US4631077A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Foam plastic air filter
Assignee: PIPERCROSSLIMITED
•
Filing: 1985-03-26
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Granted: 1986-12-23
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Expires: 2005-03-26
Abstract
Abstract An air filter comprising a first layer of reticulated foam plastic material having a thickness of between 10 mm and 20 mm and a porosity of between 5 and 60 pores to the linear inch, a second layer of reticulated foam plastic material having a thickness of between 6 mm and 10 mm and a porosity of between 60 and 100 pores to the linear inch, and at the interface between said first and second layers an open mesh substrate approximately one millimeter in thickness constricting a maximum of about ten percent of each of the first and second layers, the filter being impregnated with a flame proof retention and plasticizer additive, the first and second layers being bonded together at the interface.
Inventors
- 👤 Barry Spicer
- 👤 Joseph T. Wills
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:00
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/14; B01D39/16; B01D39/1669; B01D39/1676; B01D46/00; B01D46/24; B01D46/2403; B01D46/2411; F; F02; F02M; F02M35/00; F02M35/02; F02M35/024; B01D2239/00; B01D2239/10; Y; Y10; Y10S; Y10S55/00; Y10S55/13
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
117 words
An air filter comprising a first layer of reticulated foam plastic material having a thickness of between 10 mm and 20 mm and a porosity of 45±4 pores to the linear inch, a second layer of reticulated foam plastic material having a thickness of between 6 mm and 10 mm and a porosity of 65±2 pores to the linear inch, and at the interface between said first and second layers on open mesh substrate approximately one millimeter in thickness constricting a maximum of about ten percent of each of the first and second layers, the filter being impregnated with a flame proof retention and plasticiser additive, the first and second layers being bonded together at the interface.
Claim 2
Dependent Claim
117 words
An air filter comprising a first layer of reticulated foam plastic material having a thickness of between 10 mm and 20 mm and a porosity of 45±4 pores to the linear inch, a second layer of reticulated foam plastic material having a thickness of between 6 mm and 10 mm and a porosity of 65±2 pores to the linear inch, and at the interface between said first and second layers on open mesh substrate approximately one millimeter in thickness constricting a maximum of about ten percent of each of the first and second layers, the filter being impregnated with a flame proof retention and plasticiser additive, the first and second layers being bonded together at the interface.
References Cited (Backward Citations)
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GB1097917A
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GB1322718A
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GB1302878A
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US3882961A
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US4350507A
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US4456648A
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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) | 1989-12-22 | 1990-06-23 | 1990-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-22 | 1994-06-23 | 1994-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-22 | 1998-06-23 | 1998-12-23 | $7700.00 | Window Closed / Lapsed |