US4289946A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnetic casting apparatus
Assignee: Olin Corp
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Filing: 1978-12-26
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Granted: 1981-09-15
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Expires: 1998-12-26
Abstract
Abstract An apparatus for casting metals wherein the molten metal is contained and formed into a desired shape by the application of an electromagnetic field. A control system is utilized to minimize variations in the gap between the molten metal and an inductor which applies the magnetic field. The gap or an electrical parameter related thereto is sensed and used to control the current to the inductor.
Inventors
- 👤 John C. Yarwood
- 👤 Ik Y. Yun
- 👤 Derek E. Tyler
- 👤 Peter J. Kindlmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:35
CPC Classifications
B; B22; B22D; B22D11/00; B22D11/01; B22D11/015; H; H05; H05B; H05B6/00; H05B6/02; H05B6/06; H05B6/067
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
129 words
In an apparatus for casting materials such as metals comprising: induction means for applying a magnetic field to said material and solid state inverter means for applying an alternating current to said induction means to generate said magnetic field the improvement wherein: means are provided for sensing a reactive parameter corresponding about to the reactance or inductance of said induction means, said reactive parameter sensing means comprising: means for sensing a voltage signal applied to said induction means; means for sensing a current signal applied to said induction means; circuit means for filtering said voltage and current signals to extract the fundamental frequency thereof; and circuit means receiving said filtered voltage and current signals for generating a signal corresponding about to said reactance or inductance of said induction means.
Claim 2
Dependent Claim
129 words
In an apparatus for casting materials such as metals comprising: induction means for applying a magnetic field to said material and solid state inverter means for applying an alternating current to said induction means to generate said magnetic field the improvement wherein: means are provided for sensing a reactive parameter corresponding about to the reactance or inductance of said induction means, said reactive parameter sensing means comprising: means for sensing a voltage signal applied to said induction means; means for sensing a current signal applied to said induction means; circuit means for filtering said voltage and current signals to extract the fundamental frequency thereof; and circuit means receiving said filtered voltage and current signals for generating a signal corresponding about to said reactance or inductance of said induction means.
Claim 3
Dependent Claim
28 words
In an apparatus as in claim 1, feedback control means receiving said reactance or inductance signal for controlling the output of said means for applying said alternating current.
Claim 4
Dependent Claim
16 words
In an apparatus as in claim 1 wherein said filtering means comprises a phase-locked loop circuit.
Claim 5
Dependent Claim
13 words
In an apparatus as in claim 3 wherein said reactive parameter comprises reactance.
Claim 6
Dependent Claim
13 words
In an apparatus as in claim 3 wherein said reactive parameter comprises inductance.
Claim 7
Dependent Claim
124 words
In an apparatus for casting materials such as metals comprising: induction means for applying a magnetic field to said material and means for applying an alternating current to said induction means to generate said magnetic field; the improvement wherein said apparatus further includes: means for sensing the voltage applied to said induction means 90° out of phase to the current applied to said induction means and for generating a phase sensitive voltage signal corresponding thereto; means for sensing the current applied to said induction means for generating a voltage signal corresponding thereto; and divider circuit means for dividing said phase sensitive voltage signal by said voltage signal corresponding to said current for generating a signal corresponding about to the reactance of said induction means.
Claim 8
Dependent Claim
124 words
In an apparatus for casting materials such as metals comprising: induction means for applying a magnetic field to said material and means for applying an alternating current to said induction means to generate said magnetic field; the improvement wherein said apparatus further includes: means for sensing the voltage applied to said induction means 90° out of phase to the current applied to said induction means and for generating a phase sensitive voltage signal corresponding thereto; means for sensing the current applied to said induction means for generating a voltage signal corresponding thereto; and divider circuit means for dividing said phase sensitive voltage signal by said voltage signal corresponding to said current for generating a signal corresponding about to the reactance of said induction means.
Claim 9
Dependent Claim
63 words
In an apparatus as in claim 6 wherein said means for sensing said voltage 90° out of phase to said current comprises means for generating a phase reference signal with a phase angle of 90° means for sensing the voltage applied to said induction means and means receiving said phase reference signal and said voltage signal for providing said phase sensitive voltage signal.
Claim 10
Dependent Claim
27 words
In an apparatus as in claim 7 wherein said means for generating said phase reference signal with a phase angle of 90° comprises a phase-locked loop circuit.
Claim 11
Dependent Claim
56 words
In an apparatus as in claim 6 wherein means are provided for sensing the frequency of said current applied to said induction means for providing a frequency signal corresponding thereto and means are provided for dividing said reactance signal by said frequency signal to generate a signal corresponding about to the inductance of said induction means.
Claim 12
Dependent Claim
26 words
In an apparatus as in claim 9, feedback control means receiving said inductance signal for controlling the output of said means for applying said alternating current.
Claim 13
Dependent Claim
63 words
In an apparatus as in claim 9 wherein said means for sensing said voltage 90° out of phase to said current comprises means for generating a phase reference signal with a phase angle of 90°, means for sensing the voltage applied to said induction means and means receiving said phase reference signal and said voltage signal for providing said phase sensitive voltage signal.
Claim 14
Dependent Claim
27 words
In an apparatus as in claim 11 wherein said means for generating said phase reference signal with a phase angle of 90° comprises a phase-locked loop circuit.
Claim 15
Dependent Claim
26 words
In an apparatus as in claim 6, feedback control means receiving said reactance signal for controlling the output of said means for applying said alternating current.
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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) | 1984-09-14 | 1985-03-16 | 1985-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-14 | 1989-03-16 | 1989-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-14 | 1993-03-16 | 1993-09-15 | $7700.00 | Window Closed / Lapsed |