US3731652A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coating doctor apparatus
Assignee: Black Clawson Co
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Filing: 1972-01-24
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Granted: 1973-05-08
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Expires: 1992-01-24
Abstract
Abstract In coating doctor apparatus in which an air doctor is used to remove coating from a freshly coated web trained about a backing roll, internal baffles are eliminated and the contours of the coating return chamber are designed using flow control principles so that strong vortices and attendant misting are avoided in the coating return chamber, while at the same time subambient pressures generated along the curved surfaces of the chamber cause strong entrainment of air through the spaces between the edges of the coating chamber and the backing roll and air doctor and prevent coating material from escaping from the coating system.
Inventors
- 👤 I Reba
- 👤 E Wolthausen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:57
CPC Classifications
D; D06; D06B; D06B15/00; D06B15/09
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
210 words
Coating apparatus comprising: a. a backing roll adapted to carry a coated web in a downstream direction, b. an air doctor blade having portions including a bottom wall portion defining an outlet positioned adjacent said backing roll to direct a jet of air in an upstream direction against a coated web carried in a downstream direction by said backing roll, c. a flow control wall having an inlet end positioned adjacent said bottom wall, d. said flow control wall extending from said bottom wall in an upstream direction to a point opposite and in closely spaced relationship to said backing roll, e. said flow control wall and said backing roll defining a narrow slot at said point, f. said flow control wall extending from said slot downwardly and in said upstream direction in a curve having a radius of curvature greater than the radius of said backing roll, and g. a shroud extending in spaced, opposed relationship to said flow control wall and having an entry end positioned upstream of said inlet end of said flow control wall, h. said entry end of said shroud being spaced from said backing roll a distance substantially greater than the spacing between said flow control wall and said backing roll at said point.
Claim 2
Dependent Claim
210 words
Coating apparatus comprising: a. a backing roll adapted to carry a coated web in a downstream direction, b. an air doctor blade having portions including a bottom wall portion defining an outlet positioned adjacent said backing roll to direct a jet of air in an upstream direction against a coated web carried in a downstream direction by said backing roll, c. a flow control wall having an inlet end positioned adjacent said bottom wall, d. said flow control wall extending from said bottom wall in an upstream direction to a point opposite and in closely spaced relationship to said backing roll, e. said flow control wall and said backing roll defining a narrow slot at said point, f. said flow control wall extending from said slot downwardly and in said upstream direction in a curve having a radius of curvature greater than the radius of said backing roll, and g. a shroud extending in spaced, opposed relationship to said flow control wall and having an entry end positioned upstream of said inlet end of said flow control wall, h. said entry end of said shroud being spaced from said backing roll a distance substantially greater than the spacing between said flow control wall and said backing roll at said point.
Claim 3
Dependent Claim
22 words
The apparatus of claim 1 wherein: a. said shroud and said flow control wall extending in downwardly diverging relationship to each other.
Claim 4
Dependent Claim
32 words
The apparatus of claim 2 wherein: a. the spacing between said entry end and said backing roll is approximately equal to the minimum spacing between said shroud and said flow control wall.
Claim 5
Dependent Claim
31 words
The apparatus of claim 2 wherein: a. the spacing between said entry end and said backing roll is greater than the minimum spacing between said shroud and said flow control wall.
Claim 6
Dependent Claim
48 words
The apparatus of claim 1 wherein: a. said flow control wall and shroud terminate in opposed terminal portions, and b. a diffuser section is attached to and extends from said terminal portions c. said diffuser having wall portions extending in diverging relationship to each other from terminal portions.
Claim 7
Dependent Claim
22 words
The apparatus of claim 5 further comprising: a. vanes positioned in said diffuser section in spaced relationship to said diverging wall portions.
Claim 8
Dependent Claim
35 words
The apparatus of claim 6 wherein: a. portions of said diffuser section define an exit end thereof, and b. a sump is positioned beneath said exit end of said diffuser to collect liquid coating therefrom.
Claim 9
Dependent Claim
40 words
The apparatus of claim 7 further comprising: a. a filter chamber having an open end positioned in spaced relationship to said diffuser section with said open end facing said exit end, and b. a filter extending across said open end.
Claim 10
Dependent Claim
24 words
The apparatus of claim 1 further comprising: a. means for injecting moisture into the area defined by said flow control wall and said shroud.
Claim 11
Dependent Claim
36 words
The apparatus of claim 9 wherein said moisture injecting means comprises: a. an atomizing nozzle positioned adjacent said inlet end, b. an outlet of said nozzle being directed between said inlet end and said bottom wall.
Claim 12
Dependent Claim
39 words
The apparatus of claim 9 wherein said moisture injecting means comprises: a. an atomizing nozzle positioned adjacent said entry end of said shroud, b. an outlet of said nozzle being directed between said entry eNd and said backing roll.
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) | 1976-05-07 | 1976-11-06 | 1977-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-07 | 1980-11-06 | 1981-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-07 | 1984-11-06 | 1985-05-08 | $7700.00 | Window Closed / Lapsed |