Patent US3680844A successfully refreshed from Google Patents.
US3680844A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single worm extruder
Assignee: Uniroyal GmbH
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Filing: 1970-07-16
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Granted: 1972-08-01
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Expires: 1990-07-16
Abstract
Abstract A single worm extruder for the mixing and processing of rubber is disclosed. The worm consists of two sections, an intake section and a mixing section. The mixing section has lands countercurrent to those of the intake section for partially backfeeding the rubber on to the intake section to provide a turbulent current of material. The countercurrent lands are interrupted by gaps which collectively have the same total area as the cross-sectional area of the intake section. The gaps in the mixing section are of constant width and have a diameter of not less than 10 mm and not more than 12 mm. The mixing section has a larger core and outer diameter than the intake section.
Inventors
- 👤 Hans G L Menges
- 👤 Josef P Lehnen
- 👤 Englebert G Harms
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:08
CPC Classifications
B; B29; B29B; B29B7/00; B29B7/30; B29B7/34; B29B7/38; B29B7/40; B29B7/42; B29B7/428; B29B7/429; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/395; B29C48/50; B29C48/501; B29C48/505; B29C48/55; B29C48/63; B29C48/67; B29C48/68; B29C48/03
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
111 words
A worm extruder for rubber mixtures and the like, comprising: an intake zone having a first screw means with a helical land forming a flight in a first direction, and a mixing zone having a second screw means with at least one land forming a flight in the opposite direction from said screw means, the outer diameter of said second screw means is larger than the outer diameter of the first screw means, said lands having gaps of approximately constant width for most of the length of the gaps, whereby the material being extruded is divided and partially fed back on itself to thermally and mechanically homogenize the material being extruded.
Claim 2
Dependent Claim
111 words
A worm extruder for rubber mixtures and the like, comprising: an intake zone having a first screw means with a helical land forming a flight in a first direction, and a mixing zone having a second screw means with at least one land forming a flight in the opposite direction from said screw means, the outer diameter of said second screw means is larger than the outer diameter of the first screw means, said lands having gaps of approximately constant width for most of the length of the gaps, whereby the material being extruded is divided and partially fed back on itself to thermally and mechanically homogenize the material being extruded.
Claim 3
Dependent Claim
97 words
A worm extruder for rubber mixtures and the like, comprising: an intake zone having a first screw means with a helical land forming a flight in a first direction, and a mixing zone having a second screw means with at least one land forming a flight in the opposite direction from said first screw means, said land in said second screw, in one full turn of the screw having gaps whose total cross-sectional area is in a range of one-half to twice the cross-sectional area between an outside circumference and a core of said first screw means.
Claim 4
Dependent Claim
97 words
A worm extruder for rubber mixtures and the like, comprising: an intake zone having a first screw means with a helical land forming a flight in a first direction, and a mixing zone having a second screw means with at least one land forming a flight in the opposite direction from said first screw means, said land in said second screw, in one full turn of the screw having gaps whose total cross-sectional area is in a range of one-half to twice the cross-sectional area between an outside circumference and a core of said first screw means.
Claim 5
Dependent Claim
37 words
The extruder of claim 2 wherein the total cross-sectional area of the gaps in the land of the second screw means approximates the cross-sectional area between the outside circumference and the core of the first screw means.
Claim 6
Dependent Claim
17 words
The extruder of claim 1 wherein the gaps extend to the core of said second screw means.
Claim 7
Dependent Claim
45 words
The extruder of claim 1 wherein one side of at least one of the teeth formed by the gaps in the land of the second screw means is bevelled for at least part of its surface at right angles to the second screw means centerline.
Claim 8
Dependent Claim
41 words
The extruder of claim 1 wherein at least one side of at least one gap in the land in the second screw means is bevelled at an angle to the centerline of the second screw means to control the forward flow.
Claim 9
Dependent Claim
23 words
The extruder of claim 1 wherein the core of the second screw means is larger than the core of the first screw means.
Claim 10
Dependent Claim
21 words
The extruder of claim 1 wherein the bottom of the gaps in the land of the second screw means is rounded.
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) | 1975-08-01 | 1976-01-31 | 1976-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-01 | 1980-01-31 | 1980-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-01 | 1984-01-31 | 1984-08-01 | $7700.00 | Window Closed / Lapsed |