Patent US3884607A successfully refreshed from Google Patents.
US3884607A
Expired / Lapsed
US
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Plasticizing extrusion device employing worms
Assignee: Kleinewefers Industrie Co GmbH and Co KG
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Filing: 1974-01-15
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Granted: 1975-05-20
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Expires: 1994-01-15
Abstract
Abstract A plasticizing extruder having a pair of counterrotating worms in a housing with the helical ribs thereof interengaged in which respective axial zones of the worms are individually heated to respective temperatures and with the height of the rib means on each worm being decreased in at least one selected axial region of the respective worm.
Inventors
- 👤 Bernhard Gerhards
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:04
CPC Classifications
B; B29; B29B; B29B7/00; B29B7/30; B29B7/34; B29B7/38; B29B7/46; B29B7/48; B29B7/484; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/395; B29C48/40; B29C48/405; B29C48/50; B29C48/505; B29C48/51; B29C48/515; B29C48/53; B29C48/78; B29C48/80; B29C48/84; B29C48/845; B29C48/875; B29C48/03
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
148 words
In a plasticizing worm extruder; a housing, a pair of elongated parallel and rotatable worms in said housing having interengaged helical rib means thereon, feed opening means in said housing for supplying material to be plasticized and extruded to said worms near one end thereof and discharge opening means in said housing for the extrusion of the plasticized material from Near the other end of said worms, means in said worms for heating axial regions thereof to respective temperatures, at least one of said regions being heated to the plasticizing temperature of said material, each said worm having the radially outer ends of at least a portion of the said rib means thereon disposed close to the housing and each worm having at least one axial zone wherein the said rib means is reduced in at least the height thereof to increase the space to receive said material.
Claim 2
Dependent Claim
148 words
In a plasticizing worm extruder; a housing, a pair of elongated parallel and rotatable worms in said housing having interengaged helical rib means thereon, feed opening means in said housing for supplying material to be plasticized and extruded to said worms near one end thereof and discharge opening means in said housing for the extrusion of the plasticized material from Near the other end of said worms, means in said worms for heating axial regions thereof to respective temperatures, at least one of said regions being heated to the plasticizing temperature of said material, each said worm having the radially outer ends of at least a portion of the said rib means thereon disposed close to the housing and each worm having at least one axial zone wherein the said rib means is reduced in at least the height thereof to increase the space to receive said material.
Claim 3
Dependent Claim
28 words
A plasticizing worm extruder according to claim 1 in which the reduction in height of said rib means extends over at least about 360* of the respective worm.
Claim 4
Dependent Claim
21 words
A plasticizing worm extruder according to claim 1 in which said means for heating said worms comprise electric heating means therein.
Claim 5
Dependent Claim
35 words
A plasticizing worm extruder according to claim 3 in which said electric heating means comprise individual electric heaters in said axial regions of each worm, and means for independantly controlling the temperature of said heaters.
Claim 6
Dependent Claim
31 words
A plasticizing worm extruder according to claim 1 in which at least part of the rib means which vary in height vary gradually in the circumferential direction of the respective worm.
Claim 7
Dependent Claim
34 words
A plasticizing worm extruder according to claim 1 in which said heating means comprise electric heater cartridge means substantially cylindrical in configuration, each worm having a tubular axial cavity for receiving the cartridge means.
Claim 8
Dependent Claim
42 words
A plasticizing worm extruder according to claim 6 in which each cavity is larger in diameter than the cartridge means, and bushing means in the cavity surrounding the cartridge means and having a higher coefficient of thermal expansion than the respective worm.
Claim 9
Dependent Claim
44 words
A plasticizing worm extruder according to claim 7 in which said bushing means freely receives the cartridge means and is freely receivable in the respective cavity in unheated condition and when heated expands into tight engagement with the periphery of at least the cavity.
Claim 10
Dependent Claim
98 words
A plasticizing worm extruder according to claim 1 in which each worm comprises a plurality of axial zones including an intake zone near said one end of the worm, a first compression zone following the intake zone, a shut-off zone following the first compression zone, a vacuum zone following said shut-off zone, a second compression region following the vacuum zone, and an ejector zone following the second compression zone and disposed near said other end of the worm, the height of said rib means being reduced in said intake zone, said compression zones, and in said vacuum zone.
Claim 11
Dependent Claim
51 words
A plasticizing worm extruder according to claim 1 in which the rib means which are reduced in height gradually change in height in the circumferential direction of the respective worm with the smallest height at the upstream end in respect of the direction of movement of said material along said worms.
Claim 12
Dependent Claim
14 words
A plasticizing worm extruder according to claim 1 in which said worms are counterrotating.
References Cited (Backward Citations)
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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) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |