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US4059896A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for converting aluminum scrap into useful products

Assignee: Kobe Steel Ltd
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Filing: 1976-07-01
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Granted: 1977-11-29
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Expires: 1996-07-01
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Abstract

Abstract A process for converting aluminum scrap into finished articles by compaction, heating and extrusion. The process comprises the steps of compacting the aluminum scrap at ambient temperature into a billet having a density between 1.8 and 2.4 g/cm 3 , heating the compacted billet to a temperature between 350° and 550° C, compacting the heated billet into a dense mass having a density about 2.4 g/cm 3 either in an extrusion container, while maintaining conditions under which the air pressure at the outer periphery of the billet is lower than that in the central portion of the billet, or externally of the extrusion container, and subsequently, after completion of the second compaction, consolidating the secondly compacted billet by extrusion through an extrusion die fitted to the container while maintaining the above mentioned conditions, whereby void-free and scab-free finished articles of good quality are efficiently produced with a small apparatus using little energy.

Inventors

  • 👤 Akira Asari
  • 👤 Kenzou Tatsuno

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 21:53
CPC Classifications
B; B21; B21C; B21C27/00; B21C27/04; B21C23/00; B21C23/002; B21C23/01; B22; B22F; B22F8/00; C; C22; C22C; C22C1/00; C22C1/04; C22C1/0408; C22C1/0416; Y; Y02; Y02P; Y02P10/00; Y02P10/20; Y02W; Y02W30/00; Y02W30/50; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49751; Y10T29/49753

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 120 words
A process for converting aluminum scrap into a finished article, comprising the steps of: compacting the aluminum scrap at ambient temperature into a billet having a density between 1.8 and 2.4 g/cm 3 ; heating the compacted billet to a temperature between 350° and 550° C; compacting the heated billet into a dense mass, having a density above 2.4 g/cm 3 , while maintaining a condition under which the air pressure at the outer periphery of the billet is lower than that in the central portion of the billet; and subsequently extruding the billet after completion of the second compaction thereof from an extrusion container through an extrusion die, while maintaining said condition, so as to form the finished article.
Claim 2
Dependent Claim 120 words
A process for converting aluminum scrap into a finished article, comprising the steps of: compacting the aluminum scrap at ambient temperature into a billet having a density between 1.8 and 2.4 g/cm 3 ; heating the compacted billet to a temperature between 350° and 550° C; compacting the heated billet into a dense mass, having a density above 2.4 g/cm 3 , while maintaining a condition under which the air pressure at the outer periphery of the billet is lower than that in the central portion of the billet; and subsequently extruding the billet after completion of the second compaction thereof from an extrusion container through an extrusion die, while maintaining said condition, so as to form the finished article.
Claim 3
Dependent Claim 15 words
The process of claim 1, wherein: said second compaction is performed within said extrusion container.
Claim 4
Dependent Claim 61 words
The process of claim 2, wherein: said condition, under which the air pressure at the outer periphery of the billet is lower than that in the central portion of the billet, is maintained by heating the billet so as to create a temperature gradient therein, thereby allowing exhausted air in the extrusion container to escape therefrom during the second compaction step.
Claim 5
Dependent Claim 67 words
The process of claim 3, wherein: the temperature gradient is created along the axis of the billet, such that the portion of the billet near said die has a temperature higher than that of the portion near the ram inserted in the extrusion container, whereby exhausted air is discharged from the extrusion container through a clearance between the container and the ram during the second compaction step.
Claim 6
Dependent Claim 50 words
The process of claim 2, wherein: said condition, under which the air pressure at the outer periphery of the billet is lower than that in the central portion of the billet, is maintained by evacuating exhausted air from said extrusion container by a vacuum pump during the second compaction step.
Claim 7
Dependent Claim 47 words
The process of claim 2, wherein: said condition, under which the air pressure at the outer periphery of the billet is lower than that in the central portion of the billet, is maintained by evacuating exhausted air from said extrusion container prior to the second compaction step.
Claim 8
Dependent Claim 31 words
The process of claim 1, wherein: a plurality of billets are formed in said first compaction step and these billets are simultaneously compacted in the second compaction step and thereafter extruded.

References Cited (Backward Citations)

US2211984A Cited
US2358667A Cited
US2391752A Cited
US2639810A Cited
US2967613A Cited
US3626578A Cited
US3783494A Cited
FR2274369A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1980-11-28 1981-05-30 1981-11-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1984-11-28 1985-05-30 1985-11-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1988-11-28 1989-05-30 1989-11-29 $7700.00 Window Closed / Lapsed

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