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US3706376A
Expired / Lapsed
US
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Screen with differently tensioned surface zones
Assignee: Rhewum GmbH
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Filing: 1970-06-15
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Granted: 1972-12-19
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Expires: 1990-06-15
Abstract
Abstract A sifting machine has a strainer box defining feed-in and discharge points and a free sieve netting surface arranged and tensioned in the strainer box so that a material flow-path is defined across it from the feed-in point to the discharge point. A plurality of striker assemblies may also be arranged in the strainer box for exciting the netting surface. A plurality of fastening and tensioning devices such as clamps are provided along the edges of the netting which are parallel to the direction of the material flow-path for individually tensioning the netting, in a direction transverse to the flow-path, at different points spaced in the direction of the flow-path such that the netting is transversely tensioned to different tensions along the direction of the flow-path. Similar devices may be provided along at least one edge of the netting parallel to the material flow-path for individually tensioning the netting, in the direction of the flow-path, at different points spaced transversely to the direction of the flow-path. The striker assemblies may be operated synchronously or asynchronously.
Inventors
- 👤 Rudolf J Krause
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:22
CPC Classifications
B; B07; B07B; B07B1/00; B07B1/46; B07B1/50; B07B1/54; B01; B01D; B01D35/00; B01D35/20; B01D35/28; B07B1/28; B07B1/34; B07B1/346; B07B1/48; B07B1/49
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
230 words
In a sifting machine including a strainer box with feed-in and discharge points therein, a one-piece netting defining a material flow surface and having two opposite end portions, two opposite lateral edge portions and a free portion extending from one of the edge portions to the other, means for fastening the two lateral edges to the strainer box to thereby tension the netting, the netting defining a flow-path for the material to be screened said flow-path extending from a feed-in point at one end portion of the screen to a discharge point at the other end portion of the screen and extending longitudinally over the free portion of the netting, and a plurality of striker assemblies arranged in the strainer box adjacent to the free portion of the netting for direct excitation of the netting, the improvement wherein the fastening means comprise a plurality of individual fastening devices which are arranged along the lateral edge portions of the netting and are spaced in the direction of the flow-path for individually tensioning the netting, in a direction transverse to the flow-path, at different points spaced in the direction of the flow-path such that the netting is transversely tensioned to different tensions along said direction of the flowpath, and wherein said striker assemblies are likewise spaced in the direction of the flow-path for separately exciting the differently tensioned portions of the netting.
Claim 2
Dependent Claim
230 words
In a sifting machine including a strainer box with feed-in and discharge points therein, a one-piece netting defining a material flow surface and having two opposite end portions, two opposite lateral edge portions and a free portion extending from one of the edge portions to the other, means for fastening the two lateral edges to the strainer box to thereby tension the netting, the netting defining a flow-path for the material to be screened said flow-path extending from a feed-in point at one end portion of the screen to a discharge point at the other end portion of the screen and extending longitudinally over the free portion of the netting, and a plurality of striker assemblies arranged in the strainer box adjacent to the free portion of the netting for direct excitation of the netting, the improvement wherein the fastening means comprise a plurality of individual fastening devices which are arranged along the lateral edge portions of the netting and are spaced in the direction of the flow-path for individually tensioning the netting, in a direction transverse to the flow-path, at different points spaced in the direction of the flow-path such that the netting is transversely tensioned to different tensions along said direction of the flowpath, and wherein said striker assemblies are likewise spaced in the direction of the flow-path for separately exciting the differently tensioned portions of the netting.
Claim 3
Dependent Claim
65 words
A sifting machine as defined in claim 1, wherein said fastening means comprise a plurality of further individual fastening devices which are spaced along one of said end portions for individually tensioning the netting, in the direction of the flow-path, at different points spaced transversely to the direction of the flow-path such that the netting is longitudinally tensioned to different tensions along the transverse direction.
Claim 4
Dependent Claim
28 words
A sifting machine as defined in claim 1, wherein all of the striker assemblies which are aligned in a direction transverse to the flow-path have a common drive.
Claim 5
Dependent Claim
49 words
A sifting machine as defined in claim 3, wherein each of said striker assemblies has a beater lever and a vibrating shaft mounted in the strainer box and operatively coupled with said common drive and said beater lever, and wherein said striker assemblies are arranged below the netting surface.
Claim 6
Dependent Claim
26 words
A sifting machine as defined in claim 4, wherein each of said striker assemblies has a small diameter protruding circular member mounted on said beater lever.
Claim 7
Dependent Claim
45 words
A sifting machine as defined in claim 5, further including rubber bearings for mounting said vibrating shaft, and wherein said common drive is an electro-magnetic drive and each of said striker assemblies has a lever operatively coupled to said electro-magnetic drive and said vibrating shaft.
Claim 8
Dependent Claim
80 words
In a method of sifting material, the steps of tensioning a one-piece netting, over which material to be sifted flows along a flow-path extending from one end of the net to the other and between the lateral edges of the net, in a direction transverse to the flow-path such that the netting is tensioned to different tensions at different points spaced in the direction of the flow-path, and applying separate striker excitation to the differently tensioned portions of the netting.
Claim 9
Dependent Claim
80 words
In a method of sifting material, the steps of tensioning a one-piece netting, over which material to be sifted flows along a flow-path extending from one end of the net to the other and between the lateral edges of the net, in a direction transverse to the flow-path such that the netting is tensioned to different tensions at different points spaced in the direction of the flow-path, and applying separate striker excitation to the differently tensioned portions of the netting.
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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) | 1975-12-19 | 1976-06-19 | 1976-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-19 | 1980-06-19 | 1980-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-19 | 1984-06-19 | 1984-12-19 | $7700.00 | Window Closed / Lapsed |