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US4145591A Expired / Lapsed US ⏱️ 0.0 years remaining

Induction heating apparatus with leakage flux reducing means

Assignee: Mitsubishi Chemical Corp
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Filing: 1977-01-03
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Granted: 1979-03-20
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Expires: 1997-01-03
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Abstract

Abstract An induction heating apparatus, which comprises: a heating element with a hollow, i.e. an interior cavity, for accommodating the material-to-be-heated therein, said heating element being made of metallic material; a ring for generating magnetic flux disposed surrounding said heating element and composed of a ring core and an electric conductive wire wound round said ring core in a coil manner and electrically insulated from the ring core; and an electric conductor disposed outside the heating element as well as the ring for generating magnetic flux and having both ends thereof electrically connected with the two ends of a desired heat generating portion of said heating element, said electric conductor being devised to cover substantially the circumference of said heating element as well as said ring for generating magnetic flux.

Inventors

  • 👤 Tukasa Takeda

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 16:45
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/02; H05B6/10; H05B6/105; H05B6/108; H05B6/36; H05B6/365

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 202 words
An induction heating apparatus, which comprises: a hollow heating element for accommodating the material-to-be heated therein, said heating element being made of a metallic material; a ring for generating magnetic flux disposed surrounding said heating element and composed of a ring core and an electric conductive wire wound round said ring core to form a toroidal coil electrically insulated from the ring core; a nonferrous, highly electrically conductive, copperlike shell disposed outside the heating element and magnetic flux generating ring and having the ends thereof electrically connected with the two ends of a desired heat generating portion of the heating element, wherein said copperlike shell substantially covers the circumference of said heating element and magnetic flux generating ring, said copperlike shell being formed in a cylindrical shape capable of accommodating said heating element and magnetic flux generating ring therein; and a cylindrical member made of ferromagnetic material, said cylindrical member being disposed outside said heating element, magnetic flux generating ring and copperlike shell so as to cover them and having the ends thereof electrically connected with at least one of (1) said two ends of said desired heat generating portion of said heating element and (2) the ends of said copperlike shell.
Claim 2
Dependent Claim 202 words
An induction heating apparatus, which comprises: a hollow heating element for accommodating the material-to-be heated therein, said heating element being made of a metallic material; a ring for generating magnetic flux disposed surrounding said heating element and composed of a ring core and an electric conductive wire wound round said ring core to form a toroidal coil electrically insulated from the ring core; a nonferrous, highly electrically conductive, copperlike shell disposed outside the heating element and magnetic flux generating ring and having the ends thereof electrically connected with the two ends of a desired heat generating portion of the heating element, wherein said copperlike shell substantially covers the circumference of said heating element and magnetic flux generating ring, said copperlike shell being formed in a cylindrical shape capable of accommodating said heating element and magnetic flux generating ring therein; and a cylindrical member made of ferromagnetic material, said cylindrical member being disposed outside said heating element, magnetic flux generating ring and copperlike shell so as to cover them and having the ends thereof electrically connected with at least one of (1) said two ends of said desired heat generating portion of said heating element and (2) the ends of said copperlike shell.
Claim 3
Dependent Claim 24 words
An induction heating apparatus according to claim 1, wherein said heating element is composed of a bundle of plural number of tubular heating members.
Claim 4
Dependent Claim 43 words
An induction heating apparatus according to claim 1, wherein said heating element is constructed in the form of a vessel having a bottom wall, and said ring for generating magnetic flux is disposed near the circumference of the bottom wall of said vessel.
Claim 5
Dependent Claim 42 words
An induction heating apparatus according to claim 1 and 11, wherein said heating element is made of at least one metallic material selected from iron, carbon steel, stainless steel and heat resisting steel whose electric resistance is greater than that of copper.
Claim 6
Dependent Claim 22 words
An induction heating apparatus according to claim 1, wherein said ring core is made of silicon steel plate or mild steel plate.
Claim 7
Dependent Claim 36 words
