US3647329A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for the extrusion of cellular synthetic resins
Assignee: Reifenhauser KG
•
Filing: 1969-08-04
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Granted: 1972-03-07
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Expires: 1989-08-04
Abstract
Abstract Apparatus for the extrusion of cellular (foamed) synthetic resins and elastomers in which a masticated and plastified synthetic resin or elastomer mixture, blended with a foaming agent, is extruded through a nozzle, e.g., in the form of slab. The extruded slab is permitted to expand against a superatmospheric counterpressure during cooling in one or more chambers provided immediately ahead of the extrusion nozzle, the chambers being separated from one another by pressure-retaining gates or locks. Between each chamber, a driven or autorotating pair of calibrating rolls may form part of the pressure-retaining gate.
Inventors
- 👤 Fritz Reifenhauser
- 👤 Hans Reifenhauser
- 👤 Klaus Burggraf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:53
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/34; B29C44/36; B29C44/46; B29C44/50; B29C44/505
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
167 words
An apparatus for the extrusion of a foamed thermoplastic synthetic resin comprising an extrusion press having an extrusion die for extruding a continuous body of foamable thermoplastic synthetic resin; housing means sealingly connected to said die and defining a plurality of chambers immediately ahead of said die and successively traversed by said body, said chambers including a first pressure chamber extending from said die and second and third pressure chambers successively downstream of said first chamber; pressure-control means connected to each of said chambers for adjusting the pressure therein to control the expansion of said body; and a pressure-retentive gate formed in said housing means between a pair of successive chambers, said gate comprising a partition wall formed on said housing means on opposite sides of said body and extending toward said body but terminating short of respective surfaces of said body to define gaps therewith, and respective rolls journaled in said housing means and sealingly obstructing said gaps while rollingly engaging said body for calibrating same.
Claim 2
Independent Claim
167 words
An apparatus for the extrusion of a foamed thermoplastic synthetic resin comprising an extrusion press having an extrusion die for extruding a continuous body of foamable thermoplastic synthetic resin; housing means sealingly connected to said die and defining a plurality of chambers immediately ahead of said die and successively traversed by said body, said chambers including a first pressure chamber extending from said die and second and third pressure chambers successively downstream of said first chamber; pressure-control means connected to each of said chambers for adjusting the pressure therein to control the expansion of said body; and a pressure-retentive gate formed in said housing means between a pair of successive chambers, said gate comprising a partition wall formed on said housing means on opposite sides of said body and extending toward said body but terminating short of respective surfaces of said body to define gaps therewith, and respective rolls journaled in said housing means and sealingly obstructing said gaps while rollingly engaging said body for calibrating same.
Claim 3
Dependent Claim
38 words
The apparatus defined in claim 1, further comprising a further pair of calibrating rolls defining an outlet gate in said housing means and engaging said body for calibration thereof upon feeding said body out of said housing means.
Claim 4
Dependent Claim
29 words
The apparatus defined in claim 1, further comprising a pair of calibrating rolls immediately adjacent said die and sealingly engaging said body upon entRy thereof into said housing means.
References Cited (Backward Citations)
US2401642A
Cited
US3119147A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-07 | 1975-09-06 | 1976-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-07 | 1979-09-06 | 1980-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-07 | 1983-09-06 | 1984-03-07 | $7700.00 | Window Closed / Lapsed |