stacked on the base for air to be drawn downwards through them from an inlet duct 30 leading horizontally from a contaminated-air inlet 32 of the device. An air tight cover 34 can be secured to cover the inlet 32 of the duct when the equipment is not in use, enabling contaminated filters to be left in place during transportation. The portable device may be used for withdrawing and cleaning fibre-laden air from a working space where asbestos stripping is taking place.
Inventors
- 👤 David S. Durston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 16:15
CPC Classifications
F; F24; F24F; F24F8/00; F24F8/10; F24F8/108
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
196 words
A portable air filtration device suitable for use in drawing off and cleaning contaminated air from a working space comprising a base defining an air passageway therein; an airmover mounted on top of one side of said base; said airmover having an air inlet in an underside thereof in communication with said base passageway, a second air inlet disposed transversely to said air inlet for coupling to a remote compressed air source, and an air outlet disposed above said air inlets for discharging filtered air to the atmosphere; filtering means mounted on top of said base on a side opposite said airmover; said filtering means having an air inlet side and an air outlet side; said filtering means outlet side being in communication with said base air passageway; an inlet duct in communication with said filter means inlet side; and fastening means for retaining said filtering means between said base and inlet duct, whereby in operation of the device with said inlet duct in communication with a working space said airmover draws contaminated air from the working space through said inlet duct, said filtering means and said base air passageway and exhausts cleaned air to atmosphere.
Claim 2
Dependent Claim
196 words
A portable air filtration device suitable for use in drawing off and cleaning contaminated air from a working space comprising a base defining an air passageway therein; an airmover mounted on top of one side of said base; said airmover having an air inlet in an underside thereof in communication with said base passageway, a second air inlet disposed transversely to said air inlet for coupling to a remote compressed air source, and an air outlet disposed above said air inlets for discharging filtered air to the atmosphere; filtering means mounted on top of said base on a side opposite said airmover; said filtering means having an air inlet side and an air outlet side; said filtering means outlet side being in communication with said base air passageway; an inlet duct in communication with said filter means inlet side; and fastening means for retaining said filtering means between said base and inlet duct, whereby in operation of the device with said inlet duct in communication with a working space said airmover draws contaminated air from the working space through said inlet duct, said filtering means and said base air passageway and exhausts cleaned air to atmosphere.
Claim 3
Dependent Claim
21 words
A device according to claim 1 in which said airmover is moutned on said base with its exhaust outlet directed upwards.
Claim 4
Dependent Claim
29 words
A device according to claim 2 in which said filtering means is mounted on said base such that air from said inlet duct flows downwardly through said filter means.
Claim 5
Dependent Claim
22 words
A device according to claim 3 in which said inlet duct is fastened in generally horizontally extending relation to said filtering means.
Claim 6
Dependent Claim
47 words
A device according to claim 3 including an air-tight cover which can be secured to said duct to close said contaminated-air inlet when the device is not in use, so permitting said filtering means even when contaminated to be left in place whilst the device is transported.
Claim 7
Dependent Claim
16 words
A device according to claim 1 in which said filtering means comprises an absolute (HEPA) filter.
Claim 8
Dependent Claim
15 words
A device according to claim 6 in which said filtering means comprises also a pre-filter.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-16 | 1989-06-17 | 1989-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-16 | 1993-06-17 | 1993-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-16 | 1997-06-17 | 1997-12-17 | $7700.00 | Window Closed / Lapsed |