Patent US4795560A successfully refreshed from Google Patents.
US4795560A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screen plates
Assignee: Thermo Black Clawson Inc
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Filing: 1987-08-05
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Granted: 1989-01-03
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Expires: 2007-08-05
Abstract
Abstract A screen plate and plate and method of making a screen plate for the pressure screening of papermaking stock in pressure screening apparatus includes slots which have been cut therethrough by a machining laser beam focused at the inlet side of the plate, to provide slots with nearly straight walls with minimum taper, and which are recast and have a "glassy" appearance by reason of the melting and resolidification of the immediate wall surface, to provide a low friction path for the stock. Straight, curved and inclined or slanted slots are disclosed including slots which are at a diagonal to the axis of the cylinder. Slots or openings are disclosed which are inclined to a radius line therethrough both with and against the direction of flow of the stock along the inlet surface. Wear bars are applied to the plate for coaction with the rotating foils on the screening apparatus, in the form of strips of weld material of high hardness applied directly to the plate.
Inventors
- 👤 David E. Chupka
- 👤 Carl C. Landegger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:18
CPC Classifications
D; D21; D21D; D21D5/00; D21D5/02; D21D5/16; B; B01; B01D; B01D29/00; B01D29/11; B01D29/111; B01D29/31; B01D29/33; B23; B23K; B23K26/00; B23K26/36; B23K26/38; B23K26/382; B23K26/40; B23K31/00; B23K31/02; B23K31/025; B23K2103/00; B23K2103/02; B23K2103/04; B23K2103/05; B23K2103/18; B23K2103/26; B23K2103/50; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/496; Y10T29/49604
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
126 words
An improved metal screen plate for use in the pressure screening of papermaking stock, for removing contaminant particles therefrom in pressure screening apparatus, in which said plate has an inlet surface and an outlet surface, and a plurality of laser cut screening openings in said plate extending from said inlet surface to said outlet surface, in closely spaced relation to each other, the improvement comprising: said openings defined by walls extending generally along straight lines from said inlet surface to said outlet surface, said walls being formed of a thin layer of recast metal material from the laser cutting at the exposed surface thereof presenting a very hard interface to the flow of stock therethrough, said exposed wall surface being free of machine and tool marks.
Claim 2
Dependent Claim
126 words
An improved metal screen plate for use in the pressure screening of papermaking stock, for removing contaminant particles therefrom in pressure screening apparatus, in which said plate has an inlet surface and an outlet surface, and a plurality of laser cut screening openings in said plate extending from said inlet surface to said outlet surface, in closely spaced relation to each other, the improvement comprising: said openings defined by walls extending generally along straight lines from said inlet surface to said outlet surface, said walls being formed of a thin layer of recast metal material from the laser cutting at the exposed surface thereof presenting a very hard interface to the flow of stock therethrough, said exposed wall surface being free of machine and tool marks.
Claim 3
Dependent Claim
39 words
The screen plate of claim 1 in which said openings are in the form of elongated slots having tapered walls which diverge and form a narrow gap at said inlet surface and a wider gap at said outlet surface.
Claim 4
Dependent Claim
18 words
The screen plate of claim 1 in which said walls diverge at a total angle of about 2.5°.
Claim 5
Dependent Claim
27 words
The screen plate of claim 1 in which said openings are in the form of an individual slots arranged in at least one row in said plate.
Claim 6
Dependent Claim
40 words
The screen plate of claim 4 in which adjacent said slots are spaced from each other by land areas therebetween and further comprising means defining wear bars fromed exclusively of weld material on at least some of said land areas.
Claim 7
Dependent Claim
50 words
The screen plate of claim 4 in which at least some of said slots are positioned diagonally of said plate with respect to the thickness thereof between said surfaces at an inclination to a radius line from the center of said cylinder to the slot inlet at said inlet surface.
Claim 8
Dependent Claim
19 words
The screen plate of claim 6 in which said inclination is greater than zero degree and less than 90°.
Claim 9
Dependent Claim
14 words
The plate of claim 4 in which said slots extend axially of the plate.
Claim 10
Dependent Claim
21 words
The plate of claim 4 in which at least some of said slots extend diagonally to the axis of said plate.
Claim 11
Dependent Claim
27 words
The plate of claim 4 in which at least some of said slots extend along paths which are curved with respect to the axis of said plate.
Claim 12
Dependent Claim
22 words
The screen plate of claim 4 in which at least some of said slots are grouped in a wave-like pattern of slots.
Claim 13
Dependent Claim
22 words
The screen plate of claim 4 in which at least some of said slots are grouped in a curved pattern of slots.
Claim 14
Dependent Claim
78 words
An improved metal screen plate for use in pressure screening apparatus for the screening of papermaker's stock material for removing contaminant particles therefrom, comprising: said plate having an inlet surface on one side thereof and an outlet surface on an opposite side thereof, and having a plurality of individual laser cut elongated slots extended between said surfaces, said slots having walls formed of a thin layer of very hard recast metal from the laser cutting of said plate.
Claim 15
Dependent Claim
78 words
An improved metal screen plate for use in pressure screening apparatus for the screening of papermaker's stock material for removing contaminant particles therefrom, comprising: said plate having an inlet surface on one side thereof and an outlet surface on an opposite side thereof, and having a plurality of individual laser cut elongated slots extended between said surfaces, said slots having walls formed of a thin layer of very hard recast metal from the laser cutting of said plate.
Claim 16
Dependent Claim
29 words
The screen plate of claim 13 in which at least some of said slots are inclined at an angle of other than 90° to the inlet and outlet surfaces.
Claim 17
Dependent Claim
22 words
The plate of claim 14 in which said slots in said pattern are curved and are internested with respect to each other.
Claim 18
Dependent Claim
14 words
The plate of claim 14 in which said slots are arranged in internested chevrons.
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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) | 1992-01-03 | 1992-07-04 | 1993-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-03 | 1996-07-04 | 1997-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-03 | 2000-07-04 | 2001-01-03 | $7700.00 | Window Closed / Lapsed |