Patent US3874837A successfully refreshed from Google Patents.
US3874837A
Expired / Lapsed
US
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Die for extrusion of fine grained green carbon
Assignee: Airco Inc
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Filing: 1972-09-18
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Granted: 1975-04-01
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Expires: 1992-09-18
Abstract
Abstract A die for the extrusion of a fine-grained calcine-binder mix to form a green carbon, shaped body. The die profile is optimized according to the criteria that shear be minimized in a perfectly plastic material passed therethrough. A stress relief die extension is fitted to the end of the die for enabling a gradual expansion of the extrudate, and means are provided for cooling the die extension to control the extrudate flow field.
Inventors
- 👤 Charles P Jamieson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:14
CPC Classifications
B; B30; B30B; B30B11/00; B30B11/22; B30B11/221
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
131 words
In a die for the extrusion of a calcine-binder mix to form a green carbon, shaped extrudate, the improvement wherein: said die includes a channel, the profile of which is converged to satisfy the criteria that shear be minimized for a perfectly plastic material passed therethrough; a stress relief die extension being fitted to the output end of the die and comprising the exit section for said shaped extrudate, said die extension including a second channel diverging slightly in cross-section from the input to output ends of said extension for enabling a constrained gradual expansion of the extrudate to its final expanded thickness, so as to avoid defects generated by sudden expansion of said extrudate; and wherein means are provided for cooling said die extension to control the extrudate flow field.
Claim 2
Dependent Claim
131 words
In a die for the extrusion of a calcine-binder mix to form a green carbon, shaped extrudate, the improvement wherein: said die includes a channel, the profile of which is converged to satisfy the criteria that shear be minimized for a perfectly plastic material passed therethrough; a stress relief die extension being fitted to the output end of the die and comprising the exit section for said shaped extrudate, said die extension including a second channel diverging slightly in cross-section from the input to output ends of said extension for enabling a constrained gradual expansion of the extrudate to its final expanded thickness, so as to avoid defects generated by sudden expansion of said extrudate; and wherein means are provided for cooling said die extension to control the extrudate flow field.
Claim 3
Dependent Claim
52 words
Apparatus in accordance with claim 1, wherein said die is adapted for extrusion of plates having generally rectangular cross-sections, and wherein a first portion of said die toward the input end thereof establishes the width of said plates and a second downstream portion of said die establishes the thickness of said plates.
Claim 4
Dependent Claim
14 words
Apparatus in accordance with claim 2, wherein said second portion comprises said converged channel.
Claim 5
Dependent Claim
15 words
Apparatus in accordance with claim 3, wherein said second channel is of generally rectangular cross-section.
Claim 6
Dependent Claim
23 words
Apparatus in accordance with claim 4, wherein said means for cooling said extension are further adapted to cool adjacent portions of said die.
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) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |