US4020136A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for the sizing of tubular bodies of a thermoplastic material which are continuously extruded
Assignee: Individual
•
Filing: 1972-09-14
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Granted: 1977-04-26
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Expires: 1992-09-14
Abstract
Abstract In a method and a device for vacuum sizing extruded bodies of plastics material, the sizing operation is subdivided, in sequence, between the two or more portions of the cross-sectional outline of the extruded blank. Cooling means can act in cooperation with the sizing tools proper.
Inventors
- 👤 Giosue Zaro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 01:30
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/88; B29C48/90; B29C48/901; B29C48/903; B29C48/03; B29C48/09; B29C48/885; B29C48/904; B29C48/911; B29C48/9115; B29C48/912; B29C48/9135; B29C48/919
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
139 words
A method for the sizing of a tubular blank of a thermoplastic material in a sizing tool, said method comprising extruding the tubular blank through an extrusion head from which the blank exits in a plastic state, and subjecting the plastic blank to the action of a vacuum, in sequence, first over no more than a fraction of its outer surface so as to press said fraction only against part of the sizing tool which is provided with a cross-sectional outline for said fraction of the finished tubular article, and subsequently subjecting the balance of the plastic blank to a vacuum to press said balance against the balance of the sizing tool to give the balance of the blank its finished shape, that part of the blank which is not subjected to vacuum being subjected to ambient atmospheric conditions.
Claim 2
Independent Claim
139 words
A method for the sizing of a tubular blank of a thermoplastic material in a sizing tool, said method comprising extruding the tubular blank through an extrusion head from which the blank exits in a plastic state, and subjecting the plastic blank to the action of a vacuum, in sequence, first over no more than a fraction of its outer surface so as to press said fraction only against part of the sizing tool which is provided with a cross-sectional outline for said fraction of the finished tubular article, and subsequently subjecting the balance of the plastic blank to a vacuum to press said balance against the balance of the sizing tool to give the balance of the blank its finished shape, that part of the blank which is not subjected to vacuum being subjected to ambient atmospheric conditions.
Claim 3
Dependent Claim
17 words
A method according to claim 1, wherein the vacuum is applied in more than two sequential steps.
Claim 4
Dependent Claim
23 words
A method according to claim 1, wherein each part of the blank is subjected to cooling simultaneously with the application of vacuum thereto.
Claim 5
Dependent Claim
18 words
A method according to claim 1, wherein the vacuum is applied sequentially to equal fractions of the blank.
Claim 6
Dependent Claim
21 words
A method as claimed in claim 1 wherein said fraction is no more than half the section of the tubular blank.
Claim 7
Independent Claim
105 words
A device comprising an extrusion head for extruding a tubular blank of thermoplastic material, first and second sizing tools arranged in sequence downstreams of said head and angularly displaced with respect to one another around the longitudinal axis of the extruded blank, said tools being located at such a distance from the extrusion head that the thermoplastic material is plastically deformable when received by said tools, each of said two tools having a cross-sectional profile substantially corresponding to a corresponding fraction of a cross-sectional profile desired for a finished extrudate, said tools each having a set of openings adapted for communication with a vacuum source.
Claim 8
Independent Claim
105 words
A device comprising an extrusion head for extruding a tubular blank of thermoplastic material, first and second sizing tools arranged in sequence downstreams of said head and angularly displaced with respect to one another around the longitudinal axis of the extruded blank, said tools being located at such a distance from the extrusion head that the thermoplastic material is plastically deformable when received by said tools, each of said two tools having a cross-sectional profile substantially corresponding to a corresponding fraction of a cross-sectional profile desired for a finished extrudate, said tools each having a set of openings adapted for communication with a vacuum source.
Claim 9
Dependent Claim
17 words
A device according to claim 6, comprising further sizing tools corresponding to the first and second tools.
Claim 10
Dependent Claim
16 words
A device according to claim 6, comprising cooling means cooperating with each of said sizing tools.
Claim 11
Dependent Claim
43 words
A device as claimed in claim 6, wherein each tool is so dimensioned and shaped that no more than a fraction of the blank is subjected to vacuum and pulled thereagainst while the balance of the blank is exposed to ambient atmospheric conditions.
Claim 12
Dependent Claim
21 words
A device as claimed in claim 6 wherein said fraction is no more than half the section of the tubular blank.
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) | 1980-04-25 | 1980-10-25 | 1981-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-25 | 1984-10-25 | 1985-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-25 | 1988-10-25 | 1989-04-26 | $7700.00 | Window Closed / Lapsed |