US5200072A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screen plates and methods of manufacture
Assignee: AHLSTROM PUMPS Inc
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Filing: 1990-08-16
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Granted: 1993-04-06
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Expires: 2010-08-16
Abstract
Abstract The screen cylinder includes a screening plate having contoured grooves along an inflow side and a backing cylinder having a plurality of openings therethrough and disposed on the outflow side of the screening cylinder. The contoured grooves are elongated in the axial direction and are closely circumferentially spaced one from the other about the screen cylinder. In one embodiment, circumferentially extending grooves are formed along the outflow side of the screening cylinder whereby pulp flows through the contoured grooves into the recesses and then through the openings of the backing cylinder. In another embodiment, the recesses are formed on the inflow side of the backing cylinder, the screening cylinder being provided with elongated slots along its outflow side in registry with the contoured slots. In this manner, increased flow capacity is provided. Additionally, the screening cylinder is removable when worn for replacement by a fresh screening cylinder which may then be secured to the backing cylinder.
Inventors
- 👤 Frey A. Frejborg
- 👤 Lassi J. Halonen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:12
CPC Classifications
D; D21; D21D; D21D5/00; D21D5/02; D21D5/16; B; B01; B01D; B01D29/00; B01D29/01; B01D29/05; B01D29/11; B01D29/13; B01D29/15; B01D29/23; B01D2201/00; B01D2201/18; B01D2201/184; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/496; Y10T29/49604; Y10T29/49616; Y10T29/4962; Y10T29/49826; Y10T29/49863; Y10T29/49865
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
186 words
A screen cylinder comprising: a generally cylindrical screening medium having a plurality of openings therethrough; a generally cylindrical structural backing plate for structurally supporting said screening medium and having a plurality of openings therethrough; and said screening medium and said structural backing plate lying concentrically one within the other and having respective opposed surfaces in engagement with one another at an interface therebetween whereby said backing plate structurally supports said screening medium; one of said screening medium and said backing plate having a plurality of circumferentially extending recesses formed in its opposing surface and opening at the opposing surface of the other of said screening medium and said backing plate at the interface thereof establishing communication between the respective openings of said screening medium and said backing plate; a plurality of axially spaced projections spaced one from the other in the axial direction defining said recesses and projecting radially from one of said screening medium and said backing plate at said interface; the openings in said screening medium being elongated and extending in a generally axial direction substantially normal to the circumferential extent of said recesses.
Claim 2
Dependent Claim
186 words
A screen cylinder comprising: a generally cylindrical screening medium having a plurality of openings therethrough; a generally cylindrical structural backing plate for structurally supporting said screening medium and having a plurality of openings therethrough; and said screening medium and said structural backing plate lying concentrically one within the other and having respective opposed surfaces in engagement with one another at an interface therebetween whereby said backing plate structurally supports said screening medium; one of said screening medium and said backing plate having a plurality of circumferentially extending recesses formed in its opposing surface and opening at the opposing surface of the other of said screening medium and said backing plate at the interface thereof establishing communication between the respective openings of said screening medium and said backing plate; a plurality of axially spaced projections spaced one from the other in the axial direction defining said recesses and projecting radially from one of said screening medium and said backing plate at said interface; the openings in said screening medium being elongated and extending in a generally axial direction substantially normal to the circumferential extent of said recesses.
Claim 3
Dependent Claim
23 words
A screen cylinder according to claim 1 including means for releasably connecting said screening medium and said backing plate one to the other.
Claim 4
Dependent Claim
23 words
A screen cylinder according to claim 2 wherein said connecting means includes welding said screening medium and said backing plate to one another.
Claim 5
Dependent Claim
24 words
A screen cylinder according to claim 2 wherein said connecting means includes gluing said screen medium and said backing plate one to the other.
Claim 6
Dependent Claim
24 words
A screen cylinder according to claim 2 wherein said connecting means includes soldering said screen medium and said backing plate one to the other.
Claim 7
Dependent Claim
19 words
A screen cylinder according to claim 1 wherein said recesses are formed in the surface of said screening medium.
Claim 8
Dependent Claim
23 words
A screen cylinder according to claim 6 including rivets for releasably connecting said screening medium and said backing plate one to the other.
Claim 9
Dependent Claim
42 words
A screen cylinder according to claim 1 wherein said recesses extend axially at least plural times the axial extent of said projections, said openings in said screening medium having an extent sufficient to span in the axial direction two or more recesses.
Claim 10
Dependent Claim
19 words
A screen cylinder according to claim 1 wherein said recesses are formed in the surface of said backing plate.
Claim 11
Dependent Claim
159 words
A screen plate for screening pulp flowing therethrough comprising: a screening medium having a plurality of slots therethrough and extending generally parallel to one another, said slots having contoured portions on an inflow side of said screening medium; a structural backing plate having a plurality of openings therethrough; said screening medium and said structural backing plate lying in registration one with the other and having respective opposed surfaces in engagement with one another at an interface therebetween whereby said backing plate structurally supports said screening medium; one of said screening medium and said backing plate having a plurality of recesses formed in its opposing surface and opening at the opposite surface of the other of said screening medium and said backing plate at the interface thereof establishing communication between the openings of said backing plate and said slots of said screening medium; whereby pulp may flow sequentially through said slots, said recesses and said openings in said backing plate.
Claim 12
Dependent Claim
159 words
A screen plate for screening pulp flowing therethrough comprising: a screening medium having a plurality of slots therethrough and extending generally parallel to one another, said slots having contoured portions on an inflow side of said screening medium; a structural backing plate having a plurality of openings therethrough; said screening medium and said structural backing plate lying in registration one with the other and having respective opposed surfaces in engagement with one another at an interface therebetween whereby said backing plate structurally supports said screening medium; one of said screening medium and said backing plate having a plurality of recesses formed in its opposing surface and opening at the opposite surface of the other of said screening medium and said backing plate at the interface thereof establishing communication between the openings of said backing plate and said slots of said screening medium; whereby pulp may flow sequentially through said slots, said recesses and said openings in said backing plate.
Claim 13
Dependent Claim
66 words
A screen plate according to claim 10 wherein said screening medium and said backing plate are cylindrical and lie one within the other, said recesses extending circumferentially and substantially uninterruptedly about said one of said screening medium and said backing plate, said slots in said screening medium extending in a generally axial direction and in a direction substantially normal to the circumferential extent of said recesses.
Claim 14
Dependent Claim
28 words
A screen cylinder according to claim 11 wherein said slots have an extent sufficient to span, continuously and without interruption, in the axial direction two or more recesses.
Claim 15
Dependent Claim
109 words
A screen cylinder according to claim 11 wherein said cylindrical screening medium has elongated outflow slots formed in the opposing surface of said screening medium in radial registry with said contoured slot portions and substantially coextensive therewith, reduced slots in registry with said contoured slot portions and said outflow slots and communicating therebetween, said recesses and said contoured slot portions being formed on the inflow sides of said backing plate and said cylindrical screening medium, respectively, whereby pulp may flow sequentially through said contoured slot portions, said reduced slots and said outflow slots of said screening medium and then through said recesses and said openings of said backing plate.
Claim 16
Dependent Claim
74 words
A screen cylinder according to claim 11 wherein said cylindrical screening medium has reduced slots in registry with said contoured slot portions and in communication therewith, said contoured slot portions and said recesses being formed on inflow and outflow sides of said screening medium, respectively, whereby pulp may flow sequentially through said contoured slot portions, said reduced slots, and said recesses of said screening medium and then through said openings of said backing plate.
Claim 17
Dependent Claim
23 words
A screen cylinder according to claim 10 including means for releasably connecting said cylindrical screening and said backing cylinder one to the other.
Claim 18
Dependent Claim
20 words
A screen plate according to claim 10 wherein said recesses are formed in the opposing surface of said screening medium.
Claim 19
Dependent Claim
19 words
A screen plate according to claim 10 wherein said recesses are formed in the surface of said backing plate.
Claim 20
Independent Claim
163 words
A method of manufacturing a screen for use in screening for pulp, said screen being formed of a screening plate and a backing plate, said screening plate having first and second opposite faces, comprising the steps of: (a) forming elongated, substantially parallel, grooves in said first face, each groove having a side face and a bottom; (b) forming openings through the bottom of the grooves in said first face and into the screening plate to terminate within the screening plate short of said second face thereof; (c) forming elongated grooves in the second face of said screening plate inclined relative to the longitudinal extent of the grooves formed in step (a) and to a depth to expose the openings formed in step (b) so that the openings extend entirely through said screening plate, and leave a plurality of ridges in the second face spaced one from the other therealong and extending in a direction inclined relative to the longitudinal extent of said grooves.
Claim 21
Independent Claim
163 words
A method of manufacturing a screen for use in screening for pulp, said screen being formed of a screening plate and a backing plate, said screening plate having first and second opposite faces, comprising the steps of: (a) forming elongated, substantially parallel, grooves in said first face, each groove having a side face and a bottom; (b) forming openings through the bottom of the grooves in said first face and into the screening plate to terminate within the screening plate short of said second face thereof; (c) forming elongated grooves in the second face of said screening plate inclined relative to the longitudinal extent of the grooves formed in step (a) and to a depth to expose the openings formed in step (b) so that the openings extend entirely through said screening plate, and leave a plurality of ridges in the second face spaced one from the other therealong and extending in a direction inclined relative to the longitudinal extent of said grooves.
Claim 22
Dependent Claim
14 words
A method according to claim 18 wherein said screening plate is formed of metal.
Claim 23
Dependent Claim
23 words
A method according to claim 19 including, subsequent to steps (a), (b) and (c), hardening or plating the metal of said screening plate.
Claim 24
Dependent Claim
15 words
A method according to claim 18 wherein said screening plate is formed of a ceramic.
Claim 25
Dependent Claim
28 words
A method according to claim 18 including machining the first face of the screening layer to form ridges flat on one side and angled on the opposite side.
Claim 26
Dependent Claim
24 words
A method according to claim 18 including the step of forming the screening plate into a cylindrical shape to form a metal screen cylinder.
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) | 1996-04-05 | 1996-10-05 | 1997-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-05 | 2000-10-05 | 2001-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-05 | 2004-10-05 | 2005-04-06 | $7700.00 | Window Closed / Lapsed |