US3995076A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Progressive felting of filter elements
Assignee: Specialty Materials Inc
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Filing: 1975-05-19
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Granted: 1976-11-30
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Expires: 1995-05-19
Abstract
Abstract A method for progressively vacuum forming a fibre batt about a porous member whereby, accretion, consolidation and dewatering of the batt occurs under constant vacuum conditions and includes continuously introducing a vacuum through a fixed porous arbor disposed in a tank containing a slurry of fibrous material in water, to thereby define a fixed vacuum zone between sealed first and second portions of the arbor, for the progressive formation of a fibrous batt in the vacuum zone, and continuously advancing the arbor through the vacuum zone at a preselected constant rate of travel.
Inventors
- 👤 Marcel Clarence Sicard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:47
CPC Classifications
D; D21; D21J; D21J7/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
230 words
A method for progressively vacuum forming a fibre batt about a porous member whereby, accretion, consolidation and dewatering of said batt occur under constant vacuum conditions including the steps of: placing a porous felting arbor into a tank containing a slurry of fibrous material in water; disposing said felting arbor about a vacuum standpipe positioned within said tank, said standpipe being integrally formed with a fixed porous arbor at its uppermost portion; introducing a vacuum into said standpipe through a vacuum pump connected thereto; advancing said felting arbor out of said tank subsequent to the introduction of said vacuum; causing said fibrous material to be accreted on to said felting arbor by the action of said vacuum on said slurry through said felting arbor; sealing off a first portion of said fixed porous arbor with respect to said porous felting arbor for a preselected distance below the slurry level of said tank; sealing off a second portion of said fixed porous arbor with respect to said porous felting arbor at a prescribed distance above the slurry level; continuously introducing a vacuum through said fixed porous arbor to thereby define a fixed length vacuum zone between said sealed first and second portions for the progressive formation of said fibrous batt in said vacuum zone, and continuously advancing said felting arbor through said vacuum zone at a preselected constant rate of travel.
Claim 2
Independent Claim
230 words
A method for progressively vacuum forming a fibre batt about a porous member whereby, accretion, consolidation and dewatering of said batt occur under constant vacuum conditions including the steps of: placing a porous felting arbor into a tank containing a slurry of fibrous material in water; disposing said felting arbor about a vacuum standpipe positioned within said tank, said standpipe being integrally formed with a fixed porous arbor at its uppermost portion; introducing a vacuum into said standpipe through a vacuum pump connected thereto; advancing said felting arbor out of said tank subsequent to the introduction of said vacuum; causing said fibrous material to be accreted on to said felting arbor by the action of said vacuum on said slurry through said felting arbor; sealing off a first portion of said fixed porous arbor with respect to said porous felting arbor for a preselected distance below the slurry level of said tank; sealing off a second portion of said fixed porous arbor with respect to said porous felting arbor at a prescribed distance above the slurry level; continuously introducing a vacuum through said fixed porous arbor to thereby define a fixed length vacuum zone between said sealed first and second portions for the progressive formation of said fibrous batt in said vacuum zone, and continuously advancing said felting arbor through said vacuum zone at a preselected constant rate of travel.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-11-30 | 1980-05-31 | 1980-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-30 | 1984-05-31 | 1984-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-30 | 1988-05-31 | 1988-11-30 | $7700.00 | Window Closed / Lapsed |