An induction heating apparatus according to claim 1, wherein said cylindrical member is made of one ferromagnetic material selected from malleable iron, electromagnetic wrought iron, carbon steel, cast steel, silicon steel, nickel.chrome steel and nickel.iron alloy.
Claim 8
Dependent Claim 258 words
An induction heating apparatus, which comprises: a hollow heating element for accommodating the material-to-be heated therein, said heating element being made of a metallic material; a ring for generating magnetic flux disposed surrounding said heating element and composed of a ring core and an electric conductive wire wound round said ring core to form a toroidal coil electrically insulated from the ring core; an electric conductor disposed outside the heating element and magnetic flux generating ring and having both ends thereof electrically connected with the two ends of a desired heat generating portion of the heating element respectively, wherein said electric conductor substantially covers the circumference of said heating element and magnetic flux generating ring, said electric conductor being formed in a cylindrical shape capable of accommodating said heating element and magnetic flux generating ring therein; and a cylindrical member made of ferromagnetic material, said cylindrical member being disposed outside said heating element, magnetic flux generating ring and electric conductor so as to cover them and having both ends thereof electrically connected with the two ends of a desired heat generating portion of said heating element or both ends of said electric conductor, respectively, wherein said electric conductor comprises an inner conductor shell which substantially covers the circumference of said heating element as well as said ring for generating magnetic flux and an outer conductor shell which is disposed outside said inner conductor shell and provided with a further ring core, said further ring core being interposed in between the inner conductor shell and the outer conductor shell.
Claim 9
Dependent Claim 258 words
An induction heating apparatus, which comprises: a hollow heating element for accommodating the material-to-be heated therein, said heating element being made of a metallic material; a ring for generating magnetic flux disposed surrounding said heating element and composed of a ring core and an electric conductive wire wound round said ring core to form a toroidal coil electrically insulated from the ring core; an electric conductor disposed outside the heating element and magnetic flux generating ring and having both ends thereof electrically connected with the two ends of a desired heat generating portion of the heating element respectively, wherein said electric conductor substantially covers the circumference of said heating element and magnetic flux generating ring, said electric conductor being formed in a cylindrical shape capable of accommodating said heating element and magnetic flux generating ring therein; and a cylindrical member made of ferromagnetic material, said cylindrical member being disposed outside said heating element, magnetic flux generating ring and electric conductor so as to cover them and having both ends thereof electrically connected with the two ends of a desired heat generating portion of said heating element or both ends of said electric conductor, respectively, wherein said electric conductor comprises an inner conductor shell which substantially covers the circumference of said heating element as well as said ring for generating magnetic flux and an outer conductor shell which is disposed outside said inner conductor shell and provided with a further ring core, said further ring core being interposed in between the inner conductor shell and the outer conductor shell.
Claim 10
Dependent Claim 24 words
An induction heating apparatus according to claim 7, wherein said heating element is composed of a bundle of plural number of tubular heating members.
Claim 11
Dependent Claim 43 words
An induction heating apparatus according to claim 7, wherein said heating element is constructed in the form of a vessel having a bottom wall, and said ring for generating magnetic flux is disposed near the circumference of the bottom wall of said vessel.
Claim 12
Dependent Claim 40 words
An induction heating apparatus according to claim 7, wherein said heating element is made of at least one metallic material selected from iron, carbon steel, stainless steel and heat resisting steel whose electric resistance is greater than that of copper.
Claim 13
Dependent Claim 22 words
An induction heating apparatus according to claim 7, wherein said ring core is made of silicon steel plate or mild steel plate.
Claim 14
Dependent Claim 36 words
An induction heating apparatus according to claim 7, wherein said cylindrical member is made of one ferromagnetic material selected from malleable iron, electromagnetic wrought iron, carbon steel, cast steel, silicon steel, nickel.chrome steel and nickel.iron alloy.

References Cited (Backward Citations)

US1362622A Cited
US2513242A Cited
US2563883A Cited
US3219786A Cited
US3440384A Cited
US3520980A Cited
US3843858A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-03-19 1982-09-18 1983-03-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-03-19 1986-09-18 1987-03-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-03-19 1990-09-18 1991-03-20 $7700.00 Window Closed / Lapsed

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