US3620286A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Casting method
Assignee: Individual
•
Filing: 1969-06-18
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Granted: 1971-11-16
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Expires: 1989-06-18
Abstract
Abstract A casting method using a mold of particulate material including magnetizable particles which is made shape-retaining by subjecting the shaped mold to a magnetic field of sufficient strength to fix the position of the particulate magnetizable mold-forming material.
Inventors
- 👤 Richard Hofmann
- 👤 Adalbert Wittmoser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:03
CPC Classifications
B; B22; B22C; B22C11/00; Y; Y10; Y10S; Y10S425/00; Y10S425/033
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
126 words
A method of metal casting comprising the steps of introducing a pattern of a material, which will be gasified upon contact with the liquid metal to be cast, into a particulate mass of moldforming material including particles of magnetizable material in an amount sufficient to rigidify said mold-forming material while the same is exposed to a magnetic field so that a mold cavity formed in said mass by introduction of said pattern will be maintained and the thus-formed mold will remain shape-retaining during exposure to said magnetic field; subjecting the thusformed mold to said magnetic field so as to rigidify said mold prior to introduction of metal to be cast into the same; and casting hot liquid metal into the thus-rigidified mold while gasifying said pattern.
Claim 2
Independent Claim
126 words
A method of metal casting comprising the steps of introducing a pattern of a material, which will be gasified upon contact with the liquid metal to be cast, into a particulate mass of moldforming material including particles of magnetizable material in an amount sufficient to rigidify said mold-forming material while the same is exposed to a magnetic field so that a mold cavity formed in said mass by introduction of said pattern will be maintained and the thus-formed mold will remain shape-retaining during exposure to said magnetic field; subjecting the thusformed mold to said magnetic field so as to rigidify said mold prior to introduction of metal to be cast into the same; and casting hot liquid metal into the thus-rigidified mold while gasifying said pattern.
Claim 3
Independent Claim
102 words
A method of metal casting comprising the steps of forming a permanently shape-retaining mold having an inner surface; covering said inner surface of said mold with a thin layer of a particulate mass of material including particles of magnetizable material in an amount sufficient to rigidify said material while the same is exposed to a magnetic field so that said layer will retain its shape during exposure to said magnetic field and define a mold cavity; and subjecting said layer to said magnetic field so as to rigidify the same prior to introduction of metal to be cast into said mold cavity.
Claim 4
Independent Claim
102 words
A method of metal casting comprising the steps of forming a permanently shape-retaining mold having an inner surface; covering said inner surface of said mold with a thin layer of a particulate mass of material including particles of magnetizable material in an amount sufficient to rigidify said material while the same is exposed to a magnetic field so that said layer will retain its shape during exposure to said magnetic field and define a mold cavity; and subjecting said layer to said magnetic field so as to rigidify the same prior to introduction of metal to be cast into said mold cavity.
Claim 5
Independent Claim
175 words
A method of metal casting comprising the steps of introducing a pattern into a particulate mass of mold-forming material so as to form a mold cavity in said mass, said mold-forming material including particles of magnetizable material selected from the group consisting of magnetizable heavy metals, magnetizable minerals and magnetizable ferrites with high remanence in an amount sufficient to rigidify said mold forming material while the same is exposed to a magnetic field so that the mold cavity formed in said mass by introduction of said pattern will be maintained and the thus-formed mold will remain shape-retaining during exposure to said magnetic field; applying an adhesive to said pattern prior to introduction of the latter into said particulated mass of mold forming material so that said adhesive upon contacting said particulate material causes at least partial adherence of particles located adjacent said pattern to each other; subjecting the thus-formed mold to said magnetic field so as to rigidify said mold; removing said pattern from said mold; and casting hot liquid metal into said mold cavity.
Claim 6
Independent Claim
175 words
A method of metal casting comprising the steps of introducing a pattern into a particulate mass of mold-forming material so as to form a mold cavity in said mass, said mold-forming material including particles of magnetizable material selected from the group consisting of magnetizable heavy metals, magnetizable minerals and magnetizable ferrites with high remanence in an amount sufficient to rigidify said mold forming material while the same is exposed to a magnetic field so that the mold cavity formed in said mass by introduction of said pattern will be maintained and the thus-formed mold will remain shape-retaining during exposure to said magnetic field; applying an adhesive to said pattern prior to introduction of the latter into said particulated mass of mold forming material so that said adhesive upon contacting said particulate material causes at least partial adherence of particles located adjacent said pattern to each other; subjecting the thus-formed mold to said magnetic field so as to rigidify said mold; removing said pattern from said mold; and casting hot liquid metal into said mold cavity.
Claim 7
Dependent Claim
68 words
A method as defined in claim 3, wherein said magnetizable material, at least in the zone of said mold cavity, is of needle shape, and orienting the needles during magnetizing said mass in such a manner that opposite points of said needles face respectively said mold cavity and away from the latter to thus prevent demagnetization of said needles during casting of hot liquid metal into said cavity.
Claim 8
Dependent Claim
17 words
A method as defined in claim 3, wherein said magnetizable particles are covered with a refractory coating.
Claim 9
Dependent Claim
29 words
A method as defined in claim 1, wherein said magnetizable material is selected from the group consisting of magnetizable heavy metals, magnetizable minerals and magnetizable ferrites with high remanence.
Claim 10
Dependent Claim
18 words
A method as defined in claim 1, wherein said magnetizable material is of sandlike, chip or needle shape.
Claim 11
Dependent Claim
24 words
A metHod as defined in claim 6, wherein said magnetizable material at least in the zone of said mold cavity is of needle shape.
Claim 12
Dependent Claim
30 words
A method as defined in claim 4, wherein said particulate mold-forming material consists essentially of a mixture of said magnetizable material and of a nonmagnetizable material of low heat conductivity.
Claim 13
Dependent Claim
13 words
A method as defined in claim 9, wherein said nonmagnetizable material is sand.
Claim 14
Dependent Claim
14 words
A method as defined in claim 1, wherein said pattern consists of foamed polystyrene.
Claim 15
Dependent Claim
30 words
A method as defined in claim 6, wherein said magnetic field is produced by activation of electric induction coils surrounding said mass of mold-forming material substantially along its entire height.
Claim 16
Dependent Claim
36 words
A method as defined in claim 12, wherein induction coils additionally arranged in the vicinity of the bottom and top portion of said mass of mold-forming material are activated so as to form a magnetic field.
Claim 17
Dependent Claim
25 words
A method as defined in claim 12, wherein the induction field formed by activation of said induction coils is subdivided into annular individually controllable portions.
Claim 18
Dependent Claim
44 words
A method as defined in claim 14, wherein magnetic fields are applied to said mold-forming material in such a manner as to rigidify the same and to counteract nonmagnetic forces acting on said pattern or the metal to be cast in the mold cavity.
Claim 19
Dependent Claim
43 words
A method as defined in claim 14, including the step of separately controlling intensity and period of application of portions of the magnetic field depending on the characteristics and temperature of the metal to be cast and the characteristics of said magnetizable particles.
Claim 20
Dependent Claim
37 words
A method as defined in claim 6, wherein a surface-improving agent is applied to the cavity-forming inner surface of said mass of mold-forming material prior to introduction of the metal to be cast into said mold cavity.
Claim 21
Dependent Claim
23 words
A method as defined in claim 17, wherein said surface-improving agent is adapted to improve the mold cavity-forming surface of said mold-forming material.
Claim 22
Dependent Claim
27 words
A method as defined in claim 17, wherein said surface-improving agent is adapted to improve the surface characteristics of the metal body being cast in said mold.
Claim 23
Dependent Claim
25 words
A method as defined in claim 6, wherein metal to be cast is introduced into said rigidified mold cavity and subjected therein to controlled cooling.
Claim 24
Dependent Claim
40 words
A method as defined in claim 2, wherein said permanently shape-retaining mold is a centrifugal mold, and said particulate magnetizable material is applied to the inner surface thereof by centrifugal force and held thereon by application of said magnetic field.
Claim 25
Dependent Claim
21 words
A method as defined in claim 2, wherein the particle size of said particulate mold-forming material is smaller than 0.7 mm.
Claim 26
Dependent Claim
23 words
A method as defined in claim 22, wherein the particle size of said particulate mold-forming material is between about 0.1 and 0.5 mm.
Claim 27
Dependent Claim
18 words
A method as defined in claim 1, wherein said magnetizable particles, respectively, are covered with a refractory coating.
Claim 28
Dependent Claim
18 words
A method as defined in claim 1, wherein said magnetizable particles, respectively, are covered with an insulating coating.
Claim 29
Dependent Claim
50 words
A method as defined in claim 1, wherein an adhesive is applied to said pattern prior to introduction of the latter into said particulate mass of mold-forming material, said adhesive upon contacting said particulate mold-forming material causing at least partial adherence of particles located adjacent said pattern to each other.
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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) | 1974-11-15 | 1975-05-17 | 1975-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-15 | 1979-05-17 | 1979-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-15 | 1983-05-17 | 1983-11-16 | $7700.00 | Window Closed / Lapsed |