US3670699A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatically charged fluidized bed apparatus
Assignee: 3M Co
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Filing: 1970-06-24
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Granted: 1972-06-20
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Expires: 1990-06-24
Abstract
Abstract Electrostatically charged fluidized bed apparatus having a porous membrane through which a continuous stream of air flows upwardly to fluidize powder in a bed above the membrane. A conductive web consisting of a layer of conductive particles incorporated into the membrane is maintained at a potential of at least 5,000 volts so that the stream of air carries electrical charges to powder suspended in the fluidized bed. Alternatively, the conductive web may be a fabric of conductive fibers mounted beneath and close to the membrane.
Inventors
- 👤 Jerald P Sargent
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:38
CPC Classifications
B; B05; B05C; B05C19/00; B05C19/02; B05C19/025; Y; Y10; Y10S; Y10S118/00; Y10S118/05
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
29 words
Fluidized bed coating apparatus as defined in claim 1 wherein the conductive web consists of a layer of graphite particles applied to the under face of the porous membrane.
Claim 2
Dependent Claim
26 words
Fluidized bed coating apparatus as defined in claim 1 wherein the conductive web consists of conductive particles incorporated into the porous membrane, which particles are fibers.
Claim 3
Dependent Claim
23 words
Fluidized bed coating apparatus as defined in claim 1 wherein the conductive web consists of a woven or nonwoven fabric of graphite fibers.
Claim 4
Dependent Claim
28 words
Fluidized bed coating apparatus as defined in claim 1 wherein the conductive web has a resistance of about 1-1,000,000 ohms measured at an electrode spacing of 1 inch.
Claim 5
Dependent Claim
62 words
A pair of closely spaced fluidized bed coating apparati as defined in claim 1, each having a relatively low opposite side wall positioned adjacent the relatively low side wall of the other, such that electrostatically charged powder in both beds is attracted to a grounded article intermediate the two relatively low side walls to deposit powder on the article from both sides.
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) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |