Patent US4826419A successfully refreshed from Google Patents.
US4826419A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for relaxing stresses at the end of oedometric compacting of a mixture of an aggregate and a binder
Assignee: Rio Tinto France SAS
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Filing: 1987-06-24
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Granted: 1989-05-02
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Expires: 2007-06-24
Abstract
Abstract The invention relates to a process for relaxing lateral stresses at the end of shaping by compacting of a block constituted by an aggregate and a binder (such as a carbon-containing paste), to which is applied a main monoaxial stress in a rigid mold having a bottom and four side walls. According to the process, at the end of compacting and along the compacting axis, there is maintained a residual stress of between 50 and 2000 kilopascals, and preferably between 100 and 500 kilopascals. At least two of the side walls of the mold are then moved apart by a few millimeters, followed by the elimination of the main stress and the extraction of the molded block. The residual stress is maintained for a period of between 1 and 20 seconds following the moving apart of the walls.
Inventors
- 👤 Benoit Coste
- 👤 Claude Vanvoren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:36
CPC Classifications
B; B30; B30B; B30B11/00; B30B11/02; B30B15/00; B30B15/02; B30B15/022; B30B11/027
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
179 words
In a molding apparatus for shaping by compacting a block comprising aggregate and binder, comprising: a main mold portion for containing the block, comprising a plurality of side walls and a rigid bottom; and means for applying a monoaxial force to the block contained in the main mold portion, in a direction substantially parallel to the side walls, for compaction of the aggregate and binder; the improvement comprising: wedge means for reversibly blocking a pair of opposed side walls in place with respect to the block during application of the force; said wedge means being vertically movable by jack means into and out of facing engagement with said pair of side walls on a face opposite the main mold portion; and horizontally aligned guide means attached to said pair of side walls such that longitudinal movement of said guide means in a direction away from said main mold portion results in translational displacement of said pair of side walls a defined distance away from the block while maintaining application of the force to relieve latent stresses in the block.
Claim 2
Dependent Claim
179 words
In a molding apparatus for shaping by compacting a block comprising aggregate and binder, comprising: a main mold portion for containing the block, comprising a plurality of side walls and a rigid bottom; and means for applying a monoaxial force to the block contained in the main mold portion, in a direction substantially parallel to the side walls, for compaction of the aggregate and binder; the improvement comprising: wedge means for reversibly blocking a pair of opposed side walls in place with respect to the block during application of the force; said wedge means being vertically movable by jack means into and out of facing engagement with said pair of side walls on a face opposite the main mold portion; and horizontally aligned guide means attached to said pair of side walls such that longitudinal movement of said guide means in a direction away from said main mold portion results in translational displacement of said pair of side walls a defined distance away from the block while maintaining application of the force to relieve latent stresses in the block.
Claim 3
Dependent Claim
221 words
In a molding apparatus for shaping by compacting a block comprising aggregate and binder, comprising: a main mold portion for containing the block, comprising a plurality of side walls and a rigid bottom; and means for applying a monoaxial force to the block contained in the main mold portion, in a direction substantially parallel to the side walls, for compaction of the aggregate and binder; the improvement comprising: at least one guidance member (10) fixed at one end to a face of a displaceable wall (7), outwardly of said main mold portion, and having a head (11) at its opposite end; a fixed, rigid post (18) adjacent to said displaceable wall, said at least one guidance member passing through said post; a detachable wedge (9) located between said displaceable wall and said post; and an elastic compression means located along said guidance member between said post and said head; said post and said wedge cooperating to serve as a means for reversibly blocking a pair of opposed side walls in place with respect to the block during application of the force; and said guidance member, said post and said compression means cooperating to serve as a means for translationally displacing said pair of walls away from the block while maintaining application of the force to relieve latent stresses in the block.
Claim 4
Dependent Claim
221 words
In a molding apparatus for shaping by compacting a block comprising aggregate and binder, comprising: a main mold portion for containing the block, comprising a plurality of side walls and a rigid bottom; and means for applying a monoaxial force to the block contained in the main mold portion, in a direction substantially parallel to the side walls, for compaction of the aggregate and binder; the improvement comprising: at least one guidance member (10) fixed at one end to a face of a displaceable wall (7), outwardly of said main mold portion, and having a head (11) at its opposite end; a fixed, rigid post (18) adjacent to said displaceable wall, said at least one guidance member passing through said post; a detachable wedge (9) located between said displaceable wall and said post; and an elastic compression means located along said guidance member between said post and said head; said post and said wedge cooperating to serve as a means for reversibly blocking a pair of opposed side walls in place with respect to the block during application of the force; and said guidance member, said post and said compression means cooperating to serve as a means for translationally displacing said pair of walls away from the block while maintaining application of the force to relieve latent stresses in the block.
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) | 1992-05-01 | 1992-10-31 | 1993-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-01 | 1996-10-31 | 1997-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-01 | 2000-10-31 | 2001-05-02 | $7700.00 | Window Closed / Lapsed |