Patent US5156683A successfully refreshed from Google Patents.
US5156683A
Expired / Lapsed
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Apparatus for magnetic induction edge heaters with frequency modulation
Assignee: National Steel Corp
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Filing: 1990-04-26
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Granted: 1992-10-20
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Expires: 2010-04-26
Abstract
Abstract An apparatus for galvannealing steel strip includes an applying device for applying a coating of controlled thickness of a strip. A controller controls the thickness of the applied coating. A heating furnace heats the steel strip to produce a galvannealed product. Edge heaters for heating the edges of the steel strip by magnetic induction promote uniform temperature distribution across the steel strip. The uniform temperature distribution produces more uniform galvannealing in the product. The edge heaters have preselected operating frequencies. A modulating circuit imposes a frequency modulation on the operating frequencies of the edge heaters to avoid undesirable transverse flexural resonance in the galvannealed product.
Inventors
- 👤 Nicholas V. Ross
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:58
CPC Classifications
C; C23; C23C; C23C2/00; C23C2/26; C23C2/28
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
112 words
An apparatus for galvannealing a steel strip, comprising: a bath for applying a rust-inhibiting coating to the steel strip; air knives for controlling the thickness of the applied coating; an induction coil assembly for heating the steel strip by magnetic induction to produce an alloy formation at an interface of the coating to the strip; edge heaters spaced from said induction coil assembly and disposed for heating the edges of the steel strip by magnetic induction to maintain a uniform temperature distribution across the steel strip, the edge heaters having a preselected operating frequency; and, means for modulating the operating frequency whereby undesirable transverse flexural resonance in the galvannealed product is avoided.
Claim 2
Independent Claim
112 words
An apparatus for galvannealing a steel strip, comprising: a bath for applying a rust-inhibiting coating to the steel strip; air knives for controlling the thickness of the applied coating; an induction coil assembly for heating the steel strip by magnetic induction to produce an alloy formation at an interface of the coating to the strip; edge heaters spaced from said induction coil assembly and disposed for heating the edges of the steel strip by magnetic induction to maintain a uniform temperature distribution across the steel strip, the edge heaters having a preselected operating frequency; and, means for modulating the operating frequency whereby undesirable transverse flexural resonance in the galvannealed product is avoided.
Claim 3
Dependent Claim
30 words
An apparatus as in claim 1 wherein the edge heaters are disposed before the induction coil assembly, the edge heaters preheating edges of the strip to maintain uniform temperature distribution.
Claim 4
Dependent Claim
30 words
An apparatus as in claim 1 wherein the edge heaters are disposed after the induction coil assembly, the edge heaters reheating edges of the strip to maintain uniform temperature distribution.
References Cited (Backward Citations)
US2873344A
Cited
JPS4878756A
Cited
US4357512A
Cited
US4627259A
Cited
US4795872A
Cited
US4775772A
Cited
US4778971A
Cited
US4810843A
Cited
US4761530A
Cited
US4807559A
Cited
US4845332A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-10-20 | 1996-04-20 | 1996-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-20 | 2000-04-20 | 2000-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-20 | 2004-04-20 | 2004-10-20 | $7700.00 | Window Closed / Lapsed |