US3580389A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screw conveyor
Assignee: GEA Group AG
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Filing: 1969-01-07
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Granted: 1971-05-25
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Expires: 1989-01-07
Abstract
Abstract One of two parallel screws rotatable in the same direction in a screw conveyor is rotatable at different speeds from the other screw. This periodically brings the threads of one screw into wiping and cleaning engagement with the threads of the other screw.
Inventors
- 👤 Friedrich Karl Nonnenmacher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:25
CPC Classifications
F; F04; F04C; F04C2/00; F04C2/08; F04C2/12; F04C2/14; F04C2/16; B; B01; B01F; B01F27/00; B01F27/60; B01F27/72; B01F27/721; B01F27/723; B29; B29C; B29C48/00; B29C48/25; B29C48/252; B30; B30B; B30B11/00; B30B11/22; B30B11/24; B30B11/243; B30B9/00; B30B9/02; B30B9/12; B30B9/16; B29C48/03
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
137 words
Apparatus for subjecting liquid, conveyable semisolid or solid substances to a mechanical or thermal treatment, comprising a casing formed with a feed opening at one end and a product exit at the other end, two parallel and at least partly interengaging conveyor screws mounted within said casing, said screws having the same hand and rotatable in the same direction, the distance (A) between the crests of consecutive convolutions in each screw exceeding the length of the base (B) on the shaft for forming a space (C) on the shaft between the convolutions, drive means for rotating said screws, and means for temporarily changing the angular speed of at least one of the screws while the two screws are rotating to bring opposite pairs of the facing flanks of the blade helices into selective wiping and cleaning engagement.
Claim 2
Dependent Claim
137 words
Apparatus for subjecting liquid, conveyable semisolid or solid substances to a mechanical or thermal treatment, comprising a casing formed with a feed opening at one end and a product exit at the other end, two parallel and at least partly interengaging conveyor screws mounted within said casing, said screws having the same hand and rotatable in the same direction, the distance (A) between the crests of consecutive convolutions in each screw exceeding the length of the base (B) on the shaft for forming a space (C) on the shaft between the convolutions, drive means for rotating said screws, and means for temporarily changing the angular speed of at least one of the screws while the two screws are rotating to bring opposite pairs of the facing flanks of the blade helices into selective wiping and cleaning engagement.
Claim 3
Dependent Claim
54 words
Apparatus as in claim 1, said means for changing the speed being such that the ratio between the angular velocity Wq of one screw Q having q threads and the angular velocity Wp of the other screw P having p threads temporarily meets the relation Wq/Wp p/q and temporarily meets the relation Wq/Wp p/q
Claim 4
Dependent Claim
55 words
Apparatus as in claim 2, said means for changing the speed being such that the screws rotate at such angular velocities that the ratio Wq/Wp differs from the ratio p/q until adjacent thread sides of the two screws contact, whereafter the screws rotate at such angular velocities that the ratio Wq/Wp equals the ratio p/q.
Claim 5
Dependent Claim
15 words
Apparatus as in claim 3, one screw being rotated constantly at a constant angular velocity.
Claim 6
Dependent Claim
34 words
Apparatus as in claim 4, said other screw, which is not constantly driven at a constant angular velocity, having a higher or lower angular velocity imparted to it by a summing differential gear unit.
Claim 7
Dependent Claim
29 words
Apparatus as in claim 5, the main drive motion being imparted to the summing differential gear unit by the screw shaft which is driven at a constant angular velocity.
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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) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